Unidirectional MEMS microphone and electronic equipment

Abstract

The utility model provides a unidirectional MEMS microphone and an electronic device, the unidirectional MEMS microphone comprises a packaging structure formed by assembling a PCB and a metal housing, the PCB inside the packaging structure is provided with an ASIC chip and an MEMS chip, the PCB inside the packaging structure is also provided with a silicon wafer, the PCB is provided with a main sound hole and an auxiliary sound hole in a penetrating manner, and the main sound hole and the auxiliary sound hole are communicated with each other. And the main sound hole and the auxiliary sound hole are respectively arranged at the positions of the PCB corresponding to the MEMS chip and the silicon wafer. According to the utility model, the problem that a conventional MEMS microphone has no directional pickup capability can be solved.

Description

Technical Field

[0001] This utility model relates to the field of MEMS microphone technology, and in particular to a unidirectional MEMS microphone and electronic device. Background Technology

[0002] Conventional MEMS microphones are packaged structures formed by assembling a PCB board and a metal casing, such as... Figure 1 As shown, an ASIC chip 3' and a MEMS chip 2' are disposed on the PCB board 4' inside the package structure formed by assembling the PCB board 4' and the metal shell 1'. A sound hole 5' is disposed on the PCB board 4' corresponding to the MEMS chip 2', communicating with the outside. The sound hole 5' is used to transmit external sound pressure to the diaphragm of the MEMS chip 2' inside the package structure. This MEMS microphone is an omnidirectional microphone, with the same ability to pick up sound from all directions, therefore it lacks directional sound pickup capability. To solve this problem, there is an urgent need to provide a new unidirectional MEMS microphone. Utility Model Content

[0003] In view of the above problems, the purpose of this utility model is to provide a unidirectional MEMS microphone and electronic device to solve the problem that conventional MEMS microphones do not have directional sound pickup capability.

[0004] This utility model provides a unidirectional MEMS microphone, comprising: a package structure formed by assembling a PCB board and a metal shell; an ASIC chip and a MEMS chip are disposed on the PCB board inside the package structure; a silicon wafer is also disposed on the PCB board inside the package structure; and a main sound hole and a secondary sound hole are disposed through the PCB board.

[0005] The main sound hole and the secondary sound hole are respectively located at positions corresponding to the MEMS chip and the silicon wafer.

[0006] Preferably, the distance between the main sound hole and the secondary sound hole is 1.5-5mm.

[0007] Preferably, a back hole and a vent hole are provided on the silicon wafer, and the vent hole is located at a position where the secondary acoustic hole extends along the direction of the back hole.

[0008] Preferably, the secondary sound hole is connected to the back hole, and the vent hole is connected to the secondary sound hole through the back hole.

[0009] Preferably, the size of the vent hole is 10-50 μm.

[0010] Preferably, the number of vent holes is at least one.

[0011] Preferably, the silicon wafer is fabricated using semiconductor technology.

[0012] Preferably, the ASIC chip and the MEMS chip, and the ASIC chip and the PCB board are electrically connected by gold wires.

[0013] Preferably, a solder pad is provided on a PCB board outside the packaging structure, and the PCB board is electrically connected to external devices through the solder pad.

[0014] The present invention also provides an electronic device, including the above-described unidirectional MEMS microphone, wherein,

[0015] The main sound port of the unidirectional MEMS microphone faces the direction of the sound source, while the secondary sound port of the unidirectional MEMS microphone faces away from the direction of the sound source.

[0016] As can be seen from the above technical solution, the unidirectional MEMS microphone and electronic device provided by this utility model achieves directional sound pickup by setting two sound holes on the PCB board, namely a main sound hole and a secondary sound hole. It has strong sound pickup capability in the direction of the main sound hole and suppresses sound pickup in the direction of the secondary sound hole. In practical applications, the main sound hole faces the sound source, and the secondary sound hole faces away from the sound source, thus solving the problem that conventional MEMS microphones lack directional sound pickup capability.

[0017] To achieve the foregoing and related objectives, one or more aspects of the present invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the present invention. However, these aspects indicate only a few of the various ways in which the principles of the present invention can be used. Furthermore, the present invention is intended to include all such aspects and their equivalents. Attached Figure Description

[0018] Other objects and results of this utility model will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings, and with a more comprehensive understanding of the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of a conventional MEMS microphone structure;

[0020] Figure 2 This is a schematic diagram of a unidirectional MEMS microphone structure according to an embodiment of the present invention.

[0021] The reference numerals in the figures include: 1', metal casing; 2', MEMS chip; 3', ASIC chip; 4', PCB board; 5', sound hole; 1, metal casing; 2, MEMS chip; 3, ASIC chip; 4, PCB board; 6, main sound hole; 7, secondary sound hole; 8, vent hole; 9, silicon wafer.

[0022] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0023] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0024] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0025] In response to the aforementioned problem that conventional MEMS microphones lack directional sound pickup capabilities, this invention proposes a unidirectional MEMS microphone.

[0026] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0027] To illustrate the structure of the unidirectional MEMS microphone provided by this utility model Figure 2 A unidirectional MEMS microphone structure according to an embodiment of the present invention is shown.

[0028] like Figure 2 As shown, the unidirectional MEMS microphone provided by this utility model includes: a package structure formed by assembling a PCB board 4 and a metal shell 1; an ASIC chip 3 and a MEMS chip 2 are disposed on the PCB board 4 inside the package structure; a silicon wafer 9 is also disposed on the PCB board 4 inside the package structure; a main sound hole 6 and a secondary sound hole 7 are disposed through the PCB board 4; wherein the main sound hole 6 and the secondary sound hole 7 are respectively disposed at positions corresponding to the MEMS chip 2 and the silicon wafer 9.

[0029] This invention discloses a unidirectional MEMS microphone with directional sound pickup capability. It has strong sound pickup capability in the direction of the main sound hole 6 and sound suppression capability in the direction of the secondary sound hole 7. In other words, the unidirectional MEMS microphone is sensitive to sound from the main sound hole 6 and suppresses sound from the secondary sound hole 7, thus achieving directional sound pickup. In practical applications, the main sound hole 6 faces the direction of the sound source, and the secondary sound hole 7 faces away from the direction of the sound source.

[0030] Specifically, the distance between the main sound hole 6 and the secondary sound hole 7 is 1.5-5mm. Figure 2 In the illustrated embodiment, the ASIC chip 3 is positioned between the MEMS chip 2 and the silicon wafer 9, allowing the distance between the main sound hole 6 and the secondary sound hole 7 to reach 1.5-5 mm. In specific applications, the positions of the ASIC chip 3, MEMS chip 2, and silicon wafer 9 are not limited to... Figure 2 As shown, it is sufficient that the distance between the main sound hole 6 and the secondary sound hole 7 is 1.5-5mm.

[0031] In an embodiment of this invention, a back cavity and a vent hole 8 are provided on the silicon wafer 9. The vent hole 8 is located at a position where the secondary acoustic hole 7 extends along the direction of the back cavity. The secondary acoustic hole 7 is correspondingly connected to the back cavity, and the vent hole 8 is connected to the secondary acoustic hole 7 through the back cavity.

[0032] In this invention, the directivity is adjusted by changing the size and number of vent holes 8 on the silicon wafer 9. The size of each vent hole is 10-50 μm. There is at least one vent hole. In specific applications, the appropriate size and number of vent holes 8 are selected based on the specific size and requirements of the MEMS microphone to adjust its directivity.

[0033] The silicon wafer is fabricated using semiconductor technology. Semiconductor technology ensures high precision in the vent hole dimensions and good directional consistency.

[0034] Furthermore, in embodiments of this invention, the ASIC chip 3 and the MEMS chip 2, and the ASIC chip 3 and the PCB board 4, are electrically connected via gold wires. Pads are provided on the PCB board 4 outside the package structure, and the PCB board 4 is electrically connected to external devices through these pads.

[0035] Furthermore, the metal casing 1 is fixed to the PCB board 4 by an adhesive, wherein the adhesive is silver paste, solder paste, silicone, or epoxy. The specific adhesive is selected according to the actual situation in the application and is not limited to any one type.

[0036] In addition, the present invention also provides an electronic device, including a unidirectional MEMS microphone, wherein the main sound port 6 of the unidirectional MEMS microphone faces the direction of the sound source, and the secondary sound port 7 of the unidirectional MEMS microphone faces away from the direction of the sound source.

[0037] The specific structure of the unidirectional MEMS microphone is as described in the foregoing embodiments. Since this electronic device adopts all the technical solutions of all the foregoing embodiments, it has at least all the beneficial effects brought about by the technical solutions of the foregoing embodiments, which will not be described in detail here.

[0038] In this embodiment, the unidirectional MEMS microphone is connected to a flexible printed circuit board (FPCB) via a flexible printed circuit board. One end of the FPCB is electrically connected to the unidirectional MEMS microphone, and the other end is used to connect to an external power supply. It can be understood that the flexible printed circuit board is used to connect and conduct external circuitry to the unidirectional MEMS microphone.

[0039] In this embodiment, the electronic device can be headphones, mobile phone, computer, tablet computer, smart wearable device, etc., and is not limited thereto. In the electronic device, the unidirectional MEMS microphone can be assembled into the housing of the electronic device as a module, or it can be assembled into the housing of the electronic device as a single unit.

[0040] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the concept of the present utility model and using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A unidirectional MEMS microphone, comprising: A packaging structure formed by assembling a PCB board and a metal casing, wherein an ASIC chip and a MEMS chip are disposed on the PCB board inside the packaging structure, characterized in that a silicon wafer is also disposed on the PCB board inside the packaging structure, and a main sound hole and a secondary sound hole are disposed through the PCB board, wherein... The main sound hole and the secondary sound hole are respectively located at positions corresponding to the MEMS chip and the silicon wafer.

2. The unidirectional MEMS microphone according to claim 1, characterized in that, The distance between the main sound hole and the secondary sound hole is 1.5-5mm.

3. The unidirectional MEMS microphone according to claim 1, characterized in that, A back hole and a vent hole are provided on the silicon wafer, and the vent hole is located at a position where the secondary acoustic hole extends along the direction of the back hole.

4. The unidirectional MEMS microphone according to claim 3, characterized in that, The secondary acoustic hole is connected to the back hole, and the vent hole is connected to the secondary acoustic hole through the back hole.

5. The unidirectional MEMS microphone according to claim 3, characterized in that, The size of the vent hole is 10-50 μm.

6. The unidirectional MEMS microphone according to claim 3, characterized in that, The number of vent holes is at least one.

7. The unidirectional MEMS microphone according to claim 1, characterized in that, The silicon wafer is manufactured using semiconductor technology.

8. The unidirectional MEMS microphone according to claim 1, characterized in that, The ASIC chip and the MEMS chip, and the ASIC chip and the PCB board are respectively electrically connected by gold wires.

9. The unidirectional MEMS microphone according to claim 1, characterized in that, Pads are provided on the PCB board outside the packaging structure, and the PCB board is electrically connected to external devices through the pads.

10. An electronic device, characterized in that, Including the unidirectional MEMS microphone as described in any one of claims 1-9, wherein, The main sound port of the unidirectional MEMS microphone faces the direction of the sound source, while the secondary sound port of the unidirectional MEMS microphone faces away from the direction of the sound source.

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