Package Structure of MEMS Sensor

Abstract

A packaging structure of a MEMS sensor is disclosed, including: a first substrate and a packaging housing, the packaging housing is fixedly connected to the second surface of the first substrate and forms a cavity, a sensor assembly, which is fixedly connected to the first substrate in the cavity, the sensor assembly includes a sensor chip, the sensor chip senses vibration along a first direction or a second direction on the surface of the sensor chip, wherein the sensor chip is placed along a third direction to realize sensitivity detection in the third direction, and the first direction, the second direction and the third direction are perpendicular to each other in pairs. In the packaging structure of the MEMS sensor of the present application, by arranging the electrodes on the packaging housing in the packaging structure on a plane perpendicular to the vibration sensing direction of the sensor assembly, the function of realizing Z-axis bone vibration sensing by using an X-axis MEMS sensor is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of MEMS sensors, and particularly to a packaging structure for a MEMS sensor. Background Art

[0002] A sensor manufactured based on Micro Electro Mechanical Systems (MEMS) is called a MEMS sensor. MEMS sensors are highly regarded due to their extremely small size and good performance. A MEMS sensor generally includes a microelectromechanical structure chip and a signal processing chip electrically connected to the microelectromechanical structure. In order to prevent the chips from being broken and reduce the interference of the environment on the chips, it is necessary to protect the microelectromechanical structure chip and the signal processing chip in the MEMS sensor by setting a packaging structure. At the same time, it is also necessary to form an electrical connection between the signal processing chip and the outside through the packaging structure.

[0003] Most of the existing single-axis bone conduction microphone sensors based on MEMS acceleration chips are composed of X-axis or Y-axis MEMS acceleration chips, which can sense bone vibration signals in the X-axis or Y-axis. However, in actual applications, the demand for Z-axis bone vibration is greater. On the one hand, taking X-axis bone conduction as an example, its sensitivity in the X-axis direction is much greater than that in the Z-axis direction. Therefore, in the actual application process, the sensitivity output effect is not good, and the X-axis performance is not maximized. On the other hand, most of the existing Z-axis bone conduction sensor chips are composed of a microphone plus a mass block structure. This structure has low reliability and cannot effectively isolate the air-borne sound signal, and does not achieve the true bone conduction effect, so it has great limitations in actual applications. Summary of the Invention

[0004] In view of the above problems, an object of the present invention is to provide a packaging structure for a MEMS sensor. By setting the electrodes on the packaging shell of the packaging structure on a plane perpendicular to the vibration direction sensed by the sensor assembly, the function of sensing Z-axis bone vibration is achieved by using an X-axis MEMS sensor.

[0005] According to an aspect of the present invention, there is provided a packaging structure for a MEMS sensor, including: a first substrate and a packaging shell, the packaging shell is fixedly connected to a first surface of the first substrate and forms a cavity, a sensor assembly, which is fixedly connected to the first substrate in the cavity, the sensor assembly includes a sensor chip, and the sensor chip senses vibration along a first direction or a second direction on the surface of the sensor chip. Wherein, the sensor chip is placed along a third direction to achieve sensitivity detection in the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other pairwise.

[0006] Optionally, the first substrate and / or the encapsulation housing include: a plurality of first pads, and a plane where the first pads are located is perpendicular to a vibration direction sensed by the sensor assembly.

[0007] Optionally, when a vibration direction sensed by the sensor chip is perpendicular to a first surface of the first substrate, the first pads are located on a second surface of the first substrate.

[0008] Optionally, when a vibration direction sensed by the sensor chip is parallel to a first surface of the first substrate, the first pads are located on a side surface of the first substrate and / or the encapsulation housing that is perpendicular to the sensed vibration direction.

[0009] Optionally, the first pads extend from the first substrate to the encapsulation housing along a direction from the second surface to the first surface of the first substrate.

[0010] Optionally, it further includes: second pads, which are located on a surface of the first substrate and / or the encapsulation housing that is parallel to a vibration direction sensed by the sensor chip.

[0011] Optionally, the encapsulation housing includes: a second substrate and a third substrate. There is a through hole in the second substrate, and it is located between the first substrate and the third substrate. The through hole is used to accommodate the sensor assembly.

[0012] Optionally, the first pads or the second pads located on the first substrate and the encapsulation housing are recessed inward from a side wall surface of the first substrate and the encapsulation housing.

[0013] Optionally, adjacent pads are separated by a planar insulation region.

[0014] Optionally, the first pads or the second pads further include: a portion extending along the side wall surface to the first surface of the first substrate and the second surface of the encapsulation housing to achieve electrical connection between the first substrate and the encapsulation housing.

[0015] Optionally, the encapsulation housing includes at least one air vent hole.

[0016] Optionally, the sensor chip includes an X-axis MEMS bone conduction sensor.

[0017] The packaging structure of the MEMS sensor provided by the present invention achieves the function of Z-axis bone vibration sensing by using an X-axis MEMS bone conduction sensor, so as to achieve the maximum sensitivity output in the Z-axis direction by setting the first pad on the packaging shell of the packaging structure on the plane perpendicular to the vibration direction sensed by the sensor component. Among them, there are two ways to set the first pad on the packaging shell on the plane perpendicular to the vibration direction sensed by the sensor component. One is that the sensor component is normally connected to the substrate, and the first pad is set on the side of the sensor component on the packaging shell; the other is that the first pad is normally set on the first substrate, and the sensor component is rotated 90° from the X-axis direction to the Z-axis direction and then connected to the first substrate.

[0018] Furthermore, using an X-axis MEMS bone conduction sensor to achieve the function of a Z-axis sensor results in little change to the overall structure, mainly only the change in the wire bonding method and / or the increase in the position and number of the first pads. The substrate and the housing can be made compatible. At the same time, the advantages of the X-axis sensor are utilized, such as good reliability, high isolation degree for airborne sound, high sensitivity, higher stability and consistency of sensitivity, and more mature and stable chip process.

[0019] In a preferred embodiment, on the packaging structure of the MEMS sensor, the second surface of the first substrate and the side surfaces of the first substrate and the packaging shell are respectively provided with a second pad and a first pad. When connecting the packaging structure of the MEMS sensor to an external PCB board, both the first pad and the second pad can be used as connection pads, and different connection methods will make the MEMS sensor act as an X-axis sensor and a Z-axis sensor respectively.

[0020] Furthermore, the first pad on the side wall direction of the MEMS sensor packaging structure is arc-shaped and recessed inward from the side wall surface of the packaging structure, thereby increasing the area of the pad in a limited space and reducing the contact resistance between the first pad and the external circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Through the following description of the embodiments of the present invention with reference to the drawings, the above and other objects, features, and advantages of the present invention will become clearer. In the drawings:

[0022] Figure 1 Shows an overall appearance schematic diagram of the packaging structure of the MEMS sensor according to the first embodiment of the present invention;

[0023] Figure 2a and Figure 2b Respectively show schematic diagrams of the first surface and the second surface of the first substrate in the packaging structure of the MEMS sensor according to the first embodiment of the present invention;

[0024] Figure 3Shows a schematic diagram of the first surface of the second substrate located on the first substrate in the packaging structure of the MEMS sensor according to the first embodiment of the present invention;

[0025] Figure 4 Shows a schematic diagram of the second surface of the third substrate in the packaging structure of the MEMS sensor according to the first embodiment of the present invention;

[0026] Figure 5 Shows a schematic diagram of the sensor assembly and the first substrate in the packaging structure of the MEMS sensor according to the second embodiment of the present invention;

[0027] Figure 6a and Figure 6b Show the overall and partial schematic diagrams of the packaging structure of the MEMS sensor according to the third embodiment of the present invention, respectively. Detailed Description of the Invention

[0028] The present invention will be described in more detail below with reference to the accompanying drawings. In the respective drawings, like elements are denoted by like reference numerals. For clarity, the various parts in the drawings are not drawn to scale. In addition, some well-known parts may not be shown. For simplicity, a semiconductor structure obtained after several steps may be described in one drawing.

[0029] It should be understood that when describing the structure of a device, when a layer or a region is referred to as being "above" or "over" another layer or another region, it may mean directly above the other layer or another region, or there may be other layers or regions between it and the other layer or another region. And if the device is turned over, this layer or region will be "below" or "beneath" the other layer or region.

[0030] If it is for describing the case of being directly above another layer or another region, the expressions "directly on... above" or "above and adjacent to..." will be used herein.

[0031] The following will further describe in detail the specific embodiments of the present invention in conjunction with the accompanying drawings and embodiments.

[0032] Figure 1 Shows a schematic diagram of the overall appearance of the packaging structure of the MEMS sensor according to the first embodiment of the present invention; Figure 2a and Figure 2b Show the schematic diagrams of the first surface and the second surface of the first substrate in the packaging structure of the MEMS sensor according to the first embodiment of the present invention, respectively; Figure 3 Shows a schematic diagram of the first surface of the second substrate located on the first substrate in the packaging structure of the MEMS sensor according to the first embodiment of the present invention; Figure 4Shows a schematic diagram of the second surface of the third substrate in the packaging structure of the MEMS sensor according to the first embodiment of the present invention.

[0033] Referring Figure 1 , the packaging structure 100 of the MEMS sensor according to the first embodiment of the present application includes a first substrate 110, a second substrate 120, and a third substrate 130. The second substrate 120 and the third substrate 130 can form a packaging shell, jointly forming a square box body with the first substrate 110, and a cavity is formed inside the three substrates. The sensor assembly 140 is located in this cavity. For example, referring Figure 3 . Among them, on the side wall of the packaging structure, there are a plurality of side wall electrodes composed of the first substrate 110, the second substrate 120, and the third substrate 130, extending in the direction of the first surface and the second surface of the substrate, and adjacent side wall electrodes are separated by an insulating region.

[0034] Referring Figure 2a and Figure 2b , the first surface of the first substrate 210 is located on the plane formed by the X-axis and the Y-axis. On the first surface of the first substrate 110, there are a sealing ring 114, a first electrode 116, a first welding area 115, a first conductive channel 113, and first pads 111b and a first insulating region 112b. On the second surface of the first substrate 110, there is a second pad 117. At the same time, on one side wall of the first substrate 110, there are first pads 111a and a first insulating region 112a.

[0035] Among them, the first sealing ring 114 is used for sealing and connecting the first substrate 110 and the second substrate 120, and at the same time, the first sealing ring 114 is also a conductor. Among the four side lengths of the first surface of the first substrate 110, the first sealing ring 114 extends along three of the side lengths and leaves a certain distance from the fourth side length. In the area surrounded by the first sealing ring 114 around the first surface of the first substrate 110, the sensor assembly 140 is fixedly pasted.

[0036] The sensor assembly 140 includes a MEMS bone conduction chip and an ASIC chip. The MEMS bone conduction chip is used to sense bone vibration in the X direction. The ASIC chip can be fixedly pasted above the MEMS bone conduction chip and electrically connect the ASIC chip and the MEMS bone conduction chip through leads. In addition, the MEMS bone conduction chip is also electrically connected to the first electrode 116 through a lead. The first electrode 116 is connected to the first welding area 115 through a trace on the first surface of the first substrate 110. The first welding area 115 is a via welding area for realizing electrical interconnection between the first substrate 110 and the third substrate 130.

[0037] In the region on the first surface of the first substrate 110 that is outside the first sealing ring 114, a plurality of first pads 111b and first insulating regions 112b are formed, and the first pads 111b and the first insulating regions 112b are arranged at intervals on the first surface of the first substrate 110, as Figure 2a shown. In addition, the first pads 111b are electrically connected to the first electrodes 116 or the first welding regions 115 by routing on the first surface of the first substrate 110 or routing in the first substrate 110, thereby realizing the electrical connection between the first pads 111 and the sensor assembly 140.

[0038] On one side surface of the first substrate 110, that is, the side surface corresponding to the first pads 111b, first pads 111a are also formed. The first pads 111a on the side surface correspond to and are connected to the first pads 111b on the first surface, and adjacent first pads 111a are separated by first insulating regions 112a. The first pads 111 (including 111a and 111b) are arc-shaped structures that are recessed from the side surface of the first substrate 110 towards the inside of the first substrate 110, thereby increasing the area of the first pads 111 on the side surface of the first substrate 110.

[0039] Furthermore, on the second surface of the first substrate 110, a plurality of second pads 117 are formed. In this embodiment, the second pads 117 are also lead-out pads and can be used to connect to an external PCB board. The second pads 117 are electrically connected to the first welding regions 115 on the first surface of the first substrate 110 through first conductive channels 113, thereby realizing the electrical connection between the second pads 117 and the sensor assembly 140. In other regions on the second surface of the first substrate 110, copper cladding (not shown in the figure) is formed to enhance electromagnetic shielding, and the copper cladding is isolated from the second pads 117.

[0040] Referring to Figure 3 , the second substrate 120 has a through hole 121 that is used to accommodate the sensor assembly 140 mounted on the first surface of the first substrate 110 after the second substrate 120 is hermetically connected to the first substrate 110. Among them, copper cladding (not shown in the figure) is formed on the side walls of the through hole 121 to enhance electromagnetic shielding.

[0041] On the first surface of the second substrate 120, a second sealing ring 122 is formed. The second sealing ring 122 surrounds the through hole 121 and the connection region 125. In the connection region 125, a second welding region 124 is provided. The second welding region 124 also has a second conductive channel 123 that penetrates the connection region of the second substrate 120, realizing the electrical connection between the third welding region on the second surface of the second substrate 120 and the second welding region 124 on the first surface.

[0042] In the region outside the second sealing ring 122 on the first surface of the second substrate 120, a plurality of third pads 126b are arranged at intervals with the second insulating region 127b. On the side surface of the second substrate 120 corresponding to the third pads 126b, a plurality of third pads 126a and the second insulating region 127a are arranged at intervals, and the third pads 126a correspond to and are connected to the third pads 126b, and the second insulating region 127a corresponds to and is connected to the second insulating region 127b.

[0043] It can be understood that on the second surface of the second substrate 120, there is the same structure and layout as the first surface of the second substrate 120. Therefore, when the second surface of the second substrate 120 is hermetically connected to the first surface of the first substrate 110, the first sealing ring 114 on the first surface of the first substrate 110 and the third sealing ring on the second surface of the second substrate 120 are correspondingly connected; the connection region on the second surface of the second substrate 120 corresponds to and is connected to the region where the first welding region 115 is located on the first surface of the first substrate 110; the third welding region on the second surface of the second substrate 120 corresponds to and is connected to the first welding region 115 on the first surface of the first substrate 110; the third pads on the second surface of the second substrate 120 correspond to and are connected to the first pads 111b on the first surface of the first substrate 110; the second insulating region on the second surface of the second substrate 120 corresponds to and is connected to the first insulating region 112b on the first surface of the first substrate 110. Thus, the third pads 126 of the second substrate 120 are connected to the first electrode 116 or the first welding region 115 through the first pads 111 of the first substrate 110, and then are connected to the sensor assembly 140.

[0044] Among them, the second sealing ring 122 on the first surface of the second substrate 120 and the third sealing ring on the second surface are also conductors, and they, together with the first sealing ring 114 on the first surface of the first substrate 110, the fourth sealing ring 131 on the second surface of the third substrate 130, and the copper coating on the side wall of the through hole 121 of the second substrate 120, form an electromagnetic shielding cavity.

[0045] Further, referring to Figure 4 , on the second surface of the third substrate 130, it includes the fourth sealing ring 131, the connection region 132 located within the region of the fourth sealing ring 131, the fourth welding region 133, and the vent hole 134; the fourth pads 135c and the third insulating region 136c located outside the region of the fourth sealing ring 131, and the fourth pads 135a and the third insulating region 136a located on the side surface of the third substrate 130 corresponding to the fourth pads 135c and the third insulating region 136c.

[0046] On the first surface of the third substrate 130, a copper coating (not shown in the figure) is formed for enhancing electromagnetic shielding.

[0047] When the second surface of the third substrate 130 is hermetically connected to the first surface of the second substrate 120, the fourth sealing ring 131 on the second surface of the third substrate 130 corresponds to and is connected to the second sealing ring 122 on the first surface of the second substrate 120; the connection area 132 on the second surface of the third substrate 130 corresponds to and is connected to the connection area 125 on the first surface of the second substrate 120; the fourth welding area 133 on the second surface of the third substrate 130 corresponds to and is connected to the second welding area 124 on the first surface of the second substrate 120; the fourth pad 135c on the second surface of the third substrate 130 corresponds to and is connected to the third pad 126b on the first surface of the second substrate 120; the third insulating area 136c on the second surface of the third substrate 130 corresponds to and is connected to the second insulating area 127b on the first surface of the second substrate 120.

[0048] The packaged structure after the first substrate 110, the second substrate 120 and the third substrate 130 are connected is as Figure 1 shown. On the side of the packaged structure, a plurality of arc-shaped sidewall pads extending from the first substrate 110 to the third substrate 130 are formed by the first pad 111a, the third pad 126a and the fourth pad 135a, and a plurality of insulating area planes separating the sidewall pads are formed by the first insulating area 112a, the second insulating area 127a and the third insulating area 136a.

[0049] In the first embodiment, it is assumed that the surface of the external PCB board is located in the plane of the X-axis and the Y-axis. Then, when the second pad 117 on the second surface of the first substrate 110 is electrically connected to the external PCB board, the first surface of the first substrate 110 is also located in the plane of the X-axis and the Y-axis, and the direction in which the sensor component 140 senses vibration is parallel to the first surface of the first substrate 110, that is, the sensor component 140 is used to sense X-axis vibration; if when the sidewall pad of the first substrate 110 is electrically connected to the external PCB board, the first surface of the first substrate 110 is located in the plane of the Y-axis and the Z-axis, at this time the sensor component 140 is used to sense Z-axis vibration.

[0050] Therefore, the packaged structure of the MEMS sensor provided in the first embodiment of the present application can be used to test Z-axis vibration or X-axis vibration according to different pads connected to the external PCB board in the packaged structure.

[0051] Figure 5 FIG. shows a schematic structural diagram of a sensor component and a first substrate in a packaged structure of a MEMS sensor according to a second embodiment of the present invention. Compared with the packaged structure 100 of the MEMS sensor in the first embodiment, in the packaged structure 200 of the MEMS sensor in the second embodiment, the direction in which the sensor component senses vibration is perpendicular to the first surface of the first substrate 210.

[0052] Refer to Figure 5, on the first surface of the first substrate 210, a first sealing ring 214 is formed, a first electrode 216 and a first welding area 215 located in the first sealing ring 214, a second pad 211b and a first insulating area 212b located outside the first sealing ring 214. Among them, on the first surface of the first substrate 210, a sensor assembly 240 is also fixed. The sensor assembly 240 is connected to the first electrode 216 through a lead wire. The first electrode 216 and the first welding area 215 are electrically connected through a trace on the first surface of the first substrate 210 (not shown in the figure). The first electrode 216 or the first welding area 215 is connected to the second pad 211b through a surface trace. The first welding area 215 also includes a second conductive channel (not shown in the figure), and the second conductive channel penetrates the first substrate 210 and electrically signals are led out to the second surface of the first substrate 210.

[0053] The sensor assembly 240 is a bone conduction sensor for sensing X-axis vibration. After the sensor assembly 240 is fixed to the first substrate 210, its sensing direction is perpendicular to the first surface of the first substrate 210. On the second surface of the first substrate 210, a plurality of first pads are also formed (refer to Figure 2b ), and the first pads are electrically connected to the first welding area 215 through the second conductive channel.

[0054] When the first pads on the second surface of the first substrate 210 of the packaging structure 200 of the MEMS sensor are connected to an external PCB board, the packaging structure 200 of the MEMS sensor is used to sense Z-axis vibration; when the second pads on the side surfaces of the first substrate 210 to the third substrate of the packaging structure 200 of the MEMS sensor are connected to an external PCB board, the packaging structure 200 of the MEMS sensor is used to sense X-axis vibration.

[0055] In the second embodiment, it is considered that the surface of the external PCB board is located in the plane where the X-axis and the Y-axis are located. Then, when the first pads on the second surface of the first substrate 210 are electrically connected to the external PCB board, the first surface of the first substrate 210 is also located in the plane where the X-axis and the Y-axis are located, and the sensing direction of the sensor assembly 240 for sensing vibration is perpendicular to the first surface of the first substrate 210. At this time, the sensor assembly 240 is used to sense Z-axis vibration; if when the second pads 211 on the side surface of the first substrate 210 are electrically connected to the external PCB board, the first surface of the first substrate 210 is located in the plane where the Y-axis and the Z-axis are located, at this time the sensor assembly 240 is used to sense X-axis vibration.

[0056] Figure 6a and Figure 6bThe overall and partial schematic diagrams of the packaging structure of the MEMS sensor according to the third embodiment of the present invention are respectively shown. Compared with the second embodiment, the packaging structure of the packaging structure 300 of the MEMS sensor in the third embodiment is composed of a first substrate and a packaging shell, and no pads are formed on the sides of the first substrate and the packaging shell.

[0057] Specifically, referring to Figure 6a and Figure 6b , the packaging structure 300 of the MEMS sensor includes: a first substrate 310 and a packaging shell 320. An air vent 321 is formed on the packaging shell 320, and a cavity (not shown in the figure) is formed between the packaging shell 320 and the first substrate 310. The packaging shell is made of a metal material, for example.

[0058] The sensor assembly 340 includes a sensor for sensing X-axis vibration, which is fixed on the first surface of the first substrate 310 in the cavity. On the first surface of the first substrate 310, a first sealing ring 312 is also formed. The packaging shell 320 is fixedly connected to the packaging shell 320 through the first sealing ring 312. Inside the first sealing ring 312 on the first surface of the first substrate 310, electrodes 313 are formed. The sensor assembly 340 is electrically connected to the electrodes 313 through leads.

[0059] On the second surface of the first substrate 310, a first pad (not shown in the figure) is also formed. The electrodes 313 are electrically connected to the first pad, so as to transfer the electrical signals of the sensor assembly 340 to the first pad, and the packaging structure 300 of the MEMS sensor is electrically connected to an external PCB board through the first pad.

[0060] In the third embodiment, it is considered that the surface of the external PCB board is located in the plane where the X-axis and Y-axis are located. After the packaging structure 300 of the MEMS sensor is electrically connected to the external PCB board, the sensing direction of the sensor assembly 340 is perpendicular to the first surface of the first substrate 310. Therefore, the sensor assembly 340 can sense vibrations in the Z-axis direction.

[0061] For the packaging structure of the MEMS sensor provided by the present invention, by setting the first pad on the packaging shell in the packaging structure on the plane perpendicular to the vibration direction sensed by the sensor assembly, the function of using an X-axis MEMS bone conduction sensor to realize Z-axis bone vibration sensing is achieved, and the maximum sensitivity of the X-axis MEMS bone conduction sensor in the Z-axis direction is realized. Among them, setting the first pad on the packaging shell on the plane perpendicular to the vibration direction sensed by the sensor assembly includes two methods. One is that the sensor assembly is normally connected to the substrate, and the first pad is set on the side of the sensor assembly on the packaging shell; the other is that the first pad is normally set on the second surface of the first substrate, and the sensor assembly is rotated 90° from the X-axis direction to the Z-axis direction and then connected to the first substrate.

[0062] Furthermore, the MEMS bone conduction sensor on the X-axis is adopted to realize the function of the Z-axis sensor, with little change to the overall structure, mainly only the change in the wire bonding method and / or the increase in the position and quantity of the first pads, and both the substrate and the housing can be made compatible; meanwhile, the advantages of the X-axis sensor are utilized, such as good reliability, high isolation degree for airborne sound, high sensitivity, higher stability and consistency of sensitivity, and more mature and stable chip process.

[0063] In a preferred embodiment, on the packaging structure of the MEMS sensor, the first pads are respectively arranged on the second surface of the first substrate and the side surfaces of the first substrate and the packaging housing. When connecting the packaging structure of the MEMS sensor to an external PCB board, both the first pads and the second pads can be used for connection, and different connection methods will make the MEMS sensor serve as an X-axis sensor and a Z-axis sensor respectively.

[0064] Furthermore, the first pad on the side wall direction of the MEMS sensor packaging structure is arc-shaped and recessed inward from the side wall surface of the packaging structure, thereby increasing the area of the first pad in a limited space and reducing the contact resistance between the first pad and the external circuit.

[0065] As described above in the embodiments of the present invention, these embodiments do not elaborate on all details and do not limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the above description. The purpose of selecting and specifically describing these embodiments in this specification is to better explain the principle and practical application of the present invention, so that those skilled in the art can make good use of the present invention and its modifications based on the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A packaging structure for a MEMS sensor, characterized in that, Comprising: A first substrate and a packaging housing, the packaging housing being fixedly connected to a first surface of the first substrate and forming a cavity, and the packaging housing including at least one vent hole; A sensor assembly fixedly connected to the first substrate in the cavity, The sensor assembly includes a bone conduction sensor chip, and the sensor chip is fixedly connected to the first substrate, Wherein, the sensor chip senses vibrations along a first direction or a second direction on the surface of the sensor chip, and when the packaging structure is connected to an external PCB board, the surface of the sensor chip is placed along a third direction to sense vibrations in the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other in pairs.

2. The encapsulation structure according to claim 1, wherein On the first substrate and / or the packaging housing, there are provided: a plurality of first pads, and a plane where the first pads are located is perpendicular to the vibration direction sensed by the sensor assembly.

3. The encapsulation structure according to claim 2, wherein When the vibration direction sensed by the sensor chip is perpendicular to the first surface of the first substrate, the first pads are located on a second surface of the first substrate.

4. The encapsulation structure according to claim 2, wherein When the vibration direction sensed by the sensor chip is parallel to the first surface of the first substrate, the first pads are located on a side surface of the first substrate and / or the packaging housing that is perpendicular to the sensed vibration direction.

5. The encapsulation structure according to claim 4, wherein The first pads extend from the first substrate to the packaging housing along a direction from the second surface of the first substrate to the first surface.

6. The encapsulation structure according to any one of claims 2-5, characterized in that, Further comprising: Second pads located on a surface of the first substrate and / or the packaging housing that is parallel to the vibration direction sensed by the sensor chip.

7. The encapsulation structure according to claim 6, wherein The packaging housing includes a second substrate and a third substrate. There is a through hole penetrating through the second substrate, and the second substrate is located between the first substrate and the third substrate. The through hole is used to accommodate the sensor assembly.

8. The encapsulation structure according to claim 7, characterized in that, The first pads or the second pads located on the first substrate and the packaging housing are recessed inward from the side wall surfaces of the first substrate and the packaging housing.

9. The encapsulation structure according to claim 8, wherein, Adjacent pads are separated by a planar insulating region.

10. The encapsulation structure according to claim 8, characterized in that, The first pads or the second pads further include a portion extending along the side wall surface to the first surface of the first substrate and the second surface of the packaging housing to achieve electrical connection between the first substrate and the packaging housing.

11. The encapsulation structure according to claim 1, characterized in that, The sensor chip includes an X-axis MEMS bone conduction sensor.

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