CN201163820Y - Condenser Microphone Chip - Google Patents

Abstract

The utility model discloses condenser microphone chip relates to the microphone technique, utilizes vibrating diaphragm and basement back of the body utmost point promptly to form electric capacity and detects the structure. The vibrating diaphragm is connected with the upper surface of the back electrode through the vibrating diaphragm support to form a cantilever structure or a quasi-free vibrating diaphragm structure, the vibrating diaphragm keeps free in the horizontal direction, the residual stress of the vibrating diaphragm is fully released, and the vertical vibration performance of the vibrating diaphragm is improved; an upper stop and a lower stop are arranged at the edge of the free end of the vibrating diaphragm to keep the stable state of the vibrating diaphragm; the edge of the free end of the vibrating diaphragm can be made into a cantilever beam structure, and the lower stop is arranged below the cantilever beam structure to keep the soft vibration characteristic of the vibrating diaphragm. Countless small holes are arranged at the edge of the vibrating diaphragm to improve the frequency response characteristic and simultaneously form corrosion holes; the utility model discloses have high sensitivity, low noise, frequency bandwidth's characteristic, the chip is small, preparation simple process, easy batch production.

Description

Condenser Microphone Chip

technical field

The utility model relates to the technical field of microphones, in particular to a capacitive microphone chip.

Background technique

U.S. Patent No. 5,870,482 describes the microphone structure with the base as the back pole, and invented a cantilever beam diaphragm. One end of the cantilever beam is fixed, and the free end edge and the back pole are used to form a capacitor. The mechanical sensitivity of this structure contributes a lot to the sensitivity of the microphone. The cantilever structure The three ends are free, and the posture and reliability of the diaphragm are not easy to be guaranteed; the US published patent US2006/0093170 A1 proposes an external cantilever beam diaphragm, in which the single-membrane structure with uniform distribution of the external cantilever beam is formed by the edge of the diaphragm and the back pole. Capacitors and cantilever beams increase the contribution of mechanical sensitivity to the output sensitivity of the microphone, and have strict requirements on the residual stress of the diaphragm.

Utility model content

The purpose of the utility model is to propose a capacitive microphone chip, which can improve the performance of a cantilever beam diaphragm and an external cantilever beam diaphragm.

According to one aspect of the present invention, the present invention provides a capacitive microphone chip, the capacitive microphone chip comprises: a base; a diaphragm separated from the base by a first predetermined distance, and the diaphragm is fixed in the manner of a cantilever beam On the base; a lower stop, the lower stop is located under the diaphragm and is used to limit the displacement of the diaphragm.

In order to achieve the purpose of this utility model, a new structure is proposed, which mainly includes: a base, a diaphragm support, an upper stop, and a lower stop, wherein the base is used as a back pole and has sufficient rigidity, and a through hole is set in the middle of the base. As a sound hole; the edge of the diaphragm or the cantilever beam leading out of the edge of the diaphragm is fixed on the base through the support of the diaphragm, there is a pre-designed distance between the diaphragm and the back electrode, and the diaphragm is in the area without diaphragm support, for The horizontal free state fully releases the residual stress of the diaphragm; the free edge of the diaphragm is provided with an upper stop and a lower stop, the top of the diaphragm is the upper stop, and the bottom of the diaphragm is the lower stop There is a preset fine distance between the stopper and the diaphragm, the upper stopper and the lower stopper limit the up and down position of the diaphragm, fix the state of the diaphragm, and ensure the reliability of the diaphragm.

A cantilever structure is set on the edge of the free end of the diaphragm, and the lower stop is set under the cantilever support of the cantilever structure. When the condenser microphone is working, a voltage is applied to the diaphragm and the back electrode to make the cantilever support and the lower stop, and the sound waves make the diaphragm The resulting vibration deformation will be mainly concentrated on the cantilever, and the diaphragm will maintain its soft characteristics.

There are countless small holes on the edge of the diaphragm to improve the frequency response characteristics. At the same time, these small holes also serve as corrosion holes during the process, and the original sacrificial layer under the diaphragm is corroded through the small holes.

The edge of the diaphragm and the back electrode form a capacitive structure.

The silicon microphone chip structure of the utility model has the characteristics of simple manufacturing process, high sensitivity, low noise and wide frequency band.

Description of drawings

Fig. 1 is the top view of the capacitive microphone chip of the first embodiment of the utility model;

Fig. 2 is a sectional view of the capacitive microphone chip of the first embodiment of the present invention along the dotted line AA in Fig.

Fig. 3 is a sectional view of the capacitive microphone chip of the first embodiment of the present invention along the dotted line BB in Fig.

Fig. 4 is a bottom view of the capacitive microphone chip of the first embodiment of the present invention;

Fig. 5 is a top view of the capacitive microphone chip without diaphragm and upper stopper in the first embodiment of the present invention;

Fig. 6 is a top view of the capacitive microphone chip of the second embodiment of the present invention;

Fig. 7 is a sectional view of the capacitive microphone chip according to the second embodiment of the present invention along the dotted line AA in Fig.

Fig. 8 is a cross-sectional view of the capacitive microphone chip according to the second embodiment of the present invention along the dotted line BB in Fig.

Fig. 9 is a top view of the capacitive microphone chip without the diaphragm and the upper stop according to the second embodiment of the present invention;

Fig. 10 is a top view of the capacitive microphone chip of the third embodiment of the present invention;

Fig. 11 is a sectional view of the capacitive microphone chip according to the third embodiment of the present invention along the dotted line AA in Fig.

Fig. 12 is a sectional view of the capacitive microphone chip according to the third embodiment of the present invention along the dotted line BB in Fig.

Fig. 13 is a top view of the capacitive microphone chip without the diaphragm and the upper stopper according to the third embodiment of the present invention.

Detailed ways

The utility model has many different forms of embodiments, and three preferred examples of the utility model are shown in accompanying drawings 1-13, and these three examples are described in detail below.

Embodiment one

As shown in FIGS. 1-5 , the first embodiment of the present invention, the capacitive microphone chip according to the present invention includes: a base 21 ; and a diaphragm 25 separated from the base 21 by a first predetermined distance. The diaphragm 25 is fixed on the base in the form of a cantilever beam. The condenser microphone chip also includes a lower stopper 23, the lower stopper 23 is located below or below the diaphragm 25, and is used to limit the displacement of the diaphragm. The lower stopper 23 is connected to the base 21 , and has a second predetermined distance from the lower stopper 23 to the diaphragm 25 for limiting the displacement of the diaphragm.

The condenser microphone chip also includes an upper stopper 26, which is arranged above the diaphragm 25 and fixed to the base 21, and has a third predetermined distance from the upper stopper 26 to the diaphragm 25. , used to limit the displacement of the diaphragm.

In the example shown in the figure, the capacitive microphone chip is a capacitive microphone chip structure with the diaphragm on the top and the back electrode on the bottom. The diaphragm is shown as a square diaphragm, but it can also be circular or other shapes. As shown in Figure 1-3, its feature is that the edge of one side of the diaphragm is fixed, and the edge of the other area is free. The free edge has an upper stop and a lower stop; the base is used as the back pole, and from bottom to top are: base 21, diaphragm The support 22, the lower stop 23, the upper stop support 24, the diaphragm 25, the upper stop 26, and the lower electrode 27, the upper electrode 28, the edge of the diaphragm 25 and the base 21 form a capacitive structure.

The diaphragm support 22 is separated from the lower stopper 23 and the upper stopper 26 by a predetermined distance, so as to obtain a proper effect of limiting the displacement of the diaphragm. As shown in FIG. 3 , the upper stop 26 includes: a fixed part, which is used to fix the upper stop 26 to the base 21 through the upper stop support 24; and a stop part, the stop The blocking part is used to limit the displacement of the diaphragm. More specifically, the upper stop 26 is a substantially plate-shaped structure, and the fixed portion of the upper stop 26 is fixed to the upper stop support 24, and the stop portion of the upper stop 26 is lifted from the upper stop. The support 24 is extended. The projection of the lower stop 23 on the base 21 and the projection of the stop portion of the upper stop 26 on the base 21 at least partially overlap, or may not overlap.

As shown in FIGS. 1 and 3 , the lower stop 23 may be located at the edge of the diaphragm, and the stop portion of the upper stop 26 may be located at the edge of the diaphragm.

Alternatively, the position of the stop portion of the upper stop 26 and the lower stop 23 is the region where the amplitude of the vibration membrane is substantially the largest during the vibration process or the region where the deformation amount is the largest during deformation. For example, as shown in FIGS. 1 and 5 , the diaphragm support 22 used to fix the diaphragm to the base 21 is generally opposite to the stopper portions of the lower stopper 23 and the upper stopper 26 , that is, at the opposite sides of the diaphragm respectively. side edge.

As shown in FIG. 1 , the diaphragm support 22 of the diaphragm may be located at an edge portion of the diaphragm. The position of the diaphragm support 22 on the base can be any appropriate position and any suitable position known to those skilled in the art.

There is a through hole in the center of the base 21, which is an acoustic hole 29. As shown in FIG. 4, the acoustic hole 29 is frusto-conical, and can also be in other shapes. The substrate is a conductive material or contains a layer of a conductive material.

As shown in FIG. 5 , a diaphragm support 22 , a lower stop 23 , and an upper stop support 24 are fixedly connected to the upper surface of the base 21 . The diaphragm support 22, the lower stopper 23, and the upper stopper support 24 are in the area outside the upper opening of the acoustic hole, wherein one or more diaphragm supports 22 are located on one side of the upper opening of the acoustic hole 29, and there is a predetermined distance from the edge of the opening ; One or more lower stops 23, one or more upper stop supports 24 are located on the other side or several sides of the opening on the sound hole 29, and there is a predetermined distance from the edge of the opening. On one side of the upper surface of the substrate 21 , a lower electrode 27 is provided in the area outside the upper opening of the acoustic hole.

The diaphragm 25 covers the acoustic hole 29 , and there is a predetermined distance between the diaphragm 25 and the base 21 as a first predetermined distance. One end of the diaphragm 25 is fixed on the upper surface of the diaphragm support 22 , and the other end or several ends are suspended above the lower stop 23 , and there is a small gap as a second predetermined distance between the diaphragm 25 and the lower stop 23 of the diaphragm. There are a plurality of small holes 30 at the edge of the diaphragm 25 , and the small holes 30 are opened on the sound hole 29 and projected on the diaphragm 25 , and there is no small hole in the area of the diaphragm support 22 . The diaphragm is a conductive material or contains a layer of conductive material. The upper electrode 28 is consolidated on the diaphragm 25 in the region of the support 22 .

The upper stop 26 is fixed on the upper stop support 24, and its edge part, that is, the stop part protrudes from the edge of the diaphragm, and there is a preset distance between the upper stop 26 and the diaphragm as the third predetermined distance. tiny spacing. The upper stop support 24 can be located outside the area of the diaphragm 25 or within the area of the diaphragm 25 , the figure is outside the area of the diaphragm 25 .

The edge of the diaphragm 25 forms a capacitor with the base 21, and the diaphragm 25 is fixed at the diaphragm support 22, and other areas are in a free suspension state. There are lower stoppers 23 and The stopper portion of the upper stopper 26 restricts the vertical vibration or deformation range of the diaphragm. When the operating voltage is applied to the upper electrode 28 and the lower electrode 27, the free end of the diaphragm and the base will be deformed due to electrostatic attraction, and will be placed on the lower stop 23, which will play a supporting role; The stopper 26 restricts the diaphragm from being impacted or deformed too much, so as to ensure the reliability of the diaphragm 25 . One side of the diaphragm 25 is fixed, and the other sides are free. There is no residual stress inside the diaphragm 25, which has good vibration performance and improves its sensitivity.

Embodiment two

The second embodiment of the present utility model is shown in Fig. 6-9, and only the different parts from the first embodiment will be described below.

The condenser microphone chip includes a cantilever beam 32, one end of the cantilever beam 32 is connected to the diaphragm, and the other end of the cantilever beam 32 is located above or above the lower stop 23, and the lower stop 23 restricts the The displacement of the other end is limited to limit the displacement of the diaphragm. The lower stopper 23 may be connected to the other end of the suspension beam 32 or to the base 21 .

In FIG. 6, the suspension beam 32 is located inside the diaphragm. Alternatively, the suspension beam 32 may be located outside the diaphragm, that is, one end of the suspension beam is connected to the outer edge of the diaphragm, and the other end is located above or above the lower stopper 23 . In addition, the suspension beam 32 can be a suspension beam of any suitable structure, for example, a straight beam, a curved beam, a composite beam formed by a plurality of sub-beams (as shown in FIG. 6 ), or a straight beam and a curved beam. Combination of beams.

The capacitive microphone chip shown in the figure is a capacitive microphone chip structure in which the diaphragm is on top and the back electrode is on the bottom. It is shown as a square diaphragm, which can also be circular or other shapes. As shown in Figure 6-8, the edge of one side of the diaphragm is fixed, and the edge of the other area is free. The free edge has a cantilever beam structure. There is a lower stop under the cantilever beam structure, and an upper stop on the edge of the diaphragm. Above are: base 21, diaphragm support 22, lower stop 23, upper stop support 24, diaphragm 25, cantilever support 31, cantilever beam 32 and upper stop 26, in addition there are lower electrodes 27, upper electrodes 28, The edge of the diaphragm 25 and the base 21 form a capacitive structure.

There is a through hole in the center of the base 21, which is an acoustic hole 29. As shown in FIG. 4, the acoustic hole 29 is frusto-conical, and can also be in other shapes. The substrate is a conductive material or contains a layer of a conductive material.

As shown in FIG. 9 , a diaphragm support 22 , a lower stop 23 , and an upper stop support 24 are fixedly connected to the upper surface of the base 21 . The diaphragm support 22, the lower stopper 23, and the upper stopper support 24 are in the area outside the upper opening of the acoustic hole, wherein one or more diaphragm supports 22 are located on one side of the upper opening of the acoustic hole 29, and there is a predetermined distance from the edge of the opening ; One or more lower stops 23, one or more upper stop supports 24 are located on the other side or several sides of the opening on the sound hole 29, and there is a predetermined distance from the edge of the opening. On one side of the upper surface of the substrate 21 , a lower electrode 27 is provided in the area outside the upper opening of the acoustic hole.

The diaphragm 25 covers the acoustic hole 29 , and there is a predetermined distance between the diaphragm 25 and the back pole 21 . One end of the diaphragm 25 is fixed on the upper surface of the diaphragm support 22, and there is a cantilever beam structure at the other end or several ends of the diaphragm. The cantilever beam structure includes a cantilever support 31 and a cantilever beam 32. There is a small gap between 31 and the lower stopper 23 of the diaphragm. There are a plurality of small holes 30 on the edge of the diaphragm 25, and the small holes 30 are distributed in the area outside the opening on the acoustic hole 29 and projected on the diaphragm 25, and there are no small holes in the area of the diaphragm support 22. The diaphragm is a conductive material or contains a layer of conductive material. The upper electrode 28 is fixed on the vibrating membrane 25 in the fixed area of the support 22 .

The upper stopper 26 is fixed on the upper stopper support 24 , and its edge protrudes to cover the edge of the diaphragm, and there is a preset small distance between the upper stopper 26 and the diaphragm. The upper stop support 24 can be located outside the area of the diaphragm 25 or within the area of the diaphragm 25 , the figure is outside the area of the diaphragm 25 .

The edge of the diaphragm 25 forms a capacitance with the base 21. The diaphragm 25 is fixed at the support 22, and other areas are freely suspended. There is a lower stop 23 under the cantilever support 31 on one or several sides of the free end, and the diaphragm is free. The end edge is limited by an upper stopper 26 to fix the up and down state of the diaphragm. When the working voltage is applied to the upper electrode 28 and the lower electrode 27, due to electrostatic attraction between the diaphragm and the base, the free end of the diaphragm deforms greatly, and the cantilever support 31 will be placed on the lower stop 23, and the lower stop 23 will act as a support Function: the upper stopper 26 limits the impact or excessive deformation of the diaphragm to ensure the reliability of the diaphragm 25 . One end of the diaphragm 25 is fixed, and the other ends are free. There is no residual stress inside the diaphragm 25, and the free end is supported by the suspension beam structure. The deformation is mainly concentrated on the suspension beam during vibration, which has good vibration performance and improves its sensitivity.

Embodiment Three

As shown in Figures 10-13, in the third embodiment, except for the same part as the condenser microphone chip of the above-mentioned first and second embodiments, in the condenser microphone chip according to the third embodiment, the diaphragm supports 22 is located outside the diaphragm, and the diaphragm is fixed to the base by suspension beams 33 outside the diaphragm.

In addition, the suspension beam 33 can be a suspension beam of any suitable structure, for example, a straight beam, a curved beam, a combined beam formed by multiple sub-beams, or a combination of a straight beam and a curved beam.

The capacitive microphone chip shown in Fig. 10-13 is a capacitive microphone chip structure in which the diaphragm is on top and the back electrode is on the bottom. It is shown as a square diaphragm, which can also be circular or other shapes. As shown in Figure 10-12, the diaphragm is fixed by leading out the suspension beam, and the edges of other areas are free. The free edge has a suspension beam structure. Above are: base 21, diaphragm support 22, lower stopper 23, upper stopper support 24, diaphragm 25, cantilever support 31, cantilever beam 32, lead-out cantilever beam 33 and upper stopper 26, in addition there are lower electrodes 27, upper The electrode 28, the edge of the vibrating membrane 25 and the base 21 form a capacitive structure.

There is a through hole in the center of the base 21, which is an acoustic hole 29. As shown in FIG. 4, the acoustic hole 29 is frusto-conical, and can also be in other shapes. The substrate is a conductive material or contains a layer of a conductive material.

As shown in FIG. 13 , a diaphragm support 22 , a lower stop 23 , and an upper stop support 24 are fixedly connected to the upper surface of the base 21 . The diaphragm support 22, the lower stop 23, and the upper stop support 24 are in the area outside the upper opening of the sound hole, and one of the diaphragm supports 22 is located on the side of the upper opening of the sound hole 29, and has a predetermined distance from the edge of the opening; one or A plurality of lower stops 23 and one or more upper stop supports 24 are located on the other side or several sides of the upper opening of the sound hole 29 and have a predetermined distance from the edge of the opening. On one side of the upper surface of the substrate 21 , a lower electrode 27 is provided in the area outside the upper opening of the acoustic hole.

The diaphragm 25 covers the acoustic hole 29 , and there is a predetermined distance between the diaphragm 25 and the back pole 21 . One side of the diaphragm 25 is fixed on the upper surface of the diaphragm support 22 by leading out the suspension beam 33. There is a suspension beam structure at the other end or several ends of the diaphragm. The suspension beam structure includes a suspension beam support 31 and a suspension beam 32. The suspension beam support 31 is suspended on the lower stop 23 Above, there is a small gap between the cantilever beam support 31 and the lower stopper 23 of the diaphragm. There are a plurality of small holes 30 at the edge of the diaphragm 25 , and the small holes 30 are opened on the sound hole 29 and projected on the diaphragm 25 , and there is no small hole in the area of the diaphragm support 22 . The diaphragm is a conductive material or contains a layer of conductive material. The upper electrode 28 is fixed on the vibrating membrane 25 in the fixed area of the support 22 .

The upper stopper 26 is fixed on the upper stopper support 24 , and its edge protrudes to cover the edge of the diaphragm, and there is a preset small distance between the upper stopper 26 and the diaphragm. The upper stop support 24 can be located outside the area of the diaphragm 25 or within the area of the diaphragm 25 , the figure is outside the area of the diaphragm 25 .

The edge of the diaphragm 25 forms a capacitance with the base 21, and the diaphragm 25 is fixed at the support 22 by drawing out the suspension beam 33, and other areas are freely suspended, and there is a lower stopper 23 under the suspension beam support 31 on one or several sides of the free end. The edge of the free end of the membrane is limited by an upper stopper 26 to limit the up and down vibration or deformation of the diaphragm. When the working voltage is applied to the upper electrode 28 and the lower electrode 27, due to electrostatic attraction between the diaphragm and the base, the free end of the diaphragm deforms greatly, and the cantilever support 31 will be placed on the lower stop 23, and the lower stop 23 will act as a support Function: the upper stopper 26 limits the impact or excessive deformation of the diaphragm to ensure the reliability of the diaphragm 25 . The vibrating membrane 25 is fixed by leading out the cantilever beam 33, and the other ends are free. There is no residual stress inside the vibrating membrane 25, and the free end is supported by the cantilever beam structure. When vibrating, the deformation is mainly concentrated on the cantilever beam, which has good vibration performance and improves its sensitivity.

In the above embodiments, the diaphragm support 22 and the diaphragm 25 can be integrally formed. In this case, the diaphragm 25 is a composite film including a conductive layer, and the diaphragm support 22 area only has an insulating layer. The lower stopper 23 and the vibrating membrane 25 can be integrally formed, and there is a predetermined small distance between the lower stopper 23 and the base 21. In this case, the vibrating membrane is a composite film including a conductive layer, and there is only an insulating layer in the lower stopper area. The upper stopper 26 and the upper stopper support 24 can be integrally formed and made of insulating material.

That is, the diaphragm support 22 can be replaced by a part integrally formed under the diaphragm 25 , the lower stop 23 can be integrally formed with the diaphragm 25 , and the upper stop support 24 can be replaced by a part integrally extending downward from the upper stop 26 .

In addition, in addition to the arrangement of the upper stopper 26 and the lower stopper 23, the upper stopper 26 and the lower stopper 23 can be arranged in any other suitable position, as long as the deformation or vibration amplitude of the diaphragm 25 can be limited. .

Process realization:

The manufacturing method of the condenser microphone chip of the present invention will be described below.

The microphone chip of the utility model is made by MEMS (Micro-eletro-mechanical system) processing technology, and can have multiple technological implementation schemes, the following is a kind of specific technological steps.

The manufacturing method of the capacitive microphone chip shown in Figures 1 to 13 according to three embodiments of the present invention is as follows:

1. Select a low-resistance double-sided polished silicon wafer as the substrate 21, and grow a 2.5 μm PSG, LTO, and TEOS silicon oxide layer on the first side of the silicon wafer as a sacrificial layer, a support layer, and a stopper layer;

2. Use LPCVD method to grow 3000 on both sides of the silicon wafer silicon nitride film;

3. Use reactive ion etching to partially remove the silicon nitride film on the first side of the silicon wafer, and retain the silicon nitride at the diaphragm support, lower stop, and upper stop; partially etch the silicon nitride film on the second side to be The etched area will serve as a window for etching the silicon wafer;

4. Continue to grow 0.5 μm micron PSG, LTO, TEOS silicon oxide layer on the first side of the silicon wafer;

5. Grow 2 μm thick low-stress polysilicon on both sides of the silicon wafer by LPCVD, and form an N-type or P-type polysilicon layer by implantation or diffusion;

5. Use the method of reactive ion etching to carve out the pattern designed on the polysilicon on the first side to form the diaphragm structure;

6. Re-grow a 0.5 micron PSG, LTO, TEOS silicon oxide layer on the first side of the silicon wafer;

7. Use LPCVD to grow 1 μm thick low-stress polysilicon on both sides of the silicon wafer;

8. Carve out the designed pattern on the polysilicon layer on the first side by reactive ion etching to form an upper stopper shape;

9. Use HF solution to etch through the front silicon oxide to the silicon substrate;

10. Make the upper metal electrode and the lower metal electrode on the first side of the silicon wafer by sputtering, evaporation or electroplating;

11. To protect the first side of the silicon wafer, first remove the polysilicon layer on the second side with KOH solution, and then corrode the substrate by bulk silicon etching until the silicon oxide stops to form acoustic holes;

12. Use HF solution to corrode silicon oxide through the sound hole of the diaphragm, the edge of the diaphragm, the small holes on the diaphragm, and the gap between the diaphragm and the upper stop, and finally form the structure described in the utility model. The size of the support area of the diaphragm support, the lower stop and the upper stop is much larger than the corroded size. By reasonably controlling the corrosion time, a sufficiently large support area of the diaphragm support, the lower stop and the upper stop is retained.

Although the present invention has been described by the above embodiments, the present invention is not limited to the above embodiments. The embodiment can be modified, changed and replaced without departing from the principle and idea of the present utility model.

For example, various features, structures and parts of the above-mentioned embodiments can be combined with each other to form new embodiments, unless such combination is not feasible.

Claims (17)

1. A condenser microphone chip, characterized in that it comprises: base(21); a diaphragm (25) spaced at a first predetermined distance from the base (21), the diaphragm (25) being fixed on the base in the manner of a cantilever beam; A lower stopper (23), the lower stopper (23) is located under the diaphragm (25), and is used to limit the displacement of the diaphragm. 2. The condenser microphone chip according to claim 1, further comprising: An upper stop (26), the upper stop (26) is arranged above the diaphragm (25) and fixed to the base (21), the upper stop (26) and the diaphragm (25 ) has a third predetermined distance for limiting the displacement of the diaphragm. 3. The condenser microphone chip according to claim 2, wherein the upper stopper (26) comprises: a fixing part, which is used to fix the upper stopper (26) to the base (21); And a stop part, the stop part is used to limit the displacement of the diaphragm. 4. The condenser microphone chip according to claim 3, wherein the projection of the lower stopper (23) on the substrate (21) and the stopper portion of the upper stopper (26) are on the substrate The projections on (21) overlap at least partially. 5. The condenser microphone chip according to claim 2, wherein the lower stopper (23) is located at an edge portion of the diaphragm. 6. The condenser microphone chip according to claim 3, wherein the stopper portion of the upper stopper (26) is located at the edge portion of the diaphragm. 7. The condenser microphone chip according to claim 3, wherein the position of the stop portion of the upper stop (26) and the lower stop (23) is the area where the vibration amplitude of the diaphragm is substantially the largest during the vibration process Or the area that deforms the most during deformation. 8. The condenser microphone chip according to claim 3, wherein the fixed position of the diaphragm (25) is at the edge portion of the first side of the diaphragm (25), and the upper stopper (26) The stop portion and the lower stop (23) are at the edge portion of the second side of the diaphragm opposite to the first side. 9. The condenser microphone chip according to claim 1, wherein the diaphragm (25) is fixed to the substrate at an edge portion of the diaphragm. 10. The condenser microphone chip according to claim 1, wherein the diaphragm (25) is fixed to the base by beams (33) in a region outside the diaphragm. 11. The condenser microphone chip according to claim 3, further comprising an upper stop support (24) for fixing the upper stop (26) to the substrate. 12. The condenser microphone chip according to claim 11, wherein the upper stopper (26) is a substantially plate-shaped structure, and the fixed part of the upper stopper (26) is fixed to the upper stopper support (24) , and the stop portion of the upper stop (26) protrudes from the upper stop support (24). 13. The condenser microphone chip according to claim 1, further comprising a suspension beam (32), one end of the suspension beam (32) is connected to the diaphragm, and the other end of the suspension beam (32) is located at the lower Above the stopper (23), the displacement of the other end is limited by the lower stopper (23), thereby limiting the displacement of the diaphragm. 14. A condenser microphone chip according to claim 13, wherein said suspension beam (32) is located inside said diaphragm. 15. The condenser microphone chip according to claim 1, wherein the diaphragm (25) is fixed to the base via a diaphragm support (22). 16. The condenser microphone chip according to claim 1, wherein the lower stopper (23) is connected to the base (21), and the lower stopper (23) and the diaphragm (25) have a second predetermined distance. 17. The condenser microphone chip according to claim 1, wherein the lower stopper (23) is connected to the diaphragm (25), and the lower stopper (23) and the base (21) have A second predetermined distance.

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