CN112449294A

CN112449294A - MEMS MIC with blowing protection

Info

Publication number: CN112449294A
Application number: CN202110132717.1A
Authority: CN
Inventors: 陶继方; 刘志永; 朱法超
Original assignee: Shandong Xingang Electronic Technology Co ltd
Current assignee: Shandong Xingang Electronic Technology Co ltd
Priority date: 2021-02-01
Filing date: 2021-02-01
Publication date: 2021-03-05

Abstract

The invention provides an MEMS MIC with air blowing protection, which comprises an MEMS shell and is characterized in that: the MEMS shell lower extreme is connected with the PCB board, the income phonate hole subassembly has been seted up on the PCB board, form the sound chamber between PCB board and the MEMS shell, MEMS acoustic pressure sensor is connected with the PCB board at the sound intracavity, goes into the phonate hole subassembly and includes first income phonate hole, branch sound channel has been seted up to first income phonate hole one side, the second is gone into the phonate hole has been seted up on the branch sound channel, be connected with the elasticity sound blocking piece on the PCB board, any side edge of elasticity sound blocking piece pastes tightly with the PCB board and is connected. Through adding the elasticity sound blocking piece, shunt irregular wind, block the foreign matter, reduce wind-force, the harm of foreign matter to the chip to this effect that reaches the protection promotes the life of product greatly, no longer receives external environment's restriction, makes receipts silver performance completely released, improves sound-electricity conversion efficiency.

Description

MEMS MIC with blowing protection

Technical Field

The invention relates to the field of sound-electricity conversion, in particular to an MEMS MIC with air blowing protection.

Background

The MEMS MIC is the MIC manufactured based on the MEMS technology and comprises an MEMS sound pressure sensor chip, an ASIC chip, a front sound cavity, a rear sound cavity and an RF suppression circuit, wherein the MEMS sound pressure sensor is a micro capacitor formed by a silicon diaphragm and a silicon back plate, and then the ASIC chip converts capacitance change into an electric signal to realize sound-electricity conversion, namely simply that the capacitor is integrated on a micro silicon crystal and manufactured by adopting a surface mounting process, can bear high reflow soldering temperature and is easy to integrate with a CMOS process and other audio circuits.

The conventional MEMS MIC sound hole is formed in a PCB and a shell, external overlarge airflow easily enters an internal damage membrane through the sound hole, the influence on a product is large, the conventional MEMS MIC sound hole is a common fault and a difficult problem in the same industry at the present stage, and the conventional MEMS MIC sound hole is difficult to overcome all the time.

Disclosure of Invention

The invention aims to overcome the defects of the traditional technology and provide the MEMS MIC with the blow-up protection function, which has the advantages of receiving sound, protecting the MEMS chip and improving the sound receiving effect.

The aim of the invention is achieved by the following technical measures:

a MEMS MIC with blowing protection, includes MEMS shell, its characterized in that: the utility model discloses a MEMS sound-proof device, including MEMS shell, PCB board, sound hole subassembly, elastic sound-proof piece, MEMS shell lower extreme is connected with the PCB board, form the sound chamber between PCB board and the MEMS shell, install MEMS sound pressure sensor in the sound chamber, MEMS sound pressure sensor and PCB board fixed connection, the PCB board is multilayer structure PCB board, be equipped with into the sound hole subassembly on the PCB board, go into the sound hole subassembly and include first income sound hole and second income sound hole, the inboard etching of PCB has branch sound channel, first income sound hole and second go into through branch sound channel intercommunication between the sound hole, be equipped with the elastic sound-proof piece on the PCB board, the elastic sound-proof piece goes into the sound hole with the second and sets up relatively, the elastic sound-proof piece is fixed on the PCB board for one section, the free setting of elastic sound-.

As an improvement: the PCB is connected with an ASIC chip, and the ASIC chip is connected with the MEMS sound pressure sensor in the sound cavity through an electric circuit on the PCB.

As an improvement: the MEMS sound pressure sensor comprises a silicon vibrating diaphragm and a silicon back plate, the silicon vibrating diaphragm and the silicon back plate are arranged in parallel, a supporting sleeve is fixedly connected to the edge of the silicon back plate, and the supporting sleeve is fixedly connected with the PCB.

As an improvement: the first sound inlet hole is arranged opposite to the MEMS sound pressure sensor.

As an improvement: the second sound inlet hole is opposite to the elastic sound-blocking sheet.

As an improvement: at least one of the first sound inlet hole and the second sound inlet hole penetrates through the PCB.

As an improvement: the first sound inlet hole penetrates through the PCB, and the first sound inlet hole is communicated with the sound cavity and the outside.

As an improvement: the second sound inlet hole does not penetrate through the PCB, and the second sound inlet hole is communicated with the sound cavity and the branch sound channel.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the advantages that:

through involving to improve the upgrading to traditional PCB, increase new components and parts, combine the geomechanics, relevant knowledge such as acoustics carries out subversive design to the product, reach the effect that has the protection with this, compare with conventional MIC, MIC sound chamber passageway that has the blowing is longer, through adding the elasticity sound blocking piece, shunt irregular wind, block the foreign matter, reduce wind-force, the foreign matter is to the harm of chip, reach the effect of protection with this, promote the life of product greatly, no longer receive external environment's restriction, make the radio reception performance completely released, improve the sound-electricity conversion efficiency.

The invention is further described with reference to the following figures and detailed description.

Drawings

FIG. 1 is a schematic structural view of embodiment 1 of the present invention.

Fig. 2 is a schematic structural view of a use state of embodiment 1 of the present invention.

FIG. 3 is a schematic structural diagram of embodiment 2 of the present invention.

Fig. 4 is a schematic structural view of a use state of embodiment 2 of the present invention.

In the figure: 1-a MEMS housing; 2-a PCB board; 3-a sound entry port assembly; 4-elastic sound-blocking sheet; 5-an ASIC chip; 6-MEMS sound pressure sensor; 31-a first sound inlet hole; 32-branch sound track; 33-a second sound inlet hole; 61-silicon back plate; 62-a silicon diaphragm; 63-support the sleeve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1: a MEMS MIC with blowing protection comprises a MEMS shell 1 and is characterized in that: 1 lower extreme of MEMS shell is connected with PCB board 2, form the sound chamber between PCB board 2 and the MEMS shell 1, install MEMS acoustic pressure sensor 6 in the sound chamber, MEMS

acoustic pressure sensor

6 and 2 fixed connection of PCB board, PCB board 2 is multilayer structure PCB board, be equipped with into vocal hole subassembly 3 on the PCB board 2, go into vocal hole subassembly 3 and go into vocal hole 33 including first income vocal hole 31 and second, the etching has branch sound track 32 in the PCB board 2, first income vocal hole 31 and second go into to go into between the vocal hole 33 through branch sound track 32 intercommunication, be equipped with elasticity sound blocking piece 4 on the PCB board 2, elasticity sound blocking piece 4 and second go into the relative setting of vocal hole 33, elasticity sound blocking piece 4 is fixed on PCB board 2 for one section, the free setting of the other end of elasticity sound blocking piece 4.

The PCB 2 is connected with an ASIC chip 5, and the ASIC chip 5 is installed in the sound cavity. The ASIC chip 5 is connected with the copper-coated circuit and the electronic elements on the PCB 2, and the ASIC chip 5 is arranged in the sound cavity to effectively protect the ASIC chip 5 and other electronic elements from being damaged.

The MEMS sound pressure sensor 6 comprises a silicon diaphragm 62 and a silicon back plate 61, the silicon diaphragm 62 and the silicon back plate 61 are arranged oppositely in parallel, the edge of the silicon back plate 61 is connected with a supporting sleeve 63, and the supporting sleeve 63 is connected with the PCB 2. The support sleeve 63 is disposed opposite to the first sound inlet hole 31, so that sound input from the first sound inlet hole 31 is transmitted to the silicon diaphragm 62 and the silicon back plate 61.

The first sound inlet hole 31 is arranged opposite to the MEMS sound pressure sensor 6. The first sound inlet hole 31 can effectively conduct sound to the MEMS sound pressure sensor 6, so that the MEMS sound pressure sensor 6 can better process the sound, and the sound can be collected more directly.

The second sound inlet hole 33 is arranged opposite to the elastic sound-blocking sheet 4. Elastic sound-blocking piece 4 lid is in the top of second

income sound hole

33, 4 one ends of elastic sound-blocking piece are fixed on PCB board 2 through the mode of welding or adhesion, when gaseous when blowing in and the gaseous velocity of flow is too fast, gaseous will back open elastic sound-blocking piece 4, and gaseous one end that can set up through elastic sound-blocking piece 4 is free gets into the sound chamber to it is the same to make 6 inside and outside atmospheric pressures of MEMS acoustic pressure sensor, thereby reaches the purpose of protecting MEMS acoustic pressure sensor with the mode of balanced atmospheric pressure.

At least one of the first and second

sound inlet holes

31 and 33 penetrates the PCB 2.

The first sound inlet hole 31 penetrates through the PCB 2, and the first sound inlet hole 31 is communicated with the sound cavity and the outside. The first sound inlet hole 31 is opposite to the MEMS sound pressure sensor 6, and the support sleeve 63 of the MEMS sound pressure sensor 6 is disposed at the same position as the first sound inlet hole 31.

The second sound inlet hole 33 does not penetrate through the PCB 2, and the second sound inlet hole 33 communicates the sound cavity with the branch sound channel 32. The branch sound channel 32 is communicated with the second sound inlet hole 33 and then continuously extends a distance forwards, and when the branch sound channel is internally blown up in use, a part of gas can pass through the second sound inlet hole 33.

Blowing when using, gas will flow to first income sound hole 31 and second income sound hole 33, and the gas of first income sound hole 31 will direct action at MEMS acoustic pressure sensor 6, can damage silicon vibrating diaphragm 62 when the gas flow is too big, so after the gas that passes through second income sound hole 33 blows elastic sound-proof piece 4 when the gas flow is too big, the gas of blowing in will enter the sound chamber through second income sound hole 33, thereby make the pressure about silicon vibrating diaphragm 62 the same, thereby protection silicon vibrating diaphragm 62 is not damaged, extension MEMS acoustic pressure sensor 6's life.

Example 2: the first sound inlet hole 31 does not penetrate through the PCB 2, and the first sound inlet hole 31 communicates the sound cavity with the branch sound channel 32. The first sound inlet hole 31 is opposite to the MEMS sound pressure sensor 6, and the support sleeve 63 of the MEMS sound pressure sensor 6 is disposed at the same position as the first sound inlet hole 31.

The second sound inlet hole 33 penetrates through the PCB 2, the second sound inlet hole 33 is communicated with the sound cavity and the outside, the side end of the second sound inlet hole 33 is communicated with the branch sound channel 32, the branch sound channel 32 is communicated with the first sound inlet hole 31 and then continues to extend forwards for a certain distance, and when the air is blown inwards in use, most of air can pass through the second sound inlet hole 33.

When the MEMS sound pressure sensor is used, sound can be transmitted to the first sound inlet hole 31 through the branch sound channel 32, the elastic sound blocking piece 4 cannot be opened when the air flow does not reach the condition of damaging the silicon diaphragm 62, and the elastic sound blocking piece 4 can be opened when the air flow reaches the condition of possibly damaging the silicon diaphragm 62, so that gas enters a sound cavity, and the MEMS sound pressure sensor 6 is protected from being damaged. Other structural features are the same as those of embodiment 1.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A MEMS MIC with blow protection, comprising a MEMS enclosure (1), characterized in that: the MEMS sound pressure sensor is characterized in that a PCB (2) is connected to the lower end of the MEMS shell (1), a sound cavity is formed between the PCB (2) and the MEMS shell (1), an MEMS sound pressure sensor (6) is installed in the sound cavity, the MEMS sound pressure sensor (6) is fixedly connected with the PCB (2), the PCB (2) is a multilayer PCB, a sound hole assembly (3) is arranged on the PCB (2), the sound hole assembly (3) comprises a first sound hole (31) and a second sound hole (33), a branch sound channel (32) is etched in the PCB (2), the first sound hole (31) and the second sound hole (33) are communicated through the branch sound channel (32), an elastic sound blocking sheet (4) is arranged on the PCB (2), the elastic sound blocking sheet (4) and the second sound hole (33) are arranged relatively, and the elastic sound blocking sheet (4) is fixed on the PCB (2) in one section, the other end of the elastic sound-blocking sheet (4) is arranged in a free manner.

2. A MEMS MIC with blow-up protection as claimed in claim 1, wherein: the MEMS sound pressure sensor is characterized in that an ASIC chip (5) is connected to the PCB (2), and the ASIC chip (5) is connected with the MEMS sound pressure sensor (6) through an electric circuit on the PCB (2) in the sound cavity.

3. A MEMS MIC with blow-up protection as claimed in claim 1, wherein: MEMS acoustic pressure sensor (6) are including silicon vibrating diaphragm (62) and silicon back plate (61), silicon vibrating diaphragm (62) and silicon back plate (61) parallel arrangement, silicon back plate (61) edge fixedly connected with support sleeve (63), support sleeve (63) and PCB board (2) fixed connection.

4. A MEMS MIC with blow-up protection as claimed in claim 1, wherein: the first sound inlet hole (31) is arranged opposite to the MEMS sound pressure sensor (6).

5. A MEMS MIC with blow-up protection as claimed in claim 1, wherein: the second sound inlet hole (33) is opposite to the elastic sound-blocking sheet (4).

6. A MEMS MIC with blow-up protection as claimed in claim 1, wherein: at least one of the first sound inlet hole (31) and the second sound inlet hole (33) penetrates through the PCB (2).

7. A MEMS MIC with blow-off protection according to claim 6, wherein: the first sound inlet hole (31) penetrates through the PCB (2), and the first sound inlet hole (31) is communicated with the sound cavity and the outside.

8. A MEMS MIC with blow-off protection according to claim 6, wherein: the second sound inlet hole (33) does not penetrate through the PCB (2), and the second sound inlet hole (33) is communicated with the sound cavity and the branch sound channel (32).