CN213661943U

CN213661943U - MEMS microphone chip

Info

Publication number: CN213661943U
Application number: CN202022770540.1U
Authority: CN
Inventors: 赵转转; 柏杨; 张睿
Original assignee: AAC Acoustic Technologies Shenzhen Co Ltd
Current assignee: AAC Technologies Holdings Shenzhen Co Ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2021-07-09
Anticipated expiration: 2030-11-25
Also published as: WO2022110270A1

Abstract

The utility model provides a MEMS microphone chip, MEMS microphone chip including have the basement of back of the body chamber and set up in electric capacity structure on the basement, electric capacity structure include with the fixed vibrating diaphragm of basement and with the backplate that the vibrating diaphragm interval set up, being close to of backplate vibrating diaphragm one side with being close to of vibrating diaphragm at least one of basement one side is equipped with insulating arch, insulating arch includes first bellying and the second bellying that a plurality of intervals set up, the height of first bellying is greater than the height of second bellying. The utility model discloses can effectively reduce the adhesion of vibrating diaphragm and backplate or basement, prevent that the microphone from becoming invalid.

Description

MEMS microphone chip

[ technical field ] A method for producing a semiconductor device

The utility model belongs to the technical field of the microphone, especially, relate to a MEMS microphone chip.

[ background of the invention ]

An MEMS (Micro-Electro-Mechanical System) microphone is an electric transducer manufactured by using a micromachining technology, and has the characteristics of small volume, good frequency response characteristics, low noise and the like. With the development of miniaturization and lightness of electronic devices, MEMS microphones are increasingly widely used for these devices. The existing capacitive MEMS microphone chip mainly comprises a substrate structure with a back cavity, a vibrating diaphragm and a fixed back plate structure which are positioned on the upper part of the substrate, wherein the vibrating diaphragm and the fixed back plate form a capacitive system. When sound pressure acts on the diaphragm, pressure difference exists on two sides of the diaphragm, so that the diaphragm moves close to or away from the backboard, capacitance change between the diaphragm and the backboard is caused, conversion from a sound signal to an electric signal is realized, and the working principle of the MEMS condenser microphone is realized.

After the sound pressure acts on the vibrating diaphragm, the vibrating diaphragm is close to the back plate under the action of the electric field force and the sound pressure until the electric field force, the sound pressure and the elastic force of the vibrating diaphragm reach balance, at the moment, when a small disturbance is applied to the microphone, the speed of the change of the electric field force of the vibrating diaphragm is greater than the elastic force, the vibrating diaphragm is attached to the insulating bulge on the back plate, and the adhesion force between the vibrating diaphragm and the insulating bulge must be overcome to restore the original shape of the vibrating diaphragm. In the related art, a plurality of insulation bulges between the diaphragm and the back plate or the substrate are all at the same height, when the density of the insulation bulges is small, the insulation bulges are not enough to prevent the diaphragm from continuously deforming due to large disturbance, the diaphragm is attached to the back plate or the substrate, and the adhesion force is increased; when the density of the insulation bulges is higher, the effective adhesion force is increased because the number of the insulation bulges adsorbing the vibrating diaphragm is increased, and the voltage is reduced to be insufficient to overcome the adhesion force, so that the microphone fails.

[ Utility model ] content

An object of the utility model is to provide a MEMS microphone chip can effectively reduce the adhesion of vibrating diaphragm and backplate or basement, prevents that the microphone from becoming invalid.

The technical scheme of the utility model as follows: the utility model provides a MEMS microphone chip, including the basement that has the back cavity and set up in capacitor structure on the basement, capacitor structure include with the fixed vibrating diaphragm of basement and with the backplate that the vibrating diaphragm interval set up which characterized in that: at least one of one side of the back plate close to the vibrating diaphragm and one side of the vibrating diaphragm close to the substrate is provided with an insulating bulge, the insulating bulge comprises a plurality of first bulge parts and a plurality of second bulge parts which are arranged at intervals, and the height of the first bulge parts is greater than that of the second bulge parts.

Furthermore, the first protruding portion and the second protruding portion are arranged on one side, close to the diaphragm, of the back plate, a plurality of third protruding portions are arranged on one side, close to the substrate, of the diaphragm, and the heights of the third protruding portions are the same.

Furthermore, one side of the diaphragm, which is close to the substrate, is provided with the first protruding portion and the second protruding portion, one side of the back plate, which is close to the diaphragm, is provided with a plurality of third protruding portions, and the heights of the third protruding portions are the same.

Further, the first bulge part and the second bulge part are arranged on one side of the back plate close to the diaphragm and one side of the diaphragm close to the substrate.

Further, the first protruding portions and the second protruding portions are alternately arranged in sequence.

Further, at least one second protruding portion is arranged between every two adjacent first protruding portions.

Further, the first convex parts and the second convex parts are distributed at equal intervals.

Furthermore, a through hole penetrating through the insulating bulge along the vibration direction of the diaphragm is formed in the insulating bulge.

Further, the insulating protrusion is of a columnar structure.

Further, the MEMS microphone chip further includes a supporting member fixed on the substrate and used for supporting the capacitor structure.

The beneficial effects of the utility model reside in that: because the insulation bulge on one side of the back plate close to the vibrating diaphragm or one side of the vibrating diaphragm close to the substrate comprises the first bulge parts and the second bulge parts which are arranged at intervals, and the height of the first bulge parts is greater than that of the second bulge parts, when disturbance is small, the first bulge parts play a role of blocking to prevent the vibrating diaphragm from being attached to the back plate or the substrate in a large area, at the moment, the adhesion force is small, the elastic force of the vibrating diaphragm can overcome the action of the adhesion force and the electric field force to separate from the insulation bulge only by reducing the voltage, and the vibrating diaphragm deforms to recover to the initial state; when the disturbance is large, the first bulge part is not enough to prevent the diaphragm from continuously deforming, the second bulge part further plays a role in blocking, so that the diaphragm is prevented from being attached to the back plate or the substrate, and the first bulge part and the second bulge part form an uneven adhesion surface, so that the adhesion force with the diaphragm can be effectively reduced.

[ description of the drawings ]

Fig. 1 is a schematic diagram of an overall structure of a MEMS microphone chip according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a split structure of a MEMS microphone chip according to a first embodiment of the present invention;

fig. 3 is a schematic cross-sectional structural diagram of a MEMS microphone chip according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a deformation state of a diaphragm when a small disturbance is applied to a MEMS microphone chip according to a first embodiment of the present invention;

fig. 5 is a schematic diagram illustrating a deformation state of a diaphragm when a large disturbance is applied to a MEMS microphone chip according to a first embodiment of the present invention;

FIG. 6 is a schematic view of the structure of the insulation bump in FIG. 2;

fig. 7 is a schematic cross-sectional structural diagram of a MEMS microphone chip according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a deformation state of the diaphragm when a large disturbance is applied to the MEMS microphone chip according to the second embodiment of the present invention;

fig. 9 is a schematic cross-sectional structure diagram of a MEMS microphone chip according to a third embodiment of the present invention.

[ detailed description ] embodiments

The present invention will be further described with reference to the accompanying drawings and embodiments.

The first embodiment is as follows:

referring to fig. 1 to 3, an MEMS microphone chip according to an embodiment of the present invention includes a substrate 1 having a back cavity 11 and a capacitor structure 2 disposed on the substrate 1, wherein the capacitor structure 2 includes a diaphragm 22 fixed to the substrate 1 and a back plate 21 spaced from the diaphragm 22. The MEMS microphone chip further comprises a support member 3 which is arranged on the substrate 1 and fixedly connected with the substrate 1, the capacitor structure 2 is fixed on the support member 3, and the support member 3 is made of an insulating material.

In this embodiment, an insulating protrusion 4 is disposed on a side of the back plate 21 close to the diaphragm 22, the insulating protrusion 4 includes a plurality of first protruding portions 41 and second protruding portions 42 disposed at intervals, and a height of the first protruding portion 41 is greater than a height of the second protruding portion 42. As shown in fig. 4, when the disturbance applied to the microphone is small, the first protruding portion 41 acts as a barrier to prevent the diaphragm 22 from being attached to the backplate 21 in a large area, and at this time, the adhesion force is small, and only by reducing the voltage, the elastic force of the diaphragm 22 can overcome the effects of the adhesion force and the electric field to separate from the first protruding portion 41, and the deformation of the diaphragm 22 returns to the initial state; as shown in fig. 5, when the disturbance is large, the first protruding portion 41 is not enough to prevent the diaphragm 22 from further deforming, the second protruding portion 42 further acts as a stop to prevent the diaphragm 22 from adhering to the backplate 21, and the first protruding portion 41 and the second protruding portion 42 form a rugged adhesion surface, which can effectively reduce the adhesion force with the diaphragm 22. Further, a plurality of third protruding portions 43 are disposed on one side of the diaphragm 22 close to the substrate 1, and the heights of the plurality of third protruding portions 43 are the same.

The heights of the first protruding portion 41 and the second protruding portion 42 refer to the extending lengths of the first protruding portion 41 and the second protruding portion 42 from the surface of the back plate 21 near the diaphragm 22 toward the diaphragm 22, and the height difference between the first protruding portion 41 and the second protruding portion 42 can be adjusted according to actual requirements. In this embodiment, the first protruding portions 41 and the second protruding portions 42 are sequentially and alternately arranged, and one second protruding portion 42 is disposed between two adjacent first protruding portions 41, and the first protruding portions 41 and the second protruding portions 42 have a height shape, so as to further reduce the adhesion force with the diaphragm 22. In other possible embodiments, the number of the second protruding portions 42 between two adjacent first protruding portions 41 may also be two, three, or four, and the like, which is not limited in this embodiment. Preferably, the first protruding portion 41 and the second protruding portion 42 are distributed at equal intervals, and the first protruding portion 41 and the second protruding portion 42 are distributed in a row and a column on the side of the back plate 21 close to the diaphragm 22, so that not only the whole appearance is more beautiful, but also the deformation of the diaphragm 22 when contacting the insulating protrusion 4 is more uniform.

In this embodiment, as shown in fig. 6, the insulating protrusion 4 is provided with a through hole 44 penetrating through the insulating protrusion 4 along the vibration direction of the diaphragm 22, and the through hole 44 can reduce the adhesion force generated by the contact between the insulating protrusion 4 and the diaphragm 22. It is understood that in other possible embodiments, a groove may be formed on the contact surface of the insulating protrusion 4 and the diaphragm 22, which may also reduce the adhesion between the insulating protrusion 4 and the diaphragm 22. The insulating protrusion 4 has a columnar structure, and may have a columnar shape or a square columnar shape, but the shape of the insulating protrusion 4 is not limited thereto.

Example two:

referring to fig. 7, fig. 7 is a diagram of a MEMS microphone chip according to a second embodiment of the present invention, which is basically the same as the MEMS microphone chip according to the first embodiment, and the difference is the arrangement positions of the first protruding portion 41 and the second protruding portion 42.

In this embodiment, a first protrusion 41 and a second protrusion 42 are disposed on a side of the diaphragm 22 close to the substrate 1, a plurality of third protrusions 43 are disposed on a side of the backplate 21 close to the diaphragm 22, and heights of the plurality of third protrusions 43 are the same. As shown in fig. 8, when the sound pressure acts downward on the diaphragm 22, the first protrusion 41 and the second protrusion 42 with different heights on the side of the diaphragm 22 close to the substrate 1 can act under different disturbances, when the disturbance is small, the first protrusion 41 can play a role in blocking, when the disturbance is large, the first protrusion 41 is not enough to prevent the diaphragm 22 from continuing to deform, and at this time, the second protrusion 42 further blocks the diaphragm 22 from being attached to the substrate 1.

Example three:

referring to fig. 9, fig. 9 is a MEMS microphone chip according to a third embodiment of the present invention, which is substantially the same as the MEMS microphone chips according to the first and second embodiments, and the difference is the arrangement positions of the first protruding portion 41 and the second protruding portion 42.

In this embodiment, the side of the back plate 21 close to the diaphragm 22 and the side of the diaphragm 22 close to the substrate 1 are both provided with the first protruding portion 41 and the second protruding portion 42, so that the diaphragm 22 can be effectively prevented from being attached to the substrate 1 and the back plate 21 under different sound pressures.

To sum up, the embodiment of the present invention provides a MEMS microphone chip, because the insulating protrusion 4 on the side of the backplate 21 close to the vibrating diaphragm 22 or the vibrating diaphragm 22 close to the substrate 1 includes the first protruding portion 41 and the second protruding portion 42 that are arranged at a plurality of intervals, and the height of the first protruding portion 41 is greater than the height of the second protruding portion 42, when the disturbance is small, the first protruding portion 41 plays a role of blocking, prevent the vibrating diaphragm 22 from being attached to the backplate 21 or the substrate 1 in a large area, at this time, the adhesion force is small, only by reducing the voltage, the elastic force of the vibrating diaphragm 22 can overcome the effect of the adhesion force and the electric field force to separate from the insulating protrusion, and the vibrating diaphragm 22 deforms to recover the initial state; when the disturbance is large, the first protruding portion 41 is not enough to prevent the diaphragm 22 from further deforming, and the second protruding portion 42 further acts as a barrier to prevent the diaphragm 22 from adhering to the backplate 21 or the substrate 1, and the first protruding portion 41 and the second protruding portion 42 form an uneven adhesion surface, so that the adhesion force with the diaphragm 22 can be effectively reduced.

The above embodiments of the present invention are only described, and it should be noted that, for those skilled in the art, modifications can be made without departing from the inventive concept, but these all fall into the protection scope of the present invention.

Claims

1. The utility model provides a MEMS microphone chip, including the basement that has the back cavity and set up in capacitor structure on the basement, capacitor structure include with the fixed vibrating diaphragm of basement and with the backplate that the vibrating diaphragm interval set up which characterized in that: at least one of one side of the back plate close to the vibrating diaphragm and one side of the vibrating diaphragm close to the substrate is provided with an insulating bulge, the insulating bulge comprises a plurality of first bulge parts and a plurality of second bulge parts which are arranged at intervals, and the height of the first bulge parts is greater than that of the second bulge parts.

2. The MEMS microphone chip of claim 1, wherein the first protrusion and the second protrusion are disposed on a side of the backplate close to the diaphragm, and a plurality of third protrusions are disposed on a side of the diaphragm close to the substrate, and the heights of the third protrusions are the same.

3. The MEMS microphone chip of claim 1, wherein the first protrusion and the second protrusion are disposed on a side of the diaphragm close to the substrate, and a plurality of third protrusions are disposed on a side of the backplate close to the diaphragm, and the heights of the third protrusions are the same.

4. The MEMS microphone chip of claim 1, wherein the first and second protruding portions are disposed on both a side of the backplate adjacent to the diaphragm and a side of the diaphragm adjacent to the substrate.

5. The MEMS microphone chip of claim 1, wherein the first and second protrusions are alternately arranged in sequence.

6. The MEMS microphone chip of claim 5, wherein at least one second protruding portion is disposed between two adjacent first protruding portions.

7. The MEMS microphone chip of claim 1, wherein the first and second bumps are equidistantly distributed.

8. The MEMS microphone chip of any one of claims 1 to 7, wherein the insulating protrusion is provided with a through hole penetrating through the insulating protrusion in a vibration direction of the diaphragm.

9. The MEMS microphone chip of any one of claims 1 to 7, wherein the insulating bump is a columnar structure.

10. The MEMS microphone chip of claim 1, further comprising a support member affixed to the substrate and configured to support the capacitive structure.