MEMS sensor and electronic atomization device

Abstract

The utility model discloses an MEMS sensor and an electronic atomization device. The MEMS sensor comprises a substrate, a base plate, a first polar plate, a second polar plate and a conductive contact. The first surface of the substrate is provided with a groove, the second surface of the substrate is provided with a Wheatstone bridge circuit, and a bridge arm of the Wheatstone bridge circuit comprises a piezoresistor; the substrate covers the groove to form a sealed cavity; the first polar plate is arranged on the bottom wall of the groove; the second polar plate is arranged on the substrate and is spaced from the first polar plate; the conductive contact is arranged on the substrate and / or the base plate and is electrically connected with at least one of the first polar plate and the second polar plate; the first pole plate and the second pole plate are configured to be capable of repelling or attracting each other under the power-on condition. Through the mode, the deflection of the strain film is always small, so that the problem that the deformation of the substrate does not have ideal linear change with the pressure is well improved, and the detection precision of the MEMS sensor is improved.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a MEMS sensor and an electronic atomization device. Background Art

[0002] In recent years, with the rapid development of MEMS (Micro-Electro-Mechanical System) technology, MEMS technology has been widely used in the field of sensors. Traditional MEMS piezoresistive pressure sensors are based on the single-crystal silicon piezoresistive effect. They usually use a Wheatstone bridge structure to convert external pressure signals into corresponding electrical signals. By measuring the value of the electrical signal, the size of the external pressure signal can be known. However, this type of MEMS piezoresistive pressure sensor has the problem of inaccurate detection. Utility Model Content

[0003] The present application provides a MEMS sensor and an electronic atomization device, which are used to solve the problem of inaccurate detection of MEMS sensors.

[0004] According to the first aspect of the present application, some embodiments of the present application provide a MEMS sensor, including a substrate, a base plate, a first electrode plate, a second electrode plate and a conductive contact; the substrate has a first surface and a second surface relative to each other; the first surface has a groove, the second surface has a Wheatstone bridge circuit, and the bridge arm of the Wheatstone bridge circuit includes a varistor; the substrate covers the groove to form a sealed cavity; the first electrode plate is arranged on the bottom wall of the groove; the second electrode plate is arranged on the base plate and is spaced apart from the first electrode plate; the conductive contact is arranged on the substrate and / or the base plate, and is electrically connected to at least one of the first electrode plate and the second electrode plate; wherein the first electrode plate and the second electrode plate are configured to repel or attract each other when power is supplied.

[0005] In some embodiments, the first plate and the second plate form a parallel plate capacitor, and the conductive contact includes a first conductive contact electrically connected to the first plate and a second conductive contact electrically connected to the second plate.

[0006] In some embodiments, the first electrode plate is disposed on the bottom surface of the groove; the second electrode plate is disposed on the surface of the substrate exposed to the sealed cavity; the first electrode plate and the second electrode plate are disposed opposite to each other.

[0007] In some embodiments, one of the first pole plate and the second pole plate includes a permanent magnetic material, and the other is an electromagnet; the conductive contact is electrically connected to the electromagnet to change the polarity of the electromagnet.

[0008] In some embodiments, the first pole plate and the second pole plate are both electromagnets; the conductive contacts are electrically connected to the first pole plate and the second pole plate, respectively, for changing the polarity of the electromagnets.

[0009] In some embodiments, the substrate has a first conductive hole and a second conductive hole; the first conductive contact is arranged on the surface of the substrate facing away from the substrate and is electrically connected to the first electrode through the first conductive hole, and the second conductive contact is arranged on the surface of the substrate facing away from the substrate and is electrically connected to the second electrode through the second conductive hole.

[0010] In some of the embodiments, the Wheatstone bridge circuit includes four groups of piezoresistors and four groups of conductive areas, the piezoresistors produce resistance changes in response to pressure changes applied to the substrate, thereby converting pressure signals into electrical signals; the conductive areas are used to lead out the electrical signals.

[0011] In some of the embodiments, the substrate is a semiconductor substrate; each group of the varistors includes two sub-varistors arranged in parallel and spaced apart, and a heavily doped contact region formed between the sub-varistors, and the heavily doped contact region is used to electrically connect the two sub-varistors arranged in parallel and spaced apart.

[0012] In some of the embodiments, the varistor and the heavily doped contact region are formed on the substrate, the substrate is further covered with a dielectric layer, and the four groups of conductive regions are formed on the dielectric layer.

[0013] In some of the embodiments, a side of the dielectric layer away from the substrate is further covered with a passivation layer, and the four groups of conductive regions are respectively at least partially exposed from the passivation layer.

[0014] According to the second aspect of the present application, some embodiments of the present application provide an electronic atomization device, including a liquid storage unit, an atomization component, a MEMS sensor, a power supply and a control circuit; the liquid storage unit is used to store an aerosol generating matrix, and the liquid storage unit has an aerosol inlet end and an outlet end; the atomization component is arranged on the airflow path from the inlet end to the outlet end, and is used to atomize the aerosol generating matrix; the MEMS sensor is the MEMS sensor provided in any of the above embodiments; the MEMS sensor is arranged on the airflow channel of the electronic atomization device, and is used to detect the air pressure change in the airflow channel; the power supply is used to provide voltage to the atomization component and the MEMS sensor; the control circuit is electrically connected to the power supply, the atomization component and the MEMS sensor respectively; the control circuit is used to apply an electrical signal to the first electrode plate and the second electrode plate according to the change in output voltage caused by the air pressure change of the MEMS sensor in the airflow channel, so that the first electrode plate and the second electrode plate attract or repel each other, so that the change in the output voltage of the MEMS sensor is less than or equal to a preset threshold.

[0015] In some embodiments, the preset threshold is zero; the control circuit is also used to detect whether the change in the output voltage of the MEMS sensor is zero; and when it is detected that the change in the output voltage of the MEMS sensor is zero, the magnitude of the air pressure is determined based on the electrical signal applied to the first electrode plate and the second electrode plate.

[0016] According to the MEMS sensor of the above embodiment, by setting the first electrode plate on the bottom wall of the groove, and the second electrode plate on the substrate, and being spaced apart from the first electrode plate, the first electrode plate and the second electrode plate are configured to repel or attract each other when powered on. When the substrate of the sensor is subjected to pressure in a direction close to the substrate, the first electrode plate and the second electrode plate can be powered on so that the charge on the first electrode plate is the same as the charge on the second electrode plate, thereby causing the first electrode plate to be displaced in a direction away from the substrate, thereby offsetting the displacement of the substrate in a direction close to the substrate caused by changes such as airflow; when the substrate of the sensor is subjected to pressure in a direction away from the substrate, the first electrode plate and the second electrode plate can be powered on so that the charge on the first electrode plate is opposite to the charge on the second electrode plate, thereby causing the first electrode plate to be displaced in a direction close to the substrate, thereby offsetting the displacement of the substrate in a direction away from the substrate caused by changes such as airflow; therefore, in the process of using the MEMS sensor, the deflection of the strain film is always small, thereby greatly improving the problem that the deformation of the substrate does not change in an ideal linear manner with the pressure, thereby improving the detection accuracy of the MEMS sensor of the embodiment of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A top view of a MEMS sensor provided in some embodiments of the present application;

[0019] Figure 2 for Figure 1 Schematic diagram of the cross section along line II-II;

[0020] Figure 3 A schematic diagram of the structure of a MEMS sensor provided in some embodiments of the present application;

[0021] Figure 4 A schematic diagram of the structure of a MEMS sensor provided in some other embodiments of the present application;

[0022] Figure 5 A schematic diagram of the structure of a MEMS sensor provided in some other embodiments of the present application;

[0023] Figure 6 A flowchart of a method for preparing a MEMS sensor provided in some embodiments of the present application;

[0024] Figure 7 for Figure 6 Flowchart of S10;

[0025] Figure 8 for Figure 6 Flowchart of S30;

[0026] Fig. 9 for Figure 6 Flowchart of S40;

[0027] Fig.10 A flowchart of a method for preparing a MEMS sensor provided in some other embodiments of the present application;

[0028] Fig.11 A schematic diagram of the structure of an electronic atomization device provided in some embodiments of the present application;

[0029] Fig.12 for Fig.11 Functional module diagram of the electronic atomization device.

[0030] Description of Figure Numbers:

[0031] 10-substrate, 11-first surface, 12-second surface, 13-groove, 14-Wheatstone bridge circuit, 140-varistor, 141-sub-varistor, 142-conductive area, 143-heavily doped contact area, 144-conductive lead, 15-dielectric layer, 16-passivation layer; 20-substrate, 21-first conductive hole, 22-second conductive hole, 23-third conductive hole; 30-first electrode, 31-first lead, 32-second lead; 40-conductive contact, 41-first conductive contact; 42-second conductive contact; 70-second electrode; 80-first sealing ring; 90-second sealing ring; 100-MEMS sensor; 200-liquid storage component; 300-atomization component; 400-control circuit; 1000A-liquid storage unit, 1000B-control unit, 1000-electronic atomization device DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two (including two), such as two, three, etc., unless otherwise clearly and specifically defined, and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0036] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0037] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the relative orientation or position relationship between the components in a certain specific posture (as shown in the drawings) shown in the drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0038] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] In recent years, with the rapid development of MEMS technology, MEMS technology has been widely used in the field of sensors. Traditional MEMS sensors are based on the single-crystal silicon piezoresistive effect, and usually use a Wheatstone bridge structure to convert external pressure signals into corresponding electrical signals, and measure the value of the electrical signal to obtain the size of the external pressure signal.

[0040] However, the inventors of the present application discovered through research that as the external pressure increases, the displacement (or "deformation") of the strain membrane in the sensor structure will not always show an ideal linear change, causing the resistance value of the bridge arm of the Wheatstone bridge to not always change linearly, that is, the deflection of the strain membrane increases and the linearity deteriorates, which in turn leads to poor linearity of the test results. This type of MEMS sensor has the problem of inaccurate detection.

[0041] The inventors of the present application compensate for the deflection of the strain film by providing the first electrode plate 30 and the second electrode plate 70, thereby greatly improving the problem that the deformation of the substrate does not change in an ideal linear manner with the pressure, thereby improving the detection accuracy of the MEMS sensor of the embodiment of the present application.

[0042] The present application is described in detail below with reference to the accompanying drawings and embodiments.

[0043] Please refer to Figure 1 and Figure 2 , Figure 1 A top view of a MEMS sensor provided in some embodiments of the present application; Figure 2 for Figure 1 Schematic diagram of the cross section along line II-II.

[0044] The MEMS sensor 100 provided in the embodiment of the present application includes a substrate 10 , a base plate 20 , a first electrode plate 30 , a second electrode plate 70 and a conductive contact 40 .

[0045] In one embodiment, the material of the substrate 10 can be a silicon-based material, such as a single crystal silicon wafer, which is a common semiconductor device substrate, on which a metal layer can be deposited and metal ions can be doped to construct a semiconductor device. In another embodiment, the MEMS sensor 100 needs to have a rollable property. In this case, polyacetamide / polyimide (Polyimide, PI), that is, PI film can be selected as the substrate 10 substrate, and then a single crystal silicon layer is deposited thereon to prepare a rollable MEMS sensor 100. The embodiment of the present application is introduced by taking the substrate 10 as a semiconductor substrate 10 as an example.

[0046] In some embodiments, the substrate 10 has a first surface 11 and a second surface 12 opposite to each other, and the distance between the first surface 11 and the second surface 12 is the thickness of the substrate 10. The first surface 11 has a groove 13, and the cross-sectional shape of the groove 13 along the thickness direction of the substrate 10 is not limited, for example, it can be a square, a rectangle or a trapezoid, etc., and the present application does not make specific restrictions on this. The second surface 12 has a Wheatstone bridge circuit 14, and the bridge arm of the Wheatstone bridge circuit 14 includes a varistor 140.

[0047] In some embodiments, see Figure 1The Wheatstone bridge circuit 14 includes four groups of varistors 140. The varistors 140 can generate resistance changes in response to pressure changes on the substrate 10, thereby converting pressure signals into electrical signals. Each group of varistors 140 includes two parallel and spaced sub-varistors 141. In one embodiment, the four groups of varistors 140 are arranged in the same direction, for example Figure 1 In the X direction, four groups of varistors 140 are located in the central area of ​​the substrate 10, forming Figure 1 In another embodiment, the four groups of varistors 140 are arranged in different directions. For example, two groups of varistors 140 are arranged in accordance with Figure 1 The other two groups of varistors 140 are arranged along the Y direction. Optionally, in another embodiment, the four groups of varistors 140 are arranged in a rectangular shape (not shown), and the arrangement directions of the four groups of varistors 140 are consistent.

[0048] In some embodiments, the Wheatstone bridge circuit 14 further includes four groups of conductive areas 142 for leading out electrical signals. Figure 1 As shown, four groups of varistors 140 are respectively arranged in the middle of the substrate 10, and four conductive areas 142 are respectively arranged around the four groups of varistors 140. Specifically, the four conductive areas 142 are respectively arranged at the four corners of the substrate 10. In another embodiment, the four groups of varistors 140 are respectively arranged at the four corners of the substrate 10 (not shown), and the four conductive areas 142 are arranged in the middle of the substrate 10.

[0049] Furthermore, in some embodiments, the Wheatstone bridge circuit 14 further includes a heavily doped contact region 143 formed between the sub-varistors 141, the heavily doped contact region 143 being used to electrically connect two parallel and spaced sub-varistors 141 in the group of varistors 140, and the heavily doped contact region 143 being a region having conductive properties after the semiconductor is doped with metal ions. Figure 2 and Figure 3In some embodiments, the varistor 140 and the heavily doped contact region 143 are formed on the substrate 10, and the substrate 10 is also covered with a dielectric layer 15. The four groups of conductive regions 142 are formed on the dielectric layer 15. The dielectric layer 15 can be used as a protective layer and an insulating layer. The material of the dielectric layer 15 can be silicon dioxide or silicon nitride. The dielectric layer 15 can have a through hole, and the conductive region 142 and its conductive lead 144 can be electrically connected to the varistor 140 through the through hole on the dielectric layer 15. Optionally, the material of the conductive lead 144 is at least one of copper, nickel-chromium alloy, iron, or platinum. Optionally, in some embodiments, the side of the dielectric layer 15 away from the substrate 10 is also covered with a passivation layer 16, and the four groups of conductive regions 142 are at least partially exposed to the passivation layer 16. The passivation layer 16 has a dense surface and can be used to resist water vapor corrosion and device oxidation, etc., wherein the passivation layer 16 has a hollow area corresponding to the conductive area 142, so that the conductive area 142 is exposed to the external environment to facilitate the extraction of electrical signals.

[0050] In some embodiments, the substrate 20 may be a glass substrate or a ceramic substrate, etc. The substrate 20 may cover the groove 13 and enclose the substrate 10 to form a sealed cavity, that is, Figure 2 The indicated groove 13 is a sealed cavity. In one embodiment, the substrate 20 can be bonded to the substrate 10 to form a sealed cavity. For example, in some embodiments, the substrate 20 and the substrate 10 can be bonded by metal chromium under a preset temperature and / or preset pressure. The specific preset temperature and pressure need to be determined according to the bonding material and the actual equipment used. It is not described in detail here. Those skilled in the art can understand the concept of this embodiment based on the above description. In other embodiments, the substrate 20 can be directly bonded to the substrate 10.

[0051] In some embodiments, the first electrode plate 30 is disposed on the bottom wall of the groove 13, the first electrode plate 30 is conductive and is spaced apart from the substrate 20. The second electrode plate 70 is disposed on the substrate 20 and is spaced apart from the first electrode plate 30, and the first electrode plate 30 and the second electrode plate 70 are configured to repel or attract each other when powered on. The first electrode plate 30 and the second electrode plate 70 are configured to repel or attract each other when powered on based on the principle that like charges repel and opposite charges attract, such as Figure 2 As shown; or the magnetic principle that like charges repel and opposite charges attract, such as Figure 3 shown.

[0052] See also Figure 2In some embodiments, the first electrode plate 30 and the second electrode plate 70 form a parallel plate capacitor. The first electrode plate 30 is disposed on the bottom surface of the groove 13, which is the surface of the groove 13 close to the substrate 20. The second electrode plate 70 is disposed on the surface of the substrate 20 exposed to the sealed cavity, which is the surface of the substrate 20 close to the substrate 10. The first electrode plate 30 and the second electrode plate 70 are disposed opposite to each other. When charges of opposite electrical properties are applied to the first electrode plate 30 and the second electrode plate 70, according to the principle of opposites attracting, the two electrodes are displaced relatively close to each other. In some embodiments of the present application, the first electrode plate 30 is displaced in a direction close to the substrate 20 after being energized. Figure 2 In the embodiment, the direction close to the substrate 20 may refer to the vertically downward direction, that is, the opposite direction of the Z direction, which is defined as the first direction; when the first electrode plate 30 and the second electrode plate 70 are charged with the same electrical property, according to the principle of like charges repelling each other, the two electrodes are relatively displaced away from each other. In some embodiments of the present application, the first electrode plate 30 is displaced away from the substrate 20 after being energized. Figure 2 In the embodiment, the direction away from the substrate 20 may refer to a vertically upward direction, that is, a Z direction, which is defined as a second direction and will be used as an example for description in subsequent embodiments.

[0053] In some embodiments, the material of the first electrode plate 30 can be platinum, nickel, tungsten, etc., which are suitable as thermal deformation resistors and suitable as capacitor plates. Among them, metal platinum is a good thermistor, and its resistance value changes linearly with temperature; the material of the second electrode plate 70 can also be gold, platinum, nickel, copper, tin oxide, manganese oxide, etc., which are suitable as capacitor plates.

[0054] Further, in some embodiments, the conductive contact 40 includes a first conductive contact 41 electrically connected to the first electrode plate 30 and a second conductive contact 42 electrically connected to the second electrode plate 70. The first conductive contact 41 and the second conductive contact 42 can be arranged on the substrate 10 at the same time, or can be arranged on the substrate 20 at the same time, or can be arranged on the substrate 10 partially, and the remaining part can be arranged on the substrate 20. The present application does not make specific restrictions on this. The present application takes the first conductive contact 41 and the second conductive contact 42 arranged on the substrate 20 as an example for introduction. In some embodiments of the present application, the material of the first conductive contact 41 is the same as the material of the first electrode plate 30, and the material of the second conductive contact 42 is the same as the material of the second electrode plate 70, so that the contact resistance can be reduced, the heat generation can be reduced, and the energy utilization rate can be improved. Optionally, in other embodiments, the material of the first conductive contact 41 can be different from the material of the first electrode plate 30, and / or the material of the second conductive contact 42 can be different from the material of the second electrode plate 70.

[0055] Furthermore, in some embodiments, the substrate 20 has a first conductive hole 21 and a second conductive hole 22, the first conductive contact 41 is arranged on the surface of the substrate 20 away from the substrate 10 and is electrically connected to the first electrode 30 through the first conductive hole 21 and the first lead 31, and the second conductive contact 42 is arranged on the surface of the substrate 20 away from the substrate 10 and is electrically connected to the second electrode 70 through the second conductive hole 22.

[0056] Specifically, in some embodiments, the number of the first conductive hole 21 is one, the number of the second conductive hole 22 is one, one end of the first electrode 30 is connected to a first lead 31, the first conductive hole 21 is used to lead out the first lead 31, and the same material as the first lead 31 is deposited in the first conductive hole 21, thereby forming a first conductive contact 41. The same material as the second electrode 70 can be deposited in the second conductive hole 22, thereby forming a second conductive contact 42. This embodiment can realize the electrical connection between the first conductive contact 41 and the first electrode 30, and the electrical connection between the second conductive contact 42 and the second electrode 70. The first conductive contact 41 can be used to energize the first electrode 30, and the second conductive contact 42 can be used to energize the second electrode 70. The structure is simple and the preparation method is quick.

[0057] Optionally, in other embodiments, the first conductive hole 21 and the second conductive hole 22 may also be arranged on the substrate 10, or one is arranged on the substrate 10 and the other is arranged on the substrate 20. The present application does not make any specific restrictions and can be selected as needed. The embodiment of the present application is introduced by taking the first conductive hole 21 and the second conductive hole 22 arranged on the substrate 20 as an example.

[0058] Please also see Figure 3 and Figure 4 In other embodiments, one of the first pole plate 30 and the second pole plate 70 includes a permanent magnetic material, and the other is an electromagnet; the conductive contact 40 is electrically connected to the electromagnet to change the polarity of the electromagnet. Specifically, the polarity of the permanent magnetic material is fixed. The embodiment of the present application is introduced with the polarity of the permanent magnetic material close to the electromagnet as the N pole. The magnetism of the electromagnet close to the permanent magnetic material can be determined by Ampere's rule. Therefore, the polarity of the electromagnet can be changed by changing the direction of the current in the electromagnet. When the magnetism of the electromagnet close to the permanent magnetic material is the N pole, the first pole plate 30 and the second pole plate 70 repel each other. When the magnetism of the electromagnet close to the permanent magnetic material is the S pole, the first pole plate 30 and the second pole plate 70 attract each other.

[0059] See also Figure 3In one embodiment, the first pole plate 30 is a permanent magnetic material, the second pole plate 70 is an electromagnet, and the conductive contact 40 includes two second conductive contacts 42 arranged at intervals, and the two second conductive contacts 42 are electrically connected to the second pole plate 70, and are used to pass a DC voltage to the second pole plate 70 to change its polarity. Correspondingly, the substrate 20 has two second conductive holes 22 arranged at intervals, and the same material as the second pole plate 70 is deposited in each second conductive hole 22 to form two second conductive contacts 42. In this embodiment, the second pole plate 70 located on the substrate 20 is set as an electromagnet, and it is unnecessary to arrange leads for the second pole plate 70, and the structure is simple and easy to prepare.

[0060] See also Figure 4 In another embodiment, the first pole plate 30 is an electromagnet, the second pole plate 70 is a permanent magnetic material, and the conductive contact 40 includes two first conductive contacts 41 arranged at intervals, and the two first conductive contacts 41 are electrically connected to the first pole plate 30 through two first leads 31, and are used to pass a DC voltage to the first pole plate 30 to change its polarity. Correspondingly, the substrate 20 has two first conductive holes 21 arranged at intervals, each first conductive hole 21 is used to lead out a corresponding first lead 31, and each first conductive hole 21 is deposited with the same material as the corresponding first lead 31 to form two first conductive contacts 41. In this embodiment, the second pole plate 70 located on the substrate 20 is set as an electromagnet, which can omit the arrangement of the leads of the second pole plate 70, and the structure is simple and easy to prepare.

[0061] Optionally, see Figure 5 In some other embodiments, the first electrode plate 30 and the second electrode plate 70 are both electromagnets; the conductive contact 40 is electrically connected to the first electrode plate 30 and the second electrode plate 70, respectively, for changing the polarity of the electromagnet. The conductive contact 40 includes two first conductive contacts 41 arranged at intervals, and the two first conductive contacts 41 are electrically connected to the first electrode plate 30 through two first leads 31, and are used to pass a DC voltage to the first electrode plate 30 to change its polarity. Further, the conductive contact 40 also includes two second conductive contacts 42 arranged at intervals, and the two second conductive contacts 42 are electrically connected to the second electrode plate 70, and are used to pass a DC voltage to the second electrode plate 70 to change its polarity.

[0062] The pressure compensation principle of the MEMS sensor 100 in the above embodiment of the present application is introduced below:

[0063] Strain film: The bottom wall of the sealed cavity at the groove 13 and the area projected on the substrate 10 along the second direction (Z direction) together constitute the strain film. In some embodiments, the strain film at least includes a portion of the substrate 10 and the first electrode plate 30 .

[0064] When the strain film is subjected to pressure in the first direction, the strain film also moves in the first direction. At this time, a DC voltage can be applied to the first electrode plate 30 and the second electrode plate 70 respectively, so that the charge on the first electrode plate 30 and the charge on the second electrode plate 70 are the same, for example, both are positive or negative, so that the first electrode plate 30 and the second electrode plate 70 repel each other, so that the strain film moves in the second direction, thereby compensating for the deflection of the strain film, that is, the deflection of the strain film is reduced, and the influence of the deflection of the strain film on the linearity of the test result is reduced. When it is detected that the output voltage of the Wheatstone bridge circuit 14 is the initial value, for example, zero, that is, the pressure in the first direction on the strain film is offset by the deformation force caused by the heating caused by the power supply, the magnitude of the pressure applied in the first direction can be calculated according to the magnitude of the voltage input to the first electrode plate 30 and the second electrode plate 70.

[0065] Optionally, when the strain film is subjected to pressure in the second direction, the strain film also moves in the second direction. At this time, a DC voltage can be applied to the first electrode plate 30 and the second electrode plate 70 respectively, so that the charge on the first electrode plate 30 and the charge on the second electrode plate 70 are opposite, for example, the charge on the first electrode plate 30 is positive, and the charge on the second electrode plate 70 is negative, or the charge on the first electrode plate 30 is negative, and the charge on the second electrode plate 70 is positive, so that the first electrode plate 30 and the second electrode plate 70 attract each other, so that the strain film moves in the first direction, thereby compensating for the deflection of the strain film, that is, the deflection of the strain film is reduced, and the influence of the deflection of the strain film on the linearity of the test result is reduced. When it is detected that the output voltage of the Wheatstone bridge circuit 14 is the initial value, for example, zero, that is, the pressure in the second direction on the strain film is offset by the deformation force caused by the heating caused by the power supply, the magnitude of the pressure in the second direction applied can be calculated according to the magnitude of the voltage input to the first electrode plate 30 and the second electrode plate 70.

[0066] Furthermore, in some embodiments, a first sealing ring 80 is provided on the first surface 11 of the substrate 10, and a second sealing ring 90 is provided on the surface of the substrate 20 close to the substrate 10. The first sealing ring 80 and the second sealing ring 90 are arranged opposite to each other, so that the substrate 10 and the substrate 20 are bonded to form a sealed cavity.

[0067] See also Figure 6 , Figure 6 Flow chart of a method for preparing a MEMS sensor 100 provided in some embodiments of the present application. The method for preparing a MEMS sensor 100 provided in an embodiment of the present application at least includes:

[0068] S10: providing a substrate 10, wherein the substrate 10 has a first surface 11 and a second surface 12 opposite to each other, and a Wheatstone bridge circuit 14 is formed on the second surface 12;

[0069] The substrate 10 is a semiconductor substrate 10, for example, a SOI (Silicon On Insulator) silicon wafer. Figure 7 , step S10 may include:

[0070] S11: forming four groups of varistors 140 on the second surface 12 of the substrate 10;

[0071] The varistor 140 generates a resistance change in response to the pressure change applied to the substrate 10, thereby converting the pressure signal into an electrical signal. In some embodiments, each group of varistors 140 includes two sub-varistors 141 arranged in parallel and spaced apart. Further, in one embodiment, step S11 also includes forming a heavily doped contact region 143 on the second surface 12 of the substrate 10. The heavily doped contact region 143 can be formed between the sub-varistors 141 to electrically connect the sub-varistors 141 in the group of varistors 140. The heavily doped contact region 143 is a region having conductive properties after the semiconductor is doped with metal ions.

[0072] S12: forming a dielectric layer 15 on the second surface 12 of the substrate 10 and forming a via hole in the dielectric layer 15;

[0073] The position of the via hole corresponds to the varistor 140 to expose the varistor 140 .

[0074] S13: forming a conductive lead 144 and a conductive area 142 on the dielectric layer 15;

[0075] S14 : forming a passivation layer 16 on the dielectric layer 15 , and patterning the passivation layer 16 to expose the conductive region 142 .

[0076] The passivation layer 16 may be patterned by etching.

[0077] S20: forming a groove 13 on the first surface 11 of the substrate 10, and disposing a first electrode plate 30 on the bottom wall of the groove 13;

[0078] The formation method of the groove 13 is not limited, for example, the groove 13 can be formed by etching, solution corrosion or mechanical cutting. The formation method of the first electrode plate 30 can be selected according to the material of the first electrode plate 30, and this application does not make specific restrictions. Step S20 can also include: forming a first lead 31 on both sides of the first electrode plate 30;

[0079] S30: providing a substrate 20, and disposing a second electrode plate 70 on one side of the substrate 20;

[0080] See also Figure 8 In some embodiments, step S30 further includes:

[0081] S31: forming a first conductive hole 21 and a second conductive hole 22 which are spaced apart from each other on the substrate 20, and extending the first lead 31 out of the first conductive hole 21 to form a first conductive contact 41;

[0082] S32 : forming a second electrode plate 70 covering the second conductive hole 22 on one side of the substrate 20 , and extending the material of the second electrode plate 70 out of the second conductive hole 22 to form a second conductive contact 42 .

[0083] In one embodiment, the number of the first conductive hole 21 is one, the number of the second conductive hole 22 is one, and the two are arranged at intervals. When the substrate 20 is a glass substrate, the first conductive hole 21 and the second conductive hole 22 can be formed by burning the substrate 20 using a TGV (through glass via) process.

[0084] In step S30 , the process may further include: cleaning the substrate 20 to make the substrate 20 and the substrate 10 more closely bonded.

[0085] S40 : Covering the groove 13 with the substrate 20 , so that the first electrode plate 30 and the second electrode plate 70 are arranged opposite to each other.

[0086] After the side of the substrate 20 provided with the second electrode plate 70 covers the groove 13, a sealed cavity is formed between the substrate 20 and the substrate 10, and the first electrode plate 30 and the second electrode plate 70 are arranged opposite to each other and spaced apart. It can be understood that the number and position of the first conductive holes 21 and the second conductive holes 22 and the number and position of the first conductive contacts 41 and the second conductive contacts 42 are related to the principle based on the aforementioned MEMS sensor 100, and the embodiment of the present application only exemplarily illustrates the corresponding Figure 2 The steps included in the method for preparing the MEMS sensor 100 in the embodiment are similar to those in other embodiments and will not be described in detail herein.

[0087] See also Fig. 9 , step S40 comprises:

[0088] S41: forming a first sealing ring 80 on the outer periphery of the first surface 11 of the substrate 10;

[0089] The first sealing ring 80 may be made of chromium, aluminum, copper or gold, and may be formed by sputtering and photolithography.

[0090] S42: forming a second sealing ring 90 on the outer periphery of one side of the substrate 20;

[0091] S43 : Align and bond the first sealing ring 80 and the second sealing ring 90 to electrically connect the first lead 31 and the first conductive contact 41 , and form the groove 13 into a sealed cavity.

[0092] After the first sealing ring 80 is bonded to the second sealing ring 90 , the groove 13 is formed as a sealed cavity between the base plate 20 and the substrate 10 , and the first electrode plate 30 and the second electrode plate 70 are arranged opposite to each other, thereby forming a parallel plate capacitor.

[0093] Optionally, see Fig.10 , a flowchart of a method for preparing a MEMS sensor provided in some other embodiments of the present application, the method corresponding to the preparation Figure 5 The MEMS sensor 100 shown. Specifically, the method includes:

[0094] S101: forming a varistor 140 and a heavily doped contact region 143 on the second surface 12 of the substrate 10;

[0095] S102: forming a dielectric layer 15 on the second surface 12 of the substrate 10, forming a via hole on the dielectric layer 15, the position of the via hole corresponds to the position of the varistor 140; forming a conductive lead 144 on the dielectric layer 15, and forming a conductive area 142 at the end of the conductive lead 144;

[0096] S103: forming a passivation layer 16 on the dielectric layer 15, and forming via holes at positions of the passivation layer 16 corresponding to the conductive regions 142, so that the conductive regions 142 are exposed;

[0097] S104: forming a groove 13 on the first surface 11 of the substrate 10, and disposing a first electrode plate 30 and a first lead 31 electrically connected to the first electrode plate 30 on the bottom wall of the groove 13; and forming a first sealing ring 80 on the outer periphery of the first surface 11 of the substrate 10;

[0098] S105: providing a substrate 20, and forming two first conductive holes 21 and two second conductive holes 22 on the substrate 20;

[0099] S106: forming a first conductive contact 41 at each first conductive hole 21 , forming a second electrode 70 at the second conductive hole 22 , the material of the second electrode 70 extending out of each second conductive hole 22 to form a second conductive contact 42 , and forming a second sealing ring 90 on the periphery of the substrate 20 ;

[0100] S107 : Align the first sealing ring 80 and the second sealing ring 90 to bond the substrate 10 and the base plate 20 together.

[0101] The MEMS sensor 100 provided in the above embodiment of the present application realizes the detection of the pressure outside the cavity by means of mutual compensation of the pressure inside and outside the cavity, and the deflection of the strain membrane is small, with higher linearity; by monitoring the moment when the output voltage of the Wheatstone bridge circuit 14 is zero, the pressure test can be concretely represented to the moment when the output voltage of the Wheatstone bridge circuit 14 is zero, with higher sensitivity.

[0102] It should be pointed out that the position, material, size, function, etc. of each layer structure involved in the preparation method of the above-mentioned MEMS sensor 100 of the present application may correspond to the same as those in the implementation of the above-mentioned MEMS sensor 100 of the present application. For relevant details, please refer to the above-mentioned implementation, and no further details will be given here.

[0103] An exemplary embodiment of the application of the MEMS sensor 100 to an electronic atomization device is described below.

[0104] Please also see Fig.11 and Fig.12 , Fig.11 An electronic atomization device provided for some embodiments of the present application; Fig.12 for Fig.11 Functional module diagram of the electronic atomization device.

[0105] The electronic atomization device 1000 provided in the embodiment of the present application includes a liquid storage unit 1000A and a control unit 1000B; the liquid storage unit 1000A includes a liquid storage component 200 and an atomization component 300; the control unit 1000B includes a MEMS sensor 100, a control circuit 400 and a power supply 500. The control unit 1000B also includes a battery cell and the like.

[0106] In some embodiments, the liquid storage component 200 is used to store an aerosol-generating matrix, which can be a solid matrix or liquid substance of plant leaves with a specific aroma or substance, and can generate an aerosol for users to inhale under the condition of heating without burning. The electronic atomization device 1000 of the present application can be used in different fields, such as medical treatment, beauty or leisure inhalation. The liquid storage component 200 has an aerosol inlet end and an outlet end.

[0107] The atomizing assembly 300 is disposed on the airflow path from the air inlet end to the air outlet end and is in fluid communication with the liquid storage assembly 200, and is used to atomize the aerosol-generating matrix from the liquid storage assembly 200 into an aerosol. The atomizing assembly 300 may generate an aerosol in any manner, for example, by ultrasonic vibration or heating to atomize the aerosol-generating matrix.

[0108] The MEMS sensor 100 is a MEMS sensor 100 provided in any of the above embodiments. The MEMS sensor 100 is disposed in the air flow channel of the electronic atomization device 1000, such as upstream of the atomization assembly 300, and is used to detect changes in air pressure in the air flow channel. The MEMS sensor 100 of this embodiment can be used as an air flow start switch. When a user draws on the electronic atomization device 1000, the MEMS sensor 100 of this embodiment can be used to detect the user's puffing action and output a control signal to the control circuit 400, thereby driving the control circuit to output a voltage to the atomization assembly 300.

[0109] The power source 500 can be used to provide voltage to the atomization assembly 300 and the MEMS sensor 100. The power source 500 can be a rechargeable battery cell, or a replaceable disposable battery cell, etc.

[0110] The control circuit 400 is electrically connected to the atomization assembly 300, the MEMS sensor 100 and the power supply 500, respectively. The control circuit 400 is used to control the power supply 500 to apply an electrical signal to the first electrode plate 30 and the second electrode plate 70 according to the change in the output voltage caused by the change in air pressure in the air flow channel of the MEMS sensor 100, so that the first electrode plate 30 and the second electrode plate 70 apply a force to the bottom wall of the groove 13 that is close to or away from the substrate 20, so that the change in the output voltage of the MEMS sensor 100 is less than or equal to a preset threshold value, thereby compensating for the drift of the relationship between the resistance value and pressure of the varistor 140 caused by the compressive deformation of the substrate 10.

[0111] It can be understood that the change of air pressure in the air flow channel will cause the change of the resistance of the piezoresistor 140, thereby causing the change of the output voltage Vout of the MEMS sensor 100, and the change of the output voltage Vout of the MEMS sensor 100 reflects the air pressure in the air flow channel, that is, the pressure on the MEMS sensor 100. When the pressure on the MEMS sensor 100 is greater than a certain value, that is, when the change of the output voltage Vout of the MEMS sensor 100 exceeds the preset threshold, the substrate 10 is compressed and deformed, causing the drift of the relationship between the resistance and pressure of the piezoresistor 140. By applying voltage to the first electrode plate 30 and the second electrode plate 70, the first electrode plate 30 and the second electrode plate 70 are attracted or repelled from each other, so that when the change of the output voltage Vout of the MEMS sensor 100 is less than or equal to the preset threshold, the drift of the relationship between the resistance and pressure of the piezoresistor 140 caused by the compression and deformation of the substrate 10 is compensated. The preset threshold is the change in the output voltage Vout corresponding to the drift in the relationship between the resistance value of the varistor 140 and the pressure caused by the compression deformation of the substrate 10 , and can be obtained in advance through experiments.

[0112] In some embodiments, the control circuit 400 is further used to detect whether the force applied by the first electrode plate 30 to the bottom wall of the groove 13 offsets the deformation of the bottom wall of the groove 13 caused by the air pressure, and when it is detected that the force applied by the first electrode plate 30 to the bottom wall of the groove 13 offsets the deformation of the bottom wall of the groove 13 caused by the air pressure, the magnitude of the air pressure is determined according to the electrical signal applied to the first electrode plate 30. The control circuit 400 is also used to control the operation of the atomization assembly 300 according to the magnitude of the air pressure detected by the MEMS sensor 100.

[0113] The working principle of the MEMS sensor 100 of this embodiment is described below in conjunction with the process of a user smoking the electronic atomization device 1000:

[0114] When the user starts to inhale, the MEMS sensor 100 is subjected to the second direction (eg Figure 2 The substrate 10 is displaced (or "deformed") in the second direction by the pressure in the Z direction (i.e., the vertically upward direction) shown in FIG. 1 . Since the Wheatstone bridge circuit 14 includes a piezoresistor 140, the change in the resistance value of the piezoresistor 140 causes the voltage output signal Vout of the Wheatstone bridge circuit 14 to change. Based on the change in the voltage output signal Vout, the user's suction action can be detected. When the substrate 10 is displaced in the second direction, a DC voltage is applied to the first electrode plate 30 and the second electrode plate 70, so that the first electrode plate 30 and the second electrode plate 70 attract each other, so that the first electrode plate 30 is displaced in the first direction, thereby offsetting the displacement in the second direction caused by the airflow fluctuation, so that the voltage signal output Vout of the Wheatstone bridge circuit 14 returns to 0.

[0115] When the user performs a blowing action or an airflow fluctuation is caused by suction, a positive pressure may be generated in the electronic atomization device 1000 . Therefore, in addition to the displacement in the second direction, the substrate 10 may also be displaced along the first direction.

[0116] When the substrate 10 is subjected to a first direction (such as Figure 2 When the displacement in the first direction occurs due to the pressure effect (blowing or air flow fluctuation effect) in the opposite direction of the Z direction shown, that is, the vertical downward direction, the first electrode plate 30 and the second electrode plate 70 can be repelled from each other by applying a DC voltage to the first electrode plate 30 and the second electrode plate 70, thereby causing the first electrode plate 30 and the substrate 10 to produce a displacement in the second direction, thereby offsetting the displacement in the first direction caused by the pressure effect in the first direction. When the displacement in the first direction and the displacement in the second direction are completely offset, the voltage output Vout value of the Wheatstone bridge circuit 14 is 0.

[0117] It can be seen that according to the different installation positions of the MEMS sensor 100 of this embodiment, it can sensitively detect arbitrarily set pressures in the first direction and the second direction. Compared with the piezoresistive sensor in the related art, it not only has higher accuracy, but also has a wider application range.

[0118] In the electronic atomization device 1000 of the present embodiment, when subjected to pressure in the second direction, a DC voltage can be applied to the first electrode plate 30 and the second electrode plate 70 so that the first electrode plate 30 and the second electrode plate 70 attract each other, causing the first electrode plate 30 to be displaced in the first direction, thereby offsetting the displacement of the strain film in the second direction caused by suction; when subjected to pressure in the first direction, a DC voltage can be applied to the first electrode plate 30 and the second electrode plate 70 so that the first electrode plate 30 and the second electrode plate 70 repel each other, causing the displacement of the first electrode plate 30 in the second direction, thereby offsetting the displacement of the strain film in the first direction caused by airflow disturbance. Therefore, during the entire use process, the deflection of the strain film is always small, thereby improving the problem that the deformation of the substrate 10 does not change ideally linearly with the pressure, thereby improving the detection accuracy of the MEMS sensor 100 of the embodiment. Moreover, condensation is easily formed in the air flow channel of the electronic atomization device 1000; since the first electrode plate 30 and the second electrode plate 70 are sealed in the groove 13, the chance of the first electrode plate 30 and the second electrode plate 70 being corroded or contaminated by the condensation can be reduced.

[0119] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0120] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0121] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A MEMS sensor, characterized in that: include: A substrate having a first surface and a second surface opposite to each other; the first surface having a groove, the second surface having a Wheatstone bridge circuit, and a bridge arm of the Wheatstone bridge circuit including a varistor; A substrate covering the groove to form a sealed cavity; A first electrode plate, disposed on the bottom wall of the groove; A second electrode plate, disposed on the substrate and spaced apart from the first electrode plate; and a conductive contact, disposed on the substrate and / or the base plate, and electrically connected to at least one of the first electrode plate and the second electrode plate; The first electrode plate and the second electrode plate are configured to repel or attract each other when powered on.

2. The MEMS sensor according to claim 1, characterized in that: The first plate and the second plate form a parallel plate capacitor, and the conductive contacts include a first conductive contact electrically connected to the first plate and a second conductive contact electrically connected to the second plate.

3. The MEMS sensor according to claim 2, characterized in that: The first electrode plate is arranged on the bottom surface of the groove; the second electrode plate is arranged on the surface of the substrate exposed to the sealed cavity; the first electrode plate and the second electrode plate are arranged opposite to each other.

4. The MEMS sensor according to claim 1, characterized in that: One of the first pole plate and the second pole plate includes a permanent magnetic material, and the other is an electromagnet; the conductive contact is electrically connected to the electromagnet to change the polarity of the electromagnet.

5. The MEMS sensor according to claim 1, characterized in that: The first pole plate and the second pole plate are both electromagnets; the conductive contacts are electrically connected to the first pole plate and the second pole plate respectively, and are used to change the polarity of the electromagnets.

6. The MEMS sensor according to claim 2, characterized in that: The substrate has a first conductive hole and a second conductive hole; the first conductive contact is arranged on the surface of the substrate away from the substrate and is electrically connected to the first electrode through the first conductive hole, and the second conductive contact is arranged on the surface of the substrate away from the substrate and is electrically connected to the second electrode through the second conductive hole.

7. The MEMS sensor according to claim 1, characterized in that: The Wheatstone bridge circuit includes four groups of piezoresistors and four groups of conductive areas. The piezoresistors generate resistance changes in response to pressure changes applied to the substrate, thereby converting pressure signals into electrical signals. The conductive areas are used to lead out the electrical signals.

8. The MEMS sensor according to claim 7, characterized in that: The substrate is a semiconductor substrate; each group of the varistors includes two sub-varistors arranged in parallel and at intervals, and a heavily doped contact region formed between the sub-varistors, and the heavily doped contact region is used to electrically connect the two sub-varistors arranged in parallel and at intervals.

9. The MEMS sensor according to claim 8, characterized in that: The varistor and the heavily doped contact region are formed on the substrate, the substrate is also covered with a dielectric layer, and the four groups of conductive regions are formed on the dielectric layer.

10. The MEMS sensor according to claim 9, characterized in that: The side of the dielectric layer away from the substrate is also covered with a passivation layer, and the four groups of conductive areas are respectively at least partially exposed from the passivation layer.

11. An electronic atomization device, characterized in that: include: A liquid storage unit, used for storing an aerosol-generating substrate, wherein the liquid storage unit has an aerosol inlet end and an outlet end; An atomizing assembly, disposed on the air flow path from the air inlet end to the air outlet end, for atomizing the aerosol generating matrix; The MEMS sensor is a MEMS sensor as claimed in any one of claims 1 to 10; the MEMS sensor is arranged on the air flow channel of the electronic atomization device, and is used to detect the air pressure change in the air flow channel; A power supply, used to provide voltage to the atomization assembly and the MEMS sensor; A control circuit is electrically connected to the power supply, the atomization assembly and the MEMS sensor respectively; The control circuit is used to apply an electrical signal to the first electrode plate and the second electrode plate according to the change in output voltage of the MEMS sensor caused by the change in air pressure in the air flow channel, so that the first electrode plate and the second electrode plate repel or attract each other, so that the change in output voltage of the MEMS sensor is less than or equal to a preset threshold.

12. The electronic atomization device according to claim 11, characterized in that: The preset threshold is zero; the control circuit is also used to detect whether the change in the output voltage of the MEMS sensor is zero; and when it is detected that the change in the output voltage of the MEMS sensor is zero, the magnitude of the air pressure is determined according to the electrical signal applied to the first electrode plate and the second electrode plate.

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