Microphone sensor, packaging structure and bone conduction microphone

Abstract

The utility model discloses a microphone sensor, a packaging structure and a bone conduction microphone, and the microphone sensor comprises a vibration unit which comprises a first vibration membrane and a mass block disposed at one side of the first vibration membrane; and the signal sensing unit comprises a second vibrating diaphragm and a back polar plate which are arranged at an interval, the signal sensing unit is arranged on one side or the other side, where the mass block is arranged, of the first vibrating diaphragm, and a first cavity is formed between the signal sensing unit and the first vibrating diaphragm. According to the microphone sensor provided by the embodiment of the utility model, sound collection based on the bone conduction principle can be realized, and the influence of external wind sound and other factors on the sound receiving effect can be effectively avoided.

Description

Technical Field

[0001] The utility model generally relates to the field of sensor technology, and more specifically, to a microphone sensor, a packaging structure and a bone conduction microphone. Background Art

[0002] The microphone of a traditional headset usually collects the user's voice by using the principle of air vibration to conduct sound waves. However, when the microphone collects the user's voice, it is often affected by factors such as external wind noise, the installation direction of the microphone and its directivity, resulting in unsatisfactory sound collection.

[0003] In view of this, there is an urgent need to provide a new microphone solution so as to better collect sound and effectively avoid the influence of external factors such as wind noise on the sound reception effect. Utility Model Content

[0004] In order to at least solve one or more of the technical problems mentioned above, the utility model proposes a microphone sensor, a packaging structure of a microphone sensor and a bone conduction microphone solution in multiple aspects.

[0005] In a first aspect, the utility model provides a microphone sensor, comprising: a vibration unit, comprising a first vibration membrane and a mass block arranged on one side of the first vibration membrane; a signal sensing unit, comprising a second vibration membrane and a back plate arranged at intervals, the signal sensing unit being arranged on one side or the other side of the first vibration membrane where the mass block is arranged, and forming a first cavity between the signal sensing unit and the first vibration membrane.

[0006] In some embodiments, the volume of the first cavity is 0.075-0.25 mm 3 .

[0007] In some other embodiments, the vibration unit and the signal sensing unit are connected by wafer bonding.

[0008] In some further embodiments, a thickness of a bonding medium between the vibration unit and the signal sensing unit is less than 10 μm.

[0009] In some embodiments, the bonding medium between the vibration unit and the signal sensing unit includes at least one of a silicon oxide medium, a metal medium, a photoresist medium, and a polymer medium.

[0010] In other embodiments, the vibration unit also includes a first substrate, which is arranged on the same side of the first vibration membrane as the mass block and surrounds the mass block, or the first substrate is arranged on the other side of the first vibration membrane; and / or the signal sensing unit also includes a second substrate having a hollow structure, and the second vibration membrane and the back plate are arranged at one end of the second substrate and cover the hollow structure.

[0011] In some further embodiments, the first vibration membrane is connected to the first substrate by deposition; and / or the second vibration membrane and the back plate are connected to one end of the second substrate by deposition.

[0012] In some embodiments, the other end of the second substrate of the signal sensing unit is connected to the one side or the other side of the first vibration membrane, and the hollow structure forms the first cavity.

[0013] In some other embodiments, the back plate or the second vibration membrane of the signal sensing unit is connected to an end of the first substrate away from the first vibration membrane to enclose the first substrate to form the first cavity.

[0014] In some further embodiments, the second vibration membrane is located between the back plate and the first vibration membrane; and a distance between the first vibration membrane and the second vibration membrane is greater than 100 μm.

[0015] In some embodiments, when the first substrate and the mass block are arranged on the same side of the first vibration membrane and the other end of the second substrate of the signal sensing unit is connected to the other side of the first vibration membrane, the thickness of the mass block is less than or equal to the thickness of the first substrate.

[0016] In some other embodiments, the first substrate and the mass block are disposed on the same side of the first vibration membrane, and the thickness of the mass block is smaller than the thickness of the first substrate.

[0017] In some further embodiments, the vibration unit includes a plurality of mass blocks, and adjacent mass blocks are spaced apart from each other.

[0018] In some embodiments, the outer diameter of the vibration unit is equal to the outer diameter of the signal sensing unit, and the first substrate has an electrical through hole connected to the back plate; or the outer diameter of the vibration unit is smaller than the outer diameter of the signal sensing unit to expose part of the back plate.

[0019] In some other embodiments, the area of ​​the first vibration membrane is greater than the area of ​​the second vibration membrane.

[0020] In some further embodiments, the longitudinal section of the hollow structure is a trapezoid, and the upper base of the trapezoid is covered by the second vibration membrane and the back pole plate.

[0021] In some embodiments, an inner diameter of the second substrate is smaller than a diameter of a vibrating area of ​​the first diaphragm; and the microphone sensor further includes a spacer connected between the second substrate and the first diaphragm.

[0022] In some other embodiments, the second substrate includes a supporting portion and a defining portion, the defining portion is located between the supporting portion and the first vibration membrane, and the inner diameter of the supporting portion is smaller than the inner diameter of the defining portion to form the hollow structure having a stepped shape.

[0023] In some further embodiments, the vibration unit includes the first substrate, and the first substrate is located on a side of the first vibration membrane facing away from the first cavity, and the first substrate has a first channel connecting the first vibration membrane and the outside of the vibration unit.

[0024] In some embodiments, the signal sensing unit includes the second substrate, and the second substrate has a second channel connecting the hollow structure and the outside of the signal sensing unit.

[0025] In some other embodiments, the thickness of the vibration unit is 300 μm-600 μm; the thickness of the signal sensing unit is 300 μm-400 μm.

[0026] In some other embodiments, the mass block is a metal mass block or a single crystal silicon mass block.

[0027] In a second aspect, the utility model provides a packaging structure of a microphone sensor, comprising: a shell; a circuit board, which together with the shell forms a second cavity; and a microphone sensor according to any one of the first aspects of the utility model, which is located in the second cavity, and the side of the first vibration membrane facing away from the first cavity or the side of the signal sensing unit facing away from the first cavity faces the circuit board, and forms a third cavity between the circuit board and the microphone sensor.

[0028] In some embodiments, the housing has a first opening connecting the second cavity with the outside; and / or the circuit board has a second opening connecting the third cavity with the outside.

[0029] In other embodiments, the side of the first vibration membrane facing away from the first cavity faces the circuit board, and the mass block is located in the third cavity, and the number of the second openings is equal to the number of the mass blocks and corresponds one to one.

[0030] In some further embodiments, the circuit board has a groove communicating with the third cavity.

[0031] In some embodiments, the groove communicates with the third cavity and the second cavity.

[0032] In some other embodiments, the packaging structure further includes an integrated circuit chip, which is disposed on the circuit board and electrically connected to the microphone sensor.

[0033] In some other embodiments, the thickness of the packaging structure is 0.95 mm-3.5 mm.

[0034] In a third aspect, the utility model provides a bone conduction microphone, comprising any packaging structure described in the second aspect of the utility model.

[0035] Through the microphone sensor, packaging structure and bone conduction microphone solution provided above, it can be understood that the embodiment of the utility model can sense the sound wave vibration conducted by tissues such as the skull or muscles to generate mechanical vibration by providing a vibration unit including a first vibration membrane and a mass block; and by providing a signal sensing unit including a second vibration membrane and a back plate arranged at intervals, and forming a first cavity between the signal sensing unit and the first vibration membrane, so that the signal sensing unit can be used to sense the pressure change in the first cavity caused by the mechanical vibration of the vibration unit to generate an electrical signal, thereby realizing a microphone solution for collecting sound based on the principle of bone conduction, and effectively avoiding the influence of external factors such as wind noise on the sound reception effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present invention will become easy to understand. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0037] Figure 1a A schematic diagram of an existing microphone structure is shown;

[0038] Figure 1b A schematic diagram showing another existing microphone structure;

[0039] Figure 2a A cross-sectional schematic diagram of a microphone sensor according to some embodiments of the present utility model is shown;

[0040] Figure 2b shows a cross-sectional schematic diagram of a microphone sensor according to some other embodiments of the utility model;

[0041] Figure 3aA schematic diagram showing a microphone sensor in which a mass block and a first substrate are located on different sides of a first diaphragm according to some embodiments of the present invention;

[0042] Figure 3b A schematic diagram showing a microphone sensor in which a mass block and a first substrate are located on different sides of a first diaphragm according to other embodiments of the utility model;

[0043] Figure 4 A schematic diagram of a microphone sensor including an electrical through hole according to an embodiment of the utility model is shown;

[0044] Figure 5 A schematic diagram of a microphone sensor including multiple mass blocks according to an embodiment of the utility model is shown;

[0045] Figure 6a A schematic diagram showing a microphone sensor having a first channel on a first substrate;

[0046] Figure 6b A schematic diagram showing a microphone sensor having a second channel on a second substrate;

[0047] Figure 7a A schematic diagram showing a microphone sensor in which the outer diameter of the signal sensing unit is larger than the outer diameter of the vibration unit according to some embodiments of the present invention;

[0048] Figure 7b A schematic diagram showing a microphone sensor in which the outer diameter of the signal sensing unit is larger than the outer diameter of the vibration unit according to other embodiments of the present utility model;

[0049] Figure 8a A schematic diagram of a microphone sensor in which the hollow structure of the second substrate is set to be trapezoidal according to an embodiment of the utility model is shown;

[0050] Figure 8b A schematic diagram showing a microphone sensor according to an embodiment of the present utility model, in which the inner diameter of the second substrate is smaller than the diameter of the vibrating area of ​​the first vibration membrane;

[0051] Figure 8c A schematic diagram showing a microphone sensor according to an embodiment of the present utility model, wherein the second substrate includes a supporting portion and a defining portion;

[0052] Fig. 9 A schematic diagram showing a packaging structure according to an embodiment of the utility model is shown;

[0053] Fig.10a A schematic diagram of a packaging structure including a first opening according to an embodiment of the utility model is shown;

[0054] Fig.10bA schematic diagram showing a packaging structure including a second opening according to an embodiment of the utility model is shown;

[0055] Fig.10c A schematic diagram showing a packaging structure including a first opening and a second opening according to an embodiment of the utility model is shown;

[0056] Fig.11a Shows Figure 6a A schematic diagram of the packaging structure of the microphone sensor shown;

[0057] Fig.11b A schematic diagram showing a packaging structure with a groove on a circuit board according to an embodiment of the utility model is shown;

[0058] Fig.11c A schematic diagram showing a packaging structure in which the mass block and the first substrate have the same thickness according to an embodiment of the utility model;

[0059] Fig.11d A schematic diagram showing a packaging structure in which a groove connects a third cavity and a second cavity according to an embodiment of the utility model;

[0060] Fig.12 A schematic diagram of a packaging structure including a plurality of second openings according to an embodiment of the utility model is shown. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0062] It should be understood that the terms "include" and "comprises" used in the description and claims of the present invention indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0063] It should also be understood that the terms used in this utility model specification are only for the purpose of describing specific embodiments, and are not intended to limit the utility model. As used in the utility model specification and claims, the singular forms of "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the utility model specification and claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0064] The inventors have found that the current microphones for collecting sound based on the bone conduction principle are usually assembled from components such as a mass block, a vibration membrane, and a MEMS (micro-electromechanical system) microphone chip. For example, Figure 1a FIG. 1 is a schematic diagram showing an existing microphone structure. Figure 1a As shown in FIG. 1 , the MEMS microphone chip 101 in the microphone structure is electrically connected to the integrated circuit chip 107 and is packaged by the circuit board 104 and the circuit board cover 105, while the mass member 102 and the vibration membrane 103 are packaged by the metal cover 106, and the metal cover 106 is connected to the circuit board cover 105 to form a microphone structure. The vibration cavity 108 in the microphone structure is formed by the vibration membrane 103, the metal cover 106, the circuit board cover 105 and the MEMS microphone chip 101.

[0065] For example, Figure 1b FIG. 1 shows a schematic diagram of another existing microphone structure. Figure 1b As shown in FIG. 1 , the MEMS microphone chip 101, the integrated circuit chip 107 and the mass member 102 in the microphone structure are arranged on both sides of the vibration membrane 103 and are packaged by the circuit board 104 and the circuit board cover 105. In the microphone structure, the vibration cavity 108 is formed by the circuit board cover 105, the vibration membrane 103 and the MEMS microphone chip 101.

[0066] However, the mass block, diaphragm and MEMS (micro-electromechanical system) microphone chip in the above microphone structure cannot form an independent and complete structure, so it is necessary to design the layout and connection relationship of each component during packaging, resulting in a complex packaging process, greater packaging difficulty and higher packaging cost. In addition, the connection between each component and the circuit board 104, circuit board cover 105, metal cover 106 and other structures in the above microphone structure is usually bonded with glue, resulting in inaccurate alignment of each component, thereby affecting the sensitivity of the microphone, and because the thickness of the glue is difficult to control, the thickness uniformity of the microphone structure after the components are bonded is poor.

[0067] Based on this, the utility model provides a new solution to design an independently set microphone sensor, which can not only collect sound based on the principle of bone conduction to avoid the influence of external factors such as wind noise on the sound collection effect, but also effectively reduce the packaging difficulty and cost when packaging. The specific implementation method of the utility model will be described in detail below with reference to the accompanying drawings.

[0068] Figure 2a A cross-sectional schematic diagram of a microphone sensor according to some embodiments of the present invention is shown. Figure 2b The cross-sectional schematic diagram of the microphone sensor according to some other embodiments of the utility model is shown. Figure 2a and Figure 2b An exemplary description is given.

[0069] like Figure 2a and Figure 2b As shown in , the utility model provides a microphone sensor 200, including a vibration unit 210 and a signal sensing unit 220, wherein the vibration unit 210 includes a first vibration membrane 211 and a mass block 212 arranged on one side of the first vibration membrane 211; the signal sensing unit 220 may include a second vibration membrane 221 and a back plate 222 arranged at intervals, and the signal sensing unit 220 may be arranged on a side 2111 of the first vibration membrane 211 where the mass block 212 is arranged (that is, the signal sensing unit 220 and the mass block 212 are arranged on the same side of the first vibration membrane 211, for example Figure 2b ) or the other side 2112 (e.g. Figure 2a ), and a first cavity 230 is formed between the signal sensing unit 220 and the first vibration membrane 211.

[0070] In such Figure 2a In the illustrated embodiment, the signal sensing unit 220 may be disposed on the other side 2112 of the first vibration membrane 211 relative to the mass block 212 (i.e., the signal sensing unit 220 and the mass block 212 are disposed on different sides of the first vibration membrane 211), and the mass block 212 may be located outside the first cavity 230. Figure 2b In some other embodiments shown, the signal sensing unit 220 can be arranged on a side 2111 of the first vibration membrane 211 where the mass block 212 is arranged. In this case, the mass block 212 can be located in the first cavity 230. In some embodiments, the mass block 212 can be a metal mass block or a single crystal silicon mass block. In other embodiments, the mass block 212 can be in the shape of a cube, a cuboid, a cylinder, etc. In some embodiments, the first vibration membrane 211 and the mass block 212 can be an integrally formed structure. In other embodiments, the mass block 212 can be connected to one side of the first vibration membrane 211 by electroplating.

[0071] The second vibration membrane 221 and the back plate 222 of the signal sensing unit 220 are spaced apart and can constitute a flat capacitor. The second vibration membrane 221 and the back plate 222 are equivalent to the two poles of the capacitor. A metal electrode can be deposited on the back plate 222 so that a certain amount of charge can be stored thereon to generate an electrical signal. Figure 2a In the embodiment shown, the second vibration membrane 221 may be located between the back plate 222 and the first vibration membrane 211. Figure 2b In some other embodiments shown, the back plate 222 may be located between the first vibration membrane 211 and the second vibration membrane 221, and the back plate 222 may have a hole to connect the first cavity 230 and the second vibration membrane 221. In some embodiments, the distance between the first vibration membrane 211 and the second vibration membrane 221 may be greater than 100 μm. According to such a configuration, even if the second vibration membrane 221 is located between the back plate 222 and the first vibration membrane 211, the risk of adhesion between the first vibration membrane 211 and the second vibration membrane 221 can be effectively avoided.

[0072] In some embodiments, the vibration unit 210 may further include a first substrate 213, and the signal sensing unit 220 may further include a second substrate 223 having a hollow structure 225. In other embodiments, the vibration unit 210 and the signal sensing unit 220 may be combined to form a first cavity 230. Figure 2b In the embodiment shown, one end 2131 of the first substrate 213 of the vibration unit 210 is connected to the first vibration membrane 211, and the other end 2132 of the first substrate 213 is connected to the signal sensing unit 220 (for example, the back plate 222 of the signal sensing unit 220) to enclose the signal sensing unit 220 to form a first cavity 230. Figure 2a In some other embodiments, one end 2231 of the second substrate 223 of the signal sensing unit 220 can be connected to the back plate 222 or the second vibration membrane 221, and the other end 2232 of the second substrate 223 can be connected to the first vibration membrane 211 of the vibration unit 210 to form a first cavity 230 together with the first vibration membrane 211. In this example, the first cavity 230 overlaps with the hollow structure 225.

[0073] like Figure 2a As shown in , the first substrate 213 and the mass block 212 can be arranged on the same side of the first vibration membrane 211, that is, the first substrate 213 is arranged on the side 2111 of the first vibration membrane 211 where the mass block 212 is arranged, and the first substrate 213 can surround the mass block 212. The first substrate 213 can be in a shape such as a cylinder or a square cylinder to surround the mass block 212, and there is a gap between the first substrate 213 and the mass block 212, so that the mass block 212 can vibrate in the space formed by the first substrate 213.

[0074] like Figure 2a As further shown in the figure, the second vibration membrane 221 and the back plate 222 can be arranged at one end 2231 of the second substrate 223 and cover the hollow structure 225 of the second substrate 223. The hollow structure refers to a structure that is hollow in the middle. In some embodiments, the second substrate 223 can be a cylindrical structure such as a cylindrical shape or a square cylindrical shape. The second vibration membrane 221 and the back plate 222 are arranged at one end 2231 of the second substrate 230 and cover the hollow structure, which can be understood as covering one bottom surface of the cylindrical structure, while the other bottom surface (i.e., the other end 2232 of the second substrate 223) is open.

[0075] In such Figure 2a and 2b In the illustrated embodiment, the thickness of the mass block 212 may be less than or equal to the thickness of the first substrate 213. When the thickness of the mass block 212 is equal to the thickness of the first substrate 213, it is beneficial to reduce the complexity of the manufacturing process, and it is also beneficial to increase the mass of the mass block 212, thereby facilitating the improvement of the sensing sensitivity of the microphone sensor. When the thickness of the mass block 212 is less than the thickness of the first substrate 213, the mass block 212 may have enough space to vibrate.

[0076] In some embodiments, the first vibration membrane 211 can be connected to the first substrate 213 by deposition. The deposition method here can be implemented by a deposition process in a semiconductor process. Compared with the connection method using glue bonding, the connection method using deposition is conducive to reducing the thickness of the vibration unit.

[0077] In some other embodiments, the second vibration membrane 221 and the back plate 222 can be connected to one end 2231 of the second substrate 223 by deposition. The deposition method here can be implemented by a deposition process in a semiconductor process. Compared with the connection method using glue bonding, the connection method using deposition is conducive to reducing the thickness of the signal sensing unit.

[0078] In some embodiments, the vibration unit and the signal sensing unit are formed by deposition, so that the vibration unit and the signal sensing unit of the required size can be obtained by cutting the first substrate and the second substrate. In other embodiments, the outer diameter of the vibration unit and the signal sensing unit can be the same, so that the two are easier to install and align when connected, and the overall size consistency of the microphone sensor can be ensured.

[0079] In some embodiments, the vibration unit 210 and the signal sensing unit 220 may be connected by wafer bonding. Figure 2a In the embodiment shown in , the other end 2232 of the second substrate 223 and the first vibration membrane 211 can be connected by wafer bonding. Figure 2b In the illustrated embodiment, the other end 2132 of the first substrate 213 and the signal sensing unit 220 may be connected by wafer bonding. Wafer bonding refers to a connection method in which two wafers are bonded and the surfaces of the joints are subjected to external forces to form a whole, and the bonding interface reaches a specific strength. The vibration unit 210 and the signal sensing unit 220 may be formed on wafers and bonded.

[0080] In some other embodiments, the thickness of the bonding medium between the vibration unit 210 and the signal sensing unit 220 may be less than 10 μm. Figure 2a In the embodiment shown in , the bonding medium may be located between the other end 2232 of the second substrate 223 and the first vibrating membrane 211. Figure 2b In the illustrated embodiment, the bonding medium may be located between the other end 2132 of the first substrate 213 and the signal sensing unit 220. In some embodiments, the bonding medium between the vibration unit 210 and the signal sensing unit 220 may include at least one of a silicon oxide medium, a metal medium, a photoresist medium, and a polymer medium. In some embodiments, the metal medium may include at least one of a gold medium, a germanium medium, a tin medium, and the like. In other embodiments, the photoresist medium may include a photosensitive medium, and the like.

[0081] It can be understood that the use of wafer bonding to connect the vibration unit 210 and the signal sensing unit 220 can make the thickness of the bonding medium smaller and more uniform, effectively improving the alignment accuracy when the vibration unit 210 and the signal sensing unit 220 are connected, and is also beneficial to reducing the size (such as thickness) of the microphone sensor to meet the development needs of miniaturization of microphone sensors.

[0082] In some embodiments, the volume of the first cavity 230 may be 0.075-0.25 mm 3 , for example 0.075mm 3 、0.09mm 3 , 0.1mm 3 , 0.15mm 3 , 0.175mm 3 , 0.2mm 3 , 0.225mm 3 , 0.25mm 3 In some preferred embodiments, the volume of the first cavity 230 may be 0.15-0.25 mm 3 Furthermore, compared to Figure 2a In the case where the signal sensing unit 220 is disposed on the other side 2112 of the first vibration membrane 211 relative to the mass block 212, Figure 2bWhen the middle signal sensing unit 220 is disposed on the side 2111 (ie, the same side) of the first vibration membrane 211 where the mass block 212 is disposed, the volume of the first cavity 230 will be smaller, which is more conducive to further improving the sensing sensitivity of the microphone sensor.

[0083] Combination of the above Figure 2a and 2b The structure of the microphone sensor according to the embodiment of the utility model is described exemplarily. It can be understood that when the microphone sensor 200 senses the vibration of external tissue, the mass block 212 will drive the first vibration membrane 211 to be swung, thereby causing the space in the first cavity 230 to be compressed or expanded, and further drive the vibration of the second vibration membrane 221 to generate an electrical signal on the back plate 222. Therefore, the microphone sensor according to the embodiment of the utility model can collect sound based on the principle of bone conduction to avoid the influence of external factors such as wind sound.

[0084] It can also be understood that the microphone sensor according to the embodiment of the utility model is a complete and independent device. When packaging it, there is no need to perform separate position design and connection for the mass block, first vibration membrane, second vibration membrane, back plate and other components in the microphone sensor, which can help reduce the difficulty and cost of packaging, and will not change the volume of the first cavity during packaging, which is conducive to ensuring the sensing sensitivity of the packaging structure after packaging.

[0085] Further, Figure 2a and Figure 2b What is shown in the figure is exemplary and not restrictive. For example, the mass block 212 may not be limited to being located on the same side of the first vibration membrane 211 as the first substrate 213 as shown in the figure, and may also be located on different sides of the first vibration membrane 211 in other embodiments. Figure 3a A schematic diagram of a microphone sensor in which a mass block and a first substrate are located on different sides of a first diaphragm according to some embodiments of the present invention is shown. Figure 3b Schematic diagrams of microphone sensors in which the mass block and the first substrate are located on different sides of the first diaphragm according to other embodiments of the present invention are shown. Figure 3a and Figure 3b An exemplary description is given.

[0086] like Figure 3a and Figure 3bAs shown in , the microphone sensor 200 may include a vibration unit 210 and a signal sensing unit 220, wherein the mass block 212 and the first substrate 213 of the vibration unit 210 may be located on different sides of the first vibration membrane 211, for example, the mass block 212 is located on one side 2111 of the first vibration membrane 211, and the first substrate 213 is located on the other side 2112 of the first vibration membrane 211, and the signal sensing unit 220 may include a back plate 222, a second vibration membrane 221 and a second substrate 223 having a hollow structure 225.

[0087] In such Figure 3a In the microphone sensor 200 shown, the other end 2232 of the second substrate 223 of the signal sensing unit 220 is connected to a side 2111 of the first vibration membrane 211 where the mass block 212 is disposed, and the mass block 212 is located in the first cavity 230. In other embodiments, the thickness of the mass block 212 may be less than the thickness of the second substrate 223.

[0088] In such Figure 3b In the microphone sensor 200 shown, the first substrate 213 has two ends, which are respectively connected to the first vibration membrane 211 and the signal sensing unit 220, wherein the end connected to the first vibration membrane 211 is an end 2131 close to the first vibration membrane 211, and the end connected to the signal sensing unit 220 is the other end 2132 away from the first vibration membrane 211. The back plate 222 or the second vibration membrane 221 of the signal sensing unit 220 is connected to the other end 2132 of the first substrate 213 away from the first vibration membrane 211, so as to enclose the first substrate 213 and the first vibration membrane 211 to form a first cavity 230.

[0089] and Figure 2a and 2b Similar to the microphone sensor shown, in some embodiments, Figure 3a and Figure 3b The vibration unit 210 and the signal sensing unit 220 in the microphone sensor 200 shown in FIG. 2 can be connected by wafer bonding, for example Figure 3a The first vibration membrane 211 shown in FIG. 1 is connected to the other end 2232 of the second substrate 223 by wafer bonding. Figure 3b The signal sensing unit 220 in the first substrate 213 is connected to the other end 2132 of the first substrate 213 by wafer bonding. In other embodiments, Figure 3a and 3b The first vibration membrane 211 of the vibration unit 210 in the microphone sensor 200 shown in FIG. 1 can be connected to the first substrate 213 by deposition, and the second vibration membrane 221 and the back plate 222 in the signal sensing unit 220 can be connected to the second substrate 223 by deposition. This will not be repeated here.

[0090] Combination of the above Figure 2a-Figure 3b The microphone sensor including the first substrate and the second substrate according to the embodiment of the utility model is described exemplarily. In some embodiments, the thickness of the vibration unit can be 300μm-600μm, such as 300μm, 350μm, 400μm, 450μm, 500μm, 550μm, 600μm, etc.; the thickness of the signal sensing unit can be 300μm-400μm, such as 300μm, 350μm, 400μm, etc. The thickness of the signal sensing unit can be the total thickness of the back plate, the second vibration membrane and the second substrate. The thickness of the vibration unit can be the total thickness of the first vibration membrane and the first substrate, or the total thickness of the mass block, the first vibration membrane and the first substrate.

[0091] It is to be understood that the above description is exemplary rather than limiting. For example, Figure 3a The second vibration membrane 221 shown in FIG. 2 may not be limited to being located between the first vibration membrane 211 and the back plate 222. In some embodiments, the back plate 222 may be located between the first vibration membrane 211 and the second vibration membrane 221. It can also be understood that by Figure 3a The other end 2232 of the second substrate 223 of the signal sensing unit 220 shown in FIG. 1 is connected to the first vibration membrane 211, so that the back plate 222 can be completely exposed so that it can be directly used for electrical connection with an external integrated circuit chip. Figure 2b and 3b In the microphone sensor 200 shown in the figure, the electrical connection between the back plate 222 and the external integrated circuit chip can also be achieved by setting an electrical through hole. Figure 4 Provide explanation.

[0092] Figure 4 FIG. 1 is a schematic diagram of a microphone sensor including an electrical through hole according to an embodiment of the present utility model. Figure 4 As shown in FIG. 1 , the microphone sensor 200 may include a vibration unit 210 and a signal sensing unit 220. Figure 2b The difference from the embodiment shown in is that Figure 4 The first substrate 213 of the vibration unit 210 shown in the figure may have an electrical through hole 214 connected to the back plate 222 and / or the second vibration membrane 221. The electrical through hole 214 may pass through the first substrate 213 from one end 2131 to the other end 2132 and the portion where the first vibration membrane 211 and the first end 2131 of the first substrate 213 are connected, so that the electrical through hole 214 can be used for the electrical connection between the back plate 222 and / or the second vibration membrane 221 and an external device. Similarly, Figure 3b The first substrate 213 of the vibration unit 210 shown in FIG. 2 may also have Figure 4 The electrical through hole is Figure 3bThe electrical through hole 214 can be used to electrically connect the back plate 222 and / or the second vibration membrane 221 with external devices. In some embodiments, the electrical through hole 214 can include a through silicon via (TSV) or the like.

[0093] The above is an exemplary description of the microphone sensor of the embodiment of the utility model in combination with multiple figures. It can be understood that the figures are exemplary and not restrictive. For example, the number of mass blocks may not be limited to only one as shown in the figure, but may be more as needed. Figure 5 An exemplary description is given.

[0094] Figure 5 FIG. 1 shows a schematic diagram of a microphone sensor including multiple mass blocks according to an embodiment of the present utility model. Figure 5 As shown in the figure, the microphone sensor 200 may include a vibration unit 210 and a signal sensing unit 220, wherein the vibration unit 210 may include a first vibration membrane 211, multiple mass blocks (such as mass block 1 212-1 and mass block 212-2 in the figure, etc.) and a first substrate 213, and the signal sensing unit 220 may include a second vibration membrane 221, a back plate 222 and a second substrate 223, and adjacent mass blocks (mass block 1 212-1 and mass block 212-2) may be separated and arranged.

[0095] In some embodiments, multiple mass blocks (mass block one 212-1 and mass block two 212-2) and the first substrate 213 can be arranged on the same side of the first vibration membrane 211, and adjacent mass blocks (mass block one 212-1 and mass block two 212-2) can be separated by part of the first substrate 213a, or can be separated by other separation structures. While the multiple mass blocks are separated and arranged, the first vibration membrane 211 can also be separated accordingly, so that each mass block drives the corresponding part of the first vibration membrane to vibrate to form multiple vibration sub-units. In other embodiments, the sizes of the multiple mass blocks can be the same or different. In the case where the sizes of the multiple mass blocks are different, the multiple mass blocks can be used to sense sounds of different frequencies to generate vibrations of different frequencies, which is beneficial to increase the sensing bandwidth of the microphone sensor.

[0096] Understandably, Figure 5The structure shown is schematic and non-restrictive. For example, the multiple mass blocks and the first substrate 213 may not be limited to being arranged on the same side of the first vibration membrane 211 as shown in the figure. In other embodiments, the multiple mass blocks and the first substrate 213 may be arranged on different sides of the first vibration membrane 211. In some other embodiments, the multiple mass blocks may be arranged on different sides of the first vibration membrane 211. For another example, the relative position relationship between the signal sensing unit 220 and the vibration unit 210 may not be limited to the second substrate 223 being connected to the first vibration membrane 211 as shown in the figure. It may also be that the end of the first substrate 213 away from the first vibration membrane is connected to the back plate or the second vibration membrane. In such an embodiment, the number of mass blocks may also be set to multiple.

[0097] It can also be understood that the structures of the first substrate and the second substrate may not be limited to Figure 2a-Figure 5 As shown in , other structures may also be included. Figure 6a and Figure 6b An exemplary description is given.

[0098] Figure 6a FIG. 1 shows a schematic diagram of a microphone sensor having a first channel on a first substrate. Figure 2a The microphone sensor shown in Figure 6a The first substrate 213 of the microphone sensor 200 shown in the figure may have a first channel 215 connecting the first vibration membrane 211 and the outside of the vibration unit 210. The outside of the vibration unit 210 may be the outside of the first substrate 213. The first channel 215 may be located at the bottom end of the first substrate 213 as shown in the figure, or may be arranged in the middle of the side wall of the first substrate 213 to penetrate the side wall of the first substrate to form a channel.

[0099] Figure 6b A schematic diagram of a microphone sensor having a second channel on a second substrate is shown. Figure 2b The microphone sensor shown, Figure 6b The second substrate 223 of the microphone sensor 200 shown in the figure may have a second channel 224 connecting the hollow structure and the outside of the signal sensing unit 220. The outside of the signal sensing unit 220 may be the outside of the second substrate 223. The second channel 224 may be located at the bottom end of the second substrate 223 as shown in the figure, or may be disposed in the middle of the side wall of the second substrate 223 to penetrate the side wall of the second substrate to form a channel.

[0100] pass Figure 6a The first channel 215 is set, or by Figure 6bThe second channel 224 is provided in the package of the microphone sensor 200, which can increase the cavity space formed on the side of the microphone sensor 200 facing away from the first cavity 230, thereby facilitating the reduction of the damping of the mass block 212 and other components, and improving the sensing sensitivity of the microphone sensor 200. Fig.11a The packaging structure described is further described.

[0101] Combination of the above Figure 6a and Figure 6b An exemplary description is given of a microphone sensor including a first channel or a second channel according to an embodiment of the utility model. It can be understood that the above description is exemplary. For example, the mass block and the first substrate may not be limited to being arranged on the same side of the first vibration membrane as shown in the figure. In other embodiments, the mass block and the first substrate may be arranged on different sides of the first vibration membrane.

[0102] It can also be understood that in the above embodiments described in conjunction with the multiple figures, the outer diameter of the vibration unit may be equal to the outer diameter of the signal sensing unit, but it is not limited thereto. In other embodiments, the outer diameter of the vibration unit may be different from the outer diameter of the signal sensing unit. Figure 7a and Figure 7b An exemplary description is given.

[0103] Figure 7a A schematic diagram of a microphone sensor in which the outer diameter of the signal sensing unit is larger than the outer diameter of the vibration unit according to some embodiments of the present invention is shown. Figure 2a The microphone sensor shown in Figure 7a The outer diameter of the signal sensing unit 220 of the microphone sensor 200 shown in FIG. 2 may be greater than the outer diameter of the vibration unit 210 . In some embodiments, the outer diameter of the signal sensing unit 220 may be the outer diameter of the second substrate 223 , and the outer diameter of the vibration unit 210 may be the outer diameter of the first substrate 213 .

[0104] Figure 7b A schematic diagram of a microphone sensor in which the outer diameter of the signal sensing unit is larger than the outer diameter of the vibration unit according to some other embodiments of the present invention is shown. Figure 2b The microphone sensor shown in Figure 7b The outer diameter of the vibration unit 210 of the microphone sensor 200 shown in the figure can be smaller than the outer diameter of the signal sensing unit 220 to expose a portion of the back plate and / or the second vibration membrane (for example, the area 240 within the circle in the figure). The exposed portion of the electrode on the back plate and / or the portion of the second vibration membrane can be used to electrically connect an external integrated circuit chip to the back plate and / or the second vibration membrane.

[0105] Combination of the above Figure 7a and Figure 7b An exemplary description is given of a microphone sensor in which the outer diameter of the vibration unit according to the embodiment of the present invention is smaller than the outer diameter of the signal sensing unit.

[0106] The above is an exemplary description of the microphone sensor according to multiple embodiments of the present invention in combination with multiple drawings. The present invention also provides multiple implementation methods that are conducive to further improving the performance of the microphone sensor. For example, in other embodiments, the area of ​​the first vibration membrane can be set to be larger than the area of ​​the second vibration membrane. According to such a setting, using the Pascal principle, the change in air pressure in the first cavity caused by the vibration of the mass block can help amplify the signal generated by the back plate when it is transmitted to the second vibration membrane. The following will be combined with Figure 8a-8c Various implementations are described exemplarily.

[0107] Figure 8a A schematic diagram of a microphone sensor in which the hollow structure of the second substrate is set to a trapezoidal shape according to an embodiment of the utility model is shown. Figure 2a The microphone sensor shown in Figure 8a The longitudinal section of the hollow structure 225 of the second substrate 223 of the microphone sensor 200 shown in the figure may be a trapezoid, and the upper base of the trapezoid may be covered by the second vibration membrane 221 and the back plate 222. The trapezoid includes two parallel bases, and the shorter base is the upper base, so the smaller bottom surface of the hollow structure 225 is covered with the second vibration membrane 221 and the back plate 222, so that the area of ​​the first vibration membrane 211 is larger than that of the second vibration membrane 221, which is conducive to signal amplification.

[0108] Figure 8b A schematic diagram of a microphone sensor according to an embodiment of the present invention is shown in which the inner diameter of the second substrate is smaller than the diameter of the vibrating area of ​​the first vibration membrane. Figure 2a The microphone sensor shown in Figure 8b The inner diameter D1 of the second substrate 223 of the microphone sensor 200 shown in the figure may be smaller than the diameter D2 of the vibrating region 2113 of the first vibrating membrane 211. The inner diameter D1 of the second substrate 223 may be the diameter of the hollow structure inside the second substrate 223. In other embodiments, the vibrating region 2113 of the first vibrating membrane 211 may be the region where the first vibrating membrane 211 is suspended inside the first substrate 213, and the diameter D2 of the vibrating region 2113 of the first vibrating membrane 211 may be equal to the inner diameter of the first substrate 213.

[0109] like Figure 8bAs further shown in FIG. 2 , in some other embodiments, the microphone sensor 200 may further include a gasket 250, which may be connected between the second substrate 223 and the first vibration membrane 211. In some embodiments, the gasket 250 may be annular, and the inner diameter of the annular gasket is greater than the inner diameter D1 of the second substrate 223. In other embodiments, the number of gaskets 250 may be set to multiple, distributed between the second substrate 223 and the first vibration membrane 211. In some other embodiments, the gasket 250 may be a block with a certain thickness. In some embodiments, when the vibration unit and the signal sensing unit are connected by wafer bonding, a bonding medium may be used as the gasket 250.

[0110] According to such a configuration, not only can the area of ​​the first vibration membrane 211 be made larger than the area of ​​the second vibration membrane 221 , which is beneficial to signal amplification, but it can also be used to limit the vibration amplitude (or vibration height, or vibration distance) of the first vibration membrane 211 to avoid destructive deformation of the first vibration membrane 211 .

[0111] It is understood that the gasket 250 can be used to separate the signal sensing unit 220 and the vibration unit 210, thereby providing a vibration space for the first vibration membrane 211. It is also understood that the above description is exemplary and not restrictive. For example, the gasket 250 may not be limited to the structure shown in the figure, which may be an additional arrangement, or may be integrally formed with the second substrate 223. Figure 8c An exemplary description is given.

[0112] Figure 8c FIG. 1 shows a schematic diagram of a microphone sensor according to an embodiment of the present utility model, wherein the second substrate includes a supporting portion and a limiting portion. Figure 8c As shown in , the second substrate 223 of the microphone sensor 200 may include a supporting portion 227 and a defining portion 228, wherein the defining portion 228 is located between the supporting portion 227 and the first vibrating membrane 211, and the inner diameter D3 of the supporting portion 227 is smaller than the inner diameter D4 of the defining portion 228, so as to form a hollow structure having a stepped shape in a longitudinal section. In some embodiments, the defining portion 228 and the supporting portion 227 may be integrated. In other embodiments, the thickness of the supporting portion 227 may be greater than the thickness of the defining portion 228.

[0113] It is understandable that the setting of the support portion 227 can reduce the area of ​​the second vibration membrane 221, so that the area of ​​the first vibration membrane 211 is larger than the area of ​​the second vibration membrane 221, which is conducive to signal amplification, and can also be used to limit the vibration amplitude of the first vibration membrane 211 to avoid destructive deformation of the first vibration membrane 211. The setting of the limiting portion 228 can be conducive to providing a certain vibration space for the first vibration membrane 211.

[0114] Combination of the above Figure 8a-8c Various implementations of the first vibration membrane 211 having an area greater than the second vibration membrane 221 according to the embodiment of the utility model are described in an exemplary manner. It can be understood that the above description is exemplary rather than restrictive. For example, it is not limited to the second substrate being connected to the first vibration membrane in the figure (that is, the signal sensing unit in the figure is located above the vibration unit), and the end of the first substrate away from the first vibration membrane can also be connected to the signal sensing unit (that is, similar to Figure 2b and Figure 3b In this case, setting a trapezoidal hollow structure 225, or setting the inner diameter D1 of the second substrate 223 to be smaller than the diameter D2 of the vibrating area of ​​the first vibration membrane 211, can still be beneficial to signal amplification.

[0115] The utility model also provides a packaging structure of a microphone sensor for the aforementioned combination Figure 2a-Figure 8c Any of the microphone sensors is packaged. The following will be further described in conjunction with a plurality of drawings.

[0116] Fig. 9 FIG. 1 is a schematic diagram showing a packaging structure according to an embodiment of the present utility model. Fig. 9 As shown in the figure, the packaging structure 300 may include: a housing 301; a circuit board 302, which is surrounded by the housing 301 to form a second cavity 303; and Figure 2a-Figure 8c Any of the microphone sensors 200 described above is located in the second cavity 303. Taking the vibration unit shown in the figure as an example, which is arranged on the circuit board 302, the side of the first vibration membrane 211 facing away from the first cavity 230 faces the circuit board 302, and a third cavity 304 is formed between the first vibration membrane 211 and the circuit board 302.

[0117] In some embodiments, the circuit board 302 may be at least one of a printed circuit board, an ultra-thin circuit board, a flexible circuit board, etc. In other embodiments, the package structure 300 may further include an integrated circuit chip (ASIC) 305, which may be disposed on the circuit board 302 in the second cavity 303 and electrically connected to the microphone sensor 200 to output the signal sensed by the microphone sensor 200. In other embodiments, the thickness T of the package structure 300 may be 0.95 mm-3.5 mm, for example, 0.95 mm, 1 mm, 1.1 mm, 1.15 mm, 1.5 mm, 1.75 mm, 2 mm, 2.15 mm, 2.5 mm, 2.75 mm, 3 mm, 3.15 mm, 3.5 mm, etc. In some preferred embodiments, the thickness T of the package structure 300 may be 1.15 mm. In some embodiments, the length L of the package structure 300 may be 2.3 mm-4.72 mm (e.g., 2.3 mm, 2.5 mm, 2.7 mm, 3 mm, 3.2 mm, 3.5 mm, 3.7 mm, 4 mm, 4.2 mm, 4.5 mm, 4.7 mm, 4.72 mm, etc.), and the width (the dimension perpendicular to the paper in the figure, not shown) may be 1.6 mm-3.76 mm (e.g., 1.6 mm, 2 mm, 2.15 mm, 2.3 mm, 2.65 mm, 2.8 mm, 3 mm, 3.2 mm, 3.45 mm, 3.65 mm, 3.76 mm, etc.). In some preferred embodiments, the length L of the package structure 300 may be 3.2 mm, and the width may be 2.65 mm.

[0118] Combination of the above Fig. 9 The packaging structure according to the embodiment of the utility model is described exemplarily. It can be understood that the above description is exemplary rather than restrictive. For example, the mass block may not be limited to being arranged on the side of the first vibration membrane facing away from the first cavity as shown in the figure, but may also be arranged on the side of the first vibration membrane facing away from the first cavity as shown in the figure. Figure 2b or Figure 3a As shown, the microphone sensor is arranged on the side of the first vibration membrane facing the first cavity. For example, when the microphone sensor is arranged in the second cavity 303, it is not limited to Figure 2a or Figure 3a The vibration unit shown is arranged on a circuit board, and may also be, for example Figure 2b or Figure 3b The signal sensing unit shown is arranged on a circuit board. For another example, the packaging structure may not be limited to the sealed structure shown in the figure, but may also have an opening to improve the sensing sensitivity of the microphone sensor. Figure 10a-Figure 10c An exemplary description is given.

[0119] Fig.10a FIG. 1 is a schematic diagram showing a packaging structure including a first opening according to an embodiment of the present utility model. Fig.10aAs shown, the packaging structure 300 may include a housing 301, a circuit board 302, a microphone sensor 200 and an integrated circuit chip 305 to package Figure 7b Taking the microphone sensor 200 as an example, the exposed portion of the back plate 222 and / or the second vibration membrane 221 in the microphone sensor 200 may be directly or indirectly electrically connected to the integrated circuit chip 305 .

[0120] like Fig.10a As further shown in FIG. 3 , the housing 301 may have a first opening 306 that connects the second cavity 303 with the outside of the package body. The number of the first openings 306 may be one or more. The first openings 306 may be provided at, for example, the top of the housing 301 shown in the figure, or may be provided at the side of the housing 301 as required. The provision of the first openings 306 may help to expand the volume of the second cavity 303, thereby reducing the damping of each element in the microphone sensor, so as to improve the sensitivity of the microphone sensor.

[0121] Fig.10b FIG. 1 is a schematic diagram showing a packaging structure including a second opening according to an embodiment of the present utility model. Fig.10a The package structure shown in is different from that shown in Fig.10b The circuit board 302 in the package structure 300 shown in FIG. 1 has a second opening 307 connecting the third cavity 304 with the outside of the package. The number of the second openings 307 can be one or more. The second openings 307 can be arranged in the area of ​​the circuit board 302 covered by the third cavity 304. The arrangement of the second openings 307 can help to expand the volume of the third cavity 304, thereby reducing the damping of various components such as the mass block, so as to improve the sensitivity of the microphone sensor.

[0122] Fig.10c FIG. 1 is a schematic diagram showing a packaging structure including a first opening and a second opening according to an embodiment of the present utility model. Fig.10c As shown in , in some embodiments, the packaging structure 300 may include a first opening and a second opening at the same time, that is, the housing 301 has a first opening 306, and the circuit board 302 has a second opening 307. According to such a configuration, the volumes of the second cavity 303 and the third cavity 304 may be increased at the same time to reduce the damping of the elements of the microphone sensor, which is beneficial to improving the sensing sensitivity of the microphone sensor.

[0123] Combination of the above Figure 10a-Figure 10cThe packaging structure according to the embodiment of the utility model is described exemplarily. It can be understood that what is shown in the figure is illustrative and not restrictive. For example, the outer diameter of the vibration unit may not be limited to being smaller than the signal sensing unit, but may be set to be the same, and an electrical through hole may be set on the first substrate of the vibration unit. For another example, the signal sensing unit may not be limited to being connected to the circuit board as shown in the figure, but the vibration unit may be connected to the circuit board, which will not be repeated here. For another example, the method of expanding the volume of the third cavity and / or the second cavity may not be limited to only including the opening method shown in the figure, but may also be achieved by other methods. The following will be combined with Figure 11a-Figure 11d Further explanation.

[0124] Fig.11a Shows Figure 6a Schematic diagram of the packaging structure of the microphone sensor shown in FIG. Fig.11a As shown in FIG. , the package structure 300 may include a housing 301, a circuit board 302, a microphone sensor 200 and an integrated circuit chip 305 to package, for example, Figure 6a Taking the microphone sensor 200 as an example, the first base 213 of the vibration unit may have a first channel 215. The provision of the first channel 215 enables the microphone sensor to connect the third cavity 304 with the second cavity 303 when arranged on the circuit board 302, thereby increasing the volumes of the third cavity 304 and the second cavity 303 at the same time, which is beneficial to improving the sensitivity of the microphone sensor.

[0125] Fig.11b FIG. 1 is a schematic diagram showing a packaging structure having a groove on a circuit board according to an embodiment of the utility model. Fig.11b As shown in FIG. , the packaging structure may include a housing 301, a circuit board 302, a microphone sensor 200 and an integrated circuit chip 305 to package, for example, Figure 2a Taking the microphone sensor 200 shown as an example, a third cavity 304 is formed between the vibration unit of the microphone sensor 200 and the circuit board 302, and the circuit board 302 may have a groove 308 that is connected to the third cavity 304 and surrounded by the microphone sensor 200. In some embodiments, the groove 308 may be located on the side of the circuit board 302 facing the third cavity 304, and may not penetrate the circuit board 302. In other embodiments, the circuit board 302 is a multilayer board, and some layers may be removed from the multilayer board to form the groove 308. The number of the grooves 308 may be one or more. The size of the grooves 308 may be set as needed. By setting the grooves 308, the volume of the third cavity 304 may be increased to improve the sensitivity of the microphone sensor.

[0126] Fig.11cFIG. 1 is a schematic diagram showing a packaging structure in which the mass block and the first substrate have the same thickness according to an embodiment of the present invention. Fig.11b The package structure shown is different from Fig.11c The thickness of the mass block 212 shown in FIG. 1 is the same as the thickness of the first substrate 213. Fig.11c In the illustrated embodiment, the groove 308 can not only be used to expand the volume of the third cavity 304 , but also provide a vibration space for the mass block 212 .

[0127] Fig.11d A schematic diagram of a packaging structure in which a groove connects the third cavity and the second cavity according to an embodiment of the utility model is shown. Fig.11b The package structure shown is different from Fig.11d The microphone sensor 200 shown in the figure does not completely surround the groove 308, and the groove 308 can communicate with the third cavity 304 and the second cavity 303. According to such a configuration, the volumes of the third cavity 304 and the second cavity 303 can be increased at the same time, which is beneficial to improve the sensitivity of the microphone sensor.

[0128] Combination of the above Figure 11a-Figure 11d The packaging structure according to the multiple embodiments of the present invention is described exemplarily. It can be understood that the above description is exemplary rather than restrictive. For example, the first channel 215 may not be limited to Fig.11a Individual settings as shown in Figure 11b-Figure 11d Any of the grooves 308 shown are provided at the same time to achieve the effect of increasing the volume of the third cavity 304 and the second cavity 303 at the same time. For example, in the case where the third cavity is formed on the side of the signal sensing unit facing away from the first cavity (for example Figure 2b , 3b , 4, 6b or 7b), the second substrate may have a second channel, and / or by providing a groove, it can be achieved with Fig.11a , Fig.11b and Fig.11d For another example, the number of mass blocks may not be limited to one as shown in the figure, but may be set to multiple as required, and similar means as described above may also be used to achieve the technical effect of improving the sensitivity of the microphone.

[0129] Fig.12 FIG. 2 shows a schematic diagram of a packaging structure including a plurality of second openings according to an embodiment of the present utility model. Fig.12As shown in , the packaging structure may include a housing 301, a circuit board 302, a microphone sensor 200 and an integrated circuit chip 305, wherein the housing 301 and the circuit board 302 together form a second cavity 303, the vibration unit of the microphone sensor 200 may include a plurality of mass blocks (such as mass block 1 212-1 and mass block 212-2 in the figure, etc.), the side of the first vibration membrane 211 facing away from the first cavity 230 faces the circuit board 302, and the plurality of mass blocks may be located in the third cavity, wherein the sizes of the plurality of mass blocks may be designed according to different frequency requirements to increase the sensing bandwidth of the microphone sensor 200. Further, the circuit board 302 may have a plurality of second openings (such as second opening 1 307-1 and second opening 2 307-2 in the figure, etc.), and the number of the second openings may be equal to the number of mass blocks and correspond one to one.

[0130] Taking the two mass blocks and two second openings in the figure as an example, mass block 1 212-1 and mass block 2 212-2 can be separated, so that the third cavity can also be divided into two (for example, third cavity 1 304-1 and third cavity 2 304-2 in the figure), mass block 1 212-1 is in the third cavity 1 304-1, and mass block 2 212-2 is in the third cavity 2 304-2. A second opening can be set on the circuit board 302 corresponding to each third cavity, so that each second opening corresponds to a corresponding mass block to expand the volume of the corresponding third cavity. Fig.12 As shown in , the second opening 307-1 can correspond to the mass block 212-1 to expand the volume of the third cavity 304-1 where the mass block 212-1 is located; the second opening 307-2 can correspond to the mass block 212-2 to expand the volume of the third cavity 2 304-2 where the mass block 212-2 is located.

[0131] Understandably, Fig.12 The packaging structure shown in and the above description are exemplary rather than restrictive. For example, the number of mass blocks may not be limited to two as shown in the figure, and may be more or less as needed.

[0132] Furthermore, the utility model also provides a bone conduction microphone, which may include the above-mentioned Figure 9-12 Any of the packaging structures described in .

[0133] In order to facilitate understanding of the difference between the packaging structure of the embodiment of the utility model and the existing microphone structure, a further comparative explanation will be given below in combination with Table 1 and Table 2. Table 1 shows the comparison results of some features of the packaging structure of an embodiment of the utility model and the existing microphone structure. Table 2 shows the volume ratio of the first cavity of the packaging structure of an embodiment of the utility model to the volume ratio of the first cavity of the existing microphone structure.

[0134] Table 1:

[0135]

[0136]

[0137] Table 2:

[0138]

[0139] It should be noted that, for the sake of comparison, Tables 1 and 2 above only take one embodiment of the packaging structure of an embodiment of the utility model as an example. It can be understood that the size of the packaging structure of the embodiment of the utility model may not be limited to what is shown in Tables 1 and 2. For example, the thickness of the packaging structure may not be limited to 1.15 mm in the table, but may also be 1 mm, or 1.1 mm, etc.

[0140] As shown in Table 1, compared with Figure 1a and Figure 1b Compared with the existing microphone structure shown in the figure, the packaging structure of the microphone sensor packaged in the embodiment of the utility model has a smaller packaging thickness and packaging volume. Figure 1a and Figure 1b As shown in the microphone structure, the microphone sensor in the embodiment of the utility model is an independent device, the volume of the mass block is smaller, the area of ​​the first vibration membrane does not exceed the area of ​​the entire microphone sensor, the structural layout is more compact, and thus has a smaller packaging volume.

[0141] In addition, in addition to the structural setting of the microphone sensor of the above-mentioned embodiment of the utility model, the embodiment of the utility model can also adopt a wafer bonding connection method, which is beneficial to reduce the thickness of the microphone sensor, thereby reducing the thickness of the packaging structure, and can also reduce the alignment tolerance, so that the packaging difficulty of the microphone sensor of the embodiment of the utility model is significantly lower than the packaging difficulty of other existing microphone structures.

[0142] It can be seen from Table 1 that compared with Figure 1a and Figure 1b The volume of the first cavity of the packaging structure of the present invention is significantly reduced to only 0.15-0.25 mm. 3 , accounting for only 1.4% to 2.3% of the volume of the packaging structure. As can be seen from Table 2, the volume of the first cavity of the packaging structure of the embodiment of the utility model only accounts for less than 6% of the volume of the vibration cavity of the existing microphone structure. Based on this, it can be seen that compared with the existing microphone structure, the microphone sensor and its packaging structure of the embodiment of the utility model have better sensing sensitivity.

[0143] In summary, the microphone sensor of the embodiment of the utility model includes a vibration unit and a signal sensing unit, and forms a first cavity between the signal sensing unit and the first vibration membrane, which can form an independent device, which is conducive to reducing the difficulty of packaging, and can realize a microphone solution for collecting sound based on the principle of bone conduction, effectively avoiding the influence of external factors such as wind noise on the sound reception effect.

[0144] In some embodiments, the volume of the first cavity formed by connecting the vibration unit and the signal sensing unit is set to 0.075-0.25 mm 3 , which is helpful to improve the sensing sensitivity of the microphone sensor, and at the same time can help reduce the volume of the mass block, thereby helping to reduce the volume of the microphone sensor and its packaging structure. In other embodiments, by setting the vibration unit and the signal sensing unit to be connected in a wafer bonding manner, it is helpful to reduce the thickness of the microphone sensor and reduce the alignment tolerance, thereby reducing the thickness of its packaging structure and the packaging difficulty.

[0145] Although multiple embodiments of the utility model have been shown and described herein, it is obvious to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art may think of many changes, modifications and alternatives without departing from the idea and spirit of the utility model. It should be understood that in the process of practicing the utility model, various alternatives to the embodiments of the utility model described herein may be adopted. The attached claims are intended to define the scope of protection of the utility model, and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A microphone sensor, characterized in that: include: A vibration unit, comprising a first vibration membrane and a mass block arranged on one side of the first vibration membrane; The signal sensing unit comprises a second vibration membrane and a back plate which are arranged at intervals. The signal sensing unit is arranged on one side or the other side of the first vibration membrane where the mass block is arranged, and forms a first cavity between the signal sensing unit and the first vibration membrane.

2. The microphone sensor according to claim 1, characterized in that: The volume of the first cavity is 0.075-0.25 mm 3 .

3. The microphone sensor according to claim 1, characterized in that: The vibration unit and the signal sensing unit are connected in a wafer bonding manner.

4. The microphone sensor according to claim 3, characterized in that: The thickness of the bonding medium between the vibration unit and the signal sensing unit is less than 10 μm.

5. The microphone sensor according to any one of claims 1 to 4, characterized in that: The vibration unit further includes a first substrate, wherein the first substrate and the mass block are arranged on the same side of the first vibration membrane and surround the mass block, or the first substrate is arranged on the other side of the first vibration membrane; and / or The signal sensing unit further includes a second substrate having a hollow structure, and the second vibration membrane and the back plate are arranged at one end of the second substrate and cover the hollow structure.

6. The microphone sensor according to claim 5, characterized in that: The first vibration membrane is connected to the first substrate by deposition; and / or The second vibration membrane and the back plate are connected to one end of the second substrate in a deposition manner.

7. The microphone sensor according to claim 5, characterized in that: The other end of the second substrate of the signal sensing unit is connected to the one side or the other side of the first vibration membrane, and the hollow structure forms the first cavity.

8. The microphone sensor according to claim 5, characterized in that: The back plate or the second vibration membrane of the signal sensing unit is connected to an end of the first substrate away from the first vibration membrane to enclose the first substrate and form the first cavity.

9. The microphone sensor according to claim 7, characterized in that: The second vibration membrane is located between the back plate and the first vibration membrane; and The distance between the first vibration membrane and the second vibration membrane is greater than 100 μm.

10. The microphone sensor according to claim 7, characterized in that: When the first substrate and the mass block are arranged on the same side of the first vibration membrane and the other end of the second substrate of the signal sensing unit is connected to the other side of the first vibration membrane, the thickness of the mass block is less than or equal to the thickness of the first substrate.

11. The microphone sensor according to claim 8, characterized in that The first substrate and the mass block are arranged on the same side of the first vibration membrane, and the thickness of the mass block is smaller than the thickness of the first substrate.

12. The microphone sensor according to claim 5, characterized in that: The vibration unit includes a plurality of mass blocks, and adjacent mass blocks are spaced apart from each other.

13. The microphone sensor according to claim 8, characterized in that The outer diameter of the vibration unit is equal to the outer diameter of the signal sensing unit, and the first substrate has an electrical through hole connected to the back plate and / or the second vibration membrane; or The outer diameter of the vibration unit is smaller than the outer diameter of the signal sensing unit so as to expose a portion of the back plate.

14. The microphone sensor according to claim 1, characterized in that An area of ​​the first vibration membrane is larger than an area of ​​the second vibration membrane.

15. The microphone sensor according to claim 5, characterized in that The longitudinal section of the hollow structure is a trapezoid, and the upper base of the trapezoid is covered by the second vibration membrane and the back pole plate.

16. The microphone sensor according to claim 7, characterized in that The inner diameter of the second substrate is smaller than the diameter of the vibrating area of ​​the first vibration membrane; and The microphone sensor further includes a spacer connected between the second substrate and the first diaphragm.

17. The microphone sensor according to claim 7, characterized in that: The second substrate includes a supporting portion and a defining portion, the defining portion is located between the supporting portion and the first vibration film, and an inner diameter of the supporting portion is smaller than an inner diameter of the defining portion to form the hollow structure having a stepped shape.

18. The microphone sensor according to claim 7, characterized in that The vibration unit includes the first substrate, and the first substrate is located on a side of the first vibration membrane facing away from the first cavity, and the first substrate has a first channel connecting the first vibration membrane and the outside of the vibration unit.

19. The microphone sensor according to claim 8, characterized in that The signal sensing unit includes the second substrate, and the second substrate has a second channel communicating with the hollow structure and the outside of the signal sensing unit.

20. The microphone sensor according to claim 5, characterized in that The thickness of the vibration unit is 300 μm-600 μm; The signal sensing unit has a thickness of 300 μm-400 μm.

21. The microphone sensor according to claim 1, characterized in that The mass block is a metal mass block or a single crystal silicon mass block.

22. A packaging structure of a microphone sensor, characterized in that: include: case; A circuit board, which is enclosed with the shell to form a second cavity; as well as According to any one of claims 1-21, the microphone sensor is located in the second cavity, and the side of the first vibration membrane facing away from the first cavity or the side of the signal sensing unit facing away from the first cavity faces the circuit board, and forms a third cavity between the first vibration membrane and the circuit board.

23. The packaging structure according to claim 22, characterized in that: The housing has a first opening connecting the second cavity with the outside; and / or The circuit board has a second opening communicating with the third cavity and the outside.

24. The packaging structure according to claim 23, characterized in that: The side of the first vibration membrane facing away from the first cavity faces the circuit board, and the mass block is located in the third cavity. The number of the second openings is equal to the number of the mass blocks and corresponds one to one.

25. The packaging structure according to any one of claims 22 to 24, characterized in that: The circuit board has a groove communicating with the third cavity.

26. The packaging structure according to claim 25, characterized in that: The groove communicates with the third cavity and the second cavity.

27. The packaging structure according to claim 22, characterized in that: Also includes The integrated circuit chip is arranged on the circuit board and is electrically connected to the microphone sensor.

28. The packaging structure according to claim 22, characterized in that: The packaging structure has a thickness of 0.95 mm to 3.5 mm.

29. A bone conduction microphone, characterized in that: Comprising a packaging structure according to any one of claims 22-28.

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