阅读说明：本技术 用于拾取语音的骨传导加速度计 (Bone conduction accelerometer for picking up voice ) 是由 凌方舟 丁希聪 蒋乐跃 黄黎 于 2021-08-17 设计创作，主要内容包括：本发明提供一种用于拾取语音的骨传导加速度计,其采用体硅工艺加工制作,其包括：微机电系统部件,其为电容式加速度计,微机电系统部件用于感应骨振动信号并将该骨振动信号转换为电信号,微机电系统部件包括：衬底；半导体结构层,其设置于衬底上方,其包括键合框架和位于键合框架内的敏感框架；盖板,其设置于半导体结构层上方,其中,键合框架与所述半导体结构层上方的盖板和半导体结构层下方的结构围成密封腔,敏感框架位于密封腔内；信号处理部件,其用于处理微机电系统部件产生的电信号,并将电信号转换为声音信号。与现有技术相比,本发明采用骨传导加速度计实现对声音的拾取,可避免外界环境声音的干扰,且无需外壳封装来实现密封。(The invention provides a bone conduction accelerometer for picking up voice, which is processed and manufactured by a bulk silicon process and comprises the following steps: a micro-electro-mechanical system component that is a capacitive accelerometer for sensing a bone vibration signal and converting the bone vibration signal to an electrical signal, the micro-electro-mechanical system component comprising: a substrate; the semiconductor structure layer is arranged above the substrate and comprises a bonding frame and a sensitive frame positioned in the bonding frame; the cover plate is arranged above the semiconductor structure layer, a sealed cavity is enclosed by the bonding frame, the cover plate above the semiconductor structure layer and a structure below the semiconductor structure layer, and the sensitive frame is positioned in the sealed cavity; and a signal processing part for processing the electrical signal generated by the micro electro mechanical system part and converting the electrical signal into a sound signal. Compared with the prior art, the bone conduction accelerometer is used for picking up sound, so that the interference of external environment sound can be avoided, and the sealing is realized without shell packaging.)

1. A bone conduction accelerometer for picking up speech, the bone conduction accelerometer fabricated using bulk silicon processing, the bone conduction accelerometer comprising:

the system comprises a micro-electro-mechanical system component and a control unit, wherein the micro-electro-mechanical system component is a capacitive accelerometer and is used for sensing a bone vibration signal and converting the bone vibration signal into an electric signal, the micro-electro-mechanical system component comprises a substrate, a semiconductor structure layer and a cover plate, the semiconductor structure layer is arranged above the substrate, and the semiconductor structure layer comprises a bonding frame and a sensitive frame positioned in the bonding frame; the cover plate is arranged above the semiconductor structure layer, the bonding frame, the cover plate above the semiconductor structure layer and a structure below the semiconductor structure layer enclose a sealing cavity, and the sensitive frame is located in the sealing cavity;

the signal processing component is electrically connected with the micro-electromechanical system component and is used for processing the electric signal generated by the micro-electromechanical system component and converting the electric signal into a sound signal.

2. The bone conduction accelerometer for picking up speech of claim 1,

the sensitive frame can be provided with a single mass block or a multi-mass block structure and is used for detecting the acceleration of three axes generated by the bone vibration signal.

3. The bone conduction accelerometer for picking up speech of claim 2,

a groove is formed in the position, opposite to the sensitive frame, of the lower surface of the cover plate;

the lower surface of the cover plate is bonded with the upper surface of the bonding frame,

the lower surface of the bonding frame is bonded with the upper surface of the substrate.

4. The bone conduction accelerometer for picking up speech of claim 3,

the lower surface of the bonding frame is directly bonded with the upper surface of the substrate;

the lower surface of the cover plate is in eutectic bonding with the upper surface of the bonding frame.

5. The bone conduction accelerometer for picking up speech of claim 2,

the signal processing means is an application specific integrated circuit,

the signal processing component is disposed above the cover plate or at a lateral position of the mems component.

6. The bone conduction accelerometer for picking up speech of claim 2,

the signal processing part is formed on the substrate;

the upper surface of the signal processing part is bonded with the lower surface of the bonding frame.

7. The bone conduction accelerometer for picking up speech of claim 2,

the sensitive frame comprises a mass block and a fixed electrode,

when the mass block senses the bone vibration signal, the mass block moves, so that the distance between the mass block and the fixed electrode changes, and the bone vibration signal is converted into an electric signal reflecting the capacitance change between the mass block and the fixed electrode.

8. The bone conduction accelerometer for picking up speech of claim 7,

the sensitive frame further comprises anchor points and a beam structure,

the mass block is connected with the anchor point through the beam structure;

the anchor point is fixed on the structure below the semiconductor structure layer;

the fixed electrode is fixed on the structure below the semiconductor structure layer.

9. The bone conduction accelerometer for picking up speech of claim 7,

the mass block comprises an X mass block, a Y mass block and a Z mass block; the fixed electrode comprises an X-axis detection electrode, a Y-axis detection electrode and a Z-axis detection electrode,

when an X-axis bone vibration signal is input, the X mass block moves along an X axis, so that the distance between the X mass block and the X-axis detection electrode changes, and the X-axis bone vibration signal is converted into an electric signal reflecting the capacitance change between the X mass block and the X-axis detection electrode;

when a Y-axis bone vibration signal is input, the Y mass block moves along a Y axis, so that the distance between the Y mass block and the Y-axis detection electrode is changed, and the Y-axis bone vibration signal is converted into an electric signal reflecting the capacitance change between the Y mass block and the Y-axis detection electrode;

the Z-axis detection electrode is positioned below the Z mass block and has a gap with the Z mass block, when a Z-axis bone vibration signal is sensed to be input, the Z mass block can move like a seesaw, so that the distance between the Z-axis detection electrode and the Z mass block is changed, the Z-axis bone vibration signal is converted into an electric signal reflecting the capacitance change between the Z mass block and the Z-axis detection electrode,

wherein the X axis and the Y axis are perpendicular to each other and define a plane of a structure below the semiconductor structure layer, and the Z axis is perpendicular to the plane defined by the X axis and the Y axis.

10. The bone conduction accelerometer for picking up speech of claim 9,

the sensitive frame also comprises anchor points and a beam structure, wherein the anchor points comprise an X mass block anchor point, a Y mass block anchor point and a Z mass block anchor point, the beam structure comprises a transverse elastic beam structure, a longitudinal elastic beam and a torsion beam,

the X mass block is connected with the X mass block anchor point through the transverse elastic beam;

the Y mass block is connected with the Y mass block anchor point through the longitudinal elastic beam;

the Z mass block is connected with the Z mass block anchor point through the torsion beam;

the X mass block anchor point, the Y mass block anchor point and the Z mass block anchor point are fixed on a structure below the semiconductor structure layer;

the X-axis detection electrode, the Y-axis detection electrode and the Z-axis detection electrode are fixed on a structure below the semiconductor structure layer.

11. The bone conduction accelerometer for picking up speech of claim 10,

the transverse elastic beam and the X mass block anchor point are arranged in the X mass block;

the longitudinal elastic beam and the Y mass block anchor point are arranged in the Y mass block;

the torsion beam and the Z mass block anchor point are arranged in the Z mass block;

the X mass block and the Y mass block are arranged in the Z mass block.

12. Bone conduction accelerometer for picking up speech according to one of claims 8, 10 and 11,

the mass block is provided with a through hole, a blind hole, a hollow structure or a semi-hollow structure; and/or

The mass block and the beam structure are provided with anti-collision bulges.

13. A bone conduction accelerometer for picking up speech according to claim 2,

a plurality of metal layers, interlayer dielectric layers and through holes are arranged above the substrate,

the metal layer is used as an interconnection line to transmit electric signals to different positions of the chip;

the interlayer dielectric layer is made of an insulating material and is used for separating the electric connection between the metal layers;

the through holes penetrate through the interlayer dielectric layers and the metal layers to form openings of electric paths.

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of Micro-Electro-Mechanical systems (MEMS), and particularly relates to a bone conduction accelerometer for picking up voice.

[ background of the invention ]

The traditional MEMS sensor for picking up voice mainly adopts a silicon microphone, which mainly comprises a silicon diaphragm and a silicon back electrode for receiving sound, wherein air is vibrated through the sound, the silicon diaphragm senses (or is sensitive) to convert a vibration signal into an electric signal, and then the electric signal is read, so that the sound is picked up, the whole process is carried out in the air, and the external noise interference is easily caused. Bone conduction silicon microphones are recently introduced on the market, most manufacturers set a mass block on a diaphragm of the silicon microphone, vibration signals transmitted by bones enable the mass block to vibrate, sound is picked up by sensing (or sensing) vibration of the mass block, the bone conduction microphones are packaged to form a sealed cavity to isolate air sound transmission, but the microphones occupy a large space integrally and have poor sealing performance.

Therefore, it is necessary to provide a technical solution to overcome the above problems.

[ summary of the invention ]

One of the objectives of the present invention is to provide a bone conduction accelerometer for picking up voice, which has a small chip size and good sealing performance, and can pick up sound.

According to one aspect of the present invention, there is provided a bone conduction accelerometer for picking up speech, the bone conduction accelerometer fabricated using bulk silicon processing, the bone conduction accelerometer comprising: the system comprises a micro-electro-mechanical system component and a control unit, wherein the micro-electro-mechanical system component is a capacitive accelerometer and is used for sensing a bone vibration signal and converting the bone vibration signal into an electric signal, the micro-electro-mechanical system component comprises a substrate, a semiconductor structure layer and a cover plate, the semiconductor structure layer is arranged above the substrate, and the semiconductor structure layer comprises a bonding frame and a sensitive frame positioned in the bonding frame; the cover plate is arranged above the semiconductor structure layer, the bonding frame, the cover plate above the semiconductor structure layer and a structure below the semiconductor structure layer enclose a sealing cavity, and the sensitive frame is located in the sealing cavity; the signal processing component is electrically connected with the micro-electromechanical system component and is used for processing the electric signal generated by the micro-electromechanical system component and converting the electric signal into a sound signal.

Compared with the prior art, the bone conduction accelerometer for picking up voice provided by the invention comprises a MEMS component 1 and a signal processing component 2. The MEMS component 1 is a capacitive accelerometer for sensing (or sensing) a bone vibration signal and converting the bone vibration signal into an electrical signal. The signal processing component 2 is electrically connected with the MEMS component 1, and the signal processing component 2 is configured to process the electrical signal generated by the MEMS component 1 and convert the electrical signal into a sound signal. The invention adopts the bone conduction accelerometer to realize the sound pickup, can avoid the interference of external environment sound, does not need shell packaging to realize sealing, adopts the bulk silicon process for processing and preparing the MEMS chip, and has simple process, small chip size, good sealing property and good reliability.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

FIG. 1 is a schematic longitudinal cross-sectional view of a bone conduction accelerometer for picking up speech according to an embodiment of the invention;

FIG. 2 is a schematic longitudinal cross-sectional view of a bone conduction accelerometer for picking up speech according to another embodiment of the invention;

fig. 3 is a schematic diagram illustrating an overall structure of the semiconductor structure layer shown in fig. 1 and 2 according to an embodiment of the present invention.

Wherein, 1-MEMS part; 2-a signal processing component; 3-a substrate; 4-a semiconductor structure layer; 5-cover plate; 6-a bonding frame; 7-a sensitive framework; 8-a mass block; 8a-X mass block; 8b-Y mass block; 8c-Z mass block; 9-anchor point; 9a-X mass block anchor points; 9b-Y mass block anchor points; 9c-Z mass block anchor points; 10 a-transverse elastic beam; 10 b-a wale elastic beam; 10 c-torsion beam; 11-longitudinally movable thinning teeth; 12-longitudinally fixing thinning teeth; 13-Y axis detection electrodes; 14-Z axis detection electrodes; 15-a through hole; 16-convex; 17-a groove; an 18-X axis detection electrode; 19-transverse fixed comb teeth; 20-laterally movable comb teeth.

[ detailed description ] embodiments

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Unless otherwise specified, the terms connected, and connected as used herein mean electrically connected, directly or indirectly.

The bone conduction accelerometer for picking up voice provided by the invention mainly realizes the detection of sound through bone vibration. The specific working principle is that when a person speaks, sound can cause bones to vibrate slightly, a mass block in the accelerometer senses (or is sensitive to) vibration signals (namely bone vibration signals) of the bones, self capacitance of the mass block can change along with the change of the vibration signals, and the capacitance signals are processed to realize sound pickup.

Fig. 1 is a schematic longitudinal cross-sectional view of a bone conduction accelerometer for picking up voice according to an embodiment of the invention. The bone conduction accelerometer for picking up voice shown in fig. 1 includes a MEMS (Micro-Electro-Mechanical System) part 1 and a signal processing part 2.

The MEMS component 1 is a capacitive accelerometer for sensing (or sensing) a bone vibration signal and converting the bone vibration signal into an electrical signal. The signal processing component 2 is electrically connected with the MEMS component 1, and the signal processing component 2 is configured to process the electrical signal generated by the MEMS component 1 and convert the electrical signal into a sound signal.

The MEMS component 1 can be manufactured by a bulk silicon process, and the MEMS component 1 comprises a substrate 3, a semiconductor structure layer 4 and a cover plate 5. Wherein, the semiconductor structure layer 4 is arranged above the substrate 3; the semiconductor structure layer 4 comprises a bonding frame 6 and a sensitive frame 7 positioned in the bonding frame 6; the cover plate 5 is arranged above the semiconductor structure layer 4, and the lower surface of the cover plate 5 is bonded with the upper surface of the bonding frame 6; the bonding frame 6, the cover plate 5 above the semiconductor structure layer 4 and the structure below the semiconductor structure layer 4 enclose a sealed cavity (not labeled), the sensitive frame 7 is located in the sealed cavity, and in the specific embodiment shown in fig. 1, the structure below the semiconductor structure layer 4 is the substrate 3. Therefore, the substrate 3 and the cover plate 5 are used for sealing the sensitive frame 7, sound cannot be transmitted into the sensitive frame 7 through air, external noise interference can be avoided, sound transmission through vibration is achieved, the bone conduction accelerometer shown in the figure 1 is sealed with the sensitive frame 7 through the substrate 3 and the cover plate 5, a sealed environment of the bone conduction accelerometer is achieved without depending on shell packaging, the sealing effect is improved, the consistency is good, the product yield can be improved, and the bone conduction accelerometer is convenient to install.

In the specific embodiment shown in fig. 1, a groove 17 is provided on the lower surface of the cover plate 5 opposite to the sensitive frame 7; the lower surface of the bonding frame 6 is bonded to the upper surface of the substrate 3. In one embodiment, the lower surface of the bond frame 6 and the upper surface of the substrate 3 may be directly bonded; the lower surface of the cover plate 5 and the upper surface of the bonding frame 6 can adopt ALGe bonding (namely aluminum germanium eutectic bonding).

The signal processing component 2 may be an ASIC (Application Specific Integrated Circuit), which may be fabricated separately, forming a single discrete chip, and may be disposed above the cover plate 5 (as shown in fig. 1) or at a lateral position of the MEMS component 1.

Fig. 2 is a schematic longitudinal cross-sectional view of a bone conduction accelerometer for picking up voice according to another embodiment of the invention. The bone conduction accelerometer for picking up speech shown in fig. 2 comprises a MEMS component 1 and a signal processing component 2.

The MEMS component 1 shown in fig. 2 is substantially the same as the MEMS component 1 shown in fig. 1 in terms of their relative position, and for details, reference is made to the foregoing description of the MEMS component 1 shown in fig. 1, and details are not repeated here. The main difference between fig. 2 and fig. 1 is that the signal processing component 2 shown in fig. 2 is disposed between the substrate 3 and the semiconductor structure layer 4, and the signal processing component 2 serves as a structure below the semiconductor structure layer 4. Therefore, the sealing of the sensitive frame 7 is realized through the signal processing part 2 and the cover plate 5, sound cannot be transmitted to the sensitive frame 7 through air, external noise interference can be avoided, sound transmission through vibration is realized, the bone conduction accelerometer shown in the figure 2 is sealed on the sensitive frame 7 through the sealing of the signal processing part 2 and the cover plate 5, the sealing environment of the bone conduction accelerometer is not required to be realized by means of shell packaging, the sealing consistency is improved, the product yield can be improved, and the installation of the bone conduction accelerometer is facilitated.

In one embodiment, the signal processing component 2 may be fabricated directly on the substrate 3; then, the upper surface of the signal processing part 2 is bonded to the bonding frame 6.

And after the MEMS component 1 and the signal processing component 2 are electrically connected, a packaging process is carried out, the MEMS component 1 is arranged above the substrate, and then the final product is formed after fixing, leading and sealing.

The sensitive frame 7 is a sensing (or sensitive) part for picking up sound, and it can be provided with a plurality of masses (e.g., X-mass, Y-mass, Z-mass) or a single mass (common mass) for sensing (or sensitive) triaxial acceleration or bone vibration signals. In the embodiment shown in fig. 1 and 2, the sensitive frame 7 comprises a mass 8, anchor points 9, beam structures (not identified) and fixed electrodes (not identified). Wherein, the mass block 8 is connected with the anchor point 9 through the beam structure, and the anchor point 9 is fixed on the structure below the semiconductor structure layer 4; the fixed electrode is fixed on a structure below the semiconductor structure layer 4, and in the embodiment shown in fig. 1, the structure below the semiconductor structure layer 4 is the substrate 3; in the specific embodiment shown in fig. 2, the structure below the semiconductor structure layer 4 is the signal processing section 2. When the mass 8 senses (or is sensitive to) the bone vibration signal, the mass 8 moves, so that the distance between the mass 8 and the fixed electrode changes, and the bone vibration signal is converted into an electrical signal reflecting the capacitance change between the mass 8 and the fixed electrode, where the electrical signal is the electrical signal generated by the MEMS component 1 converting the bone vibration signal.

For ease of understanding, in the following, a capacitive accelerometer in which the sensitive frame 7 is three masses is taken as an example for explanation.

The mass block 8 comprises an X mass block, a Y mass block and a Z mass block; the fixed electrode comprises an X-axis detection electrode, a Y-axis detection electrode and a Z-axis detection electrode.

Be provided with movable broach structure on the X quality piece, be provided with fixed broach structure on the X axle detects the electrode, when sensitive (or response) to X axle bone vibration signal input, can make the X quality piece drives movable broach structure and takes place the motion along the X axle, makes the movable broach that sets up on the X quality piece for the fixed broach structure that the X axle detected the electrode and set up takes place the motion, and then makes X axle detects the electrode with electric capacity between the X quality piece changes, X axle detect the electrode detect with the distance of X quality piece changes, thereby will X axle bone vibration signal converts the reflection the X quality piece with electric signal of telecommunication of electric capacity change between the X axle detects the electrode.

Be provided with movable broach structure on the Y quality piece, be provided with fixed broach structure on the Y axle detects the electrode, when sensitive (or response) to Y axle bone vibration signal input, can make the Y quality piece drives movable broach structure and takes place the motion along the Y axle, makes the movable broach that sets up on the Y quality piece for the fixed broach structure that the Y axle detected the electrode and set up takes place the motion, and then makes Y axle detects the electrode with electric capacity between the Y quality piece changes, the Y axle detect the electrode detect with the distance of Y quality piece changes, thereby will Y axle bone vibration signal converts the reflection the Y quality piece with electric capacity between the Y axle detects the electric signal of telecommunication of change.

The Z-axis detection electrode is located below the Z mass block and has a gap with the Z mass block. When a Z-axis bone vibration signal is input in a sensitive (or induction) mode, the Z mass block can move like a seesaw, the Z-axis detection electrode detects the change of the distance between the Z mass block and the Z-axis detection electrode, and therefore the Z-axis bone vibration signal is converted into an electric signal reflecting the change of the capacitance between the Z mass block and the Z-axis detection electrode.

The electric signals generated by the MEMS part 1 and reflecting the capacitance change between the X mass block and the X-axis detection electrode, the electric signals reflecting the capacitance change between the Y mass block and the Y-axis detection electrode and the electric signals reflecting the capacitance change between the Z mass block and the Z-axis detection electrode are processed by the signal processing part 2, and then the sound pickup can be realized.

Fig. 3 is a schematic diagram illustrating an overall structure of the semiconductor structure layer shown in fig. 1 and fig. 2 according to an embodiment of the present invention. The semiconductor structure layer shown in fig. 3 includes a bonding frame 6 and a sensitive frame 7 located inside the bonding frame 6. The sensitive frame 7 comprises a mass 8, anchor points 9, beam structures 10 and fixed electrodes (not identified).

In the embodiment shown in fig. 3, mass 8 comprises an X mass 8a, a Y mass 8b and a Z mass 8 c; the anchor points 9 comprise an X mass block anchor point 9a, a Y mass block anchor point 9b and a Z mass block anchor point 9 c; the beam structure 10 includes a transverse elastic beam 10a, a longitudinal elastic beam 10b, and a torsion beam 10 c; the fixed electrodes include an X-axis detection electrode 18, a Y-axis detection electrode 13, and a Z-axis detection electrode 14. To better illustrate the semiconductor structure layer of the present invention, a three-dimensional rectangular coordinate system may be established, in the embodiment shown in fig. 3, the X-axis and the Y-axis are perpendicular to each other and define a plane of the structure under the semiconductor structure layer, and the Z-axis is perpendicular to the plane defined by the X-axis and the Y-axis, and the three-dimensional rectangular coordinate system established by the X-axis, the Y-axis and the Z-axis is shown in fig. 3, wherein the X-axis is along the left-right direction, the Y-axis is along the up-down direction, and the Z-axis is along the direction perpendicular to the paper.

The X-axis detection electrode 18 is located in the X-mass block 8a, a plurality of transverse fixed comb teeth 19 parallel to the Y-axis are arranged in the X-axis detection electrode 18, a plurality of transverse movable comb teeth 20 parallel to the Y-axis are arranged in the X-mass block 8a, wherein the plurality of transverse fixed comb teeth 19 in the X-axis detection electrode 18 and the plurality of transverse movable comb teeth 20 in the X-mass block 8a are arranged in an interdigital mode to form an interdigital capacitor. When an X-axis bone vibration signal is sensed (or induced), the X mass 8a moves along the X axis, and the X-axis detection electrode 18 detects a change in distance from the X mass 8a, so as to convert the X-axis bone vibration signal into an electrical signal reflecting a change in capacitance between the X mass 8a and the X-axis detection electrode 18. In the specific embodiment shown in fig. 3, there are four X-axis detection electrodes 18 located in the X-mass block 8a, where two X-axis detection electrodes 18 are located on the left and right sides of the upper portion in the X-mass block 8a, respectively; two other X-axis detection electrodes 18 are respectively located on the left and right sides of the lower portion in the X mass 8 a.

The X mass anchor 9a and the transverse spring beam 10a are also located within the X mass 8a, wherein the X mass 8a is connected to the X mass anchor 9a via the transverse spring beam 10 a. In the embodiment shown in fig. 3, there are two transverse elastic beams 10a, which are respectively located at the left and right sides of the X mass anchor point 9a, wherein the X mass 8a is connected to the X mass anchor point 9a via one transverse elastic beam 10 a; the X mass 8a is connected to the X mass anchor 9a via a further transverse spring beam 10 a. In the specific embodiment shown in fig. 3, the transverse elastic beam 10a is placed parallel to the Y-axis (or the extension direction of the transverse elastic beam 10a is parallel to the Y-axis); two X-axis detection electrodes 18 are located above the X mass anchor 9a and between the two transverse flexible beams 10 a; the other two X-axis detection electrodes 18 are located below the X-mass anchor 9a and between the two transverse flexible beams 10 a.

The X mass block anchor point 8a is fixed on the structure below the semiconductor structure layer 4; the X-axis detection electrode 18 is fixed on the structure below the semiconductor structure layer 4; the X-mass 8a and the transverse spring beam 10a are suspended above the structure below the semiconductor structure layer 4.

The Y-axis detection electrode 13 is located in the Y mass block 8b, a plurality of longitudinal fixed comb teeth 12 parallel to the X-axis are arranged in the Y-axis detection electrode 13, a plurality of longitudinal movable comb teeth 11 parallel to the X-axis are arranged in the Y mass block 8b, wherein the plurality of longitudinal fixed comb teeth 12 in the Y-axis detection electrode 13 and the plurality of longitudinal movable comb teeth 11 in the Y mass block 8b are arranged in an interdigital mode to form an interdigital capacitor. When a Y-axis bone vibration signal is sensed (or induced), the Y mass block 8b moves along the Y axis, and the Y-axis detection electrode 13 detects a change in distance from the Y mass block 8b, so that the Y-axis bone vibration signal is converted into an electrical signal reflecting a change in capacitance between the Y mass block 8b and the Y-axis detection electrode 13. In the specific embodiment shown in fig. 3, there are four Y-axis detection electrodes 13 located in the Y mass block 8b, where two Y-axis detection electrodes 13 are respectively located at the upper and lower ends of the left side in the Y mass block 8 b; the other two Y-axis detection electrodes 13 are respectively positioned at the upper end and the lower end of the right side in the Y mass block 8 b.

The Y mass anchor 9b and the longitudinal spring beam 10b are also located within the Y mass 8b, wherein the Y mass 8b is connected to the Y mass anchor 9b via the longitudinal spring beam 10 b. In the embodiment shown in fig. 3, two longitudinal elastic beams 10b are respectively located at the upper and lower parts of the Y mass anchor point 9b, wherein the Y mass 8b is connected to the Y mass anchor point 9b through one longitudinal elastic beam 10 b; the Y mass 8b is connected to the Y mass anchor 9b via another longitudinal elastic beam 10 b. In the specific embodiment shown in fig. 3, the longitudinal elastic beam 10b is disposed parallel to the X-axis (or the extending direction of the longitudinal elastic beam 10b is parallel to the X-axis); two Y-axis detection electrodes 13 are positioned on the left side of the Y mass block anchor point 9b and between the two longitudinal elastic beams 10 b; the other two Y-axis detection electrodes 13 are located to the right of the Y-mass anchor 9b and between the two longitudinal flexible beams 10 b.

The Y mass block anchor point 9b is fixed on the structure below the semiconductor structure layer 4; the Y-axis detection electrode 13 is fixed on the structure below the semiconductor structure layer 4; the Y-mass 8b and the longitudinal elastic beam 10b are suspended above the structure below the semiconductor structure layer 4.

The Z mass anchor point 9c and the torsion beam 10c are positioned in the Z mass 8c, and the Z mass 8c is connected with the Z mass anchor point 9c through the torsion beam 10 c; the Z-axis detection electrode 14 is located below the Z mass 8c and has a gap with the Z mass 8 c. When a Z-axis bone vibration signal is sensed (or induced), the Z mass 8c is twisted or pivoted (see a seesaw-like motion) around the torsion beam 10c, and the Z-axis detection electrode 14 detects a change in distance from the Z mass 8c, so that the Z-axis bone vibration signal is converted into an electrical signal reflecting a change in capacitance between the Z mass 8c and the Z-axis detection electrode 14. In the particular embodiment shown in fig. 3, the twist beam 10c is positioned parallel to the Y-axis (or the twist beam 10c extends parallel to the Y-axis); the number of the torsion beams 10c is two, wherein one torsion beam 10c is positioned above the Z mass block anchor point 9c, and the torsion beam 10c is connected with the Z mass block anchor point 9c and the Z mass block 8 c; the other torsion beam 10c is positioned below the Z mass anchor point 9c, and the torsion beam 10c is connected with the Z mass anchor point 9c and the Z mass 8 c; two Z-axis detection electrodes 14 are provided, which are respectively provided on the left and right sides of the torsion beam 10 c.

The Z mass block anchor point 9c is fixed on the structure below the semiconductor structure layer 4; the Z-axis detection electrode 14 is fixedly arranged on the structure below the semiconductor structure layer 4; the Z mass 8c and the torsion beam 10c are suspended above the structure below the semiconductor structure layer 4.

In one embodiment, the mass block 8 may be provided with a through hole 15 (as shown in fig. 3), a blind hole, a hollow structure or a semi-hollow structure to reduce mass and improve sensitivity.

In one embodiment, the mass 8 and the beam structure 10 may be provided with anti-collision protrusions 16 (as shown in fig. 3) to prevent structural damage when subjected to a large external impact.

In one embodiment, the substrate 3 is a silicon material, and a plurality of metal layers, interlayer dielectrics and through holes are arranged above the substrate, wherein the metal layers are mainly used as interconnection lines, can be made of aluminum or copper, and transmit electric signals to different positions of a chip; the interlayer dielectric is an insulating material and is used for separating the electrical connection between the metal layers; the through holes penetrate through the dielectric layers to form openings of electric paths from one metal layer to another adjacent metal layer, namely the through holes penetrate through the dielectric layers and the metal layers to form the openings of the electric paths, and are filled with metal tungsten commonly.

It should be noted that the sensitive frame 7 in the present invention can also adopt a capacitive accelerometer structure in the prior art.

The bone conduction accelerometer for picking up voice provided by the invention can be used in the field of earphones and helmet wearables, and can be used in outdoor running, climbing, cycling and swimming.

In summary, the bone conduction accelerometer for picking up voice provided by the invention comprises a MEMS component 1 and a signal processing component 2. The MEMS component 1 is a capacitive accelerometer for sensing a bone vibration signal and converting the bone vibration signal into an electrical signal. The signal processing component 2 is electrically connected with the MEMS component 1, and the signal processing component 2 is configured to process the electrical signal generated by the MEMS component 1 and convert the electrical signal into a sound signal. The invention has the beneficial effects that: the bone conduction accelerometer is used for picking up sound, the interference of external environment sound can be avoided, the package of a shell is not needed for realizing sealing, the MEMS chip is processed and prepared by a bulk silicon process, the process is simple, the size of the chip is small, and the sealing performance and the reliability are good.

In the present invention, the terms "connected", "connecting", and the like mean electrical connections, and direct or indirect electrical connections unless otherwise specified.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above embodiment, but equivalent modifications or changes made by those skilled in the art according to the present disclosure should be included in the scope of the present invention as set forth in the appended claims.