MEMS inertial sensor, detection method, and electronic device

Abstract

The embodiment of the application provides a MEMS inertial sensor, a detection method and an electronic device; wherein the MEMS inertial sensor comprises a substrate, a first electrode, a second electrode, a mass block and an elastic beam; one side of the substrate is provided with an insulating layer; the first electrode and the second electrode are provided on the insulating layer at intervals; the mass block is provided above the substrate in suspension, the mass block comprises a first part, a second part and a third part; the elastic beam is used for connecting the substrate and the mass block, the elastic beam is connected to an anchor point of the substrate, the first part, the third part and the second part are located on two sides of the elastic beam; the second part and the second electrode form a first capacitor, and the third part and the first electrode form a second capacitor; the second capacitor can form a collapsed working mode, in the collapsed working mode, the first capacitor is used for forming a detection end, and the MEMS inertial sensor can detect and perceive according to an obtained capacitance change amount in the collapsed working mode.

Description

Technical Field

[0001] This application relates to the field of sensor detection technology, and more specifically, embodiments of this application relate to a MEMS inertial sensor, a detection method, and an electronic device. Background Technology

[0002] Currently, capacitive voice accelerometers used for voice call noise reduction suffer from low detection sensitivity, making it impossible to achieve high-definition sound pickup and noise reduction in noisy environments. To address this low sensitivity, a DC bias voltage is typically applied. A higher DC bias voltage results in higher detection sensitivity, but this can also cause the fixed and movable electrodes to attract each other, leading to detection failure.

[0003] Voice accelerometers can use single-ended capacitance detection, while traditional accelerometers typically use differential capacitance detection. From detection methods to performance characteristics, both types of accelerometers have their own advantages and disadvantages, making it difficult to achieve complementary performance advantages; therefore, they cannot be used interchangeably. Summary of the Invention

[0004] The purpose of this application is to provide a new technical solution for a MEMS inertial sensor, a detection method, and an electronic device. The two capacitors formed cooperate with each other and can be used for motion acceleration detection and can also realize a collapse working mode for voice acceleration detection, so that the MEMS inertial sensor can have dual working modes.

[0005] In a first aspect, this application provides a MEMS inertial sensor. The MEMS inertial sensor includes:

[0006] A substrate, wherein an insulating layer is provided on one side of the substrate;

[0007] A first electrode and a second electrode are disposed on the insulating layer at a distance from each other;

[0008] A mass block, which is suspended above the base, comprises a first part, a second part, and a third part;

[0009] An elastic beam is used to connect the base and the mass block. The elastic beam is connected to the anchor point of the base, and the first part, the third part and the second part are located on both sides of the elastic beam.

[0010] The second part and the second electrode form a first capacitor, and the third part and the first electrode form a second capacitor; the second capacitor can form a collapsed working mode, in which the first capacitor is used to form a detection end, and the MEMS inertial sensor can detect and sense based on the acquired capacitance change in the collapsed working mode.

[0011] Optionally, the third part is connected between the first part and the second part, and the third part and the first part are located on the same side of the elastic beam;

[0012] In the Z-axis direction, the height of the third part is greater than the height of the first part, so that the third part and the first part form a stepped structure on one side of the elastic beam.

[0013] Optionally, the first capacitor and the second capacitor can also be used to form a differential capacitance detector; wherein the first electrode and the second electrode are both detection electrodes, used as differential capacitance detection output signal ports.

[0014] Optionally, when the first capacitor and the second capacitor form a differential capacitance detector and a change in acceleration in the Z-axis direction is detected, the elastic beam undergoes torsional deformation and forms a rotating shaft, and the mass block can rotate around the formed rotating shaft.

[0015] Optionally, in the collapsed operating mode, the MEMS inertial sensor applies a first DC voltage to the first electrode, forming an electrostatic force between the first electrode and the mass block, thus forming an attracting electrode, and the mass block serves as a single-ended capacitor output signal port.

[0016] Optionally, when the first DC voltage is greater than the pull-in voltage U pull-in At that time, the first part is in contact with the insulating layer, and the mass block is electrically insulated from the first electrode, the second electrode, and the substrate.

[0017] Optionally, when a second DC voltage is applied to the first electrode, and the second DC voltage is greater than the first DC voltage, the elastic beam undergoes bending deformation, and the distance between the second portion and the first and second electrodes decreases.

[0018] Optionally, when an acceleration change is detected in the Z-axis direction, the mass block moves up and down around the contact point where the first part contacts the insulating layer, supported by the elastic beam.

[0019] Optionally, the MEMS inertial sensor can be used for voice detection by the voice acceleration sensor in the collapsed operating mode.

[0020] Optionally, the substrate is made of monocrystalline silicon or polycrystalline silicon.

[0021] Secondly, embodiments of this application provide a detection method for a MEMS inertial sensor, using the MEMS inertial sensor as described in the first aspect, the detection method comprising:

[0022] A first DC voltage is applied to the first electrode, the first part contacts the insulating layer and forms a contact point, the second capacitor formed by the third part and the first electrode enters the collapse working mode, and the elastic beam undergoes bending deformation.

[0023] The mass block moves up and down along the Z-axis around the contact point under the support of the elastic beam. The first capacitor formed by the second part and the second electrode serves as a detection terminal to obtain the capacitance change.

[0024] Optionally, the detection method of the MEMS inertial sensor further includes:

[0025] The first capacitor and the second capacitor form a differential capacitance detector, wherein both the first electrode and the second electrode serve as differential capacitance output ports;

[0026] The elastic beam undergoes torsional deformation, and the mass block rotates around the axis formed by the torsion of the elastic beam under the support of the elastic beam.

[0027] Thirdly, embodiments of this application provide an electronic device. The electronic device includes:

[0028] MEMS inertial sensors as described in the first aspect.

[0029] The beneficial effects of this application are as follows:

[0030] The MEMS inertial sensor provided in this application adopts a new structural design. In the two capacitors formed, one capacitor can be used as a detection end, and the other capacitor can form a collapse. This gives the MEMS inertial sensor a new working mode, namely the collapse working mode. This design allows the formed MEMS inertial sensor to have more working modes.

[0031] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0033] Figure 1 This is one of the structural schematic diagrams of a MEMS inertial sensor provided in the embodiments of this application;

[0034] Figure 2 This is a second schematic diagram of the structure of the MEMS inertial sensor provided in the embodiments of this application;

[0035] Figure 3 The third schematic diagram of the structure of the MEMS inertial sensor provided in the embodiments of this application;

[0036] Figure 4 Fourth schematic diagram of the structure of the MEMS inertial sensor provided in the embodiments of this application;

[0037] Figure 5 Fifth schematic diagram of the structure of the MEMS inertial sensor provided in the embodiments of this application;

[0038] Figure 6 for Figure 5 A schematic diagram of the AA section.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. MEMS inertial sensor; 2. Mass block; 2a. First part; 2b. Second part; 2c. Third part; 3. Rotating shaft; 4. Insulating layer; 5. Substrate; 6. First electrode; 7. Second electrode; 8. Elastic beam; 8a. First segment; 8b. Second segment; 9. Anchor point; 10. Contact point. Detailed Implementation

[0041] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0042] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0043] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0044] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0046] The MEMS inertial sensor and electronic device provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0047] According to one aspect of an embodiment of this application, a MEMS inertial sensor is provided, see [link to relevant documentation]. Figures 1 to 6 As shown, the MEMS inertial sensor can be used as a voice acceleration sensor for voice noise reduction, or as an acceleration sensor for motion detection, and has dual working modes.

[0048] The MEMS inertial sensor provided in this application embodiment is described in [reference]. Figures 1 to 6 The device includes: a substrate 5, a first electrode 6 and a second electrode 7, a mass block 2, and an elastic beam 8; an insulating layer 4 is provided on one side of the substrate 5; the first electrode 6 and the second electrode 7 are disposed on the insulating layer 4 at intervals; the mass block 2 is suspended above the substrate 5, and the mass block 2 includes a first part 2a, a second part 2b, and a third part 2c; the elastic beam 8 is used to connect the substrate 5 and the mass block 2, and the elastic beam 8 is connected to an anchor point 9 on the substrate 5, with the first part 2a, the third part 2c, and the second part 2b located on both sides of the elastic beam 8; the second part 2b and the second electrode 7 form a first capacitor, and the third part 2c and the first electrode 6 form a second capacitor; the second capacitor can form a collapsed working mode, in which the first capacitor is used to form a detection end, and the MEMS inertial sensor can detect and sense based on the acquired capacitance change in the collapsed working mode.

[0049] It should be noted that a capacitive sensor is a conversion device that uses various types of capacitors as sensing elements to convert the measured physical or mechanical quantity into a change in capacitance. In fact, it is a capacitor with variable parameters.

[0050] According to the structural design of the MEMS inertial sensor proposed in the above embodiments of this application, in the two capacitors formed, namely the first capacitor and the second capacitor, the first capacitor can serve as the detection end, while the second capacitor can form a collapse, which gives the MEMS inertial sensor a new working mode, namely the collapse working mode, so that the formed MEMS inertial sensor can have more working modes.

[0051] See Figure 4 and Figure 5The MEMS inertial sensor can have a large detection bandwidth in the collapse working mode, and the pull-in voltage does not need to be considered during the detection process. In the collapse working mode, it can be used as a voice acceleration sensor for voice noise reduction.

[0052] Furthermore, the MEMS inertial sensor, based on a two-capacitor design, can also achieve traditional operating conditions such as detecting changes in acceleration. It possesses high sensitivity and a high signal-to-noise ratio, and can be used as an acceleration sensor to detect motion. (See [link to relevant documentation]). Figure 3 Therefore, the MEMS inertial sensor provided in this application embodiment has dual working modes, making it flexible and convenient to use.

[0053] The MEMS inertial sensor provided in this application uses the same MEMS sensor structure but can select different operating modes. For example, it can be used for capacitive accelerometer detection, or it can be used in a collapse mode for voice acceleration detection, thereby enabling applications such as voice call noise reduction. Different resonant frequencies or bandwidths can be switched according to different application scenarios, providing flexibility without sacrificing their respective performance, thus reducing design and manufacturing costs.

[0054] The elastic beam 8 possesses a certain degree of elasticity, allowing it to deform in different ways depending on the operating conditions. (See also...) Figure 2 The elastic beam 8 includes a first segment 8a and a second segment 8b. For example, when the MEMS inertial sensor is in the collapsed operating mode of the above embodiment, the elastic beam 8 itself can undergo bending deformation. When the MEMS inertial sensor is in the conventional acceleration detection mode, the elastic beam 8 can undergo torsional deformation.

[0055] The insulating layer 4 covers the surface of the substrate 5, and the first electrode 6 and the second electrode 7 are fixed electrodes, disposed at intervals on the insulating layer 4. The insulating layer 4 serves to electrically isolate the first electrode 6, the second electrode 7, and the substrate 5. Furthermore, the first electrode 6 and the second electrode 7 have different functions in different operating modes, resulting in a MEMS inertial sensor with different operating modes.

[0056] Specifically, in the embodiments of this application, an insulating layer 4 of a predetermined thickness is provided between the substrate 5 and the two fixed electrodes, so that the two fixed electrodes are not in direct contact with the substrate 5, but are kept at a certain distance, which is the thickness (Z-axis dimension) of the insulating layer 4. The provision of the insulating layer 4 increases the distance between the substrate 5 and the first electrode 6 and the second electrode 7 from zero. According to the working principle of a capacitor, when the distance between the first electrode 6 and the second electrode 7 and the substrate 5 increases, the capacitance between the first electrode 6 and the second electrode 7 and the substrate 5 decreases, thereby reducing the coupling capacitance value between the first electrode 6 and the second electrode 7 and the substrate 5. This ensures the effective capacitance output of the MEMS inertial sensor and improves the detection accuracy of the MEMS inertial sensor.

[0057] See some examples in this application. Figure 1 As shown, the mass block 2 comprises three parts, namely the first part 2a, the second part 2b, and the third part 2c arranged side by side as shown in the above embodiment; wherein, the third part 2c is designed to be located between the first part 2a and the third part 2c.

[0058] Optionally, see Figure 1 The third part 2c is connected between the first part 2a and the second part 2b, and the third part 2c and the first part 2a are located on the same side of the elastic beam 8; in the Z-axis direction, the height of the third part 2c is greater than the height of the first part 2a, so that the third part 2c and the first part 2a form a stepped structure on one side of the elastic beam 8.

[0059] See Figure 1 As shown in the diagram, in the up, down, left, and right directions, on the right side of the elastic beam 8, the third part 2c on the mass block 2 is integrated with the first part 2a to form a stepped structure. This structural design in this application allows for an increase in the deflection inertia of the mass block 2 about the rotation axis 3 (the rotation axis 3 is formed by the torsion of the elastic beam 8) during acceleration detection operation. See [link to relevant documentation]. Figure 3 This can reduce the resonant frequency and increase detection sensitivity. Simultaneously, it can also increase the winding speed in collapse operating mode. Figure 4 The moment of inertia of contact point 10 shown in the figure is used to improve detection sensitivity.

[0060] The design of the third part 2c on the mass block 2 forming a stepped structure with the first part 2a reduces the adhesion area between the mass block 2 and the insulating layer 4 in the collapse working mode. For example, only the first part 2a adheres to the insulating layer 4, which also facilitates detachment and adhesion.

[0061] See some examples in this application. Figures 1 to 3 The first capacitor and the second capacitor can also be used to form a differential capacitance detector; wherein the first electrode 6 and the second electrode 7 are both detection electrodes and are used as differential capacitance detection output signal ports.

[0062] Specifically, see Figure 3 As shown, when the first capacitor and the second capacitor form a differential capacitance detector and a change in acceleration in the Z-axis direction is detected, the elastic beam 8 undergoes torsional deformation and forms a rotating shaft 3, and the mass block 2 can rotate around the formed rotating shaft 3.

[0063] See Figure 3 As shown, the MEMS inertial sensor proposed in this application embodiment can also be used as a capacitive accelerometer. In this case, the first capacitor and the second capacitor together form a differential capacitance detector.

[0064] When the first capacitor and the second capacitor form a differential capacitance detector, if an acceleration input in the Z-axis direction is detected, the mass block 2 will rotate around the formed axis 3. The elastic beam 8 will undergo torsional deformation to form a virtual axis 3. Based on this, the first electrode 6, the second electrode 7, and the mass block 2 constitute a differential capacitance detection motion. In this motion mode, the resonant frequency is relatively low, resulting in high detection sensitivity, making it suitable for motion detection using an accelerometer.

[0065] In some examples of this application, in the collapsed working mode, the MEMS inertial sensor can form an electrostatic force between the first electrode 6 and the mass block 2 by applying a first DC voltage to the first electrode 6. At this time, the first electrode 6 forms an attracting electrode, and the mass block 2 serves as a single-ended capacitor output signal port.

[0066] When the MEMS inertial sensor is in collapse mode, such as Figures 4 to 6 As shown, the first electrode 6 can be used as an attraction electrode. By applying a high DC voltage (i.e., the first DC voltage mentioned above), a large electrostatic force can be generated between the first electrode 6 and the mass block 2. This electrostatic force can cause the mass block 2 to move up and down around the rotating shaft 3.

[0067] When in collapse mode, both the first electrode 6 and the second electrode 7 are located between the mass block 2 and the substrate 5 in the Z-axis direction. For example, by applying a DC bias voltage to the first electrode 6, the mass block 2 can serve as an output signal port. This method results in low parasitic capacitance, which improves the sensitivity of single-ended capacitance detection without increasing the processing difficulty to reduce parasitic capacitance.

[0068] In the example above, when the first DC voltage is greater than the pull-in voltage U pull-in At that time, the first part 2a is in contact with the insulating layer 4, and the mass block 2 is electrically insulated from the first electrode 6, the second electrode 7 and the substrate 5.

[0069] When in collapse working mode, see Figures 4 to 6 The first electrode 6 is used as an attraction electrode. By applying a high DC voltage, a large electrostatic force is generated between the first electrode 6 and the mass block 2. This electrostatic force allows the mass block 2 to move up and down (deflect) around the axis 3. When the applied DC voltage is greater than the attraction voltage, the first part 2a of the mass block 2 will make contact with the insulating layer 4; however, the other two parts of the mass block 2 will not make contact with the first electrode 6. The mass block 2 is electrically insulated from the first electrode 6, the second electrode 7, and the substrate 5.

[0070] In the example above, when a second DC voltage is applied to the first electrode 6 and the second DC voltage is greater than the first DC voltage, the elastic beam 8 undergoes bending deformation, and the distance between the second part 2b and the first electrode 6 and the second electrode 7 decreases.

[0071] Specifically, when an acceleration change is detected in the Z-axis direction, the mass block 2 moves up and down around the contact point 10 where the first part 2a contacts the insulating layer 4, supported by the elastic beam 8.

[0072] For example, by increasing the DC voltage applied to the first electrode 6 (e.g., by applying a second DC voltage), the elastic beam 8 undergoes bending deformation (not torsional deformation), and the second mass block 2...

[0073] The distance between the second part 2b and the first electrode 6 and the second electrode 7 will decrease, thus increasing the capacitance of the formed electrode 5. At this time, when an external acceleration is input along the Z-axis, the mass block 2 will move up and down around the contact point 10 under the support of the elastic beam 8. (See...) Figure 4 and Figure 5 .

[0074] Among them, the elastic beam 8 undergoes bending deformation, see [reference needed]. Figure 6 The mass block 2 moves up and down along the Z-axis on the rotating shaft 3. The first electrode 6, the second electrode 7, and the second part 2b of the mass block 2 form a single-ended detection capacitor for detecting the movement of the mass block 2.

[0075] In the collapse working mode, the contact point 10 can be equivalent to a fixed constraint, and the elastic beam 8

[0076] Bending deformation occurs instead of torsional deformation. Under these conditions, the resonant frequency of the structure increases, and the detection bandwidth increases. Furthermore, as mentioned above, appropriately increasing the detection capacitance can not only compensate for the decrease in sensitivity caused by the increased resonant frequency but also increase the output sensitivity. This operating mode is very suitable for voice detection using a voice accelerometer.

[0077] 5. In addition, when the collapse working mode is switched to the acceleration detection working mode, it is only necessary to reduce the DC voltage applied to the first electrode 6 to de-engage the mass block 2 with the insulating layer 4.

[0078] The MEMS inertial sensor proposed in this application embodiment can have two operating states, namely a first state and a second state; wherein, the first state is configured for voice acceleration.

[0079] The sensor performs voice detection; the second state is configured for motion detection by the accelerometer. Specifically, the MEMS inertial sensor can be used for voice detection by the voice accelerometer in the collapsed operating mode.

[0080] In other words, the same MEMS inertial sensor structure can select different operating modes: acceleration detection mode, which can be used for motion acceleration detection; collapse mode, which can be used for voice acceleration.

[0081] Speed ​​detection enables applications such as voice call noise reduction. Different application scenarios can choose to switch different resonant frequencies or bandwidths, providing flexibility without sacrificing performance and reducing design and manufacturing costs.

[0082] Optionally, the substrate 5 is made of monocrystalline silicon or polycrystalline silicon.

[0083] Optionally, the MEMS inertial sensor further includes a controller. The controller is used to control the MEMS inertial sensor to freely switch between the collapse operating mode and the acceleration detection operating mode. The controller can be, for example, an ASIC chip or a control system, used to switch the dual operating states of the MEMS inertial sensor.

[0084] Specifically, the MEMS inertial sensor proposed in this application embodiment can select either of the following working modes by using an ASIC chip or a control system: selecting an acceleration detection working mode and selecting a collapse working mode.

[0085] According to another aspect of the embodiments of this application, a detection method for a MEMS inertial sensor is provided, the detection method comprising:

[0086] Step 101: Apply a first DC voltage to the first electrode 6, and the first part 2a contacts the insulating layer 4 to form a contact point 10; the second capacitor formed by the third part 2c and the first electrode 6 enters the collapse working mode, and the elastic beam 8 undergoes bending deformation.

[0087] Step 102: The mass block 2 moves up and down along the Z-axis around the contact point 10 under the support of the elastic beam 8. The first capacitor formed by the second part 2b and the second electrode 7 serves as a detection end to obtain the capacitance change.

[0088] Steps 101 and 102 above illustrate the collapse working mode.

[0089] In collapse mode, a large bandwidth acceleration detection signal is output.

[0090] Based on steps 101 and 102 above, the resonant frequency and detection bandwidth increase under this motion mode. At the same time, as can be seen from the above, the detection capacitance can be appropriately increased, which can not only compensate for the decrease in sensitivity caused by the increase in resonant frequency, but also increase the output sensitivity. This working mode is suitable for voice detection of voice acceleration sensors.

[0091] Optionally, the detection method shown in the above embodiments further includes the following steps 201-202:

[0092] Step 201: The first capacitor and the second capacitor form a differential capacitance detector, wherein the first electrode 6 and the second electrode 7 both serve as differential capacitance output ports.

[0093] Step 202: The elastic beam 8 undergoes torsional deformation, and the mass block 2 rotates around the axis 3 formed by the torsion of the elastic beam 8 under the support of the elastic beam 8.

[0094] Steps 201 and 202 above illustrate the working process of the MEMS inertial sensor in acceleration detection mode, in which a small-bandwidth acceleration detection signal is output.

[0095] Based on steps 201 and 202 above, the resonant frequency under this motion mode is relatively small, the detection sensitivity is relatively high, and it is suitable for motion detection of traditional accelerometers.

[0096] According to another aspect of the embodiments of this application, an electronic device is also provided. The electronic device may include the MEMS inertial sensor 1 as described above.

[0097] The electronic devices provided in this application embodiment include, but are not limited to, those used in smartphones, and can also be used in other forms of electronic devices such as tablet computers and laptops. The specific type of electronic device is not limited in this application embodiment.

[0098] The specific implementation of the electronic device in this application can refer to the various embodiments of the MEMS inertial sensor described above. Therefore, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0099] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0100] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A MEMS inertial sensor, characterized by, The MEMS inertial sensor comprises: a substrate (5) provided with an insulating layer (4) on one side; a first electrode (6) and a second electrode (7) provided on the insulating layer (4) at intervals; a mass block (2) suspended above the substrate (5), the mass block (2) comprising a first part (2a), a second part (2b) and a third part (2c); a resilient beam (8) for connecting the substrate (5) and the mass block (2), the resilient beam (8) being connected to an anchor point (9) of the substrate (5), the first part (2a), the third part (2c) and the second part (2b) being located on both sides of the resilient beam (8); the second part (2b) and the second electrode (7) form a first capacitor, and the third part (2c) and the first electrode (6) form a second capacitor; the third part (2c) is connected between the first part (2a) and the second part (2b), and the third part (2c) and the first part (2a) are located on the same side of the resilient beam (8); in the Z-axis direction, the height of the third part (2c) is greater than the height of the first part (2a), so that the third part (2c) and the first part (2a) form a stepped structure on one side of the resilient beam (8); the second capacitor can form a collapsed working mode, in which the first capacitor is used to form a detection end, and the MEMS inertial sensor can detect and perceive according to the obtained capacitance change in the collapsed working mode; the first capacitor and the second capacitor can also be used to form a differential capacitor detector; wherein the first electrode (6) and the second electrode (7) are both detection electrodes, used as differential capacitor detection output signal ports in the collapsed working mode, the MEMS inertial sensor applies a first direct current voltage to the first electrode (6), an electrostatic force is formed between the first electrode (6) and the mass block (2), the first electrode (6) forms an attracting electrode, and the mass block (2) serves as a single-ended capacitor output signal port; When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the pull-in voltage U pull-in When the first direct current voltage is greater than the 2. The MEMS inertial sensor of claim 1, wherein, when the first capacitor and the second capacitor form a differential capacitor detector, and an acceleration change in the Z-axis direction is obtained, the resilient beam (8) produces torsional deformation and forms a rotation shaft (3), and the mass block (2) can rotate around the formed rotation shaft (3).

3. The MEMS inertial sensor of claim 1, wherein, when a second direct current voltage is applied to the first electrode (6) and the second direct current voltage is greater than the first direct current voltage, the resilient beam (8) produces bending deformation, and the distance between the second part (2b) and the first electrode (6) and the second electrode (7) decreases.

4. The MEMS inertial sensor of claim 3, wherein, when an acceleration change in the Z-axis direction is obtained, the mass block (2) moves up and down around a contact point (10) where the first part (2a) contacts the insulating layer (4) under the support of the resilient beam (8).

5. The MEMS inertial sensor of claim 1, wherein, The MEMS inertial sensor can be used for voice detection of a voice acceleration sensor in the collapse working mode.

6. The MEMS inertial sensor of claim 1, wherein, The substrate (5) is made of single crystal silicon or polycrystalline silicon.

7. A method of detecting a MEMS inertial sensor as claimed in any one of claims 1-6, characterized in that, The MEMS inertial sensor (1) comprises: A first direct current voltage is applied to the first electrode (6), the first part (2a) is in contact with the insulating layer (4) and forms a contact point (10), the third part (2c) is in contact with the first electrode (6) and forms the second capacitor, the elastic beam (8) is deformed by bending, and the mass block (2) moves up and down along the Z-axis direction around the contact point (10) under the support of the elastic beam (8), the second part (2b) is in contact with the second electrode (7) and forms the first capacitor, and the first capacitor is used as a detection end to obtain a capacitance change amount.

8. The detection method of the MEMS inertial sensor according to claim 7, further comprising: The first capacitor and the second capacitor form a differential capacitor detector, wherein the first electrode (6) and the second electrode (7) are both used as differential capacitor output ports. The elastic beam (8) is deformed by torsion, and the mass block (2) rotates around the rotation shaft (3) formed by the torsion of the elastic beam (8) under the support of the elastic beam (8). The MEMS inertial sensor (1) according to any one of claims 1-6.

9. An electronic device, comprising: ​ ​

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