MEMS sensor

Abstract

The utility model provides an MEMS (micro-electromechanical system) sensor, which comprises a packaging structure consisting of a PCB (printed circuit board) and a shell, an ASIC (application specific integrated circuit) chip and an MEMS chip are arranged on the PCB inside the packaging structure, and the shell, the ASIC chip and the MEMS chip are fixed on the PCB in an embedded manner. By utilizing the MEMS sensor, the problem that the performance of the sensor is influenced due to the fact that the existing MEMS sensor is adhered by glue or solder paste and is easy to generate glue creeping or unstable adhesion can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, and more specifically, to a MEMS sensor. Background Art

[0002] The traditional MEMS sensor is a packaging structure formed by assembling a PCB and a shell, and an ASIC chip and a MEMS chip are arranged on the PCB inside the packaging structure, wherein the ASIC chip, the MEMS chip and the shell are directly bonded to the PCB with glue / solder paste. This direct bonding method is used to fix each other. If too much glue is applied, glue creeping may occur, affecting product performance. If too little glue is applied, air leakage may occur, resulting in loose adhesion. Utility Model Content

[0003] In view of the above problems, the purpose of the utility model is to provide a MEMS sensor to solve the problem that the existing MEMS sensors bonded by glue or solder paste are prone to glue creeping or loose bonding, which affects the sensor performance.

[0004] The utility model provides a MEMS sensor, comprising a packaging structure composed of a PCB board and a shell, wherein an ASIC chip and a MEMS chip are arranged on the PCB board inside the packaging structure, wherein:

[0005] The housing, the ASIC chip and the MEMS chip are embedded and fixed on the PCB board.

[0006] In addition, a preferred structure is that a housing groove for fixing the housing, an ASIC groove for fixing the ASIC chip and a MEMS groove for fixing the MEMS chip are respectively provided on the PCB board.

[0007] Adhesive is coated in each groove, and the housing, the ASIC chip and the MEMS chip are fixed in the corresponding grooves by the adhesive.

[0008] In addition, a preferred structure is that the depth of the housing groove is greater than the depth of the ASIC groove.

[0009] In addition, a preferred structure is that the depth of the MEMS groove is greater than the depth of the housing groove.

[0010] In addition, a preferred structure is that a sound hole connected to the outside is provided on the PCB board corresponding to the MEMS chip, and the sound hole is used to transfer the external sound pressure to the diaphragm of the MEMS chip inside the packaging structure.

[0011] In addition, a preferred structure is that a back hole is provided on the MEMS chip, and the back hole is provided corresponding to the acoustic hole, wherein:

[0012] The diameter of the back hole is greater than or equal to the diameter of the sound hole.

[0013] In addition, a preferred structure is that the adhesive is silver paste or solder paste or silica gel or epoxy glue.

[0014] In addition, a preferred structure is that the ASIC chip and the MEMS chip, and the ASIC chip and the PCB board are electrically connected via gold wires respectively.

[0015] In addition, a preferred structure is that a soldering pad is provided on a PCB board outside the packaging structure, and the PCB board is electrically connected to an external device through the soldering pad.

[0016] It can be seen from the above technical solution that the MEMS sensor provided by the utility model embeds and fixes the housing, ASIC chip and MEMS chip on the PCB board, thereby improving the reliability of connecting the housing, ASIC chip and MEMS chip with the PCB board and reducing the situation of poor sealing; and through the embedded fixing method, the size of the MEMS sensor package can also be reduced, thereby saving product application space. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By referring to the following description in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention, other purposes and results of the present invention will become more clear and easy to understand. In the accompanying drawings:

[0018] Figure 1 This is a schematic diagram of the cross-sectional structure of a MEMS sensor according to the first embodiment of the utility model;

[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of a MEMS sensor according to the second embodiment of the utility model;

[0020] Figure 3 This is a schematic diagram of the cross-sectional structure of a MEMS sensor according to the third embodiment of the present utility model;

[0021] Figure 4 This is a schematic diagram of a top view of a PCB board according to an embodiment of the utility model;

[0022] Figure 5 It is a schematic diagram of the cross-sectional structure of a PCB board according to an embodiment of the utility model.

[0023] The reference numerals include: 1. shell, 2. PCB board, 3. ASIC chip, 4. MEMS chip, 5. acoustic hole, 6. back hole, 7. gold wire, 8. shell groove, 9. MEMS groove, 10. ASIC groove.

[0024] The same reference numerals throughout the drawings indicate similar or corresponding features or functions. DETAILED DESCRIPTION

[0025] In the following description, for the purpose of illustration, in order to provide a comprehensive understanding of one or more embodiments, many specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details. In other examples, for ease of describing one or more embodiments, known structures and devices are shown in the form of block diagrams.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0027] In view of the aforementioned problem that the existing MEMS sensors bonded by glue or solder paste are prone to glue creeping or loose bonding, which affects the sensor performance, the utility model provides a MEMS sensor.

[0028] The specific embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

[0029] In order to illustrate the structure of the MEMS sensor provided by the utility model, Figures 1 to 5 The structure of the MEMS sensor is exemplarily indicated from different angles. Specifically, Figure 1 The cross-sectional structure of a MEMS sensor according to the first embodiment of the utility model is shown; Figure 2 The cross-sectional structure of the MEMS sensor according to the second embodiment of the utility model is shown; Figure 3 The cross-sectional structure of the MEMS sensor according to the third embodiment of the present utility model is shown; Figure 4 The top view of the PCB board according to the embodiment of the utility model is shown; Figure 5 The cross-sectional structure of a PCB board according to an embodiment of the utility model is shown.

[0030] like Figures 1 to 5 As shown together, the MEMS sensor provided by the utility model includes a packaging structure composed of a PCB board 2 and a shell 1, wherein an ASIC chip 3 and a MEMS chip 4 are arranged on the PCB board 2 inside the packaging structure, wherein the shell 1, the ASIC chip 3 and the MEMS chip 4 are embedded and fixed on the PCB board 2.

[0031] exist Figure 4 and Figure 5 In the embodiment shown, a housing groove 8 for fixing the housing 1, an ASIC groove 10 for fixing the ASIC chip 3, and a MEMS groove 9 for fixing the MEMS chip 4 are respectively provided on the PCB board 2, and an adhesive is coated in each groove, and the housing 1, the ASIC chip 3, and the MEMS chip 4 are fixed in the corresponding grooves by the adhesive. The adhesive is silver paste or solder paste or silica gel or epoxy glue. The housing 1, the ASIC chip 3, and the MEMS chip 4 are embedded and fixed on the PCB board 2 by embedding, thereby improving the reliability of connecting the housing 1, the ASIC chip 3, and the MEMS chip 4 with the PCB board 2 and reducing the situation of poor sealing.

[0032] In an embodiment of the utility model, a sound hole 5 connected to the outside is provided on the PCB board 2 corresponding to the MEMS chip 4, and the sound hole 5 is used to transfer the external sound pressure to the diaphragm of the MEMS chip 4 inside the packaging structure. A back hole 6 is provided on the MEMS chip 4, and the back hole 6 is provided corresponding to the sound hole 5, wherein the diameter of the back hole 6 is greater than or equal to the diameter of the sound hole 5. In a specific application, the size relationship between the sound hole 5 and the back hole 6 is determined according to actual conditions, and the larger the sound hole 5, the better the acoustic performance of the MEMS sensor.

[0033] In the embodiment of the utility model, the depth of the housing groove 8 is greater than the depth of the ASIC groove 10. The depth of the MEMS groove 9 is greater than the depth of the housing groove 8. In a specific application, according to actual conditions, different depths of the housing groove 8, the MEMS groove 9 and the ASIC groove 10 are set. According to the set groove depth, the size of the MEMS sensor package is reduced, thereby saving product application space.

[0034] In addition, in the embodiment of the utility model, the ASIC chip 3 and the MEMS chip 4, and the ASIC chip 3 and the PCB board 2 are electrically connected respectively through gold wires 7. A pad is provided on the PCB board 2 outside the packaging structure, and the PCB board 2 is electrically connected to an external device through the pad.

[0035] The following embodiments describe in detail MEMS sensors with different groove depths and acoustic hole sizes.

[0036] Embodiment 1

[0037] exist Figure 1 In the embodiment shown, the depth relationship between the housing groove 8, the MEMS groove 9 and the ASIC groove 10 is as follows: the depth of the housing groove 8 is greater than the depth of the ASIC groove 10, which can reduce the size of the entire MEMS sensor; and the depth of the MEMS groove 9 is slightly greater than the depth of the housing groove 8, which can increase the volume of the acoustic cavity inside the packaging structure and improve its acoustic performance. In addition, the diameter of the acoustic hole 5 on the PCB board 2 is the same as that of the back hole 6. This arrangement expands the size of the acoustic hole 5, thereby improving its acoustic performance.

[0038] Embodiment 2

[0039] exist Figure 2 In the embodiment shown, the depth relationship between the housing groove 8, the MEMS groove 9 and the ASIC groove 10 is: the depth of the housing groove 8 is greater than the depth of the ASIC groove 10 and the MEMS groove 9, and the depths of the ASIC groove 10 and the MEMS groove 9 are substantially the same. This arrangement can reduce the size of the entire MEMS sensor. In addition, the diameter of the sound hole 5 on the PCB board 2 is smaller than the diameter of the back hole 6.

[0040] Embodiment 3

[0041] exist Figure 3 In the embodiment shown, the depth relationship between the housing groove 8, the MEMS groove 9 and the ASIC groove 10 is: the depth of the housing groove 8 is greater than the depth of the ASIC groove 10 and the MEMS groove 9, and the depths of the ASIC groove 10 and the MEMS groove 9 are substantially the same. This arrangement can reduce the size of the entire MEMS sensor. In addition, the diameter of the acoustic hole 5 on the PCB board 2 is the same as that of the back hole 6. This arrangement expands the size of the acoustic hole 5, thereby improving its acoustic performance.

[0042] The above-mentioned depth relationship of the shell groove 8, MEMS groove 9 and ASIC groove 10, as well as the relationship between the diameters of the sound hole 5 and the back hole 6 of the MEMS sensor provided by the utility model are set according to specific applications. In the embodiments of the utility model, the relationship settings are not limited to the above-mentioned embodiments. In specific applications, the relationship settings can be made according to actual conditions.

[0043] It can be seen from the above embodiments that the MEMS sensor provided by the utility model embeds and fixes the housing, ASIC chip and MEMS chip on the PCB board, thereby improving the reliability of connecting the housing, ASIC chip and MEMS chip with the PCB board and reducing the situation of poor sealing; and through the embedded fixing method, the size of the MEMS sensor package can also be reduced, thereby saving product application space.

[0044] The MEMS sensor proposed according to the present invention is described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various improvements can be made to the MEMS sensor proposed by the present invention without departing from the content of the present invention. Therefore, the protection scope of the present invention should be determined by the content of the attached claims.

Claims

1. A MEMS sensor, comprising a packaging structure consisting of a PCB board and a housing, wherein: An ASIC chip and a MEMS chip are arranged on a PCB board inside the packaging structure, and the characteristics are as follows: The housing, the ASIC chip and the MEMS chip are embedded and fixed on the PCB board.

2. The MEMS sensor according to claim 1, characterized in that: The PCB board is provided with a housing groove for fixing the housing, an ASIC groove for fixing the ASIC chip, and a MEMS groove for fixing the MEMS chip. Adhesive is coated in each groove, and the housing, the ASIC chip and the MEMS chip are fixed in the corresponding grooves by the adhesive.

3. The MEMS sensor according to claim 2, characterized in that: The depth of the housing groove is greater than the depth of the ASIC groove.

4. The MEMS sensor according to claim 3, characterized in that: The depth of the MEMS groove is greater than the depth of the housing groove.

5. The MEMS sensor according to claim 3, characterized in that: A sound hole connected to the outside is arranged on the PCB board corresponding to the MEMS chip, and the sound hole is used to transfer the external sound pressure to the diaphragm of the MEMS chip inside the packaging structure.

6. The MEMS sensor according to claim 5, characterized in that: A back hole is provided on the MEMS chip, and the back hole is provided corresponding to the acoustic hole, wherein: The diameter of the back hole is greater than or equal to the diameter of the sound hole.

7. The MEMS sensor according to claim 2, characterized in that: The adhesive is silver paste or solder paste or silica gel or epoxy glue.

8. The MEMS sensor according to claim 1, wherein: The ASIC chip and the MEMS chip, and the ASIC chip and the PCB board are electrically connected via gold wires.

9. The MEMS sensor according to claim 1, wherein: A soldering pad is arranged on the PCB board outside the packaging structure, and the PCB board is electrically connected to an external device through the soldering pad.

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