Voice acceleration sensor and wearable device

Abstract

The invention provides a voice acceleration sensor and wearable equipment. Comprising a substrate, an anchor point, a first mass block and a second mass block, the first mass block and the second mass block are connected to the anchor point and located on the two sides of the anchor point, and the first mass block and the second mass block can move relative to the substrate to be close to or away from the substrate and move in opposite directions. The first mass block comprises a first sub-block and a second sub-block, the first sub-block, the second sub-block and the second mass block are sequentially arranged in the length direction of the voice acceleration sensor, and the length of the second sub-block is equal to that of the second mass block; the first sub-block is provided with a first damping part which is recessed inwards from the surface, facing the first surface, of the first sub-block, and / or the substrate is provided with a second damping part which is recessed inwards from the first surface, and the second damping part and the first sub-block are oppositely arranged in the height direction of the voice acceleration sensor. According to the technical scheme, the high-frequency dynamic sensitivity detection precision is good, and noise and temperature drift are small.

Description

Technical Field

[0001] The present application relates to the technical field of electronic products, and in particular to a voice acceleration sensor and a wearable device. Background Art

[0002] The voice accelerometer is used for voice calls. It can detect the vibration information when the user speaks and convert the vibration information into an audio signal. It is an important inertial sensor with irreplaceable applications in vibration sensing, position sensing, displacement sensing, motion state sensing, industrial control, inertial navigation and other fields. For example, the voice accelerometer made of microelectromechanical system (MEMS) technology has the advantages of easy integration, low price, small size and light weight, and has been widely used. At present, the high-frequency dynamic sensitivity of the voice accelerometer during operation is low and the noise is large. Summary of the invention

[0003] The embodiments of the present application provide a voice acceleration sensor and a wearable device, which can have better detection accuracy of high-frequency dynamic sensitivity, smaller noise and temperature drift.

[0004] In a first aspect, an embodiment of the present application provides a voice acceleration sensor, the voice acceleration sensor comprising:

[0005] a substrate comprising a first surface;

[0006] an anchor point, the anchor point being connected to the first surface, the anchor point being arranged to protrude relative to the first surface;

[0007] a first mass block and a second mass block, wherein the first mass block is connected to an end of the anchor point away from the substrate, the first mass block is located on one side of the anchor point, the first mass block can move relative to the substrate to approach or move away from the substrate, and the second mass block is connected to an end of the anchor point away from the substrate, the second mass block is located on the other side of the anchor point, the second mass block can move relative to the substrate to approach or move away from the substrate, and the movement direction of the second mass block is opposite to that of the first mass block;

[0008] The first mass block includes a first sub-block and a second sub-block connected to each other. In the length direction of the voice acceleration sensor, the first sub-block, the second sub-block and the second mass block are arranged in sequence, and the length of the second sub-block is equal to the length of the second mass block;

[0009] The first sub-block is provided with a first damping portion, which is formed by the surface of the first sub-block facing the first surface being recessed toward the interior of the first sub-block, and / or the substrate is provided with a second damping portion, which is formed by the first surface being recessed toward the interior of the substrate, and in the height direction of the voice acceleration sensor, the second damping portion is arranged opposite to the first sub-block.

[0010] It is understandable that, in the voice accelerometer, in order to reduce the gas damping of the seesaw structure of the voice accelerometer and reduce the device noise of the voice accelerometer, the distance between the movable mass block of the voice accelerometer and the housing of the voice accelerometer must be greater than the distance between the movable mass block of the voice accelerometer and the substrate of the voice accelerometer. This setting will cause the damping of the voice accelerometer to mainly come from the gas squeeze film damping between the movable mass block and the substrate.

[0011] Since the second sub-block is equal to the second mass block in length, the first sub-block is the extra portion of the first mass block compared to the second mass block. In other words, compared with the second mass block, the first mass block is a relatively large mass block, the second mass block is a relatively small mass block, and the areas of the first mass block and the second mass block are not equal.

[0012] As a result, the voice acceleration sensor will form a seesaw-like structure. Specifically, when the voice acceleration sensor is in a non-acceleration state, the distance between the first mass block and the first electrode is equal to the distance between the second mass block and the second electrode. When the voice acceleration sensor is subjected to an acceleration in a direction perpendicular to and away from the substrate, the distance between the first mass block and the first electrode increases, and the distance between the second mass block and the second electrode decreases. When the voice acceleration sensor is subjected to an acceleration in a direction perpendicular to and close to the substrate, the distance between the first mass block and the first electrode decreases, and the distance between the second mass block and the second electrode increases.

[0013] Because the areas of the first mass block and the second mass block are not equal, the damping of the first sub-block that is more than the second mass block is difficult to offset. Therefore, when the voice acceleration sensor is subjected to acceleration in a direction perpendicular to and away from the substrate, the gas squeeze film damping between the movable mass block and the substrate is set asymmetrically with the gas squeeze film damping between the movable mass block and the substrate when the voice acceleration sensor is subjected to acceleration in a direction perpendicular to and close to the substrate. This setting easily causes the detection sensitivity of the voice acceleration sensor to be greater when it is subjected to acceleration in a direction perpendicular to and away from the substrate than when it is subjected to acceleration in a direction perpendicular to and close to the substrate. In other words, the detection sensitivity of the voice acceleration sensor is different in two opposite directions perpendicular to the substrate. This difference increases with the increase of the acceleration signal frequency, and is particularly obvious near the resonant frequency in the direction perpendicular to the substrate, which has a greater impact on the high-frequency dynamic characteristics of the device.

[0014] Based on the fact that the damping between the first sub-block and the substrate is inversely proportional to the distance between the first sub-block and the substrate, the damping between the first sub-block and the substrate can be effectively reduced by increasing the distance between the first sub-block and the substrate.

[0015] Thus, by providing the first damping part and / or the second damping part, the recessed space formed by the first damping part being recessed relative to the first sub-block and / or the recessed space formed by the second damping part being recessed relative to the substrate can be utilized to increase the spacing between the first sub-block and the substrate, thereby reducing the damping between the first sub-block and the substrate. Under this arrangement, it is beneficial to reduce the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by the different detection sensitivities in two opposite directions when the voice accelerometer is subjected to accelerations in two opposite directions perpendicular to the substrate, so that the detection sensitivity of the voice accelerometer in two opposite directions perpendicular to the substrate tends to be the same, which is beneficial to reduce the device noise of the voice accelerometer, improve the high-frequency dynamic characteristics of the voice accelerometer, and improve the high-frequency detection accuracy of the voice accelerometer. Exemplarily, the high frequency can be a frequency greater than 1000 Hz.

[0016] In addition, because the areas of the first mass block and the second mass block are asymmetric, when the temperature at the bottom of the voice accelerometer rises, the gas between the substrate and the movable mass block expands, pushing the first mass block and the second mass block to twist in opposite directions, and generating different torques on both sides of the torsion axis of the first mass block and the second mass block, thereby causing temperature drift in the direction perpendicular to the substrate. This temperature drift is more common in the use of voice accelerometers, such as during high-load operation of SoC (System on Chip) and high-power transmission of RF devices, which has a greater impact on upper-level applications that call acceleration signals.

[0017] Therefore, by making the recessed space formed by the recessed first damping part relative to the first sub-block and / or utilizing the recessed space formed by the recessed second damping part relative to the substrate as an expansion space for the gas, the pressure on the bottom of the first sub-block caused by the thermal expansion of the gas between the first sub-block and the substrate is reduced, and the temperature drift along the direction perpendicular to the substrate is reduced, so that the voice acceleration sensor can have better temperature reliability, is not prone to the problem of sensor performance degradation when the temperature rises, and has better reliability.

[0018] In a possible implementation manner, the first damping portion is a first groove that is recessed from a surface of the first sub-block facing the first surface toward an interior of the first sub-block.

[0019] It can be understood that by setting the first groove as a damping groove on the first sub-block, the first groove can have a certain depth of depression relative to the surface of the first sub-block facing the first surface, thereby increasing the spacing between the first sub-block and the substrate, reducing the damping between the first sub-block and the substrate, and making the detection sensitivity of the voice acceleration sensor tend to be the same in two opposite directions perpendicular to the substrate, which is beneficial to improving the high-frequency dynamic characteristics of the sensor and reducing the device noise of the voice acceleration sensor. In addition, the space released by setting the first groove can also be used as a gas expansion space, thereby reducing the pressure on the bottom of the first sub-block due to the thermal expansion of the gas between the first sub-block and the substrate, which is beneficial to alleviate the performance degradation of the voice acceleration sensor caused by the increase in temperature and improve the performance of the voice acceleration sensor in a high temperature environment.

[0020] In one possible implementation, when the cross-sectional area of ​​the first sub-block along a direction parallel to the first mass block is equal to the cross-sectional area of ​​the second sub-block along a direction parallel to the first mass block, the depth of the first groove relative to the surface of the first sub-block facing the first surface is equal to the spacing between the second sub-block and the substrate.

[0021] In other words, when the groove depth of the first groove is equal to or greater than the distance between the second sub-block and the substrate, the damping generated by the first sub-block can be ignored.

[0022] In a possible implementation manner, the first damping portion is a first damping hole array that is recessed from the surface of the first sub-block toward the first surface toward the interior of the first sub-block, and the first damping hole array includes a plurality of first blind holes, and the plurality of first blind holes are arranged in an array on the first sub-block.

[0023] It can be understood that by setting the first damping hole array on the first sub-block, the first blind hole can have a certain depression depth relative to the surface of the first sub-block facing the first surface, thereby increasing the spacing between the first sub-block and the substrate, reducing the damping between the first sub-block and the substrate, and making the detection sensitivity of the voice accelerometer in two opposite directions perpendicular to the substrate tend to be the same, which is beneficial to improving the high-frequency characteristics of the voice accelerometer and reducing the device noise of the voice accelerometer. In addition, the space released by setting the first blind hole can also be used as the expansion space of the gas, thereby reducing the pressure on the bottom of the first sub-block due to the thermal expansion of the gas between the first sub-block and the substrate, which is beneficial to alleviate the decline in the performance of the voice accelerometer due to the increase in temperature, and improve the performance of the voice accelerometer in a high temperature environment.

[0024] In a possible implementation manner, two adjacent first blind holes are arranged at intervals and are not connected to each other; or,

[0025] Two adjacent first blind holes are arranged at intervals, the first damping hole array further includes a plurality of first ventilation grooves, and two adjacent first blind holes are connected to each other through one of the first ventilation grooves.

[0026] It can be understood that by providing a first ventilation groove between two adjacent first blind holes to enable the two to be interconnected, the flow resistance of the first damping hole array can be reduced, which is beneficial to further reduce the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by the different detection sensitivities in two opposite directions when the voice accelerometer is subjected to accelerations in two opposite directions perpendicular to the substrate, thereby reducing the device noise of the voice accelerometer.

[0027] In a possible implementation manner, the second damping portion is a second groove recessed from the first surface toward the inside of the substrate.

[0028] It can be understood that by setting a second groove as a damping groove on the substrate, the spacing between the first sub-block and the substrate can be increased due to the second groove having a certain depression depth relative to the first surface of the substrate, and the damping between the first sub-block and the substrate can be reduced, so that the detection sensitivity of the voice accelerometer tends to be the same in two opposite directions perpendicular to the substrate, which is beneficial to improving the high-frequency characteristics of the voice accelerometer and reducing the device noise of the voice accelerometer. In addition, the space released by setting the second groove can also be used as an expansion space for the gas, thereby reducing the pressure on the bottom of the first sub-block due to the thermal expansion of the gas between the first sub-block and the substrate, which is beneficial to alleviate the decline in the performance of the voice accelerometer due to the increase in temperature and improve the performance of the voice accelerometer in a high temperature environment.

[0029] In a possible implementation, when the cross-sectional area of ​​the first sub-block along a direction parallel to the first mass block is equal to the cross-sectional area of ​​the second sub-block along a direction parallel to the first mass block, the depression depth of the second groove relative to the first surface is equal to the spacing between the second sub-block and the substrate.

[0030] In other words, when the groove depth of the second groove is equal to or greater than the distance between the second sub-block and the substrate, the damping generated by the first sub-block can be ignored.

[0031] In a possible implementation, the second damping portion is a second damping hole array recessed from the first surface toward the interior of the substrate, the second damping hole array includes a plurality of second blind holes, and the plurality of second blind holes are arranged in an array on the substrate.

[0032] It can be understood that by setting the second damping hole array on the substrate, the spacing between the first sub-block and the substrate can be increased due to the second blind hole having a certain recessed depth relative to the first surface of the substrate, and the damping between the first sub-block and the substrate can be reduced, so that the detection sensitivity of the voice accelerometer in two opposite directions perpendicular to the substrate tends to be the same, which is beneficial to improving the high-frequency characteristics of the voice accelerometer and reducing the device noise of the voice accelerometer. In addition, the space released by setting the second blind hole can also be used as an expansion space for the gas, thereby reducing the pressure on the bottom of the first sub-block due to the thermal expansion of the gas between the first sub-block and the substrate, which is beneficial to alleviate the decline in the performance of the voice accelerometer due to the increase in temperature and improve the performance of the voice accelerometer in a high temperature environment.

[0033] In a possible implementation manner, two adjacent second blind holes are arranged at intervals and are not connected to each other; or,

[0034] Two adjacent second blind holes are spaced apart from each other, the second damping hole array further comprises a plurality of second ventilation grooves, and two adjacent second blind holes are connected to each other via one second ventilation groove.

[0035] It can be understood that by providing a second ventilation groove between two adjacent second blind holes to enable the two to be interconnected, the flow resistance of the second damping hole array can be reduced, which is beneficial to further reduce the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by the different detection sensitivities in two opposite directions when the voice accelerometer is subjected to accelerations in two opposite directions perpendicular to the substrate, thereby reducing the device noise of the voice accelerometer.

[0036] In a possible implementation, the first damping portion is a first damping hole array that is recessed from the surface of the first sub-block toward the first surface toward the interior of the first sub-block, and the first damping hole array includes a plurality of first through holes that are arranged in an array on the first sub-block.

[0037] It can be understood that by making the first damping hole array a through-hole array, it is possible to reduce the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by the different detection sensitivities in two opposite directions when the voice accelerometer is subjected to acceleration in two opposite directions perpendicular to the substrate, thereby improving the signal-to-noise ratio of the voice accelerometer. In addition, the space released by the first through-hole can also be used as an expansion space for the gas, thereby reducing the pressure on the bottom of the first sub-block due to the thermal expansion of the gas between the first sub-block and the substrate, which is conducive to alleviating the degradation of the performance of the voice accelerometer caused by the increase in temperature and improving the performance of the voice accelerometer in a high temperature environment.

[0038] In a possible implementation manner, the second sub-block is provided with a third damping hole array, the third damping hole array includes a plurality of second through holes, and the plurality of second through holes are arranged in an array on the second sub-block;

[0039] The second mass block is provided with a fourth damping hole array, the fourth damping hole array includes a plurality of third through holes, and the plurality of third through holes are arranged in an array on the second mass block;

[0040] The porosity of the first damping hole array is greater than the porosity of the third damping hole array, and the porosity of the third damping hole array is the same as the porosity of the fourth damping hole array.

[0041] It can be understood that the use of differentiated porosity settings in the various parts of the first mass block and the second mass block can reduce the flow resistance of each damping hole array in the first mass block and the second mass block, enhance the gas flowability in the first sub-block area, and help reduce the temperature drift of the acceleration sensor in the direction perpendicular to the substrate. In addition, since each damping hole array is actually a through-hole array, the flow resistance of the gas convection from the substrate to the movable mass block can be further reduced, and the through-hole array is simple to prepare and can be prepared when preparing the movable mass block. For example, it can be obtained by etching through a deep reactive ion etching process (DRIE).

[0042] It should be noted that the porosity of each array can be selected based on actual conditions after considering sensitivity, accuracy requirements, chip size, process conditions and other conditions. This embodiment does not limit the actual size of the porosity of each array in the first damping hole array, the third damping hole array and the fourth damping hole array.

[0043] In a possible implementation, the voice acceleration sensor also includes a movable structure, which includes a main mass block and a torsion beam, the main mass block is provided with a hollow groove, the hollow groove exposes the anchor point, at least part of the torsion beam is located in the hollow groove, one end of the torsion beam is connected to the anchor point, and the other end of the torsion beam is connected to the main mass block, the main mass block is suspended on the substrate through the torsion beam, and the hollow groove separates the main mass block into the first mass block and the second mass block.

[0044] In a possible implementation, the torsion beam includes a first beam body and a second beam body, one end of the first beam body is connected to the anchor point, the other end of the first beam body is connected to the main mass block, one end of the second beam body is connected to the anchor point, the other end of the second beam body is connected to the main mass block, and the first beam body, the anchor point and the second beam body are arranged in sequence in the width direction of the voice acceleration sensor.

[0045] It can be understood that by setting the anchor point in the middle of the hollow groove and connecting the first beam and the second beam to the two sides of the anchor point respectively, it is helpful to avoid deformation of the anchor point due to external force or heat during the packaging process, reduce the influence of stress, and ensure the detection accuracy of the voice acceleration sensor.

[0046] In a second aspect, an embodiment of the present application further provides a wearable device, comprising a circuit board and the voice acceleration sensor as described above, wherein the voice acceleration sensor is electrically connected to the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic structural diagram of a wearable device provided in an embodiment of the present application;

[0048] Figure 2 yes Figure 1 A first structural schematic diagram of a voice acceleration sensor of a wearable device is shown;

[0049] Figure 3 yes Figure 2 A structural schematic diagram of a substrate of a voice acceleration sensor shown;

[0050] Figure 4 yes Figure 2 A schematic top view of a partial structure of the voice acceleration sensor shown;

[0051] Figure 5 yes Figure 2 Another schematic top view of a partial structure of the voice acceleration sensor shown;

[0052] Figure 6 yes Figure 2 A schematic diagram of a state of the voice acceleration sensor shown;

[0053] Figure 7 yes Figure 2 Another state schematic diagram of the voice acceleration sensor shown;

[0054] Figure 8 yes Figure 1 A second structural schematic diagram of a voice acceleration sensor of a wearable device is shown;

[0055] Fig. 9 yes Figure 8 A schematic structural diagram of a movable structure of a voice acceleration sensor at one angle;

[0056] Fig.10 yes Figure 1 A third structural schematic diagram of a voice acceleration sensor of a wearable device is shown;

[0057] Fig.11 yes Fig.10 A schematic structural diagram of a substrate of a voice acceleration sensor at an angle shown;

[0058] Fig.12 yes Figure 1 A fourth structural schematic diagram of a voice acceleration sensor of a wearable device is shown;

[0059] Fig.13 yes Figure 1 A fifth structural schematic diagram of a voice acceleration sensor of a wearable device is shown;

[0060] Fig.14 yes Fig.13 A structural schematic diagram of a movable structure of the voice acceleration sensor shown at one angle;

[0061] Fig.15 yes Fig.13 Another structural schematic diagram of an angle of the movable structure of the voice acceleration sensor shown;

[0062] Fig.16 yes Fig.13 Another structural schematic diagram of an angle of the movable structure of the voice acceleration sensor shown;

[0063] Fig.17 yes Figure 1 A sixth structural schematic diagram of a voice acceleration sensor of a wearable device is shown;

[0064] Fig.18 yes Figure 1A seventh structural schematic diagram of a voice acceleration sensor for a wearable device is shown;

[0065] Fig.19 yes Fig.18 A schematic structural diagram of a movable structure of a voice acceleration sensor at one angle;

[0066] Fig.20a for Fig.19 A schematic diagram of a single unit of the first damping hole array is shown;

[0067] Fig.20b for Fig.19 A schematic diagram of a single unit of the third damping hole array is shown;

[0068] Fig.20c for Fig.19 A schematic diagram of a single unit of the fourth damping hole array shown;

[0069] Fig.21 yes Figure 1 An eighth structural schematic diagram of a voice acceleration sensor of a wearable device is shown;

[0070] Fig. 22 yes Fig.21 A structural schematic diagram of an angle of a substrate of the voice acceleration sensor shown;

[0071] Fig.23 yes Fig.21 Another structural schematic diagram of an angle of the substrate of the voice acceleration sensor shown;

[0072] Fig.24 yes Fig.21 Another structural schematic diagram of an angle of the substrate of the voice acceleration sensor shown. DETAILED DESCRIPTION

[0073] For ease of understanding, the terms involved in the embodiments of the present application are first explained.

[0074] And / or: It is just a way to describe the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0075] Multiple: refers to two or more than two.

[0076] Connection: should be understood in a broad sense. For example, A and B are connected, which can be either direct or indirect through an intermediary.

[0077] The specific implementation of the present application will be clearly described below in conjunction with the accompanying drawings.

[0078] An embodiment of the present application provides a wearable device. Among them, the wearable device may be, but is not limited to, a smart headset, a smart watch, a smart bracelet, a portable music player, a health monitoring device, smart glasses, VR (Virtual Reality) glasses, AR (Augmented Reality) glasses, smart clothing, wearables, etc. Exemplarily, the smart headset may be a TWS (True Wireless Stereo) headset, and the type of the TWS headset may be a headset or an in-ear headset. The wearable device will be described below by taking the wearable device as a smart headset as an example, but it should be understood that it is not limited to this.

[0079] See also Figure 1 , Figure 1 is a schematic diagram of the structure of the wearable device 200 provided in an embodiment of the present application. Figure 1 The appearance of the wearable device 200 shown is only for convenience of illustration and does not represent the actual appearance of the wearable device 200.

[0080] The wearable device 200 may include a housing 210, a circuit board 220 and a voice acceleration sensor 100. A receiving space A is provided in the housing 210, and the circuit board 220 and the voice acceleration sensor 100 are both located in the receiving space A of the wearable device 200. The circuit board 220 can connect the various devices in the wearable device 200 in series to realize the functions of each device in the wearable device 200. The voice acceleration sensor 100 is electrically connected to the circuit board 220, and the voice acceleration sensor 100 is used to detect acceleration. It can detect the bone vibration information when the user speaks, and convert the vibration information into an audio signal output. The voice acceleration sensor 100 is an important inertial sensor, which is mainly used in vibration sensing, position sensing, displacement sensing, motion state sensing, industrial control, inertial navigation and other fields. Exemplarily, the circuit board 220 can be a printed circuit board, a flexible circuit board or a soft-hard combination circuit board. The voice accelerometer 100 can be arranged on the circuit board 220, which can be a MEMS VACC (Voice accelerometer), also known as a bone conduction accelerometer, which is a wide-band, low-noise MEMS voice accelerometer that can be used to detect weak vibrations of the human body without being interfered by air sound, and is mainly used for TWS headset call noise reduction or heart sound, lung sound and other physiological index detection. The user can use a tapping method (such as single-clicking the shell 210, double-clicking the shell 210, multiple taps on the shell 210, single-clicking the user's skin, double-clicking the user's skin, multiple taps on the user's skin) to make the voice accelerometer 100 recognize the vibration and cooperate with the Bluetooth control processing module in the wearable device 200 to complete actions such as answering, hanging up, playing, pausing and starting the voice assistant.

[0081] Among them, the voice acceleration sensor 100 is not limited to being used in the wearable device 200, and it can also be used in devices such as mobile phones, tablet computers, e-readers, laptops, vehicle-mounted equipment, assembly line vibration detection industrial equipment, etc. The embodiments of the present application do not impose strict restrictions on this.

[0082] It should be noted that Figure 1 The purpose is only to schematically describe the connection relationship between the housing 210, the circuit board 220 and the voice acceleration sensor 100, and it does not specifically limit the connection position, specific structure and quantity of each device. The structure illustrated in the embodiment of the present application does not constitute a specific limitation on the wearable device 200. In other embodiments of the present application, the wearable device 200 may include Figure 1 More or fewer components may be shown, or some components may be combined or separated, or the components may be arranged differently. Figure 1 The components shown may be implemented in hardware, software or a combination of software and hardware.

[0083] See also Figure 2 , Figure 2 yes Figure 1 The first structural schematic diagram of the voice acceleration sensor 100 of the wearable device 200 is shown. The types of the voice acceleration sensor 100 may include a piezoresistive voice acceleration sensor, a piezoelectric voice acceleration sensor, a capacitive voice acceleration sensor, a thermal convection voice acceleration sensor, and the like.

[0084] In the embodiment of the present application, for the convenience of illustration, the voice acceleration sensor 100 is taken as a capacitive voice acceleration sensor as an example for explanation, and the capacitive voice acceleration sensor has the advantages of high sensitivity, small drift, simple structure, and simple manufacturing. As follows, the length direction of the voice acceleration sensor 100 is the first direction X, the width direction of the voice acceleration sensor 100 is the second direction Y, and the height direction of the voice acceleration sensor 100 is the third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0085] The voice acceleration sensor 100 may include a substrate 10, a housing 20, a movable structure 30, an anchor point 40, a first electrode 50 and a second electrode 60. The housing 20 is connected to the substrate 10, and the housing 20 has a cavity 21. The substrate 10 is connected to the cavity 21 and has an open end and seals the cavity 21. The cavity 21 is filled with a gas medium 70, and the gas medium 70 can be an inactive gas, such as nitrogen, helium and the like. The anchor point 40 is connected to the substrate 10 and is located in the cavity 21. The anchor point 40 is an immovable part in the voice acceleration sensor 100, which can be used as a fulcrum of the movable structure 30 to realize the movement of the movable structure 30 relative to the substrate 10. The movable structure 30 is a movable part in the voice acceleration sensor 100, and the movable structure 30 is connected to the anchor point 40. The movable structure 30 can be suspended above the substrate 10 through the anchor point 40, and the movable structure 30 can move perpendicular to the direction of the substrate 10 (i.e., the third direction Z and the opposite direction of the third direction Z). The first electrode 50 and the second electrode 60 are both connected to the substrate 10 and are located in the cavity 21. The first electrode 50 and the second electrode 60 are respectively located on both sides of the anchor point 40. The first electrode 50 can form a first detection capacitor C1 together with a part of the movable structure 30 located on the same side of the anchor point 40. The second electrode 60 can form a second detection capacitor C2 together with a part of the movable structure 30 located on the same side of the anchor point 40. The first detection capacitor C1 and the second detection capacitor C2 change in opposite directions and together form a differential capacitor structure to further improve the detection sensitivity of the voice acceleration sensor 100. By detecting the difference in the capacitance change of the first detection capacitor C1 and the second detection capacitor C2, the magnitude of the acceleration in the third direction Z or the opposite direction of the third direction Z can be obtained.

[0086] The substrate 10 may include a first surface 11 and a second surface 12 disposed opposite to each other, wherein the first surface 11 of the substrate 10 is a surface of the substrate 10 facing the movable structure 30, and the second surface 12 of the substrate 10 is a surface of the substrate 10 facing away from the movable structure 30. The first surface 11 of the substrate 10 can be connected to the first electrode 50, the second electrode 60, the anchor point 40 and the housing 20.

[0087] For a possible implementation, see Figure 3 , Figure 3 yes Figure 2 A schematic diagram of the structure of the substrate 10 of the voice acceleration sensor 100 shown. The substrate 10 may include a base 13 and an insulating layer 14, the base 13 and the insulating layer 14 are stacked, and the base 13 and the insulating layer 14 are sequentially arranged in the third direction Z. The first electrode 50 and the second electrode 60 are arranged at intervals on the surface of the insulating layer 14 away from the base 13 (that is, the first surface 11). The insulating layer 14 can be used to electrically isolate the first electrode 50, the second electrode 60 and the base 13.

[0088] Please refer again Figure 2 , the shell 20 is connected to the first surface 11 of the substrate 10. The shell 20 can be a regular or irregular three-dimensional structure with a cavity 21 (i.e., a hollow part) inside. Exemplarily, the shell 20 can be a hollow frame structure, including but not limited to regular shapes such as cubes, spheres, cylinders, regular polyhedrons, or any irregular shape. The shell 20 can be made of metal (e.g., stainless steel, copper, etc.), plastic (e.g., polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and acrylonitrile-butadiene-styrene copolymer (ABS)), inorganic non-metallic materials (e.g., single crystal silicon, doped silicon, etc.), composite materials (such as metal-based composite materials or non-metal-based composite materials), etc. For example, the material used for the shell 20 is silicon.

[0089] One end of the anchor point 40 is connected to the first surface 11 of the substrate 10, and the other end of the anchor point 40 extends in a direction away from the first surface 11 of the substrate 10. The anchor point 40 is arranged to protrude relative to the first surface 11 of the substrate 10. The anchor point 40 can provide a fixed fulcrum for the movable structure 30 to move in a direction perpendicular to the substrate 10. It should be noted that Figure 2 The anchor point 40 shown in the subsequent figures is only for convenience of illustration, and its shape and structure do not constitute a limitation on the actual shape and structure of the anchor point 40. The embodiments of the present application do not impose strict limitations on the shape, size, specific structure, etc. of the anchor point 40.

[0090] The first electrode 50 and the second electrode 60 are arranged at intervals on the first surface 11 of the substrate 10, and the first electrode 50 and the second electrode 60 are respectively located on both sides of the anchor point 40. Exemplarily, the first electrode 50 and the second electrode 60 are both flat electrodes. The flat electrodes ensure that when the movable structure 30 moves along the third direction Z and the opposite direction of the third direction Z, the electrode facing areas on the first electrode 50 and the second electrode 60 do not change. The first electrode 50 and the second electrode 60 can be formed of various conductive materials, such as a metal layer, a doped polysilicon layer, or a stacked conductor including a metal layer and a doped polysilicon layer, or other conductive materials, such as TaC (tantalum carbide), TiN (titanium nitride), TaSiN (tantalum silicon nitride), HfSiN (hafnium silicon nitride), TiSiN (titanium silicon nitride), TiCN (titanium nitride carbide), TaAlC (tantalum aluminum carbide), TiAlN (titanium aluminum nitride), TaN (tantalum nitride), PtSix (nickel platinum), Ni3Si (nickel silicide), Pt (platinum), Ru (ruthenium), W (tungsten) and a combination of one or more thereof.

[0091] Please refer to Figure 2 , Figure 4 and Figure 5 , Figure 4 yes Figure 2 A schematic top view of a partial structure of the voice acceleration sensor 100 is shown. Figure 5 yes Figure 2 Another schematic top view of a partial structure of the voice acceleration sensor 100 is shown. Figure 4 The substrate 10, the housing 20, the first electrode 50 and the second electrode 60 of the speech acceleration sensor 100 are not shown. Figure 5 The movable structure 30 and the housing 20 of the speech acceleration sensor 100 are not shown.

[0092] The movable structure 30 is connected to the anchor point 40, and the movable structure 30 is suspended above the substrate 10 through the anchor point 40. The movable structure 30 cooperates with the anchor point 40 to form a seesaw-like structure. Specifically, the movable structure 30 may include a main mass block 31 and a torsion beam 32. The main mass block 31 is provided with a hollow groove 311, and the hollow groove 311 can extend along the second direction Y and penetrate the main mass block 31 along the third direction Z. The hollow groove 311 can expose the anchor point 40. At least part of the torsion beam 32 is located in the hollow groove 311, one end of the torsion beam 32 is connected to the anchor point 40, and the other end of the torsion beam 32 is connected to the main mass block 31, and the main mass block 31 is suspended on the substrate 10 through the torsion beam 32. The main mass block 31 can be rotated around the second direction Y with the second direction Y as the axis. Exemplarily, the main mass block 31 can be in the shape of a square, a cuboid, a cylinder, a ring, etc., and the embodiments of the present application are not strictly limited.

[0093] In a possible implementation, Figure 4 As shown, the torsion beam 32 may include a first beam body 321 and a second beam body 322, one end of the first beam body 321 is connected to the anchor point 40, the other end of the first beam body 321 is connected to the main mass block 31, one end of the second beam body 322 is connected to the anchor point 40, the other end of the second beam body 322 is connected to the main mass block 31, and the first beam body 321, the anchor point 40 and the second beam body 322 are sequentially arranged in the second direction Y. In other words, in the hollow groove 311, along the extension direction of the hollow groove 311, the first beam body 321, the anchor point 40 and the second beam body 322 are sequentially arranged. By arranging the anchor point 40 in the middle position of the hollow groove 311, and connecting the first beam body 321 and the second beam body 322 to both sides of the anchor point 40 respectively, it is helpful to avoid deformation of the anchor point 40 due to external force or heat during the packaging process, reduce the influence of stress, and ensure the detection accuracy of the voice acceleration sensor 100.

[0094] Please refer to Figure 2 , Figure 4 and Figure 5 , the hollow groove 311 separates the main mass block 31 into a first mass block 33 and a second mass block 34. The first mass block 33 and the second mass block 34 are movable mass blocks, which can be connected by a torsion beam 32 and are respectively suspended on both sides of the anchor point 40. The first mass block 33 and the second mass block 34 are arranged opposite to each other in the first direction X, the first mass block 33 is located on one side of the anchor point 40, and the second mass block 34 is located on the other side of the anchor point 40. The first mass block 33 and the second mass block 34 are different in size, and the first mass block 33 and the second mass block 34 are different in mass. In the first direction X, the length of the first mass block 33 is not equal to the length of the second mass block 34. Exemplarily, in the first mass block 33 and the second mass block 34, the first mass block 33 is a relatively large mass block, and the second mass block 34 is a relatively small mass block. In the first direction X, the length of the first mass block 33 is greater than the length of the second mass block 34.

[0095] In the embodiment of the present application, the first mass block 33 can be connected to the end of the anchor point 40 away from the substrate 10 through the torsion beam 32, and the first mass block 33 can move perpendicular to the direction of the substrate 10 under the support of the torsion beam 32, so as to move relative to the substrate 10 and approach or move away from the substrate 10. Specifically, the first mass block 33 can move along the third direction Z and move away from the substrate 10, and the first mass block 33 can also move in the opposite direction of the third direction Z and approach the substrate 10.

[0096] The second mass block 34 is connected to the end of the anchor point 40 away from the substrate 10 through the torsion beam 32. The second mass block 34 can move perpendicular to the direction of the substrate 10 under the support of the torsion beam 32. The second mass block 34 can move relative to the substrate 10 to approach or move away from the substrate 10. Specifically, the second mass block 34 can move along the third direction Z to move away from the substrate 10, and the second mass block 34 can also move in the opposite direction of the third direction Z to approach the substrate 10.

[0097] The movement direction of the second mass block 34 is opposite to that of the first mass block 33. That is, when the first mass block 33 moves toward the direction close to the substrate 10, the second mass block 34 moves away from the substrate 10. When the first mass block 33 moves away from the substrate 10, the second mass block 34 moves toward the direction close to the substrate 10, so that the movable structure 30 cooperates with the anchor point 40 to form a seesaw-like structure.

[0098] The first mass block 33 and the first electrode 50 are arranged on the same side and are both located on one side of the anchor point 40. The first mass block 33 and the first electrode 50 can jointly constitute the first detection capacitor C1 described above. In the first detection capacitor C1, the first mass block 33 is a movable electrode, and the first electrode 50 is a fixed electrode. The second mass block 34 and the second electrode 60 are arranged on the same side and are both located on the other side of the anchor point 40. The second mass block 34 and the second electrode 60 can jointly constitute the second detection capacitor C2 described above. In the second detection capacitor C2, the second mass block 34 is a movable electrode, and the second electrode 60 is a fixed electrode.

[0099] It can be understood that the first mass block 33 is a movable electrode in the first detection capacitor C1, and the first electrode 50 is a fixed electrode in the first detection capacitor C1. The second mass block 34 is a movable electrode in the second detection capacitor C2, and the second electrode 60 is a fixed electrode in the second detection capacitor C2. Since the first mass block 33 and the second mass block 34 are asymmetrically arranged on both sides of the anchor point 40, the voice acceleration sensor 100 can realize a seesaw structure. When there is no external acceleration on the first mass block 33 and the second mass block 34, the first mass block 33 and the first electrode 50 are relatively still, the second mass block 34 and the second electrode 60 are relatively still, and there is no capacitance change on both sides of the seesaw structure. When the external acceleration acts on the first mass block 33 and the second mass block 34 along the third direction Z or the opposite direction of the third direction Z, an inertial force will be formed, and the inertial force will cause the first mass block 33 and the second mass block 34 to twist and form a displacement on the first mass block 33 and the second mass block 34, and the movement directions of the first mass block 33 and the second mass block 34 are opposite. The gap between the first mass block 33 and the first electrode 50 and the gap between the second mass block 34 and the second electrode 60 change, resulting in a change in the capacitance of the first detection capacitor C1 and the second detection capacitor C2. The displacement change of the first mass block 33 and the second mass block 34 is detected by the differential capacitance between the first detection capacitor C1 and the second detection capacitor C2, so as to determine the magnitude of the external acceleration.

[0100] In a specific application scenario, please refer to Figure 2 , Figure 6 and Figure 7 , Figure 6 yes Figure 2 A state diagram of the voice acceleration sensor 100 shown in FIG. Figure 7 yes Figure 2 Another state schematic diagram of the voice acceleration sensor 100 is shown.

[0101] like Figure 2 As shown, when the first detection capacitor C1 is in a zero-acceleration (ie, zero-gravity) state, the distance between the first mass block 33 and the first electrode 50 is equal to the distance between the second mass block 34 and the second electrode 60, and at this time, the capacitance of the first detection capacitor C1 is equal to that of the second detection capacitor C2.

[0102] like Figure 6As shown, when there is an acceleration input along the third direction Z, the torsion beam 32 twists, causing the first mass block 33 and the second mass block 34 to move, that is, the first mass block 33 and the second mass block 34 rotate clockwise with the second direction Y as the axis. The distance between the first mass block 33 and the first electrode 50 increases, and the capacitance of the first detection capacitor C1 decreases. The distance between the second mass block 34 and the second electrode 60 decreases, and the capacitance of the second detection capacitor C2 increases. The magnitude of the acceleration along the third direction Z can be obtained by using the difference between the first detection capacitor C1 and the second detection capacitor C2.

[0103] like Figure 7 As shown, when there is an acceleration input in the opposite direction of the third direction Z, the torsion beam 32 twists, causing the first mass block 33 and the second mass block 34 to move, that is, the first mass block 33 and the second mass block 34 rotate counterclockwise with the second direction Y as the axis. The distance between the first mass block 33 and the first electrode 50 decreases, and the capacitance of the first detection capacitor C1 increases. The distance between the second mass block 34 and the second electrode 60 increases, and the capacitance of the second detection capacitor C2 decreases. The magnitude of the acceleration in the opposite direction of the third direction Z can be obtained by using the difference between the first detection capacitor C1 and the second detection capacitor C2.

[0104] Please refer to Figure 2 and Figure 4 The first mass block 33 may include a first sub-block 331 and a second sub-block 332 connected to each other. In the first direction X, the first sub-block 331, the second sub-block 332 and the second mass block 34 are sequentially arranged. The first electrode 50 and the second sub-block 332 are arranged opposite to each other in the third direction Z, and the second electrode 60 and the second mass block 34 are arranged opposite to each other in the third direction Z. The length of the second sub-block 332 along the first direction X is equal to the length of the second mass block 34 along the first direction X.

[0105] Please refer to Figure 8 , Fig. 9 , Fig.10 , Fig.11 and Fig.12 , Figure 8 yes Figure 1 The second structural schematic diagram of the voice acceleration sensor 100 of the wearable device 200 is shown, Fig. 9 yes Figure 8 The structure diagram of the movable structure 30 of the voice acceleration sensor 100 at an angle is shown in FIG. Fig.10 yes Figure 1 The third structural diagram of the voice acceleration sensor 100 of the wearable device 200 is shown in FIG. Fig.11 yes Fig.10 The schematic diagram of the structure of the substrate 10 of the voice acceleration sensor 100 at an angle is shown. Fig.12 yes Figure 1 A fourth structural schematic diagram of the voice acceleration sensor 100 of the wearable device 200 is shown.

[0106] The first sub-block 331 is provided with a first damping portion 333, and the first damping portion 333 is recessed from the surface of the first sub-block 331 facing the first surface 11 to the inside of the first sub-block 331, and the first damping portion 333 is formed by the surface of the first sub-block 331 facing the first surface 11 recessed to the inside of the first sub-block 331. And / or, the substrate 10 is provided with a second damping portion 15, and the second damping portion 15 is recessed from the first surface 11 of the substrate 10 to the inside of the substrate 10, and the second damping portion 15 is formed by the first surface 11 of the substrate 10 recessed to the inside of the substrate 10. In the third direction Z, the second damping portion 15 is arranged opposite to the first sub-block 331.

[0107] It is understandable that, in the voice acceleration sensor 100, in order to reduce the gas damping of the seesaw structure of the voice acceleration sensor 100 and reduce the device noise of the voice acceleration sensor 100, the distance between the movable mass block of the voice acceleration sensor 100 and the housing 20 of the voice acceleration sensor 100 needs to be greater than the distance between the movable mass block of the voice acceleration sensor 100 and the substrate 10 of the voice acceleration sensor 100. This setting will cause the damping of the voice acceleration sensor 100 to mainly come from the gas squeeze film damping between the movable mass block and the substrate 10.

[0108] Since the second sub-block 332 is equal to the second mass block 34 in length, the first sub-block 331 is the extra portion of the first mass block 33 compared to the second mass block 34. In other words, compared with the second mass block 34, the first mass block 33 is a relatively large mass block, and the second mass block 34 is a relatively small mass block, and the areas of the first mass block 33 and the second mass block 34 are not equal.

[0109] As a result, the voice acceleration sensor 100 forms a seesaw-like structure. Specifically, when the voice acceleration sensor 100 is in a non-acceleration state, the distance between the first mass block 33 and the first electrode 50 is equal to the distance between the second mass block 34 and the second electrode 60. When the voice acceleration sensor 100 is subjected to an acceleration in a direction perpendicular to and away from the substrate 10, the distance between the first mass block 33 and the first electrode 50 increases, and the distance between the second mass block 34 and the second electrode 60 decreases. When the voice acceleration sensor 100 is subjected to an acceleration in a direction perpendicular to and close to the substrate 10, the distance between the first mass block 33 and the first electrode 50 decreases, and the distance between the second mass block 34 and the second electrode 60 increases.

[0110] Because the areas of the first mass block 33 and the second mass block 34 are not equal, the damping of the first sub-block 331 of the first mass block 33 that is more than the second mass block 34 is difficult to offset. Therefore, when the voice acceleration sensor 100 is subjected to acceleration in a direction perpendicular to and away from the substrate 10, the gas squeeze film damping between the movable mass block and the substrate 10 is set asymmetrically with the gas squeeze film damping between the movable mass block and the substrate 10 when the voice acceleration sensor 100 is subjected to acceleration in a direction perpendicular to and close to the substrate 10. This setting easily leads to the detection sensitivity of the voice acceleration sensor 100 subjected to acceleration in a direction perpendicular to and away from the substrate 10 being greater than the detection sensitivity of the voice acceleration sensor 100 subjected to acceleration in a direction perpendicular to and close to the substrate 10. In other words, the detection sensitivity of the voice acceleration sensor 100 is different in two opposite directions perpendicular to the substrate 10. This difference increases with the increase of the acceleration signal frequency, and is particularly obvious near the resonant frequency in the direction perpendicular to the substrate 10, which has a greater impact on the high-frequency dynamic characteristics of the device.

[0111] The damping coefficient c1 between the movable mass block and the substrate 10 satisfies the following formula:

[0112]

[0113] Wherein, μ is the dynamic viscosity of the internal gas medium 70 in the voice acceleration sensor 100 , l is the length of the movable mass block, w is the width of the movable mass block, and h is the distance between the movable mass block and the substrate 10 .

[0114] According to the above formula, the damping between the first sub-block 331 and the substrate 10 is inversely proportional to the distance between the first sub-block 331 and the substrate 10. Therefore, by increasing the distance between the first sub-block 331 and the substrate 10, the damping between the first sub-block 331 and the substrate 10 can be effectively reduced.

[0115] Thus, by providing the first damping part 333 and / or the second damping part 15, the recessed space formed by the first damping part 333 being recessed relative to the first sub-block 331 and / or the recessed space formed by the second damping part 15 being recessed relative to the substrate 10 can be utilized to increase the spacing between the first sub-block 331 and the substrate 10, and reduce the damping between the first sub-block 331 and the substrate 10. Under this arrangement, it is helpful to reduce the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by the different detection sensitivities in the two opposite directions when the voice acceleration sensor 100 is subjected to acceleration in two opposite directions perpendicular to the substrate 10, so that the detection sensitivity of the voice acceleration sensor 100 in the two opposite directions perpendicular to the substrate 10 tends to be the same, which is helpful to reduce the device noise of the voice acceleration sensor 100, improve the high-frequency dynamic characteristics of the voice acceleration sensor 100, and improve the high-frequency dynamic detection accuracy of the voice acceleration sensor. Exemplarily, the high frequency can be a frequency greater than 1000 Hz.

[0116] In addition, because the areas of the first mass block 33 and the second mass block 34 are asymmetric, when the temperature at the bottom of the voice acceleration sensor 100 rises, the gas between the substrate 10 and the movable mass block expands, pushing the first mass block 33 and the second mass block 34 to twist in opposite directions, and generating torsional torques of different magnitudes on both sides of the torsion axis of the first mass block 33 and the second mass block 34, thereby causing temperature drift in a direction perpendicular to the substrate 10. This temperature drift is more common during the use of the voice acceleration sensor 100, such as during high-load operation of the SoC (System on Chip) and high-power transmission of the RF device, which has a greater impact on the upper-layer application that calls the acceleration signal.

[0117] Therefore, by making the first damping part 333 recessed relative to the first sub-block 331 to form a recessed space, and / or utilizing the recessed space formed by the second damping part 15 recessed relative to the substrate 10 as an expansion space for the gas, the pressure on the bottom of the first sub-block 331 due to the thermal expansion of the gas between the first sub-block 331 and the substrate 10 is reduced, and the temperature drift along the direction perpendicular to the substrate 10 is reduced, so that the voice acceleration sensor 100 can have better temperature reliability, is not prone to the problem of sensor performance degradation when the temperature rises, and has better reliability.

[0118] The structural possibilities of the first damping part 333 and the second damping part 15 will be described in detail below through a plurality of different embodiments.

[0119] First embodiment:

[0120] Please refer to Figure 8 and Fig. 9, the first sub-block 331 is provided with a first damping portion 333, and the first damping portion 333 is recessed from the surface of the first sub-block 331 facing the first surface 11 to the inside of the first sub-block 331. Specifically, the first damping portion 333 is a first groove 333a recessed from the surface of the first sub-block 331 facing the first surface 11 to the inside of the first sub-block 331. The first groove 333a may extend along the second direction Y, and the recessed depth of the first groove 333a relative to the surface of the first sub-block 331 facing the first surface 11 is less than the thickness of the first sub-block 331.

[0121] It should be noted that the ratio of the opening area of ​​the first groove 333 a to the area of ​​the first sub-block 331 can be selected according to the actual application scenario, and this embodiment does not impose a strict limitation on this.

[0122] Exemplarily, the first groove 333a can be a rectangular groove. For the polysilicon process system, by increasing the thickness of the sacrificial layer of the first sub-block 331, the preparation of the damping groove (first groove 333a) at the bottom of the first sub-block 331 can be easily realized. The area of ​​the first groove 333a can be equal to the area of ​​the first sub-block 331, wherein the area of ​​the first groove 333a refers to the groove area of ​​the first groove 333a, and the area of ​​the first sub-block 331 refers to the cross-sectional area of ​​the first sub-block 331 along the direction parallel to the first mass block 33. Of course, in other embodiments, the first groove 333a can also be a groove structure with a regular shape or an irregular shape. The embodiments of the present application do not impose strict restrictions on the shape of the first groove 333a, the groove area of ​​the first groove 333a, the depression depth of the first groove 333a relative to the surface of the first sub-block 331 facing the first surface 11, etc., and can be selected according to the actual application scenario.

[0123] It can be understood that by providing the first groove 333a as a damping groove on the first sub-block 331, the first groove 333a has a certain depth of depression relative to the surface of the first sub-block 331 facing the first surface 11, so as to increase the distance between the first sub-block 331 and the substrate 10, reduce the damping between the first sub-block 331 and the substrate 10, and make the detection sensitivity of the voice acceleration sensor 100 tend to be the same in two opposite directions perpendicular to the substrate 10, which is conducive to improving the high-frequency characteristics of the voice acceleration sensor 100 and reducing the device noise of the voice acceleration sensor 100. In addition, the space released by the first groove 333a can also be used as the expansion space of the gas, thereby reducing the pressure on the bottom of the first sub-block 331 due to the thermal expansion of the gas between the first sub-block 331 and the substrate 10, which is conducive to alleviating the performance degradation of the voice acceleration sensor 100 caused by the increase in temperature and improving the performance of the voice acceleration sensor 100 in a high temperature environment.

[0124] In a specific application scenario, such as Figure 8 and Fig. 9 As shown, when the cross-sectional area of ​​the first sub-block 331 along the direction parallel to the first mass block 33 is equal to the cross-sectional area of ​​the second sub-block 332 along the direction parallel to the first mass block 33, the depression depth h2 of the first groove 333a relative to the surface of the first sub-block 331 facing the first surface 11 is equal to the spacing h1 between the second sub-block 332 and the substrate 10. That is, h2 = h1. Under this setting, the damping of the first sub-block 331 is only 1 / 8 of that of the second sub-block 332, which can be basically ignored. In other words, when the groove depth of the first groove 333a is greater than or equal to the spacing between the second sub-block 332 and the substrate 10, the damping generated by the first sub-block 331 can be ignored.

[0125] Second embodiment:

[0126] Please refer to Fig.13 , Fig.14 and Fig.15 , Fig.13 yes Figure 1 The fifth structural schematic diagram of the voice acceleration sensor 100 of the wearable device 200 is shown, Fig.14 yes Fig.13 A structural schematic diagram of a movable structure 30 of the voice acceleration sensor 100 at one angle is shown, Fig.15 yes Fig.13 Another structural schematic diagram of the movable structure 30 of the voice acceleration sensor 100 at one angle is shown.

[0127] In this embodiment, the same contents as those in the first embodiment are not repeated here. The difference from the first embodiment is that the first damping portion 333 is a first damping hole array 333b that is recessed from the surface of the first sub-block 331 facing the first surface 11 to the inside of the first sub-block 331. The first damping hole array 333b may include a plurality of first blind holes 334, each of which is recessed from the surface of the first sub-block 331 facing the first surface 11 to the inside of the first sub-block 331, and the plurality of first blind holes 334 are arranged in an array on the first sub-block 331. Exemplarily, the shape of the first blind hole 334 may be as follows: Fig.14 Alternatively, the shape of the second blind hole 151 may be as follows: Fig.15 Of course, in other embodiments, the first blind hole 334 may also be a hole structure with a regular shape or an irregular shape. The embodiment of the present application does not impose strict restrictions on the shape of the first blind hole 334, the opening area of ​​the first blind hole 334, the depression depth of the first blind hole 334 relative to the surface of the first sub-block 331 facing the first surface 11, etc., and can be selected according to the actual application scenario.

[0128] It can be understood that by setting the first damping hole array 333b on the first sub-block 331, the first blind hole 334 has a certain depression depth relative to the surface of the first sub-block 331 facing the first surface 11, so as to increase the spacing between the first sub-block 331 and the substrate 10, reduce the damping between the first sub-block 331 and the substrate 10, and make the detection sensitivity of the voice acceleration sensor 100 in two opposite directions perpendicular to the substrate 10 tend to be the same, which is conducive to improving the high-frequency characteristics of the voice acceleration sensor 100 and reducing the device noise of the voice acceleration sensor 100. In addition, the space released by the first blind hole 334 can also be used as the expansion space of the gas, thereby reducing the pressure on the bottom of the first sub-block 331 due to the thermal expansion of the gas between the first sub-block 331 and the substrate 10, which is conducive to alleviating the performance degradation of the voice acceleration sensor 100 caused by the increase in temperature and improving the performance of the voice acceleration sensor 100 in a high temperature environment.

[0129] Exemplarily, the first damping hole array 333b can be applied to the case where the silicon layer of the first sub-block 331 is relatively thin, and it can increase the distance between the first sub-block 331 and the substrate 10 on the basis of satisfying the strength of the first sub-block 331. In order to reduce the corrosion release time, the first damping hole array 333b in this embodiment can be used to replace the single first groove 333a in the first embodiment. The position of the first damping hole array 333b is consistent with the position of the first groove 333a in the first embodiment. Since the hollowing area of ​​the first damping hole array 333b in this embodiment is smaller than the hollowing area of ​​the single first groove 333a in the first embodiment, the hollowing depth of the single first blind hole 334 in the first damping hole array 333b in this embodiment can be increased to achieve the same damping value as that in the first embodiment.

[0130] In a possible implementation, Fig.14 and Fig.15 As shown, two adjacent first blind holes 334 are spaced apart and are not connected to each other.

[0131] For another possible implementation, see Fig.16 , Fig.16 yes Fig.13Another structural schematic diagram of the movable structure 30 of the voice acceleration sensor 100 at an angle is shown. Two adjacent first blind holes 334 are arranged at intervals, and the first damping hole array 333b also includes a plurality of first ventilation grooves 335, and the two adjacent first blind holes 334 are connected to each other through a first ventilation groove 335. It can be understood that by arranging the first ventilation groove 335 between the two adjacent first blind holes 334 so that the two can be connected to each other, the flow resistance of the first damping hole array 333b can be reduced, which is conducive to further reducing the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by the different detection sensitivities in the two opposite directions when the voice acceleration sensor 100 is subjected to acceleration in two opposite directions perpendicular to the substrate 10, thereby reducing the device noise of the voice acceleration sensor 100.

[0132] It should be noted that, in this embodiment, all the first blind holes 334 are interconnected, but in other embodiments, only a portion of the first blind holes 334 may be interconnected, and the embodiments of the present application do not impose strict restrictions on this. In addition, the shape and size of the first ventilation groove 335 can be selected according to the actual application scenario, and only needs to be able to connect two adjacent first blind holes 334, and the embodiments of the present application do not impose strict restrictions on this.

[0133] Third embodiment:

[0134] See also Fig.17 , Fig.17 yes Figure 1 The sixth structural schematic diagram of the voice acceleration sensor 100 of the wearable device 200 shown. In this embodiment, the same content as the second embodiment is not repeated. Unlike the second embodiment, the first damping part 333 is a first damping hole array 333c that is recessed from the surface of the first sub-block 331 toward the first surface 11 to the inside of the first sub-block 331. The first damping hole array 333c includes a plurality of first through holes 336a, each of which passes through the first sub-block 331 along the third direction Z, and the plurality of first through holes 336a are arranged in an array on the first sub-block 331. Exemplarily, the shape of the first through hole 336a can be rectangular, circular, etc. Of course, in other embodiments, the first through hole 336a can also be a hole-like structure with a regular shape or an irregular hole-like structure. The embodiment of the present application does not strictly limit the shape of the first through hole 336a, the opening area of ​​the first through hole 336a, etc., and can be selected according to the actual application scenario.

[0135] It can be understood that by making the first damping hole array 333c a through-hole array, it is possible to reduce the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by different detection sensitivities in two opposite directions when the voice acceleration sensor 100 is subjected to acceleration in two opposite directions perpendicular to the substrate 10, thereby improving the signal-to-noise ratio of the voice acceleration sensor 100. In addition, the space released by the first through-hole 336a can also be used as an expansion space for the gas, thereby reducing the pressure on the bottom of the first sub-block 331 due to the thermal expansion of the gas between the first sub-block 331 and the substrate 10, which is conducive to alleviating the performance degradation of the voice acceleration sensor 100 caused by the increase in temperature and improving the performance of the voice acceleration sensor 100 in a high temperature environment.

[0136] Fourth embodiment:

[0137] Please refer to Fig.18 and Fig.19 , Fig.18 yes Figure 1 The seventh structural schematic diagram of the voice acceleration sensor 100 of the wearable device 200 is shown, Fig.19 yes Fig.18 The structure diagram of the movable structure 30 of the voice acceleration sensor 100 at one angle is shown.

[0138] In this embodiment, the same contents as those in the third embodiment are not repeated here. The difference from the third embodiment is that the first damping portion 333 is a first damping hole array 333d that is recessed from the surface of the first sub-block 331 toward the first surface 11 toward the inside of the first sub-block 331. The first damping hole array 333d includes a plurality of first through holes 336b, each of which penetrates the first sub-block 331 along the third direction Z, and the plurality of first through holes 336b are arranged in an array on the first sub-block 331. Exemplarily, the shape of the first through hole 336b may be rectangular, circular, etc. Of course, in other embodiments, the first through hole 336b may also be a hole-like structure with a regular shape or a hole-like structure with an irregular shape. The embodiment of the present application does not impose strict restrictions on the shape of the first through hole 336b, the opening area of ​​the first through hole 336b, etc., and may be selected according to the actual application scenario.

[0139] The second sub-block 332 is further provided with a third damping hole array 337, which includes a plurality of second through holes 3371, each of which penetrates the second sub-block 332 along the third direction Z, and the plurality of second through holes 3371 are arranged in an array on the second sub-block 332. The second mass block 34 is further provided with a fourth damping hole array 338, which includes a plurality of third through holes 3381, each of which penetrates the second mass block 34 along the third direction Z, and the plurality of third through holes 3381 are arranged in an array on the second mass block 34.

[0140] Please refer to Fig.19 , Fig.20a , Fig.20b and Fig.20c , Fig.20a for Fig.19 The schematic diagram of a single unit of the first damping hole array 333d is shown. Fig.20b for Fig.19 A schematic diagram of a single unit of the third damping hole array 337 is shown, Fig.20c for Fig.19 A schematic diagram of a single unit of the fourth damping hole array 338 is shown.

[0141] The damping coefficient c2 of the first damping hole array 333d and the porosity η1 of the first damping hole array 333d satisfy the relationship:

[0142]

[0143] Wherein, η1=11 / L1, 11 is the diameter of the first through hole 336b in a single unit of the first damping hole array 333d, L 1, is the overall size of a single unit of the first damping hole array 333d, and the size of a single unit is L1×L1.

[0144] The damping coefficient c3 of the third damping hole array 337 and the porosity η2 of the third damping hole array 337 satisfy the relationship:

[0145]

[0146] Wherein, η2=12 / L2, 12 is the diameter of the second through hole 3371 in a single unit of the third damping hole array 337, L 2, is the overall size of a single unit of the third damping hole array 337, and the size of a single unit is L2×L2.

[0147] The damping coefficient c4 of the fourth damping hole array 338 and the porosity η3 of the fourth damping hole array 338 satisfy the relationship:

[0148]

[0149] Wherein, η3=13 / L3, 13 is the diameter of the third through hole 3381 in a single unit of the fourth damping hole array 338, L 3, is the overall size of a single unit of the fourth damping hole array 338, and the size of a single unit is L3×L3.

[0150] In this embodiment, the porosity η1 of the first damping hole array 333 d is greater than the porosity η2 of the third damping hole array 337 , and the porosity η2 of the third damping hole array 337 is the same as the porosity η3 of the fourth damping hole array 338 .

[0151] It can be understood that the use of differentiated porosity settings in various parts of the first mass block 33 and the second mass block 34 can reduce the flow resistance of each damping hole array in the first mass block 33 and the second mass block 34, enhance the gas flowability in the first sub-block 331 area, and help reduce the temperature drift of the acceleration sensor in the direction perpendicular to the substrate 10. In addition, since each damping hole array is actually a through-hole array, the flow resistance of the gas convection from the substrate 10 to the movable mass block can be further reduced, and the through-hole array is simple to prepare and can be prepared when preparing the movable mass block. For example, it can be obtained by etching through a deep reactive ion etching process (DRIE).

[0152] It should be noted that the porosity of each array can be selected based on actual conditions after considering sensitivity, accuracy requirements, chip size, process conditions and other conditions. This embodiment does not limit the actual size of the porosity of each array in the first damping hole array 333d, the third damping hole array 337 and the fourth damping hole array 338.

[0153] Exemplarily, by keeping the area of ​​each unit in the first damping hole array 333d, the third damping hole array 337 and the fourth damping hole array 338 the same and the number of array units the same, and making the porosity of the first damping hole array 333d greater than the porosity of the third damping hole array 337 and the porosity of the fourth damping hole array 338, the damping coefficient of the first damping hole array 333d is smaller than that of the third damping hole array 337 and the fourth damping hole array 338. For example, when the porosity η1 of the first damping hole array 333d is ≥ 0.5, and the porosity η2 of the third damping hole array 337 and the porosity η3 of the fourth damping hole array 338 are ≤ 0.2, the damping of the first damping hole array 333d is ≤ 1 / 5 of the third damping hole array 337 and / or the fourth damping hole array 338, and can be basically ignored.

[0154] Fifth embodiment:

[0155] Please refer to Fig.10 and Fig.11, the same contents as those in the first embodiment are not repeated here. The difference from the first embodiment is that the first damping part 333 is not provided on the first sub-block 331. The substrate 10 is provided with a second damping part 15, which is recessed from the first surface 11 of the substrate 10 to the inside of the substrate 10. In the third direction Z, the second damping part 15 is arranged opposite to the first sub-block 331. Specifically, the second damping part 15 is a second groove 15a recessed from the first surface 11 of the substrate 10 to the inside of the substrate 10. The second groove 15a can extend along the second direction Y, and the recess depth of the second groove 15a relative to the first surface 11 of the substrate 10 is less than the thickness of the substrate 10. The groove area of ​​the second groove 15a can be greater than or equal to the cross-sectional area of ​​the first sub-block 331 along the direction parallel to the first mass block 33. Of course, in other embodiments, the groove area of ​​the second groove 15a can also be less than the cross-sectional area of ​​the first sub-block 331 along the direction parallel to the first mass block 33.

[0156] Exemplarily, the second groove 15a can be a rectangular groove. For a single crystal silicon system, the second groove 15a can be prepared by a deep reactive ion etching (DRIE) process before bonding; for a polycrystalline process system, a thicker SiO2 sacrificial layer is required to offset the height difference after etching the second groove 15a on the substrate 10. Of course, in other embodiments, the second groove 15a can also be a groove structure with a regular shape or an irregular shape. The embodiments of the present application do not impose strict restrictions on the shape of the second groove 15a, the groove area of ​​the second groove 15a, the depth of the second groove 15a relative to the surface of the first sub-block 331 facing the first surface 11, etc., and can be selected according to the actual application scenario.

[0157] It can be understood that by providing the second groove 15a as a damping groove on the substrate 10, the spacing between the first sub-block 331 and the substrate 10 can be increased due to the second groove 15a having a certain depth of depression relative to the first surface 11 of the substrate 10, and the damping between the first sub-block 331 and the substrate 10 can be reduced, so that the detection sensitivity of the voice acceleration sensor 100 in two opposite directions perpendicular to the substrate 10 tends to be the same, which is conducive to improving the high-frequency characteristics of the voice acceleration sensor 100 and reducing the device noise of the voice acceleration sensor 100. In addition, the space released by the second groove 15a can also be used as an expansion space for gas, thereby reducing the pressure on the bottom of the first sub-block 331 due to the thermal expansion of the gas between the first sub-block 331 and the substrate 10, which is conducive to alleviating the performance degradation of the voice acceleration sensor 100 caused by the increase in temperature and improving the performance of the voice acceleration sensor 100 in a high temperature environment.

[0158] In a specific application scenario, such as Fig.10As shown, when the cross-sectional area of ​​the first sub-block 331 along the direction parallel to the first mass block 33 is equal to the cross-sectional area of ​​the second sub-block 332 along the direction parallel to the first mass block 33, the depression depth h4 of the second groove 15a relative to the first surface 11 of the substrate 10 is equal to the spacing h3 between the second sub-block 332 and the substrate 10. That is, h4=h3. Under this setting, the damping of the first sub-block 331 is only 1 / 8 of that of the second sub-block 332, which can be basically ignored. In other words, when the groove depth of the second groove 15a is greater than or equal to the spacing between the second sub-block 332 and the substrate 10, the damping generated by the first sub-block 331 can be ignored.

[0159] Sixth embodiment:

[0160] Please refer to Fig.21 , Fig. 22 and Fig.23 , Fig.21 yes Figure 1 The eighth structural schematic diagram of the voice acceleration sensor 100 of the wearable device 200 is shown, Fig. 22 yes Fig.21 A structural schematic diagram of a substrate 10 of the voice acceleration sensor 100 at an angle is shown. Fig.23 yes Fig.21 Another structural schematic diagram of a substrate 10 of the voice acceleration sensor 100 at one angle is shown.

[0161] In this embodiment, the same contents as those in the fifth embodiment are not repeated here. The difference from the fifth embodiment is that the second damping portion 15 is recessed from the first surface 11 of the substrate 10 to the interior of the substrate 10, and in the third direction Z, the second damping portion 15 is arranged opposite to the first sub-block 331. Specifically, the second damping portion 15 is a second damping hole array 15b recessed from the first surface 11 of the substrate 10 to the interior of the substrate 10. The second damping hole array 15b may include a plurality of second blind holes 151, each of which is recessed from the first surface 11 of the substrate 10 to the interior of the substrate 10, and the plurality of second blind holes 151 are arranged in an array on the substrate 10. Exemplarily, the shape of the second blind hole 151 may be as follows: Fig.21 The shape of the second blind hole 151 can be as follows: Fig. 22 Of course, in other embodiments, the second blind hole 151 may also be a hole structure with a regular shape or an irregular shape. The embodiment of the present application does not impose strict restrictions on the shape of the second blind hole 151, the opening area of ​​the second blind hole 151, the depth of the second blind hole 151 relative to the surface of the second sub-block 332 facing the second surface 12, etc., and can be selected according to the actual application scenario.

[0162] It can be understood that by providing the second damping hole array 15b on the substrate 10, the second blind hole 151 can have a certain recessed depth relative to the first surface 11 of the substrate 10, thereby increasing the spacing between the first sub-block 331 and the substrate 10, reducing the damping between the first sub-block 331 and the substrate 10, and making the detection sensitivity of the voice acceleration sensor 100 in two opposite directions perpendicular to the substrate 10 tend to be the same, which is beneficial to improving the high-frequency characteristics of the voice acceleration sensor 100 and reducing the device noise of the voice acceleration sensor 100. In addition, the space released by the second blind hole 151 can also be used as an expansion space for gas, thereby reducing the pressure on the bottom of the first sub-block 331 due to the thermal expansion of the gas between the first sub-block 331 and the substrate 10, which is beneficial to alleviate the performance degradation of the voice acceleration sensor 100 caused by the increase in temperature, and improve the performance of the voice acceleration sensor 100 in a high temperature environment.

[0163] For example, in order to reduce the corrosion release time, the second damping hole array 15b in this embodiment can be used to replace the single second groove 15a in the fifth embodiment. The position of the second damping hole array 15b is consistent with the position of the second groove 15a in the fifth embodiment. Since the hollowing area of ​​the second damping hole array 15b in this embodiment is smaller than the hollowing area of ​​the single second groove 15a in the fifth embodiment, the hollowing depth of the single second blind hole 151 in the second damping hole array 15b in this embodiment can be increased to achieve the same damping value as that of the first embodiment.

[0164] In a possible implementation, Fig. 22 and Fig.23 As shown, two adjacent second blind holes 151 are arranged at intervals and are not connected to each other.

[0165] For another possible implementation, see Fig.24 , Fig.24 yes Fig.21 Another structural schematic diagram of an angle of the substrate 10 of the voice acceleration sensor 100 shown. Two adjacent second blind holes 151 are arranged at intervals, and the second damping hole array 15b also includes a plurality of second ventilation grooves 152, and the two adjacent second blind holes 151 are interconnected through a second ventilation groove 152. It can be understood that by arranging the second ventilation groove 152 between the two adjacent second blind holes 151 so that the two can be interconnected, the flow resistance of the second damping hole array 15b can be reduced, which is conducive to further reducing the damping asymmetry, temperature asymmetry and gas thrust asymmetry in two different scenarios caused by the different detection sensitivities in the two opposite directions when the voice acceleration sensor 100 is subjected to acceleration in two opposite directions perpendicular to the substrate 10, thereby reducing the device noise of the voice acceleration sensor 100.

[0166] It should be noted that, in this embodiment, all the second blind holes 151 are interconnected, but in other embodiments, only a portion of the second blind holes 151 may be interconnected, and the embodiments of the present application do not impose strict restrictions on this. In addition, the shape and size of the second ventilation groove 152 can be selected according to the actual application scenario, and only needs to be able to connect two adjacent second blind holes 151, and the embodiments of the present application do not impose strict restrictions on this.

[0167] Seventh embodiment:

[0168] See also Fig.12 In this embodiment, the same contents as those in the first six embodiments are not described in detail. The difference from the first six embodiments is that the first sub-block 331 is provided with a first damping portion 333e, which is recessed from the surface of the first sub-block 331 facing the first surface 11 to the inside of the first sub-block 331. The substrate 10 is provided with a second damping portion 15c, which is recessed from the first surface 11 of the substrate 10 to the inside of the substrate 10. In the third direction Z, the second damping portion 15c is arranged opposite to the first sub-block 331. The specific forms and structural possibilities of the first damping portion 333e and the second damping portion 15c can be referred to the first six embodiments, which can be permutations and combinations of the forms of the first six embodiments, and this embodiment is not described in detail here.

[0169] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A voice acceleration sensor, characterized in that: The voice acceleration sensor comprises: a substrate comprising a first surface; an anchor point, the anchor point being connected to the first surface, the anchor point being arranged to protrude relative to the first surface; a first mass block and a second mass block, wherein the first mass block is connected to an end of the anchor point away from the substrate, the first mass block is located on one side of the anchor point, the first mass block can move relative to the substrate to approach or move away from the substrate, and the second mass block is connected to an end of the anchor point away from the substrate, the second mass block is located on the other side of the anchor point, the second mass block can move relative to the substrate to approach or move away from the substrate, and the movement direction of the second mass block is opposite to that of the first mass block; The first mass block includes a first sub-block and a second sub-block connected to each other. In the length direction of the voice acceleration sensor, the first sub-block, the second sub-block and the second mass block are arranged in sequence, and the length of the second sub-block is equal to the length of the second mass block; The first sub-block is provided with a first damping portion, which is formed by the surface of the first sub-block facing the first surface being recessed toward the interior of the first sub-block, and / or the substrate is provided with a second damping portion, which is formed by the first surface being recessed toward the interior of the substrate, and in the height direction of the voice acceleration sensor, the second damping portion is arranged opposite to the first sub-block.

2. The voice acceleration sensor according to claim 1, characterized in that: The first damping portion is a first groove that is recessed from a surface of the first sub-block facing the first surface toward an interior of the first sub-block.

3. The voice acceleration sensor according to claim 2, characterized in that: When a cross-sectional area of ​​the first sub-block along a direction parallel to the first mass block is equal to a cross-sectional area of ​​the second sub-block along a direction parallel to the first mass block, a depth of the first groove relative to a surface of the first sub-block facing the first surface is equal to a distance between the second sub-block and the substrate.

4. The voice acceleration sensor according to claim 1, characterized in that: The first damping portion is a first damping hole array recessed from the surface of the first sub-block toward the first surface toward the inside of the first sub-block, and the first damping hole array includes a plurality of first blind holes arranged in an array on the first sub-block.

5. The voice acceleration sensor according to claim 4, characterized in that: Two adjacent first blind holes are arranged at intervals and are not connected to each other; or, Two adjacent first blind holes are arranged at intervals, the first damping hole array further includes a plurality of first ventilation grooves, and two adjacent first blind holes are connected to each other through one of the first ventilation grooves.

6. The voice acceleration sensor according to claim 1, characterized in that: The second damping portion is a second groove recessed from the first surface toward the inside of the substrate.

7. The voice acceleration sensor according to claim 6, characterized in that: When the cross-sectional area of ​​the first sub-block along the direction parallel to the first mass block is equal to the cross-sectional area of ​​the second sub-block along the direction parallel to the first mass block, the recessed depth of the second groove relative to the first surface is equal to the distance between the second sub-block and the substrate.

8. The voice acceleration sensor according to claim 1, characterized in that: The second damping portion is a second damping hole array recessed from the first surface toward the interior of the substrate. The second damping hole array includes a plurality of second blind holes, and the plurality of second blind holes are arranged in an array on the substrate.

9. The voice acceleration sensor according to claim 8, characterized in that: Two adjacent second blind holes are arranged at intervals and are not connected to each other; or, Two adjacent second blind holes are spaced apart from each other, the second damping hole array further comprises a plurality of second ventilation grooves, and two adjacent second blind holes are connected to each other via one second ventilation groove.

10. The voice acceleration sensor according to claim 1, characterized in that: The first damping portion is a first damping hole array recessed from the surface of the first sub-block toward the first surface toward the inside of the first sub-block, and the first damping hole array includes a plurality of first through holes arranged in an array on the first sub-block.

11. The voice acceleration sensor according to claim 10, characterized in that: The second sub-block is provided with a third damping hole array, the third damping hole array includes a plurality of second through holes, and the plurality of second through holes are arranged in an array on the second sub-block; The second mass block is provided with a fourth damping hole array, the fourth damping hole array includes a plurality of third through holes, and the plurality of third through holes are arranged in an array on the second mass block; The porosity of the first damping hole array is greater than the porosity of the third damping hole array, and the porosity of the third damping hole array is the same as the porosity of the fourth damping hole array.

12. The voice acceleration sensor according to any one of claims 1 to 11, characterized in that: The voice acceleration sensor also includes a movable structure, which includes a main mass block and a torsion beam. The main mass block is provided with a hollow groove, and the hollow groove exposes the anchor point. At least part of the torsion beam is located in the hollow groove. One end of the torsion beam is connected to the anchor point, and the other end of the torsion beam is connected to the main mass block. The main mass block is suspended on the substrate through the torsion beam, and the hollow groove separates the main mass block into the first mass block and the second mass block.

13. The voice acceleration sensor according to claim 12, characterized in that: The torsion beam includes a first beam body and a second beam body, one end of the first beam body is connected to the anchor point, and the other end of the first beam body is connected to the main mass block, one end of the second beam body is connected to the anchor point, and the other end of the second beam body is connected to the main mass block, and the first beam body, the anchor point and the second beam body are arranged in sequence in the width direction of the voice acceleration sensor.

14. A wearable device, characterized in that: The wearable device comprises a circuit board and a voice acceleration sensor as described in any one of claims 1 to 13, wherein the voice acceleration sensor is electrically connected to the circuit board.

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