Microporous waterproof microphone structure and MEMS microphone

Abstract

The utility model relates to a micropore waterproof microphone structure and an MEMS microphone, comprising a housing and a sound receiving part, the end face of the top of the housing is a sound receiving surface, the surface of the sound receiving surface is provided with a plurality of sound receiving micropores, and the sound receiving micropores are uniformly distributed on the whole sound receiving surface in an array; the sound receiving part is arranged inside the shell, the sound receiving part comprises a PCB (Printed Circuit Board), an MEMS (Micro Electro Mechanical System) chip and an ASIC (Application Specific Integrated Circuit) chip, the shell is buckled on the surface of the PCB, the MEMS chip and the ASIC chip are arranged on one side, close to the shell, of the PCB, and the MEMS chip is electrically connected with the ASIC chip. According to the utility model, the plurality of sound receiving micropores are arranged on the end face of the shell, and liquid can be fixed in the plurality of sound receiving micropores by utilizing the surface tension of the liquid, so that external liquid is prevented from entering the shell. And secondly, the situation that a large-area adhesive surface is needed when the waterproof film is pasted is avoided, and the waterproof reliability is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of waterproof microphones, in particular to a microporous waterproof microphone structure and a MEMS microphone. Background Art

[0002] MEMS microphone, or micro-electromechanical system microphone, is a microphone manufactured based on MEMS technology. A MEMS microphone is a miniature device with a capacitor integrated on a micro silicon wafer, manufactured through a surface mount process. Its working principle involves using a micro-vibrating membrane to sense sound waves and convert them into electrical signals, thereby capturing and transmitting sound. MEMS microphones are very small, with the microphone element itself less than 1mm; they are lightweight and can be tightly integrated into electronic products such as smartphones, smart speakers, and headphones.

[0003] In the prior art, a sound receiving hole is provided on the sound receiving surface of a MEMS microphone. Due to the small size of the entire volume, the size of the sound receiving hole will be affected, which will affect the sound receiving effect. In order to ensure the waterproof effect, a waterproof film is attached to the surface of the sound receiving hole. When attaching the waterproof film, it needs to be attached with double-sided tape. Due to the small size of the MEMS microphone, part of the sound receiving hole may be blocked during the pasting process, affecting the sound receiving effect. In addition, the size of the effective adhesive surface is small, and the area of ​​the adhesive surface seriously affects the waterproof effect of the waterproof film. Utility Model Content

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of low waterproof reliability of the MEMS microphone waterproof membrane in the prior art.

[0005] In order to solve the above technical problems, the utility model provides a microporous waterproof microphone structure, comprising:

[0006] A housing, wherein the end surface of the top of the housing is a sound receiving surface, and a plurality of sound receiving micro holes are provided on the surface of the sound receiving surface, and the array of sound receiving micro holes is evenly distributed on the entire sound receiving surface;

[0007] The sound receiving part is arranged inside the shell, and the sound receiving part includes a PCB board, a MEMS chip and an ASIC chip. The shell is buckled on the surface of the PCB board, and the MEMS chip and the ASIC chip are arranged on a side of the PCB board close to the shell, and the MEMS chip and the ASIC chip are electrically connected.

[0008] In an embodiment of the present invention, the diameter of the sound receiving microhole is 0.001mm-0.014mm.

[0009] In one embodiment of the present invention, the distance between any two adjacent sound receiving micro holes is 0.01 mm-0.1 mm.

[0010] In one embodiment of the utility model, a gold wire is provided on a surface of the PCB board close to the housing, and the ASIC chip is electrically connected to the PCB board through the gold wire.

[0011] In one embodiment of the present invention, a packaging layer is provided on the surface of the ASIC chip, and the packaging layer covers the outside of the ASIC chip and the gold wire.

[0012] In an embodiment of the present invention, a pin is provided on a side of the PCB board away from the housing, and the pin is electrically connected to the gold wire.

[0013] In an embodiment of the present invention, the housing is fixed to the surface of the PCB board by soldering.

[0014] In an embodiment of the present invention, the shell is made of metal.

[0015] A MEMS microphone comprises the microporous waterproof microphone structure.

[0016] The above technical solution of the utility model has the following advantages compared with the prior art:

[0017] The micro-hole waterproof microphone structure and MEMS microphone described in the utility model have a sound receiving part arranged inside the shell, and a plurality of sound receiving micro-holes are provided on the end surface of the shell. The surface tension of the liquid is used to fix the liquid in the plurality of sound receiving micro-holes, thereby preventing the external liquid from entering the shell. Secondly, the waterproof film is prevented from requiring a large adhesive surface when being pasted, and the waterproof reliability is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to make the content of the utility model easier to understand, the utility model is further described in detail according to the specific embodiments of the utility model in combination with the accompanying drawings, wherein

[0019] Figure 1 It is a top view of the overall structure of the utility model;

[0020] Figure 2 It is a schematic diagram of the overall internal structure of the utility model;

[0021] Figure 3 This is a waterproof effect diagram of the sound receiving micro-holes in the utility model;

[0022] Explanation of the reference numerals in the specification: 1. housing; 2. sound receiving part; 11. sound receiving surface; 12. sound receiving microhole; 21. PCB board; 22. MEMS chip; 23. ASIC chip; 24. gold wire; 25. pin; 26. packaging layer. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0024] Embodiment 1

[0025] Reference Figure 1-Figure 3 As shown, the utility model discloses a microporous waterproof microphone structure, comprising:

[0026] A housing 1, wherein the end surface of the top of the housing 1 is a sound receiving surface 11, and a plurality of sound receiving micro holes 12 are formed on the surface of the sound receiving surface 11, and the array of the sound receiving micro holes 12 is evenly distributed on the entire sound receiving surface 11;

[0027] The sound receiving part 2 is arranged inside the shell 1, and the sound receiving part 2 includes a PCB board 21, a MEMS chip 22 and an ASIC chip 23. The shell 1 is buckled on the surface of the PCB board 21, and the MEMS chip 22 and the ASIC chip 23 are arranged on a side of the PCB board 21 close to the shell 1, and the MEMS chip 22 and the ASIC chip 23 are electrically connected.

[0028] It can be seen that the function of the MEMS chip 22 in the sound receiving part 2 of the utility model is to convert external sound waves into signal changes such as capacitance and resistance, while the ASIC chip 23 mainly converts signal changes such as capacitance and resistance into electrical signals. The MEMS chip 22 and the ASIC chip 23 are electrically connected through a harness to realize the process of converting sound signals into electrical signals. The entire sound receiving part 2 is arranged inside the housing 1, and a plurality of sound receiving micro holes 12 are provided on the end surface of the housing 1. The sound enters the interior from the sound receiving micro holes 12, and the signal is collected by the MEMS chip 22. In the utility model, the diameter of the sound receiving micro holes 12 is very small. By using the surface tension of the liquid, the liquid can be fixed in the plurality of sound receiving micro holes 12 to prevent the external liquid from entering the interior of the housing 1. Compared with the structure of installing a waterproof cloth on the surface of a larger sound receiving hole in the prior art, it can effectively play a waterproof role. Under normal circumstances, the waterproof airtight cavity is unobstructed. Since there is no obstruction of the waterproof film, the sound receiving effect is more ideal and distortion is avoided. Secondly, it avoids the need for a large area of ​​adhesive surface for the waterproof film to be pasted, and the reliability of waterproofing is higher.

[0029] Furthermore, the diameter of the sound receiving micro hole 12 is 0.001 mm-0.014 mm.

[0030] Specifically, according to the calculation formula of the diameter of the sound receiving micro hole 12:

[0031] σπd*cosθ=ρgh*π(d / 2)2

[0032] σ is the surface tension of water. At room temperature of 20°C, σ=0.073N / m, h is the water depth (here the value is 1), and d is the diameter of the hole. ρ is the density of water, θ is the contact angle, which is the angle between the tangent of the gas-liquid interface at the intersection of three phases (gas, liquid and solid) and the solid wall. When θ>90°, the wall is hydrophobic; when θ<90°, the wall is hydrophilic. The material of the radio structure hole is generally hydrophilic. Take θ=60° for easy calculation. The result obtained by calculation is d=14.9μm.

[0033] Furthermore, the distance between any two adjacent sound receiving micro holes 12 is 0.01 mm to 0.1 mm. As a preferred embodiment of the present invention, the sound receiving micro holes 12 are distributed in the central circumferential direction of the sound receiving surface 11, and the entire distribution shape can be a circle, a rectangle or other geometric shapes. And the distribution area of ​​the sound receiving micro holes 12 can be the entire sound receiving surface 11.

[0034] Furthermore, a gold wire 24 is provided on a surface of the PCB board 21 close to the housing 1 , and the ASIC chip 23 is electrically connected to the PCB board 21 via the gold wire 24 .

[0035] Specifically, the gold wires 24 on the surface of the PCB are used to connect the ASIC chip 23 , which is the same as the connection between the MEMS chip 22 and the ASIC chip 23 . The ASIC chip 23 and the gold wires 24 are connected via a wire harness.

[0036] Furthermore, a packaging layer 26 is disposed on the surface of the ASIC chip 23 , and the packaging layer 26 covers the outer sides of the ASIC chip 23 and the gold wire 24 .

[0037] Specifically, the encapsulation layer 26 is encapsulated with a soft rubber material to completely encapsulate the ASIC chip 23 and the gold wire 24, thereby protecting the ASIC chip 23 and the gold wire 24, reducing the influence of light noise, and further improving the sound collection effect.

[0038] Furthermore, a pin 25 is provided on a side of the PCB board 21 away from the housing 1 , and the pin 25 is electrically connected to the gold wire 24 .

[0039] Specifically, the entire PCB board 21 is used to carry the entire sound receiving unit 2. The surface of the PCB board 21 is provided with a circuit. The wires or copper foil on the PCB are used to realize the electrical connection between the components to ensure that the signal can be transmitted smoothly. In a MEMS microphone, the ASIC chip 23 needs to convert the physical sound pressure measurement value of the MEMS chip 22 into a digital signal and transmit it to the codec of the device. This process depends on the electrical connection on the PCB. In some high-end MEMS microphones, the PCB may also be integrated with a signal processing circuit for further processing and optimization of the signal output by the microphone, such as noise suppression, gain control, etc. These processing measures help to improve the signal-to-noise ratio and sound quality performance of the microphone.

[0040] Furthermore, the housing 1 is fixed to the surface of the PCB board 21 by soldering, so that the housing 1 is encapsulated on the surface of the PCB board 21 .

[0041] Furthermore, the shell 1 is made of metal.

[0042] Specifically, the metal shell 1 has the following functions. First, the metal shell 1 provides a solid protective layer for the sensitive components (such as MEMS chip 22, ASIC chip 23, etc.) inside the MEMS microphone to prevent them from being directly hit or scratched by external objects. The metal shell 1 has good sealing performance and can effectively prevent external pollutants such as dust and moisture from entering the microphone, keeping the internal components clean and dry, thereby extending the service life of the microphone. Secondly, the metal shell 1 also has a certain shielding effect, which can reduce the impact of external electromagnetic interference and mechanical vibration on the internal components of the microphone, thereby reducing the noise level and improving the recording quality.

[0043] Embodiment 2

[0044] A MEMS microphone comprises the microporous waterproof microphone structure described in the first embodiment.

[0045] In summary, the utility model introduces a micro-hole waterproof microphone structure and a MEMS microphone. The sound receiving part 2 is arranged inside the shell 1. A plurality of sound receiving micro-holes 12 are opened on the end face of the shell 1. The sound penetrates into the interior through the sound receiving micro-holes 12, and the signal is collected through the MEMS chip 22. In the utility model, the diameter of the sound receiving micro-holes 12 is very small. By utilizing the surface tension of the liquid, the liquid can be fixed in the plurality of sound receiving micro-holes 12 to prevent the external liquid from entering the interior of the shell 1. Compared with the structure of installing a waterproof cloth on the surface of a larger sound receiving hole in the prior art, it can effectively play a waterproof role. Under normal circumstances, the waterproof airtight cavity is unobstructed. Since there is no waterproof film to block it, the sound receiving effect is more ideal and distortion is avoided. Secondly, it avoids the need for a large adhesive surface for the waterproof film to be pasted, and the waterproof reliability is higher.

[0046] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A microporous waterproof microphone structure, characterized in that: include: A housing, wherein the end surface of the top of the housing is a sound receiving surface, and a plurality of sound receiving micro holes are provided on the surface of the sound receiving surface, and the array of sound receiving micro holes is evenly distributed on the entire sound receiving surface; The sound receiving part is arranged inside the shell, and the sound receiving part includes a PCB board, a MEMS chip and an ASIC chip. The shell is buckled on the surface of the PCB board, and the MEMS chip and the ASIC chip are arranged on a side of the PCB board close to the shell, and the MEMS chip and the ASIC chip are electrically connected.

2. The microporous waterproof microphone structure according to claim 1, characterized in that: The diameter of the sound receiving microhole is 0.001mm-0.014mm.

3. The microporous waterproof microphone structure according to claim 1, characterized in that: The distance between any two adjacent sound receiving micro holes is 0.01mm-0.1mm.

4. The microporous waterproof microphone structure according to claim 1, characterized in that: A gold wire is arranged on the surface of the PCB board close to the housing, and the ASIC chip is electrically connected to the PCB board through the gold wire.

5. The microporous waterproof microphone structure according to claim 4, characterized in that: A packaging layer is arranged on the surface of the ASIC chip, and the packaging layer covers the outer sides of the ASIC chip and the gold wire.

6. The microporous waterproof microphone structure according to claim 4, characterized in that: A pin is arranged on one side of the PCB board away from the housing, and the pin is electrically connected to the gold wire.

7. The microporous waterproof microphone structure according to claim 1, characterized in that: The shell is fixed on the surface of the PCB board by soldering.

8. The microporous waterproof microphone structure according to claim 1, characterized in that: The shell is made of metal.

9. A MEMS microphone, characterized in that: It comprises the microporous waterproof microphone structure as described in any one of claims 1-8.

Images