CN217389002U - MEMS vibration sensor - Google Patents

Abstract

The utility model discloses a MEMS vibration sensor belongs to microphone technical field. The MEMS vibration sensor comprises a shell, a PCB (printed circuit board), an acoustic element, a vibration module and a baffle, wherein the shell is hermetically connected with the PCB and encloses to form a first cavity; the vibration module is positioned in the first cavity and comprises a cofferdam, an elastic vibrating piece and a mass block, one end of the cofferdam is fixed on the inner side of the shell, the elastic vibrating piece is arranged at the other end of the cofferdam, and the shell, the cofferdam and the elastic vibrating piece are arranged in a surrounding manner to form a second cavity; the baffle plate is larger than the inner diameter of the first through hole. When the elastic vibrating reed vibrates up and down, the baffle can block the elastic vibrating reed from further moving towards the MEMS chip and the ASIC chip, and the normal use of the MEMS chip and the ASIC chip is protected.

Description

MEMS vibration sensor

Technical Field

The utility model relates to a microphone technical field especially relates to a MEMS vibration sensor.

Background

MEMS (Micro-Electro-Mechanical System) technology is an advanced semiconductor manufacturing process to realize mass production of sensors, drivers, and other devices. The traditional MEMS microphone adopts a conduction mode that an MEMS chip diaphragm receives airborne voice, and a sound pressure signal is sensed by a high-sensitivity vibrating film of the MEMS chip through a sound inlet hole to convert the sound signal into an electric signal. And the ASIC chip electrically connected with the MEMS chip outputs the signal after operational amplification. The MEMS chip is a micro capacitor formed by a polysilicon diaphragm and a back plate, and can convert sound pressure change into capacitance change, and then the capacitance reduction change of the ASIC chip is converted into an electric signal to realize sound-electricity conversion.

As shown in fig. 1, the sensor of the conventional MEMS microphone receives airborne voice through the sound inlet hole of the housing, and includes voice of a speaker and noise from the surroundings, and when the noise is large, the microphone is interfered by noise, such as the surrounding people, mechanical equipment, wind noise, etc., which seriously affects the quality of the speech. When the elastic vibrating reed of the MEMS microphone vibrates, there is a phenomenon that the elastic vibrating reed collides with the lower MEMS chip.

Therefore, it is desirable to provide a MEMS vibration sensor to solve the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a MEMS vibration sensor reduces the noise of surrounding environment, makes the conversation more clear and the voice quality is higher definition, improves speech quality, avoids elastic vibrating reed at the in-process of vibration, collides the acoustic component.

In order to realize the purpose, the following technical scheme is provided:

a MEMS vibration sensor, comprising:

a housing;

the shell is hermetically connected with the PCB and is surrounded to form a first cavity;

the vibration module is positioned in the first cavity and comprises a cofferdam and an elastic vibrating reed, one end of the cofferdam is connected with the shell, the elastic vibrating reed is arranged at the other end of the cofferdam, the shell, the cofferdam and the elastic vibrating reed are arranged in a surrounding mode to form a second cavity, and the elastic vibrating reed is provided with a first through hole;

the acoustic element comprises an MEMS chip and an ASIC chip, and is positioned in the first cavity, the MEMS chip and the ASIC chip are arranged on the PCB, and the MEMS chip and the elastic vibrating reed are arranged correspondingly;

and the first end of the baffle is fixed on the inner side of the shell, and the second end of the baffle is positioned below the elastic vibrating reed and is larger than the inner diameter of the first through hole in size.

As an alternative to the MEMS vibration sensor, a mass is further included, an upper end face of the elastic vibrating piece is provided with the mass, and/or

The lower end face of the elastic vibrating piece is provided with the mass block.

As an alternative to MEMS vibration sensors, the mass is made of metal or ceramic.

As an alternative of the MEMS vibration sensor, the mass block is provided with a second through hole, the second through hole is arranged corresponding to the first through hole, and the second end of the baffle penetrates through the second through hole and the first through hole.

As an alternative to the MEMS vibration sensor, one end of the ASIC chip is connected to the MEMS chip, and the other end of the ASIC chip is connected to the PCB board.

As an alternative of the MEMS vibration sensor, the MEMS vibration sensor further comprises a blind hole, wherein the blind hole is formed in the PCB and corresponds to the MEMS chip.

As an alternative to MEMS vibration sensors, the shape of the blind hole may be a cuboid or ellipsoid.

As an alternative to the MEMS vibration sensor, the housing is made of a metal material.

As an alternative to the MEMS vibration sensor, the surface of the elastic vibrating piece is a planar structure.

As an alternative to the MEMS vibration sensor, the surface of the elastic vibrating piece has a wave-shaped structure.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model provides a MEMS vibration sensor, casing and PCB board sealing connection enclose to establish and form first cavity, and vibration module and baffle all are located first cavity, and casing, cofferdam and elasticity trembler enclose to establish and form the second cavity, and acoustic element sets up on the PCB board and sets up with elasticity trembler relatively, adopts the mode of bone conduction, and sound spreads into the second cavity and is accepted the processing by acoustic element from the casing, reduces the noise of surrounding environment, has improved conversation quality; through stretching out first through-hole with the second end of baffle, the external diameter of the second end of baffle is greater than the internal diameter of first through-hole, and when the elasticity trembler took place to vibrate from top to bottom, the second end of baffle can block the elasticity trembler and further move towards the acoustic element, and restriction elasticity trembler is towards the amplitude of acoustic element, protects the normal use of acoustic element.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a schematic view of a prior art microphone sensor assembly;

fig. 2 is an assembly diagram of a MEMS vibration sensor according to an embodiment of the present invention;

fig. 3 is an assembly diagram of a MEMS vibration sensor according to an embodiment of the present invention.

Reference numerals:

1. a housing; 2. a PCB board; 3. a first cavity; 4. a vibration module; 5. an acoustic element; 6. a baffle plate; 7. a mass block; 8. blind holes;

41. cofferdam; 42. an elastic vibrating piece; 43. a second cavity; 44. a first through hole;

51. an ASIC chip; 52. an MEMS chip;

71. a second via.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description of the present invention and simplification of description, but do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another, and are not to be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; either mechanically or electrically. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

As shown in fig. 1, the casing of the microphone in the prior art is provided with a sound inlet hole, sound enters the casing through the sound inlet hole, and then is received and processed by the acoustic element, and due to the sound inlet hole, noise in the surrounding environment also enters the casing through the sound inlet hole, which reduces the sound quality.

In order to reduce noise in the surrounding environment, make a call clearer and voice quality higher, improve the call quality, and prevent the elastic vibrating reed from colliding with the acoustic element during the vibrating process, the embodiment provides a MEMS vibration sensor, and the details of the embodiment are described in detail below with reference to fig. 2 to 3.

Example one

As shown in fig. 2, the MEMS vibration sensor includes a housing 1, a PCB 2, a vibration module 4, and an acoustic element 5, wherein the housing 1 is made of a metal material. The shell 1 is hermetically connected with the PCB 2 and encloses to form a first cavity 3. The vibration module 4 is located in the first cavity 3, the vibration module 4 includes a cofferdam 41 and an elastic vibration piece 42, one end of the cofferdam 41 is connected with the shell 1, the elastic vibration piece 42 is arranged at the other end of the cofferdam 41, the shell 1, the cofferdam 41 and the elastic vibration piece 42 are enclosed to form a second cavity 43, the elastic vibration piece 42 is provided with a first through hole 44, the acoustic element 5 is located in the first cavity 3, and the acoustic element 5 is arranged on the PCB 2 and corresponds to the elastic vibration piece 42. The first end of the baffle 6 is connected with the shell 1, the second end of the baffle 6 extends out of the first through hole 44, and the outer diameter of the second end of the baffle 6 is larger than the inner diameter of the first through hole 44.

In short, the utility model provides a MEMS vibration sensor, casing 1 and PCB board 2 sealing connection enclose to establish and form first cavity 3, vibration module 4 and baffle 6 are all located first cavity 3, casing 1, cofferdam 41 and elastic vibrating reed 42 enclose to establish and form second cavity 43, acoustic element 5 sets up on PCB board 2 and sets up with elastic vibrating reed 42 relatively, adopt the bone conduction mode, sound spreads into second cavity 43 and is accepted the processing by acoustic element 5 from casing 1, reduce the noise of surrounding environment, the conversation quality has been improved; by extending the second end of the baffle 6 out of the first through hole 44, the outer diameter of the second end of the baffle 6 is larger than the inner diameter of the first through hole 44, when the elastic vibration piece 42 vibrates up and down, the second end of the baffle 6 can block the elastic vibration piece 42 from further moving towards the acoustic element 5, so as to reduce the amplitude of the elastic vibration piece 42 towards the acoustic element 5 and protect the acoustic element 5 from normal use.

Further, the MEMS vibration sensor further includes a mass 7, the mass 7 is disposed on an upper end surface of the elastic vibration piece 42, and/or the mass 7 is disposed on a lower end surface of the elastic vibration piece 42. The position of the mass 7 at the elastic vibrating piece 42 is arranged according to the actual use condition. Specifically, as shown in fig. 2, the mass 7 is disposed on the upper end surface of the elastic vibrating piece 42. Furthermore, the mass 7 may be made of metal or ceramic. The elastic vibrating reed 42 and the dam 41 are disposed in the first cavity 3 and fixed in the case 1 by welding or bonding.

Furthermore, the mass block 7 is provided with a second through hole 71, the second through hole 71 is arranged corresponding to the first through hole 44, and the second end of the baffle 6 sequentially extends out of the second through hole 71 and the first through hole 44. Specifically, the first through hole 44 is provided at the center of the elastic vibrating piece 42, and the second through hole 71 is provided at the center of the mass 7. The first end of the baffle 6 is a cylinder, the second end of the baffle 6 is a circular baffle, the circular baffle is connected with a cylinder and fixed on the shell 1, the elastic vibrating reed 42 and the center part of the mass block 7 are hollowed, the circular baffle of the baffle 6 is positioned below the hollowed part, and the elastic vibrating reed 42 is prevented from being pressed to the acoustic element 5 arranged below the elastic vibrating reed 42 when the vibration amplitude is too large.

Further, the acoustic element 5 includes an ASIC chip 51 and a MEMS chip 52, both the ASIC chip 51 and the MEMS chip 52 are disposed on the PCB 2, specifically, both the ASIC chip 51 and the MEMS chip 52 are adhered to the PCB 2 by glue, and the PCB 2 is disposed with a circuit for connecting the inside and the outside of the MEMS vibration sensor. One end of the ASIC chip 51 is connected to the MEMS chip 52, and the other end of the ASIC chip 51 is connected to the PCB 2. Specifically, the PCB board 2 on which the ASIC chip 51 and the MEMS chip 52 are mounted is over-reflowed, and the metal case 1 is mounted using SMT (surface mount technology) equipment.

Further, the MEMS vibration sensor further includes a blind hole 8, and the blind hole 8 is disposed in the PCB 2 and corresponds to the MEMS chip 52. Further, the shape of the blind hole 8 may be a rectangular parallelepiped, an irregular body, or an ellipsoid. The MEMS chip 52 comprises a back plate and a vibrating plate, the vibrating plate of the MEMS chip 52 is arranged corresponding to the blind hole 8, the receiving effect of the MEMS chip 52 is optimized, and the sound quality is improved.

Further, as shown in fig. 2, the surface of the elastic vibrating piece 42 has a planar structure.

The operating principle of the MEMS vibration sensor in this embodiment is as follows:

when a vibration signal is uploaded from the metal casing 1, the elastic vibrating reed 42 generates resonance after receiving the vibration signal, the vibration generated by the elastic membrane 42 generates a change of air pressure in the second cavity 43, and the air pressure signal caused by the vibration frequency and amplitude is sensed by the high-sensitivity vibration membrane of the MEMS chip 52.

Example two

Compared with the first embodiment, the basic structure of the MEMS vibration sensor provided in this embodiment is the same as that of the first embodiment, and only the surface of the elastic vibration piece 42 is different, and the structure that is the same as that of the first embodiment is not repeated in this embodiment.

As shown in fig. 3, the surface of the elastic vibrating piece 42 has a wave-like structure.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. A MEMS vibration sensor, comprising:

a housing (1);

the shell (1) is hermetically connected with the PCB (2) and encloses to form a first cavity (3);

the vibration module (4) is located in the first cavity (3), the vibration module (4) comprises a cofferdam (41) and an elastic vibrating piece (42), one end of the cofferdam (41) is connected with the shell (1), the elastic vibrating piece (42) is arranged at the other end of the cofferdam (41), the shell (1), the cofferdam (41) and the elastic vibrating piece (42) are enclosed to form a second cavity (43), and the elastic vibrating piece (42) is provided with a first through hole (44);

the acoustic element (5) comprises a MEMS chip (52) and an ASIC chip (51), and is positioned in the first cavity (3), the MEMS chip (52) and the ASIC chip (51) are arranged on the PCB (2), and the MEMS chip (52) and the elastic vibrating piece (42) are correspondingly arranged;

the first end of the baffle (6) is fixed on the inner side of the shell (1), and the second end of the baffle (6) is located below the elastic vibrating piece (42) and is larger than the inner diameter of the first through hole (44).

2. MEMS vibration sensor according to claim 1, further comprising a mass (7), an upper end face of the elastic membrane (42) being provided with the mass (7), and/or

The lower end face of the elastic vibrating piece (42) is provided with the mass block (7).

3. MEMS vibration sensor according to claim 2, characterized in that the mass (7) is made of metal or ceramic material.

4. The MEMS vibration sensor according to claim 2, wherein the mass (7) is provided with a second through hole (71), the second through hole (71) is disposed corresponding to the first through hole (44), and the second end of the baffle (6) sequentially passes through the second through hole (71) and the first through hole (44).

5. MEMS vibration sensor according to claim 1, characterized in that one end of the ASIC chip (51) is connected with the MEMS chip (52) and the other end of the ASIC chip (51) is connected with the PCB board (2).

6. The MEMS vibration sensor according to claim 5, further comprising a blind hole (8), the blind hole (8) being disposed within the PCB board (2) and being disposed in correspondence with the MEMS chip (52).

7. The MEMS vibration sensor of claim 6 wherein the blind holes are cuboid or ellipsoid in shape.

8. MEMS vibration sensor according to claim 1, characterized in that the housing (1) is made of metal.

9. The MEMS vibration sensor according to claim 1, wherein the surface of the elastic vibration piece (42) is a planar structure.

10. The MEMS vibration sensor according to claim 1, wherein the surface of the elastic vibration piece (42) is a wave-shaped structure.

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