CN107484051A

CN107484051A - Mems microphone

Info

Publication number: CN107484051A
Application number: CN201710902582.6A
Authority: CN
Inventors: 张睿
Original assignee: AAC Acoustic Technologies Shenzhen Co Ltd
Current assignee: AAC Technologies Holdings Shenzhen Co Ltd
Priority date: 2017-09-29
Filing date: 2017-09-29
Publication date: 2017-12-15
Anticipated expiration: 2037-09-29
Also published as: CN107484051B

Abstract

The invention provides a kind of MEMS microphone, including substrate with the operatic tunes, it is fixed on the back pole plate of the substrate and sets to form the vibrating membrane of capacitance structure with the back pole plate relative spacing, the back pole plate includes backboard and fixed electrode；The vibrating membrane includes effective vibration section and invalid vibration section, the effectively vibration section includes the vibration main body set with the operatic tunes face and is extended by the vibration main body and be fixed on the fixed arm of the pedestal, and the part of the operatic tunes is collectively forming effective vibrating area described in the face of the vibration main body and the fixed arm；The invalid vibration section is arranged at intervals between the two neighboring fixed arm and with the effectively vibration section, and the pedestal is at least partly fixed in the invalid vibration section；The fixed electrode is identical with the shape of the effectively vibrating area.Compared with the technology of pass, MEMS microphone acoustical behavior of the invention is more excellent.

Description

MEMS microphone

Technical field

The present invention relates to acoustic-electric field, more particularly to a kind of MEMS microphone for applying to portable type electronic product.

Background technology

The development of mechanics of communication, the user of mobile phone is more and more in the world, need of the user to mobile phone Ask and be not only satisfied with call, and the communication effect of high quality can be provided, especially current Technology of Mobile Multimedia Development, the speech quality of mobile phone becomes more important, the voice pick device of the microphone of mobile phone as mobile phone, its The quality of design directly affects speech quality.

Microphone in correlation technique, particularly MEMS microphone include the substrate with the operatic tunes, are fixed on the substrate Backboard, be fixed on the fixed electrode of the northern plate and be fixed on the substrate and set with the backboard relative spacing to be formed The vibrating diaphragm of capacitance structure.The vibrating diaphragm includes the effective vibrating area set with the operatic tunes face and prolonged by the effectively vibrating area Stretch and be fixed on the fixed area of the pedestal.

However, in the MEMS microphone of correlation technique, the area of the fixed electrode is less than the described effective of the vibrating diaphragm Vibrating area so that the effective capacitance of the MEMS microphone is relatively small, so as to cause its performance low.

Therefore, a kind of new MEMS microphone must be provided by, which having in fact, solves above-mentioned technical problem.

The content of the invention

It is an object of the invention to provide the MEMS microphone that a kind of acoustical behavior is excellent.

In order to achieve the above object, the invention provides a kind of MEMS microphone, including substrate with the operatic tunes, it is fixed on The back pole plate of the substrate and it is fixed on the substrate and is set with the back pole plate relative spacing to form capacitance structure Vibrating membrane, the back pole plate include backboard and the fixed electrode for the close vibrating membrane side for being fixed on the backboard that is sticked； The vibrating membrane includes effective vibration section and invalid vibration section, and the effectively vibration section includes shaking with what the operatic tunes face was set Dynamic main body and extend by the vibration main body and be fixed on the fixed arm of the pedestal, main body and the fixed arm of vibrating The part of the operatic tunes described in face is collectively forming effective vibrating area；The invalid vibration section is between the two neighboring fixed arm And be arranged at intervals with the effectively vibration section, the pedestal is at least partly fixed in the invalid vibration section；The fixed electrode With it is described effectively vibrating area shape it is identical or in it is scaling/reduce.

Preferably, the fixed electrode is identical with the size of the effectively vibrating area.

Preferably, the fixed electrode is more than effective vibrating area.

Preferably, the fixed electrode is less than effective vibrating area.

Preferably, the fixed arm includes four and spaced setting.

Preferably, the vibration main body is rectangular, and four fixed arms are respectively by four angles for vibrating main body Position is extended.

Preferably, the invalid vibration section includes four and four sides with the vibration main body be arranged in parallel respectively.

Preferably, the MEMS microphone also includes the supporting part for being fixed on the substrate, and the back pole plate passes through described Supporting part is fixedly supported to the substrate.

Preferably, supporting part structure annular in shape and circular vibrating membrane setting.

Compared with correlation technique, the vibrating membrane is set in effective vibration section and invalid shaken by MEMS microphone of the invention Dynamic portion, and being formed in part with of setting of the operatic tunes face of the effectively vibration section and the substrate imitates vibration area, by institute It is in identical with the shape of the effective vibrating area of the vibrating membrane to state fixed electrode and set, and the structure causes the described of the vibrating membrane to have Effectively increasing using area for vibrating area is imitated, so as to improve the effective capacitance of the MEMS microphone, farthest limitation The generation of invalid parasitic capacitance, effectively increase the acoustical behavior of the MEMS microphone.

Brief description of the drawings

Technical scheme in order to illustrate the embodiments of the present invention more clearly, make required in being described below to embodiment Accompanying drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present invention, for For those of ordinary skill in the art, on the premise of not paying creative work, it can also be obtained according to these accompanying drawings other Accompanying drawing, wherein：

Fig. 1 is the dimensional structure diagram of MEMS microphone of the present invention；

Fig. 2 is the part isometric structural decomposition diagram of MEMS microphone of the present invention；

Fig. 3 is the cut-away view of the line A-A along Fig. 1；

Fig. 4 is the structural representation of the fixed electrode of MEMS microphone of the present invention；

Fig. 5 is the structural representation of the vibrating membrane of MEMS microphone of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation describes, it is clear that described embodiment is only the part of the embodiment of the present invention, rather than whole embodiments.It is based on Embodiment in the present invention, those of ordinary skill in the art are obtained all other under the premise of creative work is not made Embodiment, belong to the scope of protection of the invention.

Please refer to Fig. 1-3, the invention provides a kind of MEMS microphone 100, including substrate 1, back pole plate 2, vibration Film 3 and supporting part 4.

The substrate 1 has the operatic tunes 11 through thereon, and the substrate 1 is silica-base material by MEMS technique machine-shapings.

The back pole plate 2 is fixed on the substrate 1.Specifically, the back pole plate 2 includes backboard 21 and fixed electrode 22.

The backboard 21 is provided with the acoustic pressure hole 211 through thereon.

Incorporated by reference to shown in ginseng Fig. 4, the fixed electrode 22 is sticked the close vibrating membrane 3 that is fixed on the backboard 21 Side.The fixed electrode 22 is provided with the through hole 221 through thereon, and the through hole 221 is connected with the acoustic pressure hole 211 matching It is logical, for balancing acoustic pressure.The fixed electrode 22 is made up of conductive material.

Incorporated by reference to shown in ginseng Fig. 5, the vibrating membrane 3 is fixed on the substrate 1 and set with the relative spacing of back pole plate 2 Put to form capacitance structure.

The vibrating membrane 3 is also made up of conductive material, so as to form the two of capacitance structure respectively with the fixed electrode 22 Pole.The vibrating membrane 3 is driven to vibrate by acoustic pressure so that the relative distance of the vibrating membrane 3 and the fixed electrode 22 produces Change, so as to change the electric capacity of the capacitance structure of the two formation, and then different electric signals is converted to, realizes that acoustic-electric is changed.

In present embodiment, specifically, the vibrating membrane 3 includes effective vibration section 31 and invalid vibration section 32.

The effectively vibration section 31 includes the vibration main body 311 set with the face of the operatic tunes 11 and by the vibration main body 311 extend and are fixed on the fixed arm 312 of the pedestal 1.

In present embodiment, the fixed arm 312 includes four and spaced setting.More excellent, the vibration main body 311 is rectangular, and four fixed arms 312 are extended by the position at four angles of the vibration main body 311 respectively.Certainly, The shape of the vibration main body 311 is not limited to this.

The part of the operatic tunes 11, which is collectively forming, described in the vibration main body 311 and the face of the fixed arm 312 effectively shakes Dynamic area (non-label).

The invalid vibration section 32 is spaced between the two neighboring fixed arm 312 and with the effectively vibration section 31 Set, described invalid at least part of vibration section 32 is fixed on the pedestal 1.

Specifically, the invalid vibration section 32 includes four and four sides with the vibration main body 311 be arranged in parallel respectively.

In present embodiment, the fixed electrode 22 is identical with the shape of the effectively vibrating area.The structure causes described The effectively vibrating area of vibrating membrane 3 is effectively increased using area, so as to improve effective electricity of the MEMS microphone 100 Hold, farthest limit the generation of invalid parasitic capacitance, effectively increase the acoustical behavior of the MEMS microphone 100. Preferably, the fixed electrode is identical with the size of the effectively vibrating area, i.e., described fixed electrode is in effective vibrating area Orthographic projection be completely superposed with the effectively vibrating area or fixed electrode is more than effective vibrating area or less than described Effective vibrating area.

The supporting part 4 is fixed on the substrate 1, and in present embodiment, the back pole plate 2 is solid by the supporting part 1 Surely it is supported in the substrate 1.It is more excellent, 4 structure annular in shape of supporting part and set around the vibrating membrane 3.

The setting of the supporting part 4 adds the significant interval distance between the back pole plate 2 and the vibrating membrane 3, keeps away Having exempted from the Oscillation Amplitude of the vibrating membrane 3 not enough influences acoustical behavior.

Above-described is only embodiments of the present invention, it should be noted here that for one of ordinary skill in the art For, without departing from the concept of the premise of the invention, improvement can also be made, but these belong to the protection model of the present invention Enclose.

Claims

1. a kind of MEMS microphone, including the substrate with the operatic tunes, it is fixed on the back pole plate of the substrate and is fixed on described Substrate is simultaneously set to form the vibrating membrane of capacitance structure with the back pole plate relative spacing, and the back pole plate includes backboard and is sticked It is fixed on the fixed electrode of the close vibrating membrane side of the backboard, it is characterised in that the vibrating membrane includes effectively shaking Dynamic portion and invalid vibration section, the effectively vibration section include the vibration main body set with the operatic tunes face and led by the vibration Body extends and is fixed on the fixed arm of the pedestal, and the part of the operatic tunes is total to described in the face of the vibration main body and the fixed arm With the effective vibrating area of formation；The invalid vibration section is between the two neighboring fixed arm and between the effectively vibration section Every setting, the pedestal is at least partly fixed in the invalid vibration section；The shape of the fixed electrode and the effectively vibrating area Shape is identical.

2. MEMS microphone according to claim 1, it is characterised in that the fixed electrode and the effectively vibrating area Size is identical.

3. MEMS microphone according to claim 1, it is characterised in that the fixed electrode is more than the effectively vibration Area.

4. MEMS microphone according to claim 1, it is characterised in that the fixed electrode is less than the effectively vibration Area.

5. MEMS microphone according to claim 1, it is characterised in that the fixed arm includes four and spaced set Put.

6. MEMS microphone according to claim 5, it is characterised in that the vibration main body is rectangular, and four described solid Fixed arm is extended by the position at four angles of the vibration main body respectively.

7. MEMS microphone according to claim 6, it is characterised in that the invalid vibration section include four and respectively with Four sides of the vibration main body be arranged in parallel.

8. MEMS microphone according to claim 1, it is characterised in that the MEMS microphone is also described including being fixed on The supporting part of substrate, the back pole plate are fixedly supported to the substrate by the supporting part.

9. MEMS microphone according to claim 8, it is characterised in that supporting part structure annular in shape and around described Vibrating membrane is set.