Airflow sensor and airflow sensor packaging structure

Abstract

The invention provides an airflow sensor and an airflow sensor packaging structure, and aims to establish a continuous flow path in a back cavity of the airflow sensor and a space outside the airflow sensor by arranging at least one pressure equalizing structure on the airflow sensor and physically isolating the pressure equalizing structure from a gap layer. The air flow sensor further comprises an air leakage channel arranged in the gap between the fixed electrode and the vibration electrode in a penetrating mode, the gap layer is communicated with the space outside the air flow sensor through the air leakage channel, an ASIC connected with the air flow sensor can be prevented from detecting a pressure difference signal in a non-working state, and the air flow sensor can be used for detecting the pressure difference signal. According to the air flow sensor provided by the invention, the problem that pollutants in the external space of the air flow sensor are diffused into the gap layer can be reduced, so that the problem of membrane absorption caused by the pollutants between the vibration electrode and the back polar plate and the problems of false triggering and short circuit caused by the problem are perfectly solved.

Description

[0001] This application is a divisional, and the application date of the parent case is September 26, 2023. The name of the invention is airflow sensor and airflow sensor packaging structure, and the application number is 202311252149.4. Technical Field

[0002] The present invention relates to the technical field of airflow sensors, and more particularly to an airflow sensor and an airflow sensor packaging structure. Background Art

[0003] Devices based on micro-electro-mechanical systems (MEMS) are called MEMS devices. The MEMS capacitive pressure sensor device includes a diaphragm and a back plate, and there is a gap between the diaphragm and the back plate. Changes in air pressure will cause the diaphragm to deform, and the capacitance between the diaphragm and the back plate will change, which will be converted into an electrical signal output.

[0004] In the case of application in airflow sensor, when the airflow sensor senses the user's inhalation, the diaphragm of the airflow sensor is deformed, and the air pressure on both sides of the diaphragm of the airflow sensor is converted into a change in the internal capacitance of the sensor to output a signal, so that the airflow sensor can be used as a switch to control the atomizer of the electronic cigarette. Existing electronic cigarettes will generate negative pressure when the user inhales, causing the diaphragm to deform under the action of negative pressure, and the chip of the application-specific integrated circuit (ASIC) detects the capacitance change of the MEMS, thereby triggering the cigarette lighting action. However, during use, backblowing sometimes occurs, that is, when the diaphragm of the airflow sensor is subjected to positive pressure, the diaphragm is deformed, and when the diaphragm returns to the equilibrium position from the deformed position, the ASIC detects the capacitance change and triggers the cigarette lighting action. However, if the backblowing time is relatively short, the cigarette lighting action will not be triggered, otherwise it will be triggered.

[0005] Therefore, it is desirable to provide an improved airflow sensor so that the diaphragm can quickly return to a balanced position after deformation. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art and provides an airflow sensor and an airflow sensor packaging structure.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] According to one aspect of the present invention, there is provided an airflow sensor, comprising:

[0009] A substrate, a vibrating electrode and a fixed electrode are stacked, wherein the substrate has a first cavity penetrating in a thickness direction thereof;

[0010] The vibration electrode has a vibration sensitive area, a gap layer is provided between the vibration sensitive area and the fixed electrode, and the vibration electrode and the fixed electrode form a variable capacitor;

[0011] The fixed electrode comprises release holes evenly distributed, the release holes are used to remove the sacrificial layer between the fixed electrode and the vibrating electrode by a solution release method, and the release holes are closed after the sacrificial layer is released to form the gap layer;

[0012] The airflow sensor further includes at least one pressure equalizing structure, the pressure equalizing structure including a pressure equalizing hole and a pressure equalizing channel, the pressure equalizing hole is arranged at the circumferential edge of the vibration sensitive area of ​​the vibration electrode, and the pressure equalizing channel is connected with the pressure equalizing hole to establish a continuous flow path between the first cavity and the space outside the airflow sensor;

[0013] The pressure equalizing structure is physically isolated from the gap layer, and the airflow sensor further includes an air leakage channel penetrating the gap between the fixed electrode and the vibrating electrode, and the gap layer is connected to the space outside the airflow sensor via the air leakage channel.

[0014] Furthermore, a first support body partially penetrates between the vibration electrode and the substrate, and a second support body partially penetrates between the fixed electrode and the vibration electrode;

[0015] The air leakage channel penetrates the second support body in a direction perpendicular to the thickness of the substrate.

[0016] Furthermore, the number of the air leakage channels is less than or equal to ten.

[0017] Furthermore, the fixed electrode is not provided with an air leakage hole communicating with the gap layer.

[0018] Furthermore, the fixed electrode includes an insulating layer and a conductive layer fixedly connected to the insulating layer, and in the thickness direction of the substrate, the conductive layer is located on a side of the insulating layer away from the vibration electrode, and the projection of the conductive layer is located within the projection range of the vibration sensitive area.

[0019] In some embodiments, the pressure equalizing channel is provided through a gap between the fixed electrode and the vibrating electrode; and an air outlet of the pressure equalizing channel is located at the gap between the fixed electrode and the vibrating electrode.

[0020] In some embodiments, the pressure equalizing channel includes a through hole disposed on the fixed electrode, and the through hole is connected to the pressure equalizing hole.

[0021] Furthermore, the air outlet of the pressure equalizing channel is located on the fixed electrode.

[0022] Furthermore, a side wall of the pressure equalizing channel adjacent to the gap layer is coated with an insulating structure.

[0023] Furthermore, the isolation structure and the insulating layer on the fixed electrode are integrally formed.

[0024] Furthermore, an anti-sticking structure is provided on a surface of the fixed electrode facing the vibration electrode.

[0025] Optionally, the anti-sticking structure is integrally formed with the insulating layer on the fixed electrode.

[0026] Furthermore, the airflow sensor further comprises an oleophobic layer, which is disposed on the surfaces of the vibrating electrode and the fixed electrode and covers the side walls of the pressure equalizing hole, the pressure equalizing channel and the air leakage channel.

[0027] According to one aspect of the present invention, there is provided an airflow sensor packaging structure, comprising a substrate, a housing and any one of the airflow sensors described above;

[0028] The substrate is fixedly connected to the shell to form a cavity, and the airflow sensor is fixedly connected to a side surface of the substrate facing the shell and is located in the cavity;

[0029] A first through hole is provided on the substrate, a second through hole is provided on the shell, the airflow sensor covers the first through hole, and the airflow sensor separates the cavity into at least a first cavity and a second cavity. The first cavity is connected to the first through hole, and the second cavity is connected to the external environment via the second through hole. The first cavity is connected to the second cavity via the pressure equalizing structure.

[0030] The airflow sensor and airflow sensor packaging structure provided by the present invention are intended to establish a continuous flow path between the first cavity of the airflow sensor and the space outside the airflow sensor by providing at least one pressure-equalizing structure on the airflow sensor, and the pressure-equalizing structure is physically isolated from the gap layer, and the airflow sensor also includes a gas leakage channel penetrating the gap between the fixed electrode and the vibrating electrode, and the gap layer is connected to the space outside the airflow sensor via the gas leakage channel, which can not only achieve pressure balance between the side surface of the vibrating electrode facing the first cavity and the side surface of the vibrating electrode away from the first cavity in the non-working state, so as to prevent the ASIC connected to the airflow sensor from detecting a pressure difference signal, thereby causing false triggering of other components. It can also reduce the diffusion (invasion) of pollutants (such as smoke oil, etc.) in the external space of the airflow sensor into the gap layer, thereby perfectly solving the problem of film absorption caused by pollutants (such as smoke oil, etc.) between the vibrating electrode and the back plate, as well as the false triggering and short circuit problems caused thereby. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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 those skilled in the art, other implementation methods can be obtained based on these drawings without paying any creative work.

[0032] Figure 1A A cross-sectional view in the main viewing direction of an airflow sensor provided by an embodiment of the present application.

[0033] Figure 1B for Figure 1A A top view of the airflow sensor provided in the embodiment.

[0034] Figure 2A A cross-sectional view in the main viewing direction of an airflow sensor provided in yet another embodiment of the present application.

[0035] Figure 2B for Figure 2A A top view of the airflow sensor provided in the embodiment.

[0036] Figure 3A A cross-sectional view in the main viewing direction of an airflow sensor provided by another embodiment of the present application.

[0037] Figure 3B for Figure 3A A top view of the airflow sensor provided in the embodiment.

[0038] Figure 4 A cross-sectional view in the main viewing direction of an airflow sensor provided by another embodiment of the present application.

[0039] Figure 5 A cross-sectional view in the main viewing direction of an airflow sensor packaging structure provided in one embodiment of the present application. DETAILED DESCRIPTION

[0040] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, 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 present invention can be understood according to specific circumstances.

[0042] At least one embodiment of the present application provides an airflow sensor, which includes: a substrate, a vibrating electrode, and a fixed electrode arranged in layers, wherein the substrate has a first cavity penetrating in a thickness direction thereof;

[0043] The vibration electrode has a vibration sensitive area, a gap layer is provided between the vibration sensitive area and the fixed electrode, the vibration electrode and the fixed electrode form a variable capacitor, and an air leakage hole is provided on the fixed electrode, and the air leakage hole is connected to the gap layer;

[0044] The airflow sensor further includes at least one pressure equalizing structure, the pressure equalizing structure including a pressure equalizing hole and a pressure equalizing channel, the pressure equalizing hole is arranged at the circumferential edge of the vibration sensitive area of ​​the vibration electrode, and the pressure equalizing channel is connected with the pressure equalizing hole to establish a continuous flow path between the first cavity and the space outside the airflow sensor;

[0045] The pressure equalizing structure is physically isolated from the gap layer, and the airflow sensor further includes an air leakage channel penetrating the gap between the fixed electrode and the vibrating electrode, and the gap layer is connected to the space outside the airflow sensor via the air leakage channel.

[0046] As can be seen from the above, the embodiment of the present application establishes a continuous flow path between the first cavity and the space outside the airflow sensor by providing at least one pressure equalizing structure on the airflow sensor, and the pressure equalizing hole of the pressure equalizing structure is provided in the vibration insensitive area of ​​the vibrating electrode, so as to achieve pressure equalization between the side surface of the vibrating electrode facing the first cavity and the side surface of the vibrating electrode away from the first cavity in the non-working state, so as to prevent the ASIC connected to the airflow sensor from detecting the pressure difference signal, thereby causing false triggering of other components. In addition, the airflow sensor also includes an air leakage channel penetrating the gap between the fixed electrode and the vibrating electrode, and the gap layer is connected to the space outside the airflow sensor via the air leakage channel, which can also reduce the diffusion (invasion) of pollutants (such as smoke oil, etc.) in the external space of the airflow sensor into the gap layer, thereby perfectly solving the problem of film absorption caused by pollutants (such as smoke oil, etc.) between the vibrating electrode and the back plate, as well as the problems of false triggering and short circuit caused thereby.

[0047] Embodiment 1

[0048] Figure 1A This is a cross-sectional view of the airflow sensor provided in an embodiment of the present application in the main viewing direction. Figure 1B for Figure 1A A top view of the airflow sensor provided in the embodiment.

[0049] like Figure 1A , Figure 1B As shown, the airflow sensor 2 includes a stacked substrate 10, a vibration electrode 30, and a fixed electrode 50, wherein the substrate 10 has a first cavity 11 that penetrates in the thickness direction thereof;

[0050] The vibration electrode 30 has a vibration sensitive region, a gap layer 42 is provided between the vibration sensitive region and the fixed electrode 50, and the vibration electrode 30 and the fixed electrode 50 form a variable capacitor;

[0051] The airflow sensor 2 further includes at least one pressure equalizing structure, the pressure equalizing structure including a pressure equalizing hole 31 and a pressure equalizing channel 43, the pressure equalizing hole 31 is arranged at the circumferential edge of the vibration sensitive area of ​​the vibration electrode 30, and the pressure equalizing channel 43 is connected to the pressure equalizing hole 31 to establish a continuous flow path between the first cavity 11 and the space outside the airflow sensor 2;

[0052] Among them, the pressure equalizing structure is physically isolated from the gap layer 42, and the airflow sensor 2 also includes a leakage channel 41 penetrating the gap between the fixed electrode 50 and the vibration electrode 30, and the gap layer 42 is connected to the space outside the airflow sensor 2 via the leakage channel 41.

[0053] In the embodiment of the present application, at least one pressure-equalizing structure is provided on the airflow sensor, and the pressure-equalizing structure is physically isolated from the gap layer, so as to establish a continuous flow path between the first cavity of the airflow sensor and the space outside the airflow sensor. This can not only achieve pressure equalization between the side surface of the vibrating electrode facing the first cavity and the side surface of the vibrating electrode away from the first cavity in a non-working state to prevent the airflow sensor from being falsely triggered, but also the airflow sensor also includes an air leakage channel passing through the gap between the fixed electrode and the vibrating electrode, and the gap layer is connected to the space outside the airflow sensor via the air leakage channel, and can also reduce the diffusion (invasion) of pollutants (such as cigarette oil, etc.) in the external space of the airflow sensor into the gap layer, thereby perfectly solving the problem of film absorption caused by pollutants (such as cigarette oil, etc.) between the vibrating electrode and the back plate, as well as the problems of false triggering and short circuit caused thereby.

[0054] Furthermore, a first support body 20 partially penetrates between the vibration electrode 30 and the substrate 10 , a second support body 40 partially penetrates between the fixed electrode 50 and the vibration electrode 30 , and the air leakage channel 41 penetrates the second support body 40 in a thickness direction perpendicular to the substrate 10 .

[0055] For example, in the embodiment of the present application, the first support 20 and the second support 40 are both insulating support bodies, such as silicon oxide or silicon nitride. The thickness of the first support 20 and the second support 40 is between 2 and 3 μm, for example, around 2.5 μm. The vibration electrode 30 and the fixed electrode 50 are arranged opposite to each other and insulated, so that an oscillation cavity for the vibration electrode 30 to vibrate is formed between the fixed electrode 50 and the vibration electrode 30, that is, a Figure 1A The gap layer 42 is shown in FIG.

[0056] Exemplarily, in this embodiment, the first support body 20 is located at the edge of the substrate 10 to support the vibration electrode 30, so that the vibration electrode 30 is suspended above the first cavity 11. Specifically, the vibration electrode 30 includes a vibration sensitive area and a support area, wherein the support area suspends the vibration electrode 30 above the first cavity 11 through the first support body 20. The second support body 40 is located at the edge of the vibration electrode 30, so that the fixed electrode 50 is suspended above the vibration electrode 30 and is insulated from the vibration electrode 30. It should be noted that the vibration electrode 30 in this embodiment is a planar membrane structure located directly above the first cavity 11. Generally, when subjected to an external force, the vibration electrode 30 is deformed, and the deformation amount of the vibration electrode 30 (the amplitude of the vibration electrode deformation) decreases successively along the direction from the geometric center of the vibration electrode 30 to the outside.

[0057] It should be understood that in the embodiment of the present invention, the air leakage channel 41 penetrates the second support body 40 in a direction perpendicular to the thickness of the substrate 10. Specifically, the air leakage channel 41 can be formed by etching a portion of the second support body 40 at the connection between the vibration electrode 30 and the fixed electrode 50 to form a notch.

[0058] In some embodiments, the fixed electrode 50 is a single-layer structure, and the entire fixed electrode 50 serves as a conductive electrode to form a variable capacitor with the vibration electrode 30. In some other embodiments, the fixed electrode 50 may also be a multi-layer structure, and the fixed electrode 50 includes a conductive layer, and the conductive layer of the fixed electrode 50 constitutes a variable capacitor with the vibration electrode 30. The embodiments of the present invention are not limited here.

[0059] In this embodiment, the pressure equalizing structure includes a pressure equalizing hole 31 and a pressure equalizing channel 43. Exemplarily, the pressure equalizing hole 31 is arranged at the circumferential edge of the vibration sensitive area of ​​the vibration electrode 30, the pressure equalizing channel 43 is penetrated in the gap between the fixed electrode 50 and the vibration electrode 30, and the pressure equalizing channel 43 is connected to the pressure equalizing hole 31 to establish a continuous flow path between the first cavity 11 of the airflow sensor 2 and the space outside the airflow sensor 2, so as to achieve pressure equalization between the side surface of the vibration electrode 30 facing the first cavity 11 and the side surface of the vibration electrode 30 away from the first cavity 11 in the non-working state, so as to prevent the ASIC connected to the airflow sensor 2 from detecting the capacitance change, thereby causing false triggering of other components.

[0060] In some embodiments, the overall pressure equalizing structure is L-shaped. When the airflow of the electronic cigarette enters the first cavity 11 of the airflow sensor 2 for operation, the airflow of the electronic cigarette acts on the vibration electrode 30, causing the vibration electrode 30 to deform, and the airflow of the electronic cigarette can be discharged to the external space of the airflow sensor 2 through the pressure equalizing hole 31 on the vibration electrode 30. In this embodiment, the second support body 40 adjacent to the pressure equalizing channel 43 can form a side wall to prevent pollutants (such as cigarette oil) entering from the pressure equalizing hole 31 from diffusing (invading) into the gap layer 42 through the pressure equalizing channel 43, thereby completely solving the film absorption problem of the vibration electrode 30 and the fixed electrode 50 caused by pollutants (such as cigarette oil).

[0061] It should be noted that, in the manufacturing process of the airflow sensor, several thousand order of magnitude release holes are usually provided on the fixed electrode 50, and the several thousand order of magnitude release holes are evenly distributed on the fixed electrode 50, so as to remove the sacrificial layer between the fixed electrode 50 and the vibrating electrode 30 by the solution release method. In the embodiment of the present application, after the sacrificial layer between the fixed electrode 50 and the vibrating electrode 30 is released to form the gap layer 42, the above-mentioned release holes need to be closed. However, since the airflow sensor 2 also includes a venting channel 41 penetrating the gap between the fixed electrode 50 and the vibrating electrode 30, the gap layer 42 is connected to the space outside the airflow sensor 2 via the venting channel 41, so as to achieve air pressure balance. Therefore, the fixed electrode 50 may not be provided with a venting hole connected to the gap layer 42, that is, all the above-mentioned release holes can be closed, so that the effective area of ​​the fixed electrode 50 facing the vibrating electrode 30 can be increased to a certain extent.

[0062] Further, the number of the air leakage channels 41 is less than or equal to 10, for example, 2, 3, 5, 6 or 8. No further details will be given here.

[0063] Compared with the thousands of release holes originally set on the fixed electrode 50, and the arrangement of all the release holes in a uniform distribution on the fixed electrode 50, the technical solution provided in the embodiment of the present application can also significantly increase the effective overlapping area between the fixed electrode 50 and the vibrating electrode 30, thereby increasing the size of the variable capacitor of the airflow sensor 2 without changing the volume of the airflow sensor itself, thereby improving the detection sensitivity of the airflow sensor 2.

[0064] Specifically, in this embodiment, the pressure equalizing channel 43 is provided through the gap between the fixed electrode 50 and the vibrating electrode 30, and the gas outlet of the pressure equalizing channel 43 is located at the gap between the fixed electrode 50 and the vibrating electrode 30. Furthermore, the flow direction of the gas containing pollutants (such as tobacco oil, etc.) discharged from the gas outlet of the pressure equalizing channel 43 is completely different from the opening direction of the pressure equalizing structure, further reducing the probability of the gas containing pollutants (such as tobacco oil, etc.) diffracting from the air leakage channel 41 into the gap layer 42, thereby increasing the service life of the product.

[0065] Embodiment 2

[0066] Figure 2A A cross-sectional view of an airflow sensor provided in a main viewing direction according to another embodiment of the present application is shown in FIG. Figure 2B for Figure 2A A top view of the airflow sensor provided in the embodiment.

[0067] like Figure 2A ,2B As shown, illustratively, Figure 2A and Figure 1A The difference is that: in this embodiment, the fixed electrode 50 includes an insulating layer 501 and a conductive layer 601 fixedly connected to the insulating layer 501, and in the thickness direction of the substrate 10, the conductive layer 601 is located on the side of the insulating layer 501 away from the vibration electrode 30, and the projection of the conductive layer 601 is located within the projection range of the vibration sensitive area.

[0068] In this embodiment, the pressure equalizing structure includes a pressure equalizing hole 31 and a pressure equalizing channel 43. Exemplarily, the pressure equalizing hole 31 is arranged at the circumferential edge of the vibration sensitive area of ​​the vibration electrode 30, the pressure equalizing channel 43 is penetrated in the gap between the insulating layer 501 of the fixed electrode 50 and the vibration electrode 30, and the pressure equalizing channel 43 is connected to the pressure equalizing hole 31 to establish a continuous flow path between the first cavity 11 of the airflow sensor 2 and the space outside the airflow sensor 2.

[0069] Similar to the first embodiment, in this embodiment, the fixed electrode 50 is not provided with an air leakage hole connected to the gap layer 42. The number of the air leakage channels 41 is less than or equal to 10. This reduces the probability that the airflow containing pollutants (such as smoke oil, etc.) in the external space of the airflow sensor 2 is diffracted into the gap layer 42 through the air leakage channel 41, thereby improving the service life of the product.

[0070] Exemplarily, in this embodiment, the airflow sensor 2 also includes a first soldering pad 701 and a second soldering pad 702, wherein the first soldering pad 701 is electrically connected to the conductive layer 601 of the fixed electrode 50 for transmitting the electrical signal of the conductive layer 601, and the second soldering pad 702 is electrically connected to the vibration electrode 30 for transmitting the electrical signal of the vibration electrode 30.

[0071] Furthermore, in order to prevent the problem of adhesion between the fixed electrode 50 and the vibration electrode 30 after film absorption, an anti-adhesion structure 52 is provided on the surface of the fixed electrode 50 facing the vibration electrode 30 to prevent the problem of adhesion between the fixed electrode 50 and the vibration electrode 30 after film absorption.

[0072] Optionally, the anti-sticking structure 52 is integrally formed with the insulating layer 501 on the fixed electrode 50 .

[0073] Embodiment 3

[0074] Figure 3A A cross-sectional view of an airflow sensor provided in another embodiment of the present application in the main viewing direction, Figure 3B for Figure 3A A top view of the airflow sensor provided in the embodiment.

[0075] like Figure 3A , 3BAs shown, illustratively, different from the aforementioned embodiment 1 and embodiment 2, in this embodiment, the pressure equalizing channel 43 includes a through hole 53 provided on the fixed electrode 50, and the through hole 53 is connected to the pressure equalizing hole 31 on the vibration electrode 30 to jointly form a pressure equalizing structure.

[0076] For example, the second support body 40 can be etched in the thickness direction to form a through hole 53, and the orthographic projection of the through hole 53 on the substrate 10 overlaps with the orthographic projection of the pressure equalizing hole 31 on the substrate 10, so that the pressure equalizing structure forms a "straight" connecting structure in the thickness direction of the substrate 10. When the airflow of the electronic cigarette enters the first cavity 11 for operation, the pressure equalizing structure establishes a continuous flow path in the space outside the first cavity 11 and the airflow sensor 2, so that the pressure of the side surface of the vibration electrode 30 facing the first cavity 11 and the side surface of the vibration electrode 30 away from the first cavity 11 can be balanced in the non-working state, so as to prevent the airflow sensor 2 from being triggered by mistake.

[0077] In some embodiments, the side wall of the pressure equalizing channel (through hole 53) adjacent to the gap layer 42 is coated with an insulating structure, and illustratively, the insulating structure and the insulating layer 501 on the fixed electrode 50 are integrally formed. That is, the side wall of the through hole 53 can be coated by the insulating layer 501 of the fixed electrode 50, thereby forming a pressure equalizing channel with the insulating layer 501, which is used together to prevent the airflow containing pollutants (such as smoke oil, etc.) from diffusing (invading) into the gap layer 42 between the vibrating electrode 30 and the fixed electrode 50.

[0078] Different from the first and second embodiments, in this embodiment, the gas outlet of the pressure equalizing channel 43 is located on the fixed electrode 50 .

[0079] In this embodiment, the pressure equalizing hole 31 and the air leakage channel 41 are arranged at a certain angle, for example, the pressure equalizing hole 31 and the air leakage channel 41 are arranged diagonally, so as to reduce the probability that the airflow containing pollutants (such as smoke oil, etc.) discharged to the external space of the airflow sensor 2 through the pressure equalizing hole 31 is diffracted from the air leakage channel 41 and enters the gap layer 42, thereby further improving the service life of the product. It should be understood that in the embodiment of the present application, as long as the distance between the arrangement of the pressure equalizing hole 31 and the air leakage channel 41 is as far as possible, the relative position relationship of the arrangement of the pressure equalizing hole 31 and the air leakage channel 41 is not strictly limited.

[0080] Embodiment 4

[0081] Figure 4 A cross-sectional view in the main viewing direction of an airflow sensor provided by another embodiment of the present application.

[0082] like Figure 4As shown, exemplarily, in the embodiment, different from the aforementioned embodiment, the airflow sensor 2 also includes an oleophobic layer 80, and the oleophobic layer 80 is arranged on the surface of the vibrating electrode 30 and the fixed electrode 50 and covers the side walls of the pressure equalizing hole 31, the pressure equalizing channel 43 and the air leakage channel 41.

[0083] The oleophobic layer 80 is, for example, a SAM material, so that all layers have a thin oleophobic layer. When pollutants (such as tobacco oil, etc.) enter the gap layer 42, they will gather on the surface of the vibrating electrode 30, and will not cause the vibrating electrode 30 and the fixed electrode 50 to be attracted. At this time, the airflow sensor in the electronic cigarette will not fail during operation. Furthermore, an oleophobic layer 80 can also be added to other structures. For example, the side wall of the first cavity 11 of the substrate 10 is also coated with an oleophobic layer 80, which further reduces the phenomenon of the fixed electrode 50 and the vibrating electrode 30 being attracted, thereby reducing the failure rate of the product.

[0084] Embodiment 5

[0085] Figure 5 A cross-sectional view in the main viewing direction of an airflow sensor packaging structure provided in one embodiment of the present application.

[0086] like Figure 5 As shown, according to another aspect of the present application, there is also provided an airflow sensor packaging structure, the airflow sensor packaging structure comprising a substrate 3, a shell 1 and the airflow sensor 2 described in any of the aforementioned embodiments; the substrate 3 is fixedly connected to the shell 1 to form a cavity, the airflow sensor 2 is fixedly connected to a side surface of the substrate 3 facing the shell 1 and is located in the cavity; a first through hole 34 is provided on the substrate 3, a second through hole 13 is provided on the shell 1, the airflow sensor 2 covers the first through hole 34, the airflow sensor 2 separates the cavity into at least a first cavity 11 and a second cavity 15, the first cavity 11 is connected to the first through hole 34, so that the airflow of the electronic cigarette enters the first cavity 11 of the airflow sensor 2 for operation, the second cavity 15 is connected to the external environment via the second through hole 13, and the first cavity 11 is connected to the second cavity 15 via the pressure equalizing structure to sense the pressure difference between the external environment of the airflow sensor packaging structure and the first through hole 34 corresponding to the airflow sensor packaging structure.

[0087] Therefore, the airflow sensor and airflow sensor packaging structure provided by the embodiment of the present invention are intended to establish a continuous flow path between the first cavity of the airflow sensor and the space outside the airflow sensor by providing at least one pressure equalizing structure on the airflow sensor, and the pressure equalizing structure is physically isolated from the gap layer, and the airflow sensor also includes a gas leakage channel penetrating the gap between the fixed electrode and the vibrating electrode, and the gap layer is connected to the space outside the airflow sensor via the gas leakage channel, which can not only achieve pressure equalization between the side surface of the vibrating electrode facing the first cavity and the side surface of the vibrating electrode away from the first cavity in the non-working state, so as to prevent the ASIC connected to the airflow sensor from detecting the pressure difference signal, thereby causing false triggering of other components. It can also reduce the diffusion (invasion) of pollutants (such as smoke oil, etc.) in the external space of the airflow sensor into the gap layer, thereby perfectly solving the problem of film absorption caused by pollutants (such as smoke oil, etc.) between the vibrating electrode and the back plate, as well as the problems of false triggering and short circuit caused thereby.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An airflow sensor, characterized in that: include: A substrate (10), a vibration electrode (30), and a fixed electrode (50) are stacked, wherein the substrate (10) has a first cavity (11) penetrating in a thickness direction thereof; The vibration electrode (30) has a vibration sensitive region, a gap layer (42) is provided between the vibration sensitive region and the fixed electrode (50), and the vibration electrode (30) and the fixed electrode (50) form a variable capacitor; The fixed electrode (50) comprises release holes that are evenly distributed, the release holes being used to remove the sacrificial layer between the fixed electrode (50) and the vibrating electrode (30) by a solution release method, and the release holes being closed after the sacrificial layer is released to form the gap layer (42); The airflow sensor (2) further comprises at least one pressure equalizing structure, the pressure equalizing structure comprising a pressure equalizing hole (31) and a pressure equalizing channel (43), the pressure equalizing hole (31) being arranged at the circumferential edge of the vibration sensitive area of ​​the vibration electrode (30), and the pressure equalizing channel (43) being connected to the pressure equalizing hole (31) to establish a continuous flow path between the first cavity (11) and the space outside the airflow sensor (2); The pressure equalizing structure is physically isolated from the gap layer (42), the airflow sensor further comprises an air leakage channel (41) penetrating the gap between the fixed electrode (50) and the vibrating electrode (30), and the gap layer (42) is connected to the space outside the airflow sensor (2) via the air leakage channel (41).

2. The airflow sensor according to claim 1, characterized in that A first support body (20) having a partial area penetrating therebetween the vibration electrode (30) and the substrate (10), and a second support body (40) having a partial area penetrating therebetween the fixed electrode (50) and the vibration electrode (30); The air leakage channel (41) penetrates the second support body (40) in a thickness direction perpendicular to the substrate (10).

3. The airflow sensor according to claim 2, characterized in that The number of the air leakage channels (41) is less than or equal to ten.

4. The airflow sensor according to claim 1, characterized in that: The fixed electrode (50) is not provided with an air leakage hole connected to the gap layer (42).

5. The airflow sensor according to claim 4, characterized in that: The fixed electrode (50) comprises an insulating layer (501) and a conductive layer (601) fixedly connected to the insulating layer (501); in the thickness direction of the substrate (10), the conductive layer (601) is located on a side of the insulating layer (501) away from the vibration electrode (30); and a projection of the conductive layer (601) is located within a projection range of the vibration sensitive area.

6. The airflow sensor according to claim 2 or 5, characterized in that: The pressure equalizing channel (43) is provided through the gap between the fixed electrode (50) and the vibrating electrode (30); The air outlet of the pressure equalizing channel (43) is located at the gap between the fixed electrode (50) and the vibrating electrode (30).

7. The airflow sensor according to claim 5, characterized in that: The pressure equalizing channel (43) comprises a through hole (53) arranged on the fixed electrode (50), and the through hole (53) is connected to the pressure equalizing hole (31).

8. The airflow sensor according to claim 7, characterized in that: The gas outlet of the pressure equalizing channel (43) is located on the fixed electrode (50).

9. The airflow sensor according to claim 7, characterized in that: The side wall of the pressure equalizing channel (43) adjacent to the gap layer (42) is coated with an insulating structure.

10. The airflow sensor according to claim 9, characterized in that The isolation structure and the insulating layer on the fixed electrode (50) are integrally formed.

11. The airflow sensor according to claim 5, characterized in that: An anti-sticking structure (52) is provided on a surface of the fixed electrode (50) facing the vibration electrode (30).

12. The airflow sensor according to claim 11, characterized in that The anti-sticking structure (52) and the insulating layer on the fixed electrode (50) are integrally formed.

13. The airflow sensor according to claim 1, wherein: The airflow sensor further comprises an oleophobic layer (80), The oleophobic layer (80) is arranged on the surfaces of the vibrating electrode (30) and the fixed electrode (50), and covers the side walls of the pressure equalizing hole (31), the pressure equalizing channel (43), and the air leakage channel (41).

14. An airflow sensor packaging structure, characterized in that: It comprises a substrate (3), a housing (1) and an airflow sensor (2) according to any one of claims 1 to 13; The substrate (3) is fixedly connected to the shell (1) to form a cavity, and the airflow sensor (2) is fixedly connected to a surface of the substrate (3) facing the shell (1) and is located in the cavity; The substrate (3) is provided with a first through hole (34), the shell (1) is provided with a second through hole (13), the airflow sensor (2) covers the first through hole (34), the airflow sensor (2) separates the cavity into at least a first cavity (11) and a second cavity (15), the first cavity (11) is connected to the first through hole (34), the second cavity (15) is connected to the external environment via the second through hole (13), and the first cavity (11) is connected to the second cavity (15) via the pressure equalization structure.

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