Vibration unit, bone voiceprint sensor and manufacturing method

Abstract

The invention discloses a vibration unit, a bone voiceprint sensor and a manufacturing method, and belongs to the technical field of acoustic sensing. The vibration unit comprises a first vibrating diaphragm, a mass block and a first supporting structure; the mass block is positioned on one side of the first vibrating diaphragm; the first supporting structure is located on the side, away from the mass block, of the first vibrating diaphragm, the first supporting structure is annular, and the orthographic projection of the mass block on the plane where the first vibrating diaphragm is located is located in an area defined by the orthographic projection of the first supporting structure on the plane where the first vibrating diaphragm is located; wherein the first vibrating diaphragm, the mass block and the first supporting structure are of an integrally-formed structure, the vibrating unit is provided with an air leakage hole penetrating through the mass block and the first vibrating diaphragm, and the air leakage hole is communicated with a space defined by the first supporting structure. The vibration unit is formed through an integrated process, the first vibrating diaphragm, the mass block and the first supporting structure of the vibration unit are of an integrated structure, and higher precision and consistency are achieved.

Description

Technical Field

[0001] The present application relates to the field of acoustic sensing technology, and in particular to a vibration unit, a bone voiceprint sensor and a manufacturing method. Background Art

[0002] Bone voiceprint sensor is a type of sensor that uses the principle of sound wave transmission through human bone vibration, and converts the vibration signal generated by sound wave into electrical signal through the chip inside the sensor. It transmits sound through bones and does not rely on sound waves in the air, so the interference of environmental noise on voice capture is greatly reduced.

[0003] Among them, the vibration unit is a component in the bone voiceprint sensor used to pick up human body sound vibrations. At present, the existing vibration unit generally includes a support block, a diaphragm and a mass block, and the above-mentioned support block, diaphragm and mass block are all independent materials. The manufacture of the vibration unit requires the support block and the mass block to be bonded to the diaphragm. During the manufacturing process, there are at least the following problems: 1. The position accuracy of the mass block bonded to the diaphragm is low, which makes it difficult to align the through holes of the mass block and the through holes of the diaphragm; 2. The adhesive easily blocks the through holes of the mass block and the diaphragm; 3. The position accuracy of the support block bonded to the diaphragm is low.

[0004] Therefore, the existing vibration units have problems of low manufacturing precision and poor consistency, which leads to poor accuracy of the bone voiceprint sensor. Summary of the invention

[0005] The embodiment of the present application provides a vibration unit, a bone voiceprint sensor and a manufacturing method. The problem of low accuracy of the vibration unit in the prior art can be solved. The technical solution is as follows:

[0006] In one aspect, a vibration unit is provided, comprising: a first diaphragm, a mass block, and a first supporting structure;

[0007] The mass block is located on one side of the first diaphragm;

[0008] The first supporting structure is located on a side of the first diaphragm away from the mass block, the first supporting structure is annular, and an orthographic projection of the mass block on the plane where the first diaphragm is located is located within a region enclosed by an orthographic projection of the first supporting structure on the plane where the first diaphragm is located;

[0009] The first diaphragm, the mass block and the first supporting structure are an integrally formed structure, and the vibration unit has an air leakage hole penetrating the mass block and the first diaphragm, and the air leakage hole is connected to the space surrounded by the first supporting structure.

[0010] Optionally, the air leakage hole includes: a first sub-air hole penetrating the mass block, and a second sub-air hole penetrating the first diaphragm;

[0011] One end of the second sub-air hole is connected to the first sub-air hole, and the other end is connected to the space surrounded by the first supporting structure;

[0012] The boundary of the orthographic projection of the first sub-aperture on the plane where the first diaphragm is located coincides with the boundary of the orthographic projection of the second sub-aperture on the plane where the first diaphragm is located.

[0013] Optionally, the vibration unit further includes: a weight layer connected to a side of the mass block away from the first diaphragm;

[0014] Wherein, at least a portion of an orthographic projection of the weight layer on the plane where the first diaphragm is located does not overlap with an orthographic projection of the air leakage hole on the plane where the first diaphragm is located.

[0015] Optionally, the density of the counterweight layer is greater than the density of the mass block.

[0016] Optionally, the counterweight layer includes: a metal electroplating layer formed by an electroplating process.

[0017] Optionally, the weight layer has a through hole, and an orthographic projection of the through hole on the plane where the first diaphragm is located overlaps with an orthographic projection of the air leakage hole on the plane where the first diaphragm is located.

[0018] Optionally, the vibration unit further includes: a second supporting structure, the second supporting structure is located on a side of the first diaphragm facing the first supporting structure and is distributed in a space surrounded by the first supporting structure;

[0019] The orthographic projection of the second supporting structure on the plane where the first diaphragm is located is located within the orthographic projection of the mass block on the plane where the first diaphragm is located, and the orthographic projection of the second supporting structure on the plane where the first diaphragm is located does not overlap with the orthographic projection of the bleed hole on the plane where the first diaphragm is located;

[0020] Wherein, the first diaphragm, the mass block, the first supporting structure and the second supporting structure are an integrally formed structure.

[0021] Optionally, a distance between the first diaphragm and a side of the second supporting structure facing away from the first diaphragm is smaller than a distance between the first diaphragm and a side of the first supporting structure facing away from the first diaphragm.

[0022] On the other hand, a bone voiceprint sensor is provided, comprising: a protective shell, a microphone assembly and a vibration unit, wherein the vibration unit is any of the vibration units described above;

[0023] The protective case forms a receiving cavity and is fixed on the microphone assembly;

[0024] The vibration unit is located in the receiving cavity and is fixed on the microphone assembly.

[0025] In another aspect, a manufacturing method of a vibration unit is provided, including:

[0026] Providing a substrate having a first surface and a second surface disposed opposite to each other;

[0027] Performing a patterning process on the first surface of the substrate to form a first support structure;

[0028] Performing a patterning process on the second surface of the substrate to form a mass block and a first diaphragm, and a vent hole penetrating the mass block and the first diaphragm;

[0029] Wherein, the first support structure is annular, and the orthographic projection of the mass block on the plane where the first diaphragm is located is within the region surrounded by the orthographic projection of the first support structure on the plane where the first diaphragm is located; the vent hole communicates with the space surrounded by the first support structure.

[0030] Optionally, after performing the patterning process on the second surface of the substrate, it further includes:

[0031] Forming a counterweight layer on the side of the mass block facing away from the first diaphragm;

[0032] Wherein, the orthographic projection of the counterweight layer on the plane where the first diaphragm is located does not overlap with the orthographic projection of the vent hole on the plane where the first diaphragm is located.

[0033] Optionally, forming a counterweight layer on the side of the mass block facing away from the first diaphragm includes:

[0034] Adopting an electroplating process to form a metal electroplating layer on the side of the mass block facing away from the first diaphragm, and the counterweight layer includes the metal electroplating layer;

[0035] Wherein, the density of the counterweight layer is greater than the density of the mass block.

[0036] Optionally, performing a patterning process on the first surface of the substrate to form a first support structure includes:

[0037] Performing a patterning process on the first surface of the substrate to form a second support structure and the first support structure;

[0038] Wherein, the second support structure is distributed in the space surrounded by the first support structure;

[0039] The positive projection of the second support structure on the plane where the first diaphragm is located is located within the positive projection of the mass block on the plane where the first diaphragm is located, and the positive projection of the second support structure on the plane where the first diaphragm is located does not coincide with the positive projection of the air vent hole on the plane where the first diaphragm is located.

[0040] Optionally, patterning the first surface of the substrate to form the second support structure and the first support structure includes:

[0041] Forming a first photoresist pattern on the first surface of the substrate;

[0042] Performing a first etching process on the area of the first surface of the substrate that is not covered by the first photoresist pattern to form a first cavity on the first surface of the substrate;

[0043] Removing the first photoresist pattern and forming a second photoresist pattern on the first surface of the substrate; the positive projection of the first cavity on the second surface of the substrate is located within the positive projection of the second photoresist pattern on the second surface of the substrate;

[0044] Performing a second etching process on the area of the second surface of the substrate that is not covered by the second photoresist pattern to form a second cavity on the first surface of the substrate; the depth of the second cavity is greater than the depth of the first cavity;

[0045] After removing the second photoresist pattern, the second support structure and the first support structure are obtained;

[0046] Wherein, the distance between the side of the second support structure facing away from the first diaphragm and the first diaphragm is less than the distance between the side of the first support structure facing away from the first diaphragm and the first diaphragm.

[0047] Optionally, patterning the second surface of the substrate to form the mass block, the first diaphragm, and the air vent hole penetrating the mass block and the first diaphragm includes:

[0048] Forming a third photoresist pattern on the second surface of the substrate; wherein, the third photoresist pattern has a first photoresist area, a second photoresist area, and a photoresist completely removed area, the thickness of the photoresist in the first photoresist area is greater than the thickness of the photoresist in the second photoresist area, and there is no photoresist in the photoresist completely removed area;

[0049] Performing a third etching process on the area of the second surface of the substrate located in the photoresist completely removed area to form the air vent hole penetrating the substrate on the second surface of the substrate;

[0050] Remove the photoresist in the second photoresist region, and perform a fourth etching process on the region of the second surface of the substrate located in the second photoresist region to form a third cavity on the second surface of the substrate;

[0051] After removing the third photoresist pattern, the mass block and the first diaphragm are obtained.

[0052] The beneficial effects brought by the technical solution provided by the embodiments of the present application are:

[0053] The vibration unit is formed by an integrated process. The first diaphragm, the mass block, and the first support structure of the vibration unit are an integrally formed structure, and the air vent holes penetrate through the mass block and the first diaphragm at the same time. Since the first diaphragm, the mass block, and the first support structure are an integrally formed structure, it is not necessary to bond the mass block to the first diaphragm with an adhesive, nor is it necessary to bond the first diaphragm to the first support structure with an adhesive. Therefore, the mass block will not tilt relative to the first diaphragm, the through holes on the mass block are aligned with the through holes on the first diaphragm, and the relative position accuracy between the first support structure and the first diaphragm is high. In the case where the above vibration unit is manufactured by a semiconductor process, multiple vibration units can be synchronously processed and formed from the same semiconductor substrate, and the consistency between multiple vibration units is high. Description of the Drawings

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0055] Figure 1 It is a schematic structural diagram of a vibration unit;

[0056] Figure 2 It is a schematic structural diagram of the vibration unit provided by the embodiments of the present application;

[0057] Figure 3 It is another schematic structural diagram of the vibration unit provided by the embodiments of the present application;

[0058] Figure 4 For Figure 3 It is a schematic cross-sectional view of the vibration unit shown at A-A';

[0059] Figure 5 For Figure 3 It is another schematic cross-sectional view of the vibration unit shown at A-A';

[0060] Figure 6 It is a schematic structural diagram of the vibration unit provided by another embodiment of the present application;

[0061] Figure 7 is Figure 6 a schematic cross-sectional view of the shown vibration unit at B-B';

[0062] Figure 8 a schematic structural view of a vibration unit provided by another embodiment of the present application;

[0063] Figure 9 a schematic structural view of a vibration unit provided by still another embodiment of the present application;

[0064] Figure 10 a schematic structural view of a bone voiceprint sensor provided by an embodiment of the present application;

[0065] Figure 11 a schematic flowchart of a manufacturing method of a vibration unit provided by an embodiment of the present application;

[0066] Figure 12 a schematic flowchart of a manufacturing method of a vibration unit provided by another embodiment of the present application;

[0067] Figure 13 a schematic process view of a manufacturing method of a vibration unit provided by another embodiment of the present application. Detailed implementation manners

[0068] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0069] Please refer to Figure 1 , Figure 1 which is a schematic structural view of a vibration unit. The current vibration unit 00 includes: a support block 01, a diaphragm 02, and a mass block 03. Among them, the material of the support block 01 can be a metal material, usually nickel silver. The material of the diaphragm 02 can be an organic material, generally polyimide. The material of the mass block 03 can be a metal material, generally nickel silver material.

[0070] The manufacturing process steps of a current vibration unit 00 can include:

[0071] 1. Coat an adhesive layer 04 on the support block 01 or the diaphragm 02.

[0072] 2. Punch holes in the diaphragm 02 by stamping to obtain a first through hole 02a.

[0073] 3. Bond the diaphragm 02 to the support block 01.

[0074] 4. Coat an adhesive layer 05 on the diaphragm 02 or the mass block 03.

[0075] 5. Glue the mass block 03 onto the diaphragm 02.

[0076] During the manufacturing process, at least the following problems exist: 1. The positional accuracy of the mass block 03 bonded to the diaphragm 02 is low, which makes it difficult to align the second through hole 03a of the mass block 03 with the first through hole 02a of the first diaphragm 02. 2. The adhesive easily blocks the through holes of the mass block 03 and the diaphragm 02. 3. The positional accuracy of the support block 01 bonded to the diaphragm 02 is low. 4. The amount of adhesive is difficult to control, resulting in overflow. 5. The mass block 03 is tilted relative to the diaphragm 02 after bonding. 6. The consistency between multiple vibration units 00 is poor.

[0077] The present application embodiment provides a vibration unit, please refer to Figures 2 to 4 , Figure 2 This is a schematic diagram of the structure of the vibration unit provided in the embodiment of the present application. Figure 3 Another structural schematic diagram of the vibration unit provided in the embodiment of the present application is shown in FIG. Figure 4 for Figure 3 The vibration unit 000 is a schematic cross-sectional view taken at AA′. The vibration unit 000 may include: a first diaphragm 010 , a mass block 030 , and a first support structure 020 .

[0078] The mass block 030 is located on one side of the first diaphragm 010 .

[0079] The first support structure 020 is located on the side of the first diaphragm 010 away from the mass block 030 . The first support structure 020 is annular, and the orthographic projection of the mass block 030 on the plane where the first diaphragm 010 is located is located in the area enclosed by the orthographic projection of the first support structure 020 on the plane where the first diaphragm 010 is located.

[0080] The first diaphragm 010, the mass block 030 and the first support structure 020 are an integrally formed structure, and the vibration unit 000 has an air leakage hole 040 penetrating the mass block 030 and the first diaphragm 010, and the air leakage hole 040 is connected to the space surrounded by the first support structure 020. The plane where the first diaphragm 010 is located is a plane parallel to the first diaphragm 010.

[0081] In an embodiment of the present application, the first diaphragm 010, the mass block 030, and the first support structure 020 are integrally formed structures, which can be formed by processes such as semiconductor processes, injection molding processes, and machining processes that can be realized, and a vibration unit 000 with high precision and good consistency can be obtained. The vent hole 040 penetrates through the mass block 030 and the first diaphragm 010 at the same time. Since the first diaphragm 010, the mass block 030, and the first support structure 020 are integrally formed structures, it is not necessary to bond the mass block 030 to the first diaphragm 010 with an adhesive, nor is it necessary to bond the first diaphragm 010 to the first support structure 020 with an adhesive. In this way, the mass block 030 will not tilt or shift in position relative to the first diaphragm 010, the through holes on the mass block 030 are aligned with the through holes on the first diaphragm 010, and the relative position accuracy between the first support structure 020 and the first diaphragm 010 is high. When the above vibration unit 000 is manufactured by a semiconductor process, multiple vibration units 000 can be formed synchronously by the same semiconductor substrate, and the consistency between multiple vibration units 000 is high.

[0082] In a possible implementation manner, please refer to Figure 5 , Figure 5 which is Figure 3 another cross-sectional schematic view of the vibration unit shown at A-A'. The vent hole 040 may include: a first sub-vent hole 040a penetrating through the mass block 030, and a second sub-vent hole 040b penetrating through the first diaphragm 010.

[0083] One end of the second sub-vent hole 040b is communicated with the first sub-vent hole 040a, and the other end is communicated with the space surrounded by the first support structure 020.

[0084] Wherein, the boundary of the orthographic projection of the first sub-vent hole 040a on the plane where the first diaphragm 010 is located coincides with the boundary of the orthographic projection of the second sub-vent hole 040b on the plane where the first diaphragm 010 is located. Alternatively, the boundary of the orthographic projection of the first sub-vent hole 040a on the plane where the first diaphragm 010 is located overlaps with the boundary of the orthographic projection of the second sub-vent hole 040b on the plane where the first diaphragm 010 is located.

[0085] The above first sub-vent hole 040a and second sub-vent hole 040b can be formed step by step. During the process of machining the mass block 030, the first sub-vent hole 040a is formed synchronously. After the machining of the mass block 030 is completed, the second sub-vent hole 040b is formed. Of course, the above first sub-vent hole 040a and second sub-vent hole 040b can be formed in the same processing step. For example, after machining the mass block 030, patterning treatment is performed on the side of the mass block 030 facing away from the first diaphragm 010 to form the first sub-vent hole 040a penetrating through the mass block 030 and the second sub-vent hole 040b penetrating through the first diaphragm 010.

[0086] In a possible implementation, please refer to Figures 6 to 7 , Figure 6 which is a schematic structural diagram of a vibration unit provided in another embodiment of the present application, Figure 7 and Figure 6 is a schematic cross-sectional view of the vibration unit shown at B-B'; the vibration unit 000 may further include: a counterweight layer 050 connected to the side of the mass block 030 facing away from the first diaphragm 010.

[0087] Wherein, at least a part of the orthographic projection of the counterweight layer 050 on the plane where the first diaphragm 010 is located does not overlap with the orthographic projection of the air vent 040 on the plane where the first diaphragm 010 is located.

[0088] Exemplarily, a general semiconductor substrate has a fixed thickness. When the thickness of the semiconductor substrate is relatively thin, the thickness of the mass block 030 will also be relatively thin, and at this time, the weight of the mass block 030 is relatively light. Since the mass of the mass block 030 affects the vibration characteristics of the vibration unit 000. A heavier mass block 030 can increase inertia, making the vibration unit 000 more sensitive to low-frequency vibrations. This is very important for capturing low-frequency sound or vibration signals. Therefore, in the embodiments of the present application, the mass of the mass block of the vibration unit 000 can be increased by adding the counterweight layer 050. At this time, the mass block 030 and the counterweight layer 050 together serve as the actual mass block of the vibration unit 000.

[0089] And during the formation of the counterweight layer 050, it is necessary to ensure that the counterweight layer 050 does not block the air vent 040. Therefore, at least a part of the orthographic projection of the counterweight layer 050 on the plane where the first diaphragm 010 is located does not overlap with the orthographic projection of the air vent 040 on the plane where the first diaphragm 010 is located. For example, the orthographic projection of the counterweight layer 050 on the plane where the first diaphragm 010 is located does not overlap with the orthographic projection of the air vent 040 on the plane where the first diaphragm 010 is located.

[0090] In some embodiments, since the vibration unit 000 needs to be assembled into a bone voiceprint sensor later, and currently there are requirements for miniaturization of the bone voiceprint sensor, the volume of the accommodation cavity formed by the protective shell is limited. Therefore, the thickness of the counterweight layer 050 cannot be too thick. Therefore, in the embodiments of the present application, the density of the counterweight layer 050 is greater than the density of the mass block 030. In this way, the thickness of the counterweight layer 050 can be controlled to be relatively thin.

[0091] Exemplarily, the counterweight layer 050 may include: a metal plating layer formed by an electroplating process.

[0092] For example, a silicon wafer is used as a substrate, and the mass block 030, the first diaphragm 010, and the first support structure 020 are integrally formed by semiconductor processes. Based on this, the counterweight layer 050 can be formed of a metal material with a density greater than that of silicon, such as copper or titanium. For example, a metal electroplated layer is formed by an electroplating process, or a metal thin film layer is formed by a thin film process such as sputtering. The counterweight layer 050 may include the above-mentioned metal electroplated layer or metal thin film layer.

[0093] In the embodiment of the present application, the counterweight layer 050 includes a metal electroplated layer formed by an electroplating process. In this way, the orthographic projection of the counterweight layer 050 on the plane where the first diaphragm 010 is located overlaps with the orthographic projection of the mass block 030 on the plane where the first diaphragm 010 is located. At this time, the center of gravity of the actual mass block formed by the counterweight layer 050 and the mass block 030 will not shift. The shift of the center of gravity of the actual mass block may cause the vibration distribution on the first diaphragm 010 to be uneven, making the bone voiceprint sensor 1000 respond inconsistently to vibration signals in different directions. This will reduce the overall sensitivity and accuracy of the sensor, and the metal electroplated layer formed by the electroplating process can overcome the above problems.

[0094] In a possible implementation, please refer to Figure 7 , the counterweight layer 050 has a through hole 051, and the orthographic projection of the through hole 051 on the plane where the first diaphragm 010 is located intersects with the orthographic projection of the air vent hole 040 on the plane where the first diaphragm 010 is located, that is, the through hole 051 communicates with the air vent hole 040.

[0095] Since the aperture of the through hole 051 provided on the counterweight layer 050 does not need to be the same as the aperture of the air vent hole 040, the aperture of the through hole 051 can be larger than the aperture of the air vent hole 040. When the counterweight layer 050 includes a metal electroplated layer, the metal electroplated layer will partially form on the inner wall of the air vent hole 040. By controlling the size relationship between the metal electroplated layer and the aperture of the air vent hole 040, the problem of the metal electroplated layer blocking the air vent hole 040 can be avoided.

[0096] In a possible implementation, please refer to Figures 7 to 9 , Figure 8 is a schematic structural diagram of a vibration unit provided in another embodiment of the present application. Figure 9 is a schematic structural diagram of a vibration unit provided in still another embodiment of the present application. The vibration unit 000 may further include: a second support structure 060, and the second support structure 060 is located on the side of the first diaphragm 010 facing the first support structure 020 and is distributed in the space surrounded by the first support structure 020.

[0097] The orthographic projection of the second support structure 060 on the plane where the first diaphragm 010 is located is located within the orthographic projection of the mass block 030 on the plane where the first diaphragm 010 is located, and the orthographic projection of the second support structure 060 on the plane where the first diaphragm 010 is located does not coincide with the orthographic projection of the air vent 040 on the plane where the first diaphragm 010 is located.

[0098] Among them, the first diaphragm 010, the mass block 030, the first support structure 020, and the second support structure 060 are integrally formed structures.

[0099] In the embodiment of the present application, the second support structure 060 can be arranged on the side of the first diaphragm 010 facing away from the mass block 030. The second support structure 060 can limit the space for relative movement between the mass block 030 and the first support structure 020, playing a limiting function, and can avoid the situation that the first diaphragm 010 is damaged due to overload when receiving external vibration signals.

[0100] For example, it can be to pattern the semiconductor substrate using semiconductor processes to form the integrated first support structure 020 and the second support structure 060 on the side of the first diaphragm 010 facing away from the mass block 030.

[0101] Please refer to Figure 8 and Figure 9 , the above-mentioned second support structure 060 can be in a ring shape or a column shape.

[0102] Exemplarily, please refer to Figure 7 , the distance between the side of the second support structure 060 facing away from the first diaphragm 010 and the first diaphragm 010 is less than the distance between the side of the first support structure 020 facing away from the first diaphragm 010 and the first diaphragm 010. The second support structure 060 with a smaller thickness does not limit the vibration of the first diaphragm 010 under normal load.

[0103] In some embodiments, the aperture of the air vent 040 can be 1 micrometer to 50 micrometers. The thickness of the first diaphragm 010 can be 5 micrometers to 20 micrometers. For example, a silicon wafer has a certain elasticity when its thickness is 5 micrometers to 20 micrometers and can be used as a diaphragm.

[0104] In summary, the vibration unit provided in the embodiments of the present application may include a first diaphragm, a mass block, and a first support structure. The first diaphragm, the mass block, and the first support structure are integrally formed structures, and the air vent holes penetrate through the mass block and the first diaphragm at the same time. Since the first diaphragm, the mass block, and the first support structure are integrally formed structures, there is no need to bond the mass block to the first diaphragm with an adhesive, nor is it necessary to bond the first diaphragm to the first support structure with an adhesive. Therefore, the mass block will not tilt relative to the first diaphragm, the through holes on the mass block are aligned with the through holes on the first diaphragm, and the relative position accuracy between the first support structure and the first diaphragm is high. In the case where the above vibration unit is manufactured by semiconductor processes, multiple vibration units can be synchronously processed and formed from the same semiconductor substrate, and the consistency between multiple vibration units is high.

[0105] The embodiments of the present application further provide a bone voiceprint sensor. Please refer to Figure 10 , Figure 10 which is a schematic structural diagram of a bone voiceprint sensor provided in the embodiments of the present application. The bone voiceprint sensor 1000 may include: a protective case 100, a microphone assembly 200, and a vibration unit 000. The vibration unit 000 is the vibration unit 000 described in any of the above embodiments.

[0106] The protective case 100 forms a receiving cavity 101 and is fixed on the microphone assembly 200. The vibration unit 000 is located in the receiving cavity 101 and is fixed on the microphone assembly 200.

[0107] In some possible implementation manners, please refer to Figure 10 , the microphone assembly 200 may include: a first substrate 201, a side plate 202, and a second substrate 203. It may further include: a sensor unit 204 located on one side of the first substrate 201; the first substrate 201 has air holes, and the air holes communicate with the pre-vibration cavity 200a of the sensor unit 204.

[0108] The side plate 202 is fixed on the side of the first substrate 201 facing away from the vibration unit 000 and is located on the outside of the microphone assembly 200.

[0109] The second substrate 203 is fixed on the side of the side plate 202 facing away from the first substrate 201 and is electrically connected to the first substrate 201 through the side plate 202.

[0110] The vibration unit 000 is located on the side of the first substrate 201 facing away from the sensor unit 204, and the side of the first support structure 020 facing away from the first diaphragm 010 is fixed on the first substrate 201.

[0111] The protective case 100 is fixed on the side of the first substrate 201 facing away from the sensor unit 204, and the vibration unit 000 is located inside the protective case 100.

[0112] Among them, the cavity formed by the first substrate 201, the side plate 202, and the second substrate 203 serves as the post-vibration cavity 200b of the sensor unit 204.

[0113] Exemplarily, the sensor unit 204 may include: an AISC chip 204b (Application-Specific Integrated Circuit chip), and a MEMS chip 204a (Micro-Electro-Mechanical Systems chip) electrically connected to the AISC chip 204b. The MEMS chip 204a has the above-mentioned pre-vibration cavity 200a.

[0114] Among them, the MEMS chip 204a has a second diaphragm, and the second diaphragm divides the microphone assembly 200 into a pre-vibration cavity 200a and a post-vibration cavity 200b. The above-mentioned AISC chip 204b and MEMS chip 204a may refer to the chips in existing bone voiceprint sensors.

[0115] The bone voiceprint sensor 1000 provided by the embodiments of the present application has the technical effects of the vibration unit 000 described in any of the above embodiments, and will not be repeated here.

[0116] The embodiments of the present application also provide a manufacturing method for a vibration unit, which can be used to manufacture the vibration unit described in any of the above embodiments. Please refer to Figure 4 And Figure 11 , Figure 11 is a schematic flowchart of the manufacturing method for the vibration unit provided by the embodiments of the present application. The manufacturing method may include:

[0117] Step S001: Provide a substrate having a first surface and a second surface disposed opposite to each other.

[0118] Step S002: Pattern the first surface of the substrate to form a first support structure.

[0119] Step S003: Pattern the second surface of the substrate to form a mass block and a first diaphragm, and an air vent hole penetrating through the mass block and the first diaphragm.

[0120] Among them, the first support structure 020 is annular, and the orthographic projection of the mass block 030 on the plane where the first diaphragm 010 is located is located within the region surrounded by the orthographic projection of the first support structure 020 on the plane where the first diaphragm 010 is located; the air vent hole 040 communicates with the space surrounded by the first support structure 020.

[0121] In the embodiments of the present application, the substrate 001 may be a commonly used semiconductor substrate, such as a single crystal silicon substrate, a sapphire substrate, a glass substrate, or other available substrates. By using a semiconductor substrate, the substrate 001 can be processed using semiconductor processes, thereby obtaining an integrated vibration unit 000, corresponding to the technical effects of the vibration unit 000 described in the above embodiments.

[0122] In a possible implementation, please refer to Figure 7 、 Figures 12 to 13 , Figure 12 which is a schematic flow chart of a manufacturing method of a vibration unit provided in another embodiment of the present application. Figure 13 which is a schematic process diagram of a manufacturing method of a vibration unit provided in another embodiment of the present application. The manufacturing method may include:

[0123] Step S101: Provide a substrate having a first surface and a second surface disposed opposite to each other.

[0124] Step S102: Pattern the first surface of the substrate to form a first support structure.

[0125] Step S103: Pattern the second surface of the substrate to form a mass block and a first vibration membrane, and a vent hole penetrating the mass block and the first vibration membrane.

[0126] Step S104: Form a counterweight layer on the side of the mass block facing away from the first vibration membrane.

[0127] Among them, the first support structure 020 is annular, and the orthographic projection of the mass block 030 on the plane where the first vibration membrane 010 is located is located within the region surrounded by the orthographic projection of the first support structure 020 on the plane where the first vibration membrane 010 is located; the vent hole 040 communicates with the space surrounded by the first support structure 020. The orthographic projection of the counterweight layer 050 on the plane where the first vibration membrane 010 is located does not overlap with the orthographic projection of the vent hole 040 on the plane where the first vibration membrane 010 is located.

[0128] In the embodiments of the present application, by forming a counterweight layer 050 on the side of the mass block 030 facing away from the first vibration membrane 010, since the mass of the mass block 030 affects the vibration characteristics of the vibration unit 000. A larger mass block 030 can increase inertia, making the vibration unit 000 more sensitive to low-frequency vibrations. This is very important for capturing low-frequency sound or vibration signals. Therefore, the embodiments of the present application can increase the mass of the mass block 030 by adding the counterweight layer 050. At this time, the mass block 030 and the counterweight layer 050 as a whole serve as the actual mass block of the vibration unit 000.

[0129] In a possible implementation, please refer to Figure 13, in the above step S102, patterning the first surface of the substrate to form the first support structure may include:

[0130] Step S201: Pattern the first surface of the substrate to form the second support structure and the first support structure. Among them, the second support structure is distributed in the space surrounded by the first support structure.

[0131] The orthographic projection of the second support structure 060 on the plane where the first diaphragm 010 is located is located within the orthographic projection of the mass block 030 on the plane where the first diaphragm 010 is located, and the orthographic projection of the second support structure 060 on the plane where the first diaphragm 010 is located does not coincide with the orthographic projection of the air vent 040 on the plane where the first diaphragm 010 is located.

[0132] In the embodiment of the present application, patterning can be used to form the first support structure 020 and the second support structure 060 on the first surface 001a of the substrate 001. In this way, the positional accuracy between the first support structure 020 and the second support structure 060 is high, and the positional accuracy between the first support structure 020 and the subsequently formed first diaphragm 010 is high.

[0133] Exemplarily, please refer to Figure 13 , in the above step S201, patterning the first surface of the substrate to form the second support structure and the first support structure may include:

[0134] Step S301: Form a first photoresist pattern on the first surface of the substrate.

[0135] Step S302: Perform a first etching process on the area of the first surface of the substrate that is not covered by the first photoresist pattern to form a first cavity on the first surface of the substrate.

[0136] Step S303: Remove the first photoresist pattern and form a second photoresist pattern on the first surface of the substrate; the orthographic projection of the first cavity on the second surface of the substrate is located within the orthographic projection of the second photoresist pattern on the second surface of the substrate.

[0137] Step S304: Perform a second etching process on the area of the second surface of the substrate that is not covered by the second photoresist pattern to form a second cavity on the first surface of the substrate; the depth of the second cavity is greater than the depth of the first cavity.

[0138] Step S305: After removing the second photoresist pattern, the second support structure and the first support structure are obtained.

[0139] Among them, the distance between the side of the second support structure 060 facing away from the first diaphragm 010 and the first diaphragm 010 is less than the distance between the side of the first support structure 020 facing away from the first diaphragm 010 and the first diaphragm 010.

[0140] As Figure 13 shown, in the embodiment of the present application, two patterning processes can be adopted to form a first cavity 001c and a second cavity 001d on the first surface 001a of the substrate 001, so as to form a first support structure 020 and a second support structure 060. Among them, the second support structure 060 is formed in the area of the substrate 001 corresponding to the area on the first surface 001a that is not covered by the first photoresist pattern 002 but is covered by the second photoresist pattern 002. The first support structure 020 is formed in the area of the substrate 001 corresponding to the area on the first surface 001a that is covered by the first photoresist pattern 002 and is covered by the second photoresist pattern 002.

[0141] In a possible implementation manner, in the above step S103, patterning the second surface of the substrate to form a mass block, a first diaphragm, and an air vent hole penetrating the mass block and the first diaphragm may include:

[0142] Step S202, forming a third photoresist pattern on the second surface of the substrate; wherein, the third photoresist pattern has a first photoresist area, a second photoresist area, and a photoresist completely removed area. The thickness of the photoresist in the first photoresist area is greater than the thickness of the photoresist in the second photoresist area, and there is no photoresist in the photoresist completely removed area.

[0143] Step S203, performing a third etching process on the area of the second surface of the substrate located in the photoresist completely removed area to form an air vent hole penetrating the substrate on the second surface of the substrate.

[0144] Step S204, removing the photoresist in the second photoresist area and performing a fourth etching process on the area of the second surface of the substrate located in the second photoresist area to form a third cavity on the second surface of the substrate; the sum of the depth of the third cavity and the depth of the second cavity is less than the thickness of the substrate.

[0145] Step S205, after removing the third photoresist pattern, obtaining the mass block and the first diaphragm.

[0146] As Figure 13As shown in the figure, in the embodiment of the present application, a vent hole 040 and a third cavity 001e are formed on the second surface 001b of the substrate 001, thereby forming a mass 030 and a first diaphragm 010. Among them, the third photoresist pattern 004 may have a first photoresist region 004b, a second photoresist region 004a, and a photoresist completely removed region 004c. In step S203, the region of the second surface 001b of the substrate 001 located within the photoresist completely removed region 004c is not covered by the photoresist, and the vent hole 040 can be formed by etching. In step S204, the third photoresist pattern 004 can be etched first by dry etching. In this way, the photoresist in the first photoresist region 004b and the second photoresist region 004a is thinned simultaneously until the photoresist in the second photoresist region 004a is removed. Then, under the mask of the photoresist in the photoresist region within the first photoresist region 004b, the region of the second surface 001b of the substrate 001 located within the second photoresist region 004b is etched to form the third cavity 001e.

[0147] The above-mentioned third photoresist pattern 004 can be formed by lithography using a gray-tone mask plate with regions of different transmittances. The gray-tone mask plate can have a non-transmissive region, a semi-transmissive region, and a transmissive region. Among them, the transmittance of the non-transmissive region is less than the transmittance of the semi-transmissive region, and the transmittance of the semi-transmissive region is less than the transmittance of the transmissive region. Taking the material of the photoresist layer as a positive photoresist as an example, after the photoresist layer is exposed and developed, the photoresist in the first photoresist region 004b and the second photoresist region 004a can be retained, and the photoresist in the photoresist completely removed region 004c can be removed, and the thickness of the photoresist in the first photoresist region 004b is greater than the thickness of the photoresist in the second photoresist region 004a. Among them, the first photoresist region 004b corresponds to the non-transmissive region in the gray-tone mask plate, the second photoresist region 004a corresponds to the semi-transmissive region in the gray-tone mask plate, and the photoresist completely removed region 004c corresponds to the transmissive region in the gray-tone mask plate.

[0148] By using the above steps S202 to S205, only one gray-tone mask plate can be used to complete the fabrication of the vent hole 040 and the third cavity 001e. Compared with multiple lithographies that require the preparation of multiple mask plates, the manufacturing method provided by the embodiment of the present application has a lower cost.

[0149] In a possible implementation manner, please refer to Figure 13 , in the above step S104, forming a counterweight layer on the side of the mass away from the first diaphragm may include:

[0150] Step S206: A metal plating layer is formed on the side of the mass away from the first diaphragm by an electroplating process. The counterweight layer may include the metal plating layer.

[0151] The density of the weight layer 050 or the metal electroplating layer is greater than the density of the mass block 030 .

[0152] Exemplarily, in the above step S206, forming a metal electroplating layer on a side of the mass block away from the first diaphragm by using an electroplating process may include:

[0153] Step S306: forming a seed layer on the side of the mass block away from the first diaphragm by using a physical vapor deposition process.

[0154] Step S307 : forming an electroplated metal layer on the side of the seed layer away from the first diaphragm by using an electroplating process.

[0155] It should be noted that, in the above manufacturing method, the definition of each structure of the vibration unit in each step and the technical effect can all refer to the vibration unit described in the above embodiment.

[0156] In summary, the manufacturing method of the vibration unit provided in the embodiment of the present application can obtain an integrated vibration unit, wherein the first diaphragm, the mass block and the first support structure are an integrated structure. The vibration unit made by semiconductor technology has high precision in the size of each structure and high consistency between multiple vibration units.

[0157] It should be noted that in the accompanying drawings, the sizes of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it may be directly on the other element, or there may be an intermediate layer. In addition, it is understood that when an element or layer is referred to as being "under" another element or layer, it may be directly under the other element, or there may be more than one intermediate layer or element. In addition, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it may be the only layer between the two layers or two elements, or there may also be more than one intermediate layer or element. Similar reference numerals throughout the text indicate similar elements.

[0158] In the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0159] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A vibration unit, characterized in that: include: A first diaphragm, a mass block, and a first supporting structure; The mass block is located on one side of the first diaphragm; The first supporting structure is located on a side of the first diaphragm away from the mass block, the first supporting structure is annular, and an orthographic projection of the mass block on the plane where the first diaphragm is located is located within a region enclosed by an orthographic projection of the first supporting structure on the plane where the first diaphragm is located; The first diaphragm, the mass block and the first supporting structure are an integrally formed structure, and the vibration unit has an air leakage hole penetrating the mass block and the first diaphragm, and the air leakage hole is connected to the space surrounded by the first supporting structure.

2. The vibration unit according to claim 1, characterized in that The air leakage hole comprises: a first sub-air hole penetrating the mass block, and a second sub-air hole penetrating the first diaphragm; One end of the second sub-air hole is connected to the first sub-air hole, and the other end is connected to the space surrounded by the first supporting structure; The boundary of the orthographic projection of the first sub-aperture on the plane where the first diaphragm is located coincides with the boundary of the orthographic projection of the second sub-aperture on the plane where the first diaphragm is located.

3. The vibration unit according to claim 1 or 2, characterized in that: The vibration unit further comprises: a weight layer connected to a side of the mass block facing away from the first diaphragm; Wherein, at least a portion of an orthographic projection of the weight layer on the plane where the first diaphragm is located does not overlap with an orthographic projection of the air leakage hole on the plane where the first diaphragm is located.

4. The vibration unit according to claim 3, characterized in that: The density of the counterweight layer is greater than the density of the mass block.

5. The vibration unit according to claim 4, characterized in that: The weight layer includes a metal electroplating layer formed by an electroplating process.

6. The vibration unit according to claim 3, characterized in that: The weight layer has a through hole, and an orthographic projection of the through hole on the plane where the first diaphragm is located overlaps with an orthographic projection of the air leakage hole on the plane where the first diaphragm is located.

7. The vibration unit according to any one of claims 1-2 and 4-6, characterized in that: The vibration unit further includes: a second supporting structure, the second supporting structure is located on a side of the first diaphragm facing the first supporting structure and is distributed in a space surrounded by the first supporting structure; The orthographic projection of the second supporting structure on the plane where the first diaphragm is located is located within the orthographic projection of the mass block on the plane where the first diaphragm is located, and the orthographic projection of the second supporting structure on the plane where the first diaphragm is located does not overlap with the orthographic projection of the bleed hole on the plane where the first diaphragm is located; Wherein, the first diaphragm, the mass block, the first supporting structure and the second supporting structure are an integrally formed structure.

8. The vibration unit according to claim 7, characterized in that: The distance between the first diaphragm and the side of the second supporting structure facing away from the first diaphragm is smaller than the distance between the first diaphragm and the side of the first supporting structure facing away from the first diaphragm.

9. A bone voiceprint sensor, characterized in that: include: A protective shell, a microphone assembly and a vibration unit, wherein the vibration unit is the vibration unit according to any one of claims 1 to 8; The protective shell is formed with a receiving cavity and is fixed on the microphone assembly; The vibration unit is located in the accommodating cavity and is fixed on the microphone assembly.

10. A method for manufacturing a vibration unit, characterized in that: include: Providing a substrate, the substrate having a first surface and a second surface disposed opposite to each other; Performing patterning on the first surface of the substrate to form a first supporting structure; Performing patterning on the second surface of the substrate to form a mass block and a first diaphragm, and an air leakage hole penetrating the mass block and the first diaphragm; Among them, the first supporting structure is annular, and the orthographic projection of the mass block on the plane where the first diaphragm is located is located in the area surrounded by the orthographic projection of the first supporting structure on the plane where the first diaphragm is located; the air leakage hole is connected to the space surrounded by the first supporting structure.

11. The manufacturing method according to claim 10, characterized in that: After patterning the second surface of the substrate, the method further comprises: forming a weight layer on a side of the mass block away from the first diaphragm; The orthographic projection of the weight layer on the plane where the first diaphragm is located does not overlap with the orthographic projection of the air leakage hole on the plane where the first diaphragm is located.

12. The manufacturing method according to claim 11, characterized in that: A weight layer is formed on a side of the mass block away from the first diaphragm, comprising: A metal electroplating layer is formed on a side of the mass block away from the first diaphragm by an electroplating process, wherein the weight layer includes the metal electroplating layer; Wherein, the density of the counterweight layer is greater than the density of the mass block.

13. The manufacturing method according to any one of claims 10 to 12, characterized in that: The first surface of the substrate is patterned to form a first support structure, comprising: Performing patterning on the first surface of the substrate to form a second supporting structure and the first supporting structure; Wherein, the second supporting structure is distributed in the space surrounded by the first supporting structure; The orthographic projection of the second supporting structure on the plane where the first diaphragm is located is located within the orthographic projection of the mass block on the plane where the first diaphragm is located, and the orthographic projection of the second supporting structure on the plane where the first diaphragm is located does not overlap with the orthographic projection of the bleed hole on the plane where the first diaphragm is located.

14. The manufacturing method according to claim 13, characterized in that: The first surface of the substrate is patterned to form a second support structure and the first support structure, comprising: forming a first photoresist pattern on a first surface of the substrate; Performing a first etching process on an area of ​​the first surface of the substrate that is not covered by the first photoresist pattern to form a first cavity on the first surface of the substrate; The first photoresist pattern is removed, and a second photoresist pattern is formed on the first surface of the substrate; the orthographic projection of the first cavity on the second surface of the substrate is located within the orthographic projection of the second photoresist pattern on the second surface of the substrate; Performing a second etching process on an area of ​​the second surface of the substrate that is not covered by the second photoresist pattern to form a second cavity on the first surface of the substrate; the depth of the second cavity is greater than the depth of the first cavity; After removing the second photoresist pattern, the second supporting structure and the first supporting structure are obtained; The distance between the first diaphragm and the side of the second supporting structure facing away from the first diaphragm is smaller than the distance between the first diaphragm and the side of the first supporting structure facing away from the first diaphragm.

15. The manufacturing method according to any one of claims 10-12 and 14, characterized in that: The second surface of the substrate is patterned to form a mass block and a first diaphragm, and an air leakage hole penetrating the mass block and the first diaphragm, comprising: A third photoresist pattern is formed on the second surface of the substrate; wherein the third photoresist pattern comprises a first photoresist area, a second photoresist area and a photoresist completely removed area, the thickness of the photoresist in the first photoresist area is greater than the thickness of the photoresist in the second photoresist area, and no photoresist exists in the photoresist completely removed area; Performing a third etching process on a region of the second surface of the substrate located in the photoresist completely removed region to form the vent hole penetrating the substrate on the second surface of the substrate; removing the photoresist in the second photoresist area, and performing a fourth etching process on a region of the second surface of the substrate located in the second photoresist area to form a third cavity on the second surface of the substrate; After removing the third photoresist pattern, the mass block and the first diaphragm are obtained.

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