MEMS microphone chip

Abstract

The microphone chip provided by the utility model comprises a substrate with a back cavity and a capacitance system fixed on the substrate and arranged above the back cavity, the capacitance system comprises a vibrating diaphragm and a back plate which are oppositely arranged at an interval, and the vibrating diaphragm comprises a vibrating part and a plurality of elastic connecting parts arranged at the edge of the vibrating part. The vibrating diaphragm is fixed on the substrate through the elastic connecting part; the vibration part comprises a middle vibration part located at the middle position and an outer vibration part connected with the middle vibration part and the elastic connection part, the backboard is provided with an anchoring part extending towards the vibration diaphragm, and the anchoring part is fixedly connected with the middle vibration part. The MEMS microphone chip provided by the utility model is high in reliability.

Description

[Technical field]

[0001] The utility model relates to the technical field of electroacoustic conversion, and in particular to a microphone chip for a portable mobile terminal. [Background technology]

[0002] MEMS microphone chips are widely used in acoustic devices, such as the common MEMS capacitive microphone structure. The MEMS microphone chip in the related art includes a substrate with a back cavity, a back plate and a diaphragm arranged on the substrate and relatively spaced. When the sound pressure acts on the diaphragm, there is a pressure difference between the two surfaces of the diaphragm facing the back plate and the two surfaces away from the back plate, causing the diaphragm to move closer to or away from the back plate, thereby causing the capacitance between the diaphragm and the back plate to change, realizing the conversion of sound signals into electrical signals.

[0003] In the related art, the diaphragm and the back plate in the MEMS microphone chip are completely separated, and the diaphragm is generally fixed to the substrate in a full-circle fixed manner, which causes the diaphragm to move too much during a drop test, reducing the reliability of the MEMS microphone chip.

[0004] Therefore, it is necessary to provide a new microphone chip to solve the above technical problems. [Contents of the utility model]

[0005] The utility model aims to provide a MEMS microphone chip with high reliability.

[0006] In order to achieve the above-mentioned purpose, the utility model proposes a MEMS microphone chip, which includes a substrate having a back cavity and a capacitor system fixed on the substrate and arranged above the back cavity, the capacitor system includes a diaphragm and a back plate arranged relatively spaced apart, the diaphragm includes a vibrating part and a plurality of elastic connecting parts arranged at the edge of the vibrating part, the diaphragm is fixed to the substrate through the elastic connecting parts; the vibrating part includes an intermediate vibrating part located in the middle position and an outer vibrating part connecting the intermediate vibrating part and the elastic connecting part, the back plate is provided with an anchoring part extending toward the diaphragm, and the anchoring part is fixedly connected to the intermediate vibrating part.

[0007] Preferably, the back plate includes an insulating layer and an electrode layer arranged on the side of the insulating layer facing the diaphragm, the electrode layer includes an electrode part that generates an electrical signal through relative movement with the diaphragm and a partition part that electrically isolates the electrode part, and the anchoring part is formed by extending from the partition part toward the diaphragm.

[0008] Preferably, the back plate comprises an insulating layer and an electrode layer provided on a side of the insulating layer facing the diaphragm, and the anchoring portion is formed on the insulating layer.

[0009] Preferably, the insulating layer includes an anchoring region which is not arranged directly opposite to the electrode layer along the vibration direction, and the anchoring region is recessed toward the diaphragm to form the anchoring portion to be fixed to the diaphragm.

[0010] Preferably, the insulating layer includes an anchoring region which is not arranged directly opposite to the electrode layer along the vibration direction, and the anchoring portion extends from the anchoring region to pass through the electrode layer and is fixed to the diaphragm.

[0011] Preferably, a plurality of the elastic connection portion spacer rings are arranged on the edge of the outer vibration portion, the elastic connection portion includes a first connection portion connected to the edge of the outer vibration portion, a second connection portion connected to the base, and an elastic portion connecting the first connection portion and the second connection portion, the elastic portion includes a plurality of mutually connected bending portions, and the bending portions are S-shaped.

[0012] Preferably, the second connecting portion is connected to the two bending portions, the vibrating portion of the diaphragm is circular, the second connecting portion includes a central axis along a radial direction, and the two bending portions are axially symmetrical structures relative to the central axis.

[0013] Preferably, the first connecting portion is arranged at an end of the bending portion away from the second connecting portion.

[0014] Compared with the related art, the diaphragm of the MEMS microphone chip provided by the utility model includes a vibrating part and a plurality of elastic connecting parts arranged on the edge of the vibrating part, and the diaphragm is fixed to the base through the elastic connecting parts; the vibrating part includes an intermediate vibrating part located in the middle position and an outer vibrating part connecting the intermediate vibrating part and the elastic connecting part, and an anchoring part extending toward the diaphragm is provided on the back plate, and the anchoring part is fixedly connected to the intermediate vibrating part; by anchoring the diaphragm to the base through a plurality of elastic connecting parts and anchoring the middle area of ​​the diaphragm to the back plate, the reliability of the MEMS microphone chip is effectively improved.

Brief Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0016] Figure 1 It is a three-dimensional diagram of the microphone chip in the utility model;

[0017] Figure 2 It is an exploded view of the microphone chip in the utility model;

[0018] Figure 3 for Figure 1 Sectional view along line AA;

[0019] Figure 4 It is a top view of the diaphragm and the second supporting part of the microphone chip of the utility model;

[0020] Figure 5 for Figure 3 A schematic diagram of an embodiment of a mid-section view;

[0021] Figure 6 for Figure 3 A schematic diagram of another embodiment of a mid-section view. [Specific implementation method]

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0023] like Figure 1-Figure 4 As shown, the utility model provides a MEMS microphone chip 100, which includes a substrate 20 with a back cavity 10 and a capacitor system 30 fixed on the substrate 20 and arranged above the back cavity 10; the capacitor system 30 includes a diaphragm 31 and a back plate 32 arranged relatively spaced apart. Under the action of sound pressure, the diaphragm 31 vibrates so that the distance between it and the back plate 32 changes, thereby causing the capacitance to change, thereby detecting sound signals. In this embodiment, the back plate 32 is located on the side of the diaphragm 31 away from the substrate 20.

[0024] The diaphragm 31 includes a vibration portion 311 and a plurality of elastic connection portions 312 disposed at edges of the vibration portion 311 . The diaphragm 31 is fixed to the substrate 20 via the elastic connection portions 312 .

[0025] The vibration part 311 includes a middle vibration part 3111 located in the middle position and an outer vibration part 3112 connecting the middle vibration part 3111 and the elastic connection part 312; the back plate 32 is provided with an anchoring part 321 extending toward the diaphragm 31, and the anchoring part 321 is fixedly connected to the middle vibration part 3111. By providing the anchoring part, the middle vibration area of ​​the diaphragm is anchored to the back plate, which can effectively prevent the diaphragm from moving too much in the reliability test, thereby improving the reliability of the diaphragm.

[0026] Specific, combined Figure 1-3 and Figure 6As shown, the back plate 32 includes an insulating layer 322 and an electrode layer 323 arranged on the side of the insulating layer 322 facing the diaphragm 31, the electrode layer 323 includes an electrode part 3231 that generates an electrical signal by relative movement with the diaphragm 31 and a partition part 3232 that is electrically isolated from the electrode part 3231, and the anchoring part 321 is formed by extending from the partition part 3232 toward the diaphragm 31.

[0027] In other embodiments, in combination Figure 1-3 and Figure 5 As shown, the anchoring portion 321 may also be formed in the insulating layer 322. Specifically, the insulating layer 322 includes an anchoring region 3221 that is not arranged directly opposite to the electrode layer 323 along the vibration direction, and the anchoring region 3221 is recessed toward the diaphragm 31 to form the anchoring portion 321 fixed to the diaphragm 31. That is, at this time, the anchoring portion 321 is the anchoring region 3221. Optionally, the anchoring portion 321 extends from the anchoring region 3221 to pass through the electrode layer 323 and is fixed to the diaphragm 31.

[0028] like Figure 4 As shown, several of the elastic connection parts 312 are arranged at the edge of the outer vibration part 3112, and the elastic connection part 312 includes a first connection part 3121 connected to the edge of the outer vibration part 3112, a second connection part 3122 connected to the substrate 20, and an elastic part 3123 connecting the first connection part 3121 and the second connection part 3122, and the elastic part 3123 includes a plurality of mutually connected bending parts 3124, and the bending parts 3124 are S-shaped. Specifically, the second connection part 3122 is connected to two of the bending parts 3124, the vibration part 311 of the diaphragm 31 is circular, the second connection part 3122 includes a central axis X along the radial direction, and the two bending parts 3124 are axially symmetrical structures relative to the central axis X; the first connection part 3121 is arranged at one end of the bending part 3124 away from the second connection part 3122.

[0029] The microphone chip 100 further includes a support portion 40 fixed to the substrate 20, one end of the elastic connection portion 312 is fixed to the outer vibration portion 3112, and the other end is fixed to the support portion 40. Specifically, the support portion 40 includes a first support portion 41 fixed to the substrate 20 and a second support portion 42 fixed to the first support portion 41, the first support portion 41 is used to fix the back plate 32, and the second support portion 42 is used to fix the diaphragm 31.

[0030] Furthermore, the back plate 32 is provided with a plurality of sound holes 324 penetrating therethrough along the vibration direction, and the anchoring portion 321 is disposed in an area of ​​the back plate 32 where the sound holes 324 are not provided.

[0031] Compared with the related art, the diaphragm of the MEMS microphone chip provided by the utility model includes a vibrating part and a plurality of elastic connecting parts arranged on the edge of the vibrating part, and the diaphragm is fixed to the base through the elastic connecting parts; the vibrating part includes an intermediate vibrating part located in the middle position and an outer vibrating part connecting the intermediate vibrating part and the elastic connecting part, and an anchoring part extending toward the diaphragm is provided on the back plate, and the anchoring part is fixedly connected to the intermediate vibrating part; by anchoring the diaphragm to the base through a plurality of elastic connecting parts and anchoring the middle area of ​​the diaphragm to the back plate, the reliability of the MEMS microphone chip is effectively improved.

[0032] The above is only an implementation method of the present invention. It should be pointed out that a person skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements are all within the protection scope of the present invention.

Claims

1. A MEMS microphone chip, comprising a substrate having a back cavity and a capacitor system fixed on the substrate and arranged above the back cavity, wherein the capacitor system comprises a diaphragm and a back plate arranged relatively spaced apart, characterized in that: The diaphragm includes a vibration part and a plurality of elastic connecting parts arranged at the edge of the vibration part, and the diaphragm is fixed to the base through the elastic connecting parts; the vibration part includes an intermediate vibration part located in the middle position and an outer vibration part connecting the intermediate vibration part and the elastic connecting parts, and the back plate is provided with an anchoring part extending toward the diaphragm, and the anchoring part is fixedly connected to the intermediate vibration part.

2. The MEMS microphone chip according to claim 1, characterized in that: The back plate includes an insulating layer and an electrode layer arranged on the side of the insulating layer facing the diaphragm, the electrode layer includes an electrode part that generates an electrical signal by relative movement with the diaphragm and a partition part that electrically isolates the electrode part, and the anchoring part extends from the partition part toward the diaphragm.

3. The MEMS microphone chip according to claim 1, characterized in that: The back plate includes an insulating layer and an electrode layer arranged on a side of the insulating layer facing the diaphragm, and the anchoring portion is formed on the insulating layer.

4. The MEMS microphone chip according to claim 3, characterized in that: The insulating layer includes an anchoring region that is not directly opposite to the electrode layer along the vibration direction, and the anchoring region is recessed toward the diaphragm to form the anchoring portion that is fixed to the diaphragm.

5. The MEMS microphone chip according to claim 3, characterized in that: The insulating layer includes an anchoring region that is not directly opposite to the electrode layer along the vibration direction, and the anchoring portion extends from the anchoring region to pass through the electrode layer and is fixed to the diaphragm.

6. The MEMS microphone chip according to claim 1, characterized in that: A plurality of elastic connection portion spacer rings are arranged on the edge of the outer vibration portion, the elastic connection portion includes a first connection portion connected to the edge of the outer vibration portion, a second connection portion connected to the base, and an elastic portion connecting the first connection portion and the second connection portion, the elastic portion includes a plurality of mutually connected bending portions, and the bending portions are S-shaped.

7. The MEMS microphone chip according to claim 6, characterized in that: The second connection portion is connected to the two bending portions, the vibration portion of the diaphragm is circular, the second connection portion includes a central axis along a radial direction, and the two bending portions are axially symmetrical structures relative to the central axis.

8. The MEMS microphone chip according to claim 7, characterized in that: The first connection portion is disposed at an end of the bending portion away from the second connection portion.

9. The MEMS microphone chip according to claim 1, characterized in that: The microphone chip further includes a supporting portion fixed on the substrate, and one end of the elastic connecting portion is fixed to the external vibration portion, and the other end is fixed to the supporting portion.

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