Membrane sensor and method for manufacturing a membrane sensor

Abstract

The application belongs to the field of MEMS sensors, and discloses a MEMS sensor and a manufacturing method thereof, which comprises: a first support base with a back cavity; a diaphragm seat ring embedded in the end side of the first support base, with a middle part corresponding to the back cavity; a diaphragm embedded in the diaphragm seat ring, with a peripheral part corresponding to the back cavity; a second support base with a cavity, which is arranged on one end of the first support base where the diaphragm is arranged, and the cavity corresponds to the diaphragm and the back cavity; a back plate with a plurality of sound holes, which is arranged on the end of the second support base away from the first support base, and covers the cavity; wherein the diaphragm seat ring is made of elastic material. The diaphragm is embedded and installed through the elastic diaphragm seat ring, so that the diaphragm has better sensitivity and compliance, and the detection is more sensitive and accurate. The anchoring connection part of the diaphragm is cancelled, which effectively avoids or reduces the problem of stress concentration of the diaphragm connection part, and reduces the risk of diaphragm damage. At the same time, the diaphragm seat ring also has the functions of silence, vibration attenuation and resonance improvement.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of MEMS sensors, and particularly relates to a MEMS sensor and a manufacturing method thereof. BACKGROUND

[0002] A MEMS (Micro-Electro-Mechanical-System) sensor is a sensor based on a micro-electro-mechanical system, and has multiple types, and can be used to detect physical quantities such as pressure, acceleration, temperature, and sound. Among them, a capacitive MEMS acoustic sensor is a widely used MEMS sensor, the core structure of which is a micro-capacitive sensor composed of a diaphragm and a back plate, which is integrated with an ASIC chip (for signal processing) to form; the principle is that the sound pressure causes the diaphragm to shift, changes the capacitance value between the diaphragm and the back plate, and the change in the capacitance value is converted into an electrical signal by the ASIC chip, thereby realizing the detection of sound.

[0003] Among them, the diaphragm is particularly important, and the performance of the diaphragm directly affects the detection result of the sensor. At present, the improvement direction of the diaphragm is mainly to optimize the performance of the diaphragm from the structure setting, material selection and fixing structure of the diaphragm, such as the improvements recorded in patents 202410887978.8 and 201780042283.8.

[0004] However, the diaphragm of the existing MEMS sensor still has a high risk of damage due to stress concentration at the fixed position during use, which affects the detection accuracy and service life of the sensor. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide a MEMS sensor and a manufacturing method thereof. The diaphragm of the sensor is embedded and installed by an elastic diaphragm race, so that the diaphragm movement has better sensitivity and compliance, making the detection more sensitive and accurate. Through embedded installation, the anchoring connection position of the diaphragm is cancelled, which can effectively avoid or reduce the problem of stress concentration of the diaphragm at the connection position, and reduce the risk of diaphragm damage. At the same time, the setting of the diaphragm race also plays the role of silence, vibration attenuation and improvement of resonance.

[0006] The technical scheme adopted by the present application is as follows:

[0007] The MEMS sensor comprises:

[0008] The first support seat has a back cavity;

[0009] The diaphragm race is embedded on one end side of the first support seat, and the middle part of the diaphragm race corresponds to the back cavity;

[0010] The diaphragm is embedded in the diaphragm race, and corresponds to cover the back cavity;

[0011] A second support seat having a cavity, the second support seat being arranged on one end of the first support seat provided with a diaphragm, the cavity corresponding to the diaphragm and the back cavity;

[0012] A back plate having a plurality of sound holes, the back plate being arranged on the end of the second support seat away from the first support seat, covering the cavity;

[0013] The diaphragm seat ring is made of an elastic material.

[0014] In an embodiment of the present application, the diaphragm seat ring comprises a lower seat ring and an upper seat ring which are adapted to each other; the diaphragm peripheral portion is embedded between the lower seat ring and the upper seat ring.

[0015] In an embodiment of the present application, the lower seat ring is embedded in the seat ring groove of the first support seat, the bottom of the lower seat ring is provided with a first embedded limiting portion adapted to the first support seat, and the upper portion of the lower seat ring is provided with a second embedded limiting portion adapted to the diaphragm; the upper seat ring is arranged on the lower seat ring and the diaphragm peripheral portion.

[0016] In an embodiment of the present application, the material of the diaphragm seat ring comprises one or more of silica gel, silicone, fluororubber and styrene-butadiene rubber, and the elastic modulus of the diaphragm seat ring is 0.8-2.5 MPa.

[0017] In an embodiment of the present application, a plurality of lugs are uniformly arranged in the circumferential direction of the diaphragm, and a smooth transition gap is arranged between adjacent lugs; the lower side of the lug is provided with an embedded mounting portion which is adapted to and embedded with the second embedded limiting portion; the diaphragm seat ring completely covers the gap.

[0018] In an embodiment of the present application, the second support seat is arranged on the first support seat and the diaphragm seat ring; the cavity of the second support seat has a tapered cavity portion which expands from the end close to the back plate to the end close to the diaphragm.

[0019] In an embodiment of the present application, an anti-sticking layer is arranged on the side of the diaphragm facing the back plate.

[0020] A MEMS sensor manufacturing method, comprising the following steps:

[0021] S100, forming a first support seat, the first support seat having a seat ring groove and a back cavity;

[0022] S200, forming a diaphragm seat ring, the diaphragm seat ring comprising a lower seat ring and an upper seat ring, the upper portion of the lower seat ring being provided with a second embedded limiting portion in the circumferential direction;

[0023] S300, forming a diaphragm, the diaphragm comprising a main film layer and an anti-sticking layer, the diaphragm having a lug and a notch part;

[0024] S400, forming a second support seat, the second support seat having a cavity;

[0025] S500, forming a back plate, the back plate having a sound hole.

[0026] In an embodiment of the present application, in step S100, specifically comprising:

[0027] S110, setting a first material layer as a first support seat, etching the first material layer to form the raceway groove;

[0028] S120, etching the first material layer to form the back cavity;

[0029] In step S200, specifically comprising:

[0030] S210, setting a second material layer as a lower raceway in the raceway groove, etching the second material layer to form the second embedded limiting part;

[0031] S220, setting a third material layer as an upper raceway on the first support seat, lower raceway and diaphragm, etching the third material layer to form the upper raceway outer circle contour;

[0032] S230, etching the middle part of the third material layer to form the upper raceway inner circle contour;

[0033] In step S300, specifically comprising:

[0034] S310, setting a fourth material layer as a diaphragm main film layer on the first support seat and lower raceway;

[0035] S320, setting a fifth material layer as a diaphragm anti-sticking layer on the fourth material layer;

[0036] S330, etching the fourth material layer and the fifth material layer to form the lug and the notch part;

[0037] In step S400, specifically comprising:

[0038] S410, setting a sixth material layer as a second support seat, etching the sixth material layer to form the cavity of the second support seat;

[0039] In step S500, specifically comprising:

[0040] S510, setting a seventh material layer as a back plate insulating layer on the second support seat;

[0041] S520, disposing a seventh material layer on the seventh material layer as a back plate conductive layer;

[0042] S530, etching the seventh material layer and the eighth material layer to form an acoustic hole.

[0043] In an embodiment of the present application, the method comprises steps S110, S210, S120, S310, S320, S330, S220, S410, S230, S510, S520, and S530 in sequence.

[0044] Compared with the prior art, the present application has the following beneficial effects:

[0045] The MEMS sensor and the manufacturing method thereof have the following advantages: the diaphragm is embedded and mounted through the elastic diaphragm seat ring, so that the diaphragm movement has better sensitivity and compliance, and the detection reaction is more sensitive and accurate; through the embedded mounting, the anchoring connection part of the diaphragm is cancelled, the problem of stress concentration of the diaphragm at the connection part can be effectively avoided or reduced, and the risk of diaphragm damage is reduced; at the same time, the diaphragm seat ring also plays the roles of silence, vibration attenuation, and resonance improvement; the manufacturing process is simple, and the processing cost is low.

[0046] The diaphragm is connected through the plurality of circumferentially distributed lug structures, and the smooth gap part between the lugs is used for transition, so that the diaphragm has a better stress mode, the generation of stress concentration during vibration is avoided or weakened, and the risk of diaphragm damage is further reduced.

[0047] The diaphragm is provided with an anti-sticking layer on the side facing the back plate, so that the adhesion between the diaphragm and the back plate when the diaphragm has a large vibration amplitude can be effectively avoided, the normal operation of the sensor is ensured, and a larger detection range is obtained; at the same time, the anti-sticking layer can effectively prevent the dust entering the sensor capacitor cavity through the acoustic hole from adhering to the diaphragm, so as to affect the performance of the diaphragm and cause the occurrence of detection distortion and insensitivity. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0049] Figure 1 It is a cross-sectional structure schematic diagram of the MEMS sensor of the present application.

[0050] Figure 2 It is an exploded schematic diagram of the cross-sectional structure of the MEMS sensor of the present application.

[0051] Figure 3 A bottom view schematic diagram of a diaphragm.

[0052] Figure 4 A schematic diagram of the structure of a part of the step of manufacturing a MEMS sensor Figure 1 .

[0053] Figure 5 A schematic diagram of the structure of a part of the step of manufacturing a MEMS sensor Figure 2 .

[0054] Figure 6 A flow chart of the main steps of the method of manufacturing a MEMS sensor of the present application.

[0055] Figure 7 A flow chart of the main steps of the method of manufacturing a MEMS sensor of the present application.

[0056] Figure 8 A flow chart of the main steps of the method of manufacturing a MEMS sensor of the present application.

[0057] Reference signs:

[0058] 1, first support base; 10, first material layer; 11, back cavity; 12, raceway groove;

[0059] 2, diaphragm raceway; 21, lower raceway; 210, second material layer; 211, first fitting limiting part; 212, second fitting limiting part; 22, upper raceway; 220, third material layer;

[0060] 3, diaphragm; 31, support lug; 311, fitting mounting part; 32, notch part; 33, main membrane layer; 330, fourth material layer; 34, anti-sticking layer; 340, fifth material layer;

[0061] 4, second support base; 40, sixth material layer; 41, cavity;

[0062] 5, back plate; 51, insulating layer; 510, seventh material layer; 52, conductive layer; 520, eighth material layer; 53, sound hole. DETAILED DESCRIPTION

[0063] In the following, only certain exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the drawings and the description are considered to be essentially exemplary rather than limiting.

[0064] In the description of the application, it should be understood that the terms "center", "upper", "lower", "front", "back", "top", "bottom", "inner", "outer", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0065] The terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "multiple" is two or more, and the meaning of "several" is at least one, unless otherwise explicitly specified and limited.

[0066] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0067] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or the contact of the first and second features through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include the vertical and oblique above of the first feature to the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include the vertical and oblique below of the first feature to the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0068] The following disclosure provides many different embodiments or examples for implementing different structures of the application. In order to simplify the disclosure of the application, the components and arrangements of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the application.

[0069] The embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0070] The embodiment of the present application provides a MEMS sensor and a manufacturing method thereof, which comprises a first support base 1, a diaphragm seat ring 2, a diaphragm 3, a second support base 4 and a back plate 5.

[0071] Specifically, as shown in the figure, Figures 1 to 3 The first support base 1 serves as a base, and the middle part has a back cavity 11 penetrating from top to bottom.

[0072] The diaphragm seat ring 2 is embedded in the seat ring groove 12 on one end side of the first support base 1, and the middle cavity part of the diaphragm seat ring 2 corresponds to the back cavity 11 of the first support base 1.

[0073] The diaphragm 3 is a vibrating element, and the peripheral part is embedded in the diaphragm seat ring 2 and is in sealed connection with the diaphragm seat ring 2. The diaphragm 3 corresponds to cover the back cavity 11 of the first support base 1, that is, the projection area completely covers the back cavity 11 of the first support base 1.

[0074] The second support base 4 is arranged on one end of the first support base 1 provided with the diaphragm 3, and the second support base 4 is connected with the first support base 1 and the diaphragm seat ring 2, so as to limit the diaphragm seat ring 2 between the first support base 1 and the second support base 4. The second support base 4 has a cavity 41, which corresponds to the diaphragm 3 and the back cavity 11 of the first support base 1 in position, and the projection area overlaps or partially overlaps.

[0075] The back plate 5 is arranged on the end side of the second support base 4 away from the first support base 1, and the back plate 5 completely covers the cavity 41. The back plate 5 is provided with a plurality of sound holes 53, and external sound can enter the cavity between the back plate 5 and the diaphragm 3 through the sound holes 53, so as to realize that the sound wave drives the diaphragm 3 to vibrate and displace. The back plate 5 and the diaphragm 3 form a variable capacitor, and when the diaphragm 3 displaces, the capacitance value changes correspondingly. The conductive layer 52 of the back plate 5 transmits the (changing) capacitance value to the ASIC chip in real time, and the ASIC chip converts the changing capacitance value into an electric signal, so as to realize the induction, detection and recording of sound.

[0076] Among them, the diaphragm seat ring 2 of the MEMS sensor is made of elastic material and has elastic deformation capacity. The diaphragm seat ring 2 is embedded and arranged between the first support base 1 and the second support base 4; at the same time, the peripheral part of the diaphragm 3 is connected by embedding in the diaphragm seat ring 2, so that the elastic deformation capacity of the diaphragm seat ring 2 can be fully utilized, and displacement and dislocation of the diaphragm seat ring 2 and the diaphragm 3 can be avoided.

[0077] This application, by setting a diaphragm seat ring 2 made of elastic material, makes the movement of the diaphragm 3 more sensitive and compliant, and makes the sensor's detection response more sensitive and accurate; and the diaphragm 3 and the diaphragm seat ring 2 are installed in a fitting manner, eliminating the anchoring connection of the diaphragm 3, which can effectively avoid or reduce the problem of stress concentration at the connection point of the diaphragm 3 and reduce the risk of damage to the diaphragm 3; at the same time, the setting of the diaphragm seat ring 2 also plays a role in silencing, damping vibration, and improving resonance.

[0078] In one embodiment, the diaphragm mount 2 includes a lower mount 21 and an upper mount 22 that are adapted to each other, and the periphery of the diaphragm 3 is embedded between the lower mount 21 and the upper mount 22. When the diaphragm 3 vibrates and shifts under the action of sound waves, its periphery can pull the diaphragm mount 2 to make a slight deformation, so as to release the stress at the connection part and play a buffering role.

[0079] like Figure 1 and Figure 2 As shown, a seat ring groove 12 is provided circumferentially on the upper end face of the first support base 1 near the back cavity 11. The lower seat ring 21 is fitted into the seat ring groove 12 and is flush with the upper end face of the first support base 1. The bottom of the lower seat ring 21 is provided with a first fitting limiting part 211 that fits into the seat ring groove 12 of the first support base 1. Preferably, the first fitting limiting part 211 is located near the inner side of the bottom of the lower seat ring 21 and is a concave part. Correspondingly, the seat ring groove 12 is provided with a matching protrusion. By fitting together, the lower seat ring 21 can be limited, and mainly the displacement of the lower seat ring 21 towards the center can be restricted, which can effectively prevent the lower seat ring 21 from falling out when the diaphragm 3 vibrates too much. Preferably, the inner wall of the lower seat ring 21 is flush with the side wall of the back cavity 11 of the first support seat 1, or extends partially into the back cavity 11, that is, the lower side of the diaphragm 3 is only in contact with the lower seat ring 21 and does not directly make hard contact with the first support seat 1.

[0080] The lower retaining ring 21 has a second fitting and limiting part 212 on its upper part, which is adapted to the periphery of the diaphragm 3. Preferably, the second fitting and limiting part 212 is a concave part, which fits into the protrusion provided on the periphery of the diaphragm 3. The upper retaining ring 22 is covered on the periphery of the lower retaining ring 21 and the diaphragm 3. The upper retaining ring 22 and the lower retaining ring 21 cooperate to limit the connection of the periphery of the diaphragm 3. The second fitting and limiting part 212 fits into the diaphragm 3, and the upper retaining ring 22 covers and presses against the periphery of the diaphragm 3 and the lower retaining ring 21, thereby limiting the diaphragm 3 and preventing it from coming off during vibration. At the same time, it can also make the diaphragm 3 adapt to elastic buffering when subjected to vibration force, avoiding problems such as emergency concentration.

[0081] Optionally, the material of the diaphragm seat ring 2 comprises one or more of a combination of silica gel, silicone, fluororubber, and styrene-butadiene rubber, and the diaphragm seat ring 2 has support and elastic deformation capabilities. Preferably, the elastic modulus of the material used to manufacture the diaphragm seat ring 2 is controlled to be within the range of 0.8-2.5 MPa; more preferably, a material with an elastic modulus of 1.2-1.5 MPa is selected to manufacture the diaphragm seat ring 2. This ensures that the diaphragm seat ring 2 has good support capability, as well as good elastic deformation and buffering capability, thereby ensuring stable installation and reliable operation of the diaphragm 3.

[0082] As shown in Figure 2 and Figure 3 , the diaphragm 3 is a circular structure, and a plurality of lugs 31 are uniformly distributed in the circumferential direction, preferably two-by-two symmetrically arranged. The lower side of each lug 31 is provided with a protruding fitting installation part 311, which is adapted to fit with the second fitting limiting part 212 on the upper part of the lower seat ring 21. The gap part 32 between adjacent lugs 31 is smoothly transitioned. The setting of the lugs 31 and the smoothly transitioned gap part 32 makes the stress on the periphery of the diaphragm 3 more uniform, and the tension between adjacent lugs 31 is good, and the periphery is not prone to deformation and damage (stress concentration).

[0083] The periphery of the diaphragm 3 is installed in the diaphragm seat ring 2, and the diaphragm seat ring 2 completely covers the gap part 32 of the periphery of the diaphragm 3 and leaves a deformation allowance, ensuring that the diaphragm 3 and the diaphragm seat ring 2 are in sealed connection, and the problem of seal failure will not occur when the diaphragm 3 vibrates.

[0084] In one embodiment, as shown in Figure 1 , Figure 2 and Figure 5 , the second support seat 4 is arranged on the first support seat 1 and the diaphragm seat ring 2, and the second support seat 4, the diaphragm 3, and the back plate 5 form a capacitor cavity. The cavity 41 of the second support seat 4 has a tapered cavity part, which is a conical cavity, and expands from the end close to the back plate 5 to the end close to the diaphragm 3 / upper seat ring 22. The setting of the tapered cavity part makes the sound waves more concentrated on the diaphragm 3, reduces sound wave loss, and makes the sensor detection more sensitive.

[0085] In one embodiment, as shown in Figure 1 , Figure 2 , Figure 4 and Figure 5As shown, the diaphragm 3 includes a main film layer 33 and an anti-sticking layer 34 located on the side of the diaphragm 3 facing the back plate 5. Optionally, the anti-sticking layer 34 is made of polytetrafluoroethylene and / or polyperfluoroethylene material. By providing the anti-sticking layer 34 on the diaphragm 3, it can effectively prevent the diaphragm 3 from sticking to the back plate 5 when the vibration amplitude of the diaphragm 3 is large, ensure the normal operation of the sensor, and the sensor has a larger detection range (range of capacitance value change); at the same time, the anti-sticking layer 34 can effectively prevent the dust entering the sensor capacitor cavity through the sound hole 53 from adhering to the diaphragm 3, affecting the performance of the diaphragm 3, causing detection distortion and insensitivity, etc.

[0086] Based on the same inventive purpose, the embodiment of the present application also provides a MEMS sensor manufacturing method for preparing the above-mentioned MEMS sensor. As shown in the figure, the manufacturing method comprises the following steps: Figures 4 to 8

[0087] S100, forming a first support seat 1, the first support seat 1 has a back cavity 11 penetrating up and down in the middle, and has a seat groove 12 provided with a diaphragm seat ring 2 at the upper end.

[0088] S200, forming a diaphragm seat ring 2, the diaphragm seat ring 2 includes a lower seat ring 21 and an upper seat ring 22 matched with each other, and the lower seat ring 21 is provided with a second fitting limiting part 212 matched with the diaphragm 3 fitting installation part 311 in the upper circumferential direction.

[0089] S300, forming a diaphragm 3, the diaphragm 3 includes a main film layer 33 and an anti-sticking layer 34, that is, including forming a main film layer 33 and an anti-sticking layer 34.

[0090] S400, forming a second support seat 4, the second support seat 4 has a cavity 41 penetrating up and down in the middle.

[0091] S500, forming a back plate 5, the back plate 5 includes an insulating layer 51 and a conductive layer 52, and has a plurality of sound holes 53 penetrating up and down, that is, including forming a plurality of sound holes 53 on the back plate 5.

[0092] Further, in step S100, when forming the first support seat 1, specifically comprising:

[0093] S110, setting a first material layer 10 as the first support seat 1, and etching the first material layer 10 to form a seat groove 12 for installing the lower seat ring 21.

[0094] S120, etching the middle part of the first material layer 10 to form a back cavity 11.

[0095] In step S200, when forming the diaphragm seat ring 2, specifically comprising:

[0096] ​S210, a second material layer 210 as the lower gasket 21 is arranged in the gasket groove 12 formed in step S110, and the second material layer 210 is etched to be flush with the upper end surface of the first support seat 1 and to form a second recessed fitting limiting part 212 on the upper side, which is adapted to the fitting mounting part 311 of the diaphragm 3. That is, the second fitting limiting part 212 is arranged in a circumferential direction at intervals and in uniform distribution, and the number of the second fitting limiting part 212 is consistent with the number of the lug 31 and the fitting mounting part 311 of the diaphragm 3. The second fitting limiting part 212 can limit the displacement of the diaphragm 3 in the radial direction and the circumferential direction.

[0097] S220, a third material layer 220 as the upper gasket 22 is arranged on the first support seat 1, the lower gasket 21 and the diaphragm 3, and then the periphery of the third material layer 220 is etched to form the outer gasket contour of the upper gasket 22. The processing of step S220 is performed after the diaphragm 3 is formed in step S300. The second material layer 210 and the third material layer 220 are preferably made of the same elastic material.

[0098] S230, then the middle part of the third material layer 220 is etched to form the inner gasket contour of the upper gasket 22.

[0099] In step S300, the diaphragm 3 is formed, specifically including:

[0100] S310, a fourth material layer 330 as the main membrane layer 33 of the diaphragm 3 is arranged on the first support seat 1 and the lower gasket 21.

[0101] S320, a fifth material layer 340 as the anti-sticking layer 34 is further arranged on the fourth material layer 330.

[0102] S330, the fourth material layer 330 and the fifth material layer 340 are etched to form the lug 31 and the notch part 32, and finally form the diaphragm 3.

[0103] In step S400, the second support seat 4 is formed, specifically including:

[0104] S410, a sixth material layer 40 as the second support seat 4 is arranged on the first support seat 1, the upper gasket 22 / third material layer 220, and the sixth material layer 40 is etched to form the cavity 41 of the second support seat 4, including forming the tapered cavity part in the cavity 41. Preferably, the etching processing of step S410 is performed synchronously with the etching processing of the middle part of the third material layer 220 in step S230, that is, after the cavity 41 of the second support seat 4 is etched, the etching of the third material layer 220 to form the inner gasket contour of the upper gasket 22 is continued.

[0105] The sixth material layer 40 and the first material layer 10 are made of the same material, which can be silicon oxide, silicon nitride, etc.

[0106] In step S500, forming the back plate 5 specifically includes:

[0107] S510, setting a seventh material layer 510 as an insulating layer 51 of the back plate 5 on the second support base 4.

[0108] S520, setting an eighth material layer 520 as a conductive layer 52 of the back plate 5 on the seventh material layer 510.

[0109] S530, etching the seventh material layer 510 and the eighth material layer 520 to form a plurality of sound holes 53, thereby completing the processing of the back plate 5.

[0110] The seventh material layer 510 is made of a material such as silicon nitride; the eighth material layer 520 and the fourth material layer 330 are made of the same material, which can be polysilicon or the like.

[0111] In one embodiment, as shown in Figure 4 、 Figure 5 and Figure 8 , the MEMS sensor manufacturing method includes the following steps performed in sequence:

[0112] S110, setting a first material layer 10 as a first support base 1, and etching the first material layer 10 to form a seat groove 12 for mounting a lower seat ring 21.

[0113] S210, setting an annular second material layer 210 as the lower seat ring 21 in the seat groove 12 formed in step S110, and etching and processing the second material layer to be flush with the upper end surface of the first support base 1, and forming an inwardly recessed second fitting limiting portion 212 on the upper side, which is adapted to the fitting mounting portion 311 of the diaphragm 3.

[0114] S120, after forming the lower seat ring 21, etching and processing the middle part of the first material layer 10 to form a back cavity 11.

[0115] S310, setting a fourth material layer 330 as a main membrane layer 33 of the diaphragm 3 on the first support base 1 and the lower seat ring 21.

[0116] S320, further setting a fifth material layer 340 as an anti-sticking layer 34 on the fourth material layer 330.

[0117] S330, etching the fourth material layer 330 and the fifth material layer 340 to form a lug 31 and a notch portion 32, and finally forming the diaphragm 3.

[0118] S220, setting a third material layer 220 as an upper seat ring 22 on the first support base 1, the lower seat ring 21 and the diaphragm 3, and then etching the peripheral part of the third material layer 220 to form the outer ring contour of the upper seat ring 22.

[0119] S410, a sixth material layer 40 as the second support seat 4 is arranged on the first support seat 1, the upper seat ring 22 / the third material layer 220, and the sixth material layer 40 is etched to form the cavity 41 of the second support seat 4, including forming the tapered cavity part in the cavity 41.

[0120] S230, then etching the middle part of the third material layer 220 to form the inner ring contour of the upper seat ring 22.

[0121] S510, a seventh material layer 510 as the insulating layer 51 of the back plate 5 is arranged on the second support seat 4.

[0122] S520, an eighth material layer 520 as the conductive layer 52 of the back plate 5 is arranged on the seventh material layer 510.

[0123] S530, the seventh material layer 510 and the eighth material layer 520 are etched to form a plurality of sound holes 53, thereby completing the processing of the back plate 5.

[0124] The MEMS sensor has simple structure and reasonable arrangement, the manufacturing method has simple process and low processing difficulty, and the cost is low.

Claims

1. A MEMS sensor, characterized by The MEMS sensor comprises: a first support seat having a back cavity; a diaphragm seat ring embedded on one end side of the first support seat, a middle part of the diaphragm seat ring corresponding to the back cavity; a diaphragm embedded in the diaphragm seat ring, a periphery of the diaphragm corresponding to cover the back cavity; a second support seat having a cavity, the second support seat being arranged on one end of the first support seat provided with the diaphragm, the cavity corresponding to the diaphragm and the back cavity; a back plate provided with a plurality of sound holes, the back plate being arranged on one end side of the second support seat away from the first support seat, covering the cavity; wherein the diaphragm seat ring is made of an elastic material; the diaphragm seat ring comprises a matched lower seat ring and an upper seat ring; the periphery of the diaphragm is embedded between the lower seat ring and the upper seat ring; the lower seat ring is embedded in the seat ring groove of the first support seat, the bottom of the lower seat ring is provided with a first embedded limiting part matched with the first support seat, and the upper part of the lower seat ring is provided with a second embedded limiting part matched with the diaphragm; the upper seat ring is arranged on the lower seat ring and the periphery of the diaphragm; a plurality of lugs are uniformly arranged on the periphery of the diaphragm, and a smooth gap part is arranged between adjacent lugs; an embedded mounting part is arranged on the lower side of the lug, and the embedded mounting part is matched with the second embedded limiting part; the diaphragm seat ring completely covers the gap part.

2. The MEMS sensor of claim 1, wherein, The material of the diaphragm seat ring comprises one or more of silica gel, silicone, fluororubber and styrene-butadiene rubber, and the elastic modulus of the diaphragm seat ring is 0.8-2.5 MPa.

3. The MEMS sensor of claim 1, wherein, The second support seat is arranged on the first support seat and the diaphragm seat ring; the cavity of the second support seat has a tapered cavity part which expands from the back plate end to the diaphragm end.

4. The MEMS sensor of claim 1, wherein, An anti-sticking layer is arranged on the side of the diaphragm facing the back plate.

5. A method of manufacturing a MEMS sensor, characterized by The MEMS sensor is the MEMS sensor according to any one of claims 1 to 4, comprising the following steps: S100, forming a first support seat, the first support seat having a seat ring groove and a back cavity; S200, forming a diaphragm seat ring, the diaphragm seat ring comprising a lower seat ring and an upper seat ring, and the upper part of the lower seat ring being provided with a second embedded limiting part in the periphery; S300, forming a diaphragm, the diaphragm comprising a main film layer and an anti-sticking layer, and the diaphragm having a lug and a gap part; S400, forming a second support seat, the second support seat having a cavity; S500, forming a back plate, the back plate having sound holes.

6. The MEMS sensor manufacturing method according to claim 5, wherein: in step S100, specifically comprising: S110, arranging a first material layer as the first support seat, and etching the first material layer to form the seat ring groove; S120, etching the first material layer to form the back cavity; in step S200, specifically comprising: S210, arranging a second material layer as the lower seat ring in the seat ring groove, and etching the second material layer to form the second embedded limiting part; S220, arranging a third material layer as the upper seat ring on the first support seat, the lower seat ring and the diaphragm, and etching the periphery of the third material layer to form the outer ring contour of the upper seat ring; S230, etching the middle part of the third material layer to form the inner ring contour of the upper seat ring; In step S300, specifically comprising: S310, setting a fourth material layer as a main diaphragm layer on the first support seat and the lower seat ring; S320, setting a fifth material layer as an anti-sticking layer on the fourth material layer; S330, etching the fourth material layer and the fifth material layer to form a lug and a notch part; In step S400, specifically comprising: S410, setting a sixth material layer as a second support seat, and etching the sixth material layer to form a cavity of the second support seat; In step S500, specifically comprising: S510, setting a seventh material layer as an insulating layer of the back plate on the second support seat; S520, setting an eighth material layer as a conductive layer of the back plate on the seventh material layer; S530, etching the seventh material layer and the eighth material layer to form a sound hole.

7. The MEMS sensor manufacturing method of claim 6, wherein, The method comprises steps S110, S210, S120, S310, S320, S330, S220, S410, S230, S510, S520, and S530 performed in sequence.

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