CN216391412U - MEMS microphone - Google Patents

Abstract

The utility model provides a MEMS microphone, which comprises a substrate with a back cavity and a capacitor system arranged on the substrate, the capacitor system comprising a back plate and a back plate opposite to the back plate and arranged on a side of the back plate. The first vibrating film on the side and the second vibrating film arranged on the other side of the back plate, the first vibrating film and the second vibrating film are spaced apart from the back plate, and the back plate is provided with several through holes, The MEMS microphone further includes a connecting column connecting the first diaphragm, the back plate and the second diaphragm. Compared with the related art, in the MEMS microphone provided by the present invention, the connecting column connects the first diaphragm, the back plate and the second diaphragm, which can improve the reliability and sensitivity of the MEMS microphone.

Description

MEMS microphone

【Technical field】

The utility model relates to the field of electro-acoustic conversion, in particular to a MEMS microphone.

【Background technique】

In recent years, mobile communication technology has developed rapidly, and consumers are increasingly using mobile communication devices, such as cellular phones, cellular phones with Internet access, personal digital assistants, or other devices for communication through dedicated communication networks, of which microphones are among the One of the important components, especially the MEMS microphone.

Micro-Electro-Mechanical System (MEMS) microphone is a kind of electric power sound transducer produced by micro-machining technology, which has the characteristics of small size, good frequency response characteristics and low noise. With the development of miniaturization and thinning of electronic devices, MEMS microphones are more and more widely used in these devices.

A MEMS microphone in the related art includes a substrate having a back cavity and a capacitive system disposed on the substrate, the capacitive system including a back plate and a first vibrator opposite to the back plate and disposed on one side of the back plate. a membrane, a second vibrating membrane arranged on the other side of the back plate, the first vibrating membrane and the second vibrating membrane are arranged at intervals from the back plate, the first vibrating membrane and the second vibrating membrane are fixed to the base through the outer edge, The displacement of the diaphragm of the MEMS microphone with this structure does not change much under the action of sound pressure, so the sensitivity of the MEMS microphone is not very high.

Therefore, it is necessary to provide an improved MEMS microphone to solve the above problems.

【Content of utility model】

The technical problem to be solved by the utility model is to provide a MEMS microphone with high sensitivity.

In order to solve the above technical problems, the present invention provides a MEMS microphone, which includes a substrate with a back cavity and a capacitor system disposed on the substrate, the capacitor system including a back plate and a back plate opposite to the back plate and disposed The first diaphragm on one side of the back plate and the second diaphragm on the other side of the back plate, the first diaphragm and the second diaphragm are spaced apart from the back plate, and the back plate is provided with There are several through holes, and the MEMS microphone further includes a connecting column connecting the first diaphragm, the back plate and the second diaphragm.

Preferably, the connection post includes an upper surface away from the base, a lower surface opposite to the upper surface, and a side surface connecting the upper surface and the lower surface, the connection post penetrates through the through hole, and the connection The upper surface of the column is connected with the first diaphragm, the lower surface is connected with the second diaphragm, and the side surface is connected with the back plate.

Preferably, the connecting column is a hollow annular structure, and the back plate is connected to the inner side surface of the connecting column.

Preferably, there are two connecting posts, which are located on both sides of the back plate respectively, and the two connecting posts are respectively sandwiched between the first diaphragm and the back plate and between the second diaphragm and the back plate.

Preferably, the connecting post connects the center positions of the first diaphragm, the back plate and the second diaphragm.

Preferably, the connecting column is integrally formed with the back plate.

Preferably, the first diaphragm includes a first body portion, a first fixing portion located on the outer periphery of the first body portion, and a first elastic member connecting the first body portion and the first fixing portion.

Preferably, the second diaphragm includes a second body portion, a second fixing portion located on the outer periphery of the second body portion, and a second elastic member connecting the second body portion and the second fixing portion.

Preferably, the MEMS is further provided with a support column passing through the through hole, and the support column is connected to the first diaphragm and the second diaphragm.

Preferably, a plurality of the support columns are provided, and the plurality of the support columns are distributed axially symmetrically with respect to the connection column.

Compared with the related art, in the MEMS microphone provided by the present invention, the connecting column connects the first diaphragm, the back plate and the second diaphragm, which can improve the reliability and sensitivity of the MEMS microphone.

【Description of drawings】

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some implementations of the present invention. For example, for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative work, wherein: FIG. 1 is a cross-sectional view of the MEMS microphone of the present invention.

【Detailed ways】

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, but not all of them. Example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Please refer to FIG. 1 , which is a MEMS microphone 100 of the present invention, which includes a substrate 11 having a back cavity 10 and a capacitor system 101 disposed on the substrate 11 . The capacitor system 101 includes a back plate 40 , a first diaphragm 20 opposite to the back plate 40 and disposed on one side of the back plate 40 , and a second diaphragm 30 disposed on the other side of the back plate 40 . , the first vibrating film 20 and the second vibrating film 30 are spaced apart from the back plate 40 , and the back plate 40 is provided with a plurality of through holes 41 . Due to the dual-diaphragm structure, the variation of the capacitance can be differentially calculated, which can improve the sensitivity of the MEMS microphone 100 .

In addition, the MEMS microphone 100 further includes a connecting column 50 connecting the first diaphragm 20 , the back plate 40 and the second diaphragm 30 . Specifically, the connection post 50 includes an upper surface 51 away from the substrate 11 , a lower surface 52 opposite to the upper surface 51 , and a side surface 53 connecting the upper surface 51 and the lower surface 52 . The connecting column 50 penetrates through the through hole 41 , the upper surface 51 of which is connected to the first diaphragm 20 , the lower surface 52 is connected to the second diaphragm 30 , and the side surface 53 is connected to the back plate 40 . As a result, the first diaphragm 20 and the second diaphragm 30 can generate a larger displacement amount under the action of the same external sound pressure, thereby further improving the sensitivity of the MEMS microphone 100 .

Preferably, the connecting column 50 is located at the center of the capacitor system 101 , that is, the connecting column 50 is located at the center of the first diaphragm 20 , the back plate 40 and the second diaphragm 30 , so that the first diaphragm 20 and the second diaphragm 30 can be 30 vibration is more stable.

In the present invention, the connecting column 50 is a hollow annular structure, the inner side surface 53 of the connecting column 50 is connected with the back plate 40 , the connecting column 50 is an insulating material, and is integrally formed with the back plate 40 , that is, the capacitor structure 101 An H-shaped back plate is arranged at the central position and is connected with the first diaphragm 20 and the second diaphragm 30 . In other embodiments, the connecting posts may also be located on both sides of the back plate, that is, sandwiched between the first diaphragm and the back plate and between the second diaphragm and the back plate, respectively. The connecting posts may also be integrally formed with the backplane. That is, at the central position of the capacitive system, a columnar back plate is arranged to connect the first diaphragm and the second diaphragm.

In this embodiment, the first diaphragm 20 includes a first body portion 21 , a first fixing portion 22 located on the outer periphery of the first body portion 21 , and connecting the first body portion 21 and the first fixing portion 22 The first elastic member 23 of the 32 of the second elastic member 33. The first fixing portion 22 and the second fixing portion 32 are fixed to the base 11, the first elastic member 23 and the second elastic member 33 can be springs, and the elastic connection can increase the vibration displacement of the first vibrating film 20 and the second vibrating film 30, Improve product sensitivity.

The MEMS microphone 100 is further provided with a support column 60 penetrating through the through hole 41 , and the support column 60 is only connected to the first diaphragm 20 and the second diaphragm 30 , but is not connected to the back plate 40 . In addition, there are a plurality of support columns 60 , all of which are located outside the connection column 50 and connected to the edges of the first body part 21 and the second body part 31 , and are distributed axially symmetrically with respect to the connection column 50 . The support column 60 is also an insulating material, and the support column 60 can avoid unnecessary deflection of the first diaphragm 20 and the second diaphragm 30 .

The above are only the embodiments of the present utility model. It should be pointed out that for those of ordinary skill in the art, improvements can be made without departing from the inventive concept of the present utility model, but these belong to The scope of protection of the utility model.

Claims (10)

1. A MEMS microphone, comprising a substrate having a back cavity and a capacitive system disposed on the substrate, the capacitive system comprising a back plate and a first opposite to the back plate and disposed on one side of the back plate; A vibrating film and a second vibrating film disposed on the other side of the back plate, the first vibrating film and the second vibrating film are spaced apart from the back plate, and the back plate is provided with a number of through holes , characterized in that: the MEMS microphone further comprises a connecting column connecting the first diaphragm, the back plate and the second diaphragm. 2 . The MEMS microphone according to claim 1 , wherein the connection post comprises an upper surface away from the base, a lower surface opposite to the upper surface, and a connection between the upper surface and the lower surface. 3 . On the side, the connecting column penetrates the through hole, the upper surface of the connecting column is connected to the first diaphragm, the lower surface is connected to the second diaphragm, the side is connected to the back board connection. 3 . The MEMS microphone according to claim 2 , wherein the connecting column is a hollow annular structure, and the back plate is connected to the inner side surface of the connecting column. 4 . 4 . The MEMS microphone according to claim 1 , wherein there are two connecting posts, which are respectively located on both sides of the back plate, and the two connecting posts are respectively clamped on the first vibration plate. 5 . between the membrane and the back plate and between the second diaphragm and the back plate. 5 . The MEMS microphone according to claim 1 , wherein the connecting post is connected to the center position of the first diaphragm, the back plate and the second diaphragm. 6 . 6 . The MEMS microphone according to claim 1 , wherein the connecting column and the back plate are integrally formed. 7 . 7 . The MEMS microphone of claim 1 , wherein the first diaphragm comprises a first body portion, a first fixing portion located on the outer periphery of the first body portion, and a first fixing portion connecting the first body portion and the MEMS microphone. 8 . the first elastic member of the first fixing part. 8 . The MEMS microphone according to claim 1 , wherein the second diaphragm comprises a second body portion, a second fixing portion located on the outer periphery of the second body portion, and a second fixing portion connecting the second body portion and the second body portion. 9 . the second elastic member of the second fixing part. 9 . The MEMS microphone according to claim 1 , wherein the MEMS is further provided with a support column passing through the through hole, and the support column connects the first diaphragm and the second diaphragm. 10 . 10 . The MEMS microphone of claim 9 , wherein a plurality of the support columns are provided, and the plurality of the support columns are distributed axially symmetrically with respect to the connection column. 11 .

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