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、屏蔽外壳以及至少两个差分式硅基麦克风芯片；电路板上开设有至少两个进声孔；屏蔽外壳罩合在电路板的一侧,与电路板形成声腔；硅基麦克风芯片均位于声腔内；各差分式硅基麦克风芯片一一对应地设置于各进声孔处,且每个差分式硅基麦克风芯片的背腔与对应位置处的进声孔连通；各差分式硅基麦克风芯片均包括第一麦克风结构和第二麦克风结构,所有的第一麦克风结构电连接,所有的第二麦克风结构电连接。利用多个差分式硅基麦克风芯片可同时增加声音信号与噪声信号,由于声音信号的变化量大于噪声信号的变化量,从而可减小共模噪声,提高信噪比和声压过载点,进而改善音质。(The application provides a silica-based microphone device and electronic equipment, this silica-based microphone device includes: the circuit board, the shielding shell and the at least two differential silicon-based microphone chips; the circuit board is provided with at least two sound inlet holes; the shielding shell covers one side of the circuit board to form an acoustic cavity with the circuit board; the silicon-based microphone chips are all 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 sound inlet hole at the corresponding position; each differential silicon-based microphone chip comprises a first microphone structure and a second microphone structure, wherein all the first microphone structures are electrically connected, and all the second microphone structures are electrically connected. The plurality of differential silicon-based microphone chips can be used for simultaneously increasing the sound signals and the noise signals, and the variation of the sound signals is larger than that of the noise signals, so that the common-mode noise can be reduced, the signal-to-noise ratio and the sound pressure overload point are improved, and the tone quality is improved.)

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;

at least two differential silicon-based microphone chips, wherein the silicon-based microphone chips are both 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 sound inlet hole at the corresponding position;

each differential silicon-based microphone chip comprises a first microphone structure and a second microphone structure, wherein all the first microphone structures are electrically connected, and all the second microphone structures are electrically connected.

2. The silicon-based microphone device of claim 1, wherein the differential silicon-based microphone chip comprises a silicon substrate, wherein the second microphone structure and the first microphone structure on the silicon substrate are stacked on one side of the silicon substrate;

the silicon substrate is provided with a through hole for forming the back cavity, and the through hole corresponds to the main body of the first microphone structure and the main body of the second microphone structure;

one side of the silicon substrate, which is far away from the second microphone structure, is fixedly connected with the circuit board, and the through hole is communicated with the sound inlet hole.

3. The silicon-based microphone device of claim 2, wherein the differential silicon-based microphone chip comprises a lower back plate, a semiconductor diaphragm and an upper back plate;

the lower back plate, the semiconductor diaphragm and the upper back plate are stacked on the silicon substrate; gaps are arranged between the upper back plate and the semiconductor vibrating diaphragm and between the semiconductor vibrating diaphragm and the lower back plate; the regions of the upper back plate and the lower back plate corresponding to the through holes are provided with airflow holes;

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.

4. The silicon-based microphone device of claim 3, wherein the upper back plate of all the first microphone structures are electrically connected for forming a first signal path; and the lower back electrode plates of all the second microphone structures are electrically connected and are used for forming a second path of signals.

5. The silicon-based microphone device as claimed in claim 4, wherein the semiconductor diaphragms of all the differential silicon-based microphone chips are electrically connected, and the semiconductor diaphragms are used for being electrically connected with 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 connected with the circuit board;

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

7. The silicon-based microphone device of claim 5, wherein the upper backplate comprises upper backplate electrodes, all of the upper backplate electrodes of the first microphone structure being electrically connected;

and/or the lower back plate comprises lower back plate electrodes, and the lower back plate electrodes of all the second microphone structures are electrically connected;

and/or the semiconductor diaphragm comprises semiconductor diaphragm electrodes, and all the semiconductor diaphragm electrodes are electrically connected.

8. The silicon-based microphone device of claim 3, 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 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.

10. An electronic device, comprising: a silicon-based microphone arrangement as claimed in any one of claims 1-9.

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 interference processing of the current silicon-based microphone to the external noise is still not ideal, the signal-to-noise ratio is increased to a limited extent, and the improvement of the audio output effect is not facilitated.

Disclosure of Invention

The application aims at the defects of the existing mode and provides a silicon-based microphone device and electronic equipment so as to solve the technical problem that the signal-to-noise ratio of the existing silicon-based microphone is not high.

In a first aspect, an embodiment of the present application provides a silicon-based microphone apparatus, including: the circuit board, the shielding shell and the at least two differential silicon-based microphone chips; the circuit board is provided with at least two sound inlet holes; the shielding shell covers one side of the circuit board to form an acoustic cavity with the circuit board; the silicon-based microphone chips are all 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 sound inlet hole at the corresponding position; each differential silicon-based microphone chip comprises a first microphone structure and a second microphone structure, wherein all the first microphone structures are electrically connected, and all the second microphone structures are electrically connected.

In one possible implementation manner, the differential silicon-based microphone chip comprises a silicon substrate, and the second microphone structure and the first microphone structure are arranged on one side of the silicon substrate in a stacked manner; the silicon substrate is provided with a through hole for forming the back cavity, and the through hole corresponds to the main body of the first microphone structure and the main body of the second microphone structure; one side of the silicon substrate, which is far away from the second microphone structure, is fixedly connected with the circuit board, and the through hole is communicated with the sound inlet hole.

In a possible implementation manner, the differential silicon-based microphone chip specifically includes a lower back plate, a semiconductor diaphragm, and an upper back plate, which are sequentially stacked; gaps are arranged between the upper back plate and the semiconductor vibrating diaphragm and between the semiconductor vibrating diaphragm and the lower back plate; the regions of the upper back plate and the lower back plate corresponding to the through holes are provided with airflow holes; 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.

In one possible implementation manner, the upper back plates of all the first microphone structures are electrically connected to form a first path of signal; and the lower back electrode plates of all the second microphone structures are electrically connected and are used for forming a second path of signals.

In one possible implementation manner, the semiconductor diaphragms of all the differential silicon-based microphone chips are electrically connected, and the semiconductor diaphragms are used for being electrically connected with a constant voltage source.

In one possible implementation manner, the silicon-based microphone device further includes a control chip; the control chip is positioned in the sound cavity and connected with the circuit board; the upper back plate is electrically connected with one signal input end of the control chip; the lower back plate is electrically connected with the other signal input end of the control chip.

In one possible implementation, the upper back plate includes an upper back plate electrode, and the upper back plates of all the first microphone structures are electrically connected through the upper back plate electrode;

and/or the lower back plate comprises lower back plate electrodes, and the lower back plates of all the second microphone structures are electrically connected through the lower back plate electrodes;

and/or the semiconductor diaphragm comprises semiconductor diaphragm electrodes, and all the semiconductor diaphragms are electrically connected through the semiconductor diaphragm electrodes.

In one possible implementation, the differential silicon-based microphone chip further includes 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.

In one possible implementation, the silicon-based microphone apparatus has any one or more of the following features: 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.

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

The technical scheme provided by the embodiment of the application has the following beneficial technical effects:

in the silicon-based microphone device provided by the embodiment of the application, at least two differential silicon-based microphone chips are arranged, the first microphone structures of the differential silicon-based microphone chips are electrically connected, and the second microphone structures of the differential silicon-based microphone chips are electrically connected, so that when the same sound wave source enters the back cavity of each differential silicon-based microphone chip from each sound inlet hole, the capacitance variation amplitude of each first microphone structure generated by the same sound wave is equal, and the sign is the same; similarly, the capacitance change amplitude of each second microphone structure generated by the same sound wave is the same, the sign is the same, the sound signal and the noise signal can be simultaneously increased by utilizing the plurality of differential silicon-based microphone chips, and the variation of the sound signal is larger than that of the noise signal, so that the common-mode noise can be reduced, the signal-to-noise ratio and the sound pressure overload point can be improved, and the sound quality can be improved.

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 single differential silicon-based microphone chip in a silicon-based microphone device according to an embodiment of the present disclosure;

fig. 3 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.

Wherein:

100-a circuit board; 110-sound inlet holes;

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

300-differential silicon-based microphone chip; 301-back cavity;

310-a first microphone structure; 311-upper back plate; 311a — upper airflow aperture; 311 b-upper back plate electrode; 312 — upper air gap;

320-a second microphone structure; 321-a lower back plate; 321 a-lower airflow aperture; 321 b-a lower back plate electrode; 322-lower air gap;

330-a semiconductor diaphragm; 331-semiconductor diaphragm electrodes;

340-a 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.

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, integers, steps, operations, elements, components, and/or groups thereof. 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 following describes the technical solutions of the present application and how to solve the above technical problems with specific embodiments.

As shown in fig. 1, an embodiment of the present application provides a silicon-based microphone apparatus, including: circuit board 100, shield can 200, and at least two differential silicon-based microphone chips 300 (only two differential silicon-based microphone chips 300 are shown in the figure). The shielding case 200 is covered on one side of the circuit board 100 to form an acoustic cavity 210 of the silicon-based microphone device with the circuit board 100.

The circuit board 100 is provided with at least two sound inlets 110 (only two sound inlets 110 are shown in the figure), and the sound inlets 110 penetrate through the circuit board 100, so as to ensure that an external sound source enters the differential silicon-based microphone chip 300 from the sound inlets 110. Each differential silicon-based microphone chip 300 is located in the sound cavity 210, the differential silicon-based microphone chips 300 are arranged in one-to-one correspondence with the sound inlet holes 110, and the back cavity 301 of each differential silicon-based microphone chip 300 is communicated with the sound inlet hole 110 at the corresponding position.

Each differential silicon-based microphone chip 300 includes a first microphone structure 310 and a second microphone structure 320, all of the first microphone structures 310 are electrically connected, and all of the second microphone structures 320 are electrically connected.

In the silicon-based microphone device provided by the embodiment, by providing at least two differential silicon-based microphone chips 300, and electrically connecting the first microphone structures 310 of the differential silicon-based microphone chips 300 and electrically connecting the second microphone structures 320 of the differential silicon-based microphone chips 300, when the same sound wave source enters the back cavities 301 of the differential silicon-based microphone chips 300 from the sound inlet holes 110, the magnitudes of the capacitance variation generated by the same sound wave of the first microphone structures 310 are equal, and the symbols are the same; similarly, the capacitance variation amplitude of each second microphone structure 320 generated by the same sound wave is the same, the sign is the same, and the plurality of differential silicon-based microphone chips 300 can be used to simultaneously add the sound signal and the noise signal.

Specifically, when the capacitance variation ranges of the plurality of differential silicon-based microphone chips 300 are superimposed, the increase of the sensitivity (corresponding to the sound signal) is twice the increase of the noise signal, taking the capacitance variation amount corresponding to the increased sound signal as 2 as an example, the increase of the sensitivity signal (corresponding to the sound signal) is 20 × log (2) to 6dB, and the calculation is performed with the log (2) equal to 0.3; the noise signal is increased byThus, the increased signal-to-noise ratio is sensitivity-to-noise signal is 3 dB. Wherein the unit dB represents decibels.

In this embodiment, the back cavity 301 of the differential silicon-based microphone chip 300 is an inlet of an acoustic wave source, and the acoustic wave enters the second microphone structure 320 and the first microphone structure 310 of the differential silicon-based microphone chip 300 from the back cavity 301, which may cause capacitance changes of the second microphone structure 320 and the first microphone structure 310, respectively, so as to convert an acoustic signal into an electrical signal. Alternatively, the cross-sectional shape of the back cavity 301 may be circular, elliptical or square.

It should be noted that the silicon-based microphone device in fig. 1 is merely illustrated as two differential silicon-based microphone chips 300. The two differential silicon-based microphone chips 300 are respectively a first differential silicon-based microphone chip and a second differential silicon-based microphone chip, and the corresponding sound inlet holes 110 are a first sound inlet hole and a second sound inlet hole. In fig. 1, the left differential silicon-based microphone chip 300 is a first differential silicon-based microphone chip, and the right differential silicon-based microphone chip 300 is a second differential silicon-based microphone chip.

Specifically, the first microphone structure 310 of the first differential silicon-based microphone chip is electrically connected to the first microphone structure 310 of the second differential silicon-based microphone chip, and the second microphone structure 320 of the first differential silicon-based microphone chip is electrically connected to the second microphone structure 320 of the second differential silicon-based microphone chip. The relative position relationship between the first microphone structure 310 and the second microphone structure 320 in each differential silicon-based microphone chip 300 and the circuit board 100 is the same.

Optionally, the circuit board 100 is a printed circuit board 100, and since the printed circuit board 100 is a rigid structure, it has structural strength to carry the shielding case 200 and the differential silicon-based microphone chip 300.

Alternatively, in order to improve the electromagnetic interference shielding effect of the differential silicon-based microphone chip 300 in the acoustic cavity 210, the shielding shell 200 is generally a metal shell made of a conductive metal material.

Alternatively, the shield case 200 is fixedly attached to the circuit board 100 by solder paste or conductive paste, thereby forming an electrical connection that can prevent external interference.

In some embodiments, as shown in fig. 1 and 2, the differential silicon-based microphone chip 300 further includes a silicon substrate 340, and the second microphone structure 320 and the first microphone structure 310 are stacked on one side of the silicon substrate 340.

Wherein, the silicon substrate 340 has a through hole 341 for forming the back cavity 301, and the through hole 341 corresponds to both the main body of the first microphone structure 310 and the main body of the second microphone structure 320, so as to ensure that the sound wave entering from the through hole 341 can cause the capacitance change of the first microphone structure 310 and the second microphone structure 320.

The side of the silicon substrate 340 away from the second microphone structure 320 is fixedly connected to the circuit board 100, and the through hole 341 communicates with the sound inlet hole 110 at a corresponding position, so that sound can enter the back cavity 301 from the sound inlet hole 110.

In this embodiment, the sound inlet 110 on the circuit board 100 is communicated with the back cavity 301 of the differential silicon-based microphone chip 300, and sound is guided into the semiconductor diaphragm 330 of the differential silicon-based microphone chip 300 through the sound inlet 110, so as to cause the semiconductor diaphragm 330 to vibrate to generate a sound signal.

In some embodiments, with continued reference to fig. 1 and 2, the differential silicon-based microphone chip 300 further includes a lower backplate 321, a semiconductor diaphragm 330, and an upper backplate 311. Wherein, the lower back plate 321, the semiconductor diaphragm 330 and the upper back plate 311 are stacked on one side of the silicon substrate 340 far away from the circuit board 100.

Gaps are provided between the upper back plate 311 and the semiconductor diaphragm 330, and between the semiconductor diaphragm 330 and the lower back plate 321. The upper back plate 311 and the lower back plate 321 are provided with air flow holes in regions corresponding to the through holes 341. The upper backplate 311 and the semiconductor diaphragm 330 have a gap to act as a capacitive structure, constituting the body of the first microphone structure 310. Likewise, a gap exists between the semiconductor diaphragm 330 and the lower back plate 321 to act as a capacitive structure, thereby constituting a body of the second microphone structure 320.

Specifically, the semiconductor diaphragm 330 may be arranged in parallel with the upper backplate 311 and separated by an upper air gap 312, thereby forming a first microphone structure 310; a semiconductor diaphragm 330 may be arranged parallel to the lower backplate 321 and separated by a lower air gap 322 to form a second microphone structure 320. It is understood that the semiconductor diaphragm 330 and the upper back plate 311 and the semiconductor diaphragm 330 and the lower back plate 321 are used to form electric fields (non-conduction). Since the semiconductor silicon substrate 340 is provided with the through hole 341 for forming the back cavity 301, the sound wave is contacted with the semiconductor diaphragm 330 through the back cavity 301 and the lower airflow hole 321a on the lower back plate 321.

Optionally, the material for preparing the semiconductor diaphragm 330 may be a polysilicon material, and the thickness of the semiconductor diaphragm 330 is less than 1 μm, which may also generate deformation under the action of a small sound wave, and the sensitivity is high. The upper back plate 311 and the lower back plate 321 are generally made of a material having a relatively high rigidity and a thickness much greater than that of the semiconductor diaphragm 330, and a plurality of upper airflow holes 311a are etched in the upper back plate 311 and a plurality of lower airflow holes 321a are etched in the lower back plate 321. Therefore, when the semiconductor diaphragm 330 is deformed by the sound wave, neither the upper back plate 311 nor the lower back plate 321 is affected to deform.

For a single differential silicon-based microphone chip 300, an upper electric field is formed in the upper air gap 312 of the first microphone structure 310 by applying a bias voltage between the semiconductor diaphragm 330 and the upper backplate 311. Similarly, by applying a bias voltage between the semiconductor diaphragm 330 and the lower backplate 321, a lower electric field is formed in the lower air gap 322 of the second microphone structure 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 sound wave, the capacitance variation of the first microphone structure 310 has the same magnitude and opposite sign as the capacitance variation of the second microphone structure.

Optionally, a side of the silicon substrate 340 away from the lower back plate 321 is fixedly connected to the circuit board 100 through silicone.

In some embodiments, as shown in fig. 2, the silicon substrate 340 and the lower back plate 321, the lower back plate 321 and the semiconductor diaphragm 330, and the semiconductor diaphragm 330 and the upper back plate 311 are arranged in an insulating manner.

Specifically, the lower back plate 321 is separated from the silicon substrate 340 by a patterned first insulating layer 350, the semiconductor diaphragm 330 is separated from the lower back plate 321 by a patterned second insulating layer 360, and the semiconductor diaphragm 330 is separated from the upper back plate 311 by a patterned third insulating layer 370, such that the silicon substrate 340, the first insulating layer 350, the lower back plate 321, the second insulating layer 360, the semiconductor diaphragm 330, the third insulating layer 370, and the upper back plate 311 are sequentially stacked.

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 the insulating layer corresponding to the through hole 341 area and the insulating layer corresponding to the electrode preparation area are removed.

In some embodiments, as shown in fig. 3, for a plurality of differential silicon-based microphone chips 300 in a silicon-based microphone device, the upper back plates 311 of all the first microphone structures 310 are electrically connected for forming a first signal; the lower backplate 321 of all the second microphone structures 320 are electrically connected for forming a second path of signals.

Specifically, the first path of signal is a signal after all the upper back plates 311 of the first microphone structures 310 are electrically connected, and the signal is a sum of capacitance variations between the upper back plate 311 of each first microphone structure 310 and the corresponding semiconductor diaphragm 330, and is used as one input of the differential signal processing chip. The second path of signal is a signal after all the lower back electrode plates 321 of the second microphone structures 320 are electrically connected, and the signal is a sum of capacitance variations between the lower back electrode plates 321 of the second microphone structures 320 and the corresponding semiconductor diaphragms 330, and is used as another input of the differential signal processing chip.

In some embodiments, all of the semiconductor diaphragms 330 of the differential silicon-based microphone chip 300 are electrically connected, and the semiconductor diaphragms 330 are used to be electrically connected to a constant voltage source, so as to form a stable electric field in the first microphone structure 310 and the second microphone structure. Alternatively, the constant voltage source may be zero voltage.

On the basis of the above embodiments, as shown in fig. 1, the silicon-based microphone apparatus further includes a control chip 400, and the control chip 400 is located in the acoustic cavity 210 and connected to the circuit board 100. The control chip 400 is used as a core component of the differential signal processing, and the upper back plate 311 of one of the first microphone structures 310 is electrically connected to a signal input end of the control chip 400, so that the first path of signal is connected to the input end of the control chip 400; the lower backplate 321 of one of the first microphone structures 310 is electrically connected to another signal input terminal of the control chip 400, so as to connect the second path of signals to the input terminal of the control chip 400. The control chip 400 performs differential signal processing on the two signals to improve the signal-to-noise ratio.

Optionally, the control chip 400 is an Application Specific Integrated Circuit (ASIC) chip, and the ASIC chip can be customized according to the design requirement of the microphone. The ASIC chip is a differential amplification signal processing chip and is reserved with pins for accessing the first path of signals and the second path of signals.

Optionally, the control chip 400 is also fixed on the circuit board 100 by a silicon gel or a red gel.

In some embodiments, as shown in fig. 3, the upper backplate 311 includes upper backplate electrodes 311b, and all of the upper backplate electrodes 311b of the first microphone structure 310 are electrically connected by wires 380.

Optionally, the lower backplate 321 includes lower backplate electrodes 321b, and the lower backplate electrodes 321b of all of the second microphone structures 320 are electrically connected by a wire 380.

Alternatively, the semiconductor diaphragm 330 includes semiconductor diaphragm electrodes 331, and all of the semiconductor diaphragm electrodes 331 are electrically connected by wires 380.

For a single differential silicon-based microphone chip 300, an upper electric field is formed in the upper air gap 312 of the first microphone structure 310 by applying a bias voltage between the semiconductor diaphragm 330 and the upper back plate 311, specifically by applying a bias voltage to the diaphragm electrode connected to the semiconductor diaphragm 330 and the upper back plate electrode 311b connected to the upper back plate 311. Similarly, by applying a bias voltage between the semiconductor diaphragm 330 and the lower backplate 321, a lower electric field is formed in the lower air gap 322 of the second microphone structure 320, in particular by applying a bias voltage on the diaphragm electrode connected to the semiconductor diaphragm 330 and the lower backplate electrode 321b connected to the lower backplate 321. 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 sound wave, the capacitance variation of the first microphone structure 310 has the same magnitude and opposite sign as the capacitance variation of the second microphone structure.

In the connection manner of the two differential silicon-based microphone chips 300 illustrated in fig. 3, the semiconductor diaphragm electrode 331 of the first differential silicon-based microphone chip (left side) and the semiconductor diaphragm electrode 331 of the second differential silicon-based microphone chip (right side) are electrically connected through a wire 380; the upper back plate electrode 311b of the first differential silicon-based microphone chip is electrically connected with the upper back plate electrode 311b of the second differential silicon-based microphone chip through a lead 380; the lower back plate electrode 321b of the first differential silicon-based microphone chip is electrically connected to the lower back plate electrode 321b of the second differential silicon-based microphone chip through a wire 380.

When the first sound wave entering from the first sound inlet and the second sound wave entering from the second sound inlet are the same sound wave source, according to the connection manner of the two differential type base microphone chips of the embodiment of the present application, the capacitance variation generated by the first sound wave of the first microphone structure 310 of the first differential type silicon-based microphone chip is equal to and consistent with the capacitance variation generated by the second sound wave of the first microphone structure 310 of the second differential type silicon-based microphone chip. Similarly, the capacitance variation generated by the first sound wave of the second microphone structure 320 of the first differential silicon-based microphone chip is equal in amplitude to and consistent with the capacitance variation generated by the second sound wave of the second microphone structure 320 of the second differential silicon-based microphone chip. Because the two first microphone structures 310 are connected in parallel and the two second microphone structures 320 are connected in parallel, the silicon-based microphone device packaged by the two differential silicon-based microphone chips 300 of the embodiment can increase the ratio of the sound signal to the noise signal, thereby reducing the common mode noise and further realizing a higher signal-to-noise ratio of the silicon-based microphone.

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 electrodes (e.g., the upper back plate 311 and the lower back plate 321). 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 further provides an electronic device, including: the silicon-based microphone device in the foregoing embodiments.

The electronic device provided by this embodiment includes a silicon-based microphone device having at least two differential silicon-based microphone chips 300, in which the first microphone structures 310 of the differential silicon-based microphone chips 300 are electrically connected and the second microphone structures 320 of the differential silicon-based microphone chips 300 are electrically connected, so that the sound signals and the noise signals can be simultaneously increased.

Optionally, the electronic device in the above embodiments may be a mobile phone, a recording pen, or a translator.

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.