CN201657310U

CN201657310U - Mems microphone

Info

Publication number: CN201657310U
Application number: CN2010201258821U
Authority: CN
Inventors: 储著明
Original assignee: Aac Microelectroincs Technology (changzhou) Co Ltd; AAC Acoustic Technologies Shenzhen Co Ltd
Current assignee: AAC Technologies Pte Ltd
Priority date: 2010-03-08
Filing date: 2010-03-08
Publication date: 2010-11-24
Anticipated expiration: 2020-03-08

Abstract

The utility model relates to the field of a mini microphone, in particular to an MEMS (micro-electro-mechanical system) microphone which is applied to electronic equipment and has higher sensitivity. An insulating layer is arranged between a back plate and a vibrating film, and the insulating layer is provided with a through hole which is overlapped with the area of an acoustic hole to form a distributing capacitance system. The microphone is beneficial to the adjustment of the absorption voltage between the back plate and the vibrating film, reduces the suspending area as the insulating layer is supported between the vibrating film and the back plate to prevent the vibrating film and the back plate from collapsing and gluing, improves the sensitivity of the vibrating film, and is good for improving the reliability thereof.

Description

The MEMS microphone

[technical field]

The utility model relates to the mini microphone field, specifically refers to a kind of being applied on the electronic equipment, has MEMS (micro-electro-mechanical system) microphone of sensitivity more.

[background technology]

Development along with wireless telecommunications, Global Mobile Phone Users is more and more, the user not only is satisfied with conversation to the requirement of mobile phone, and want high-quality communication effect can be provided, especially at present the development of mobile multimedia technology, the speech quality of mobile phone becomes more important, and the microphone of mobile phone is as the voice pick device of mobile phone, and its design quality directly influences speech quality.

And the microphone of using more and better performances at present is the Si semiconductor microphone, the Si semiconductor microphone is built back pole plate and vibrating diaphragm on silicon wafer, and with suitable circuit connection, utilize the chemical etching technology with smooth and simple the placing in the substrate of vibrating diaphragm, make it do free vibration completely with sound, the electric field change that forms between the vibrating diaphragm of vibration and the back pole plate promptly produces the signal of telecommunication on the circuit.Usually the MEMS microphone comprises backboard, vibrating diaphragm relative with backboard and that be connected by the support portion, backboard is provided with acoustic holes, this acoustic holes can be delivered to the sound air-flow on the vibrating diaphragm, and acoustic pressure drives the relative backboard vibration of vibrating diaphragm, forms an operatic tunes between described vibrating diaphragm and the backboard; Being respectively equipped with conductive layer on vibrating diaphragm and the backboard also can power up, but the part mutually insulated that powers up, the operatic tunes between vibrating diaphragm and the backboard is just formed the capacitor with electric capacity like this, being directly proportional between two plates of the value of electric capacity and electric capacity over against area, and the distance between two plates of electric capacity is inversely proportional to.The microphone acoustic holes position of this kind structure is over against the zone line of vibrating diaphragm, and the zone line mechanical sensitivity height of vibrating diaphragm, the edge substantially all is strapped on the pedestal, because the marginal position level is low, then cause the waste of vibrating diaphragm center, and easily cause the subsiding of vibrating diaphragm and backboard, adhesion, certainly will reduce sensitivity of microphone, shorten the useful life of microphone.

[utility model content]

The purpose of this utility model is to solve the subsiding of vibrating diaphragm and backboard, adhesion, certainly will reduce the problem of sensitivity of microphone, and propose a kind of MEMS microphone.

In order to achieve the above object, the technical solution of the utility model is as follows:

A kind of MEMS microphone comprises the backboard that has acoustic holes, is provided with insulating barrier, vibrating diaphragm and electrode layer on the backboard successively, and wherein said acoustic holes is arranged in array, and offers the through hole overlapping with the acoustic holes area on the insulating barrier.

Preferably, described electrode layer is provided with a plurality of mesopores, and the entity between the mesopore is the electrode unit of array arrangement, and the via area on electrode unit and the insulating barrier is overlapping.

The single monnolithic case of described acoustic holes is polygon, and each acoustic holes is arranged by a plurality of slots hole and constituted.

The single monnolithic case of described acoustic holes is hexagon.

Through hole on the described insulating barrier is a manhole.

The utility model MEMS microphone, between backboard and vibrating diaphragm, be provided with insulating barrier, offer the through hole overlapping on the described insulating barrier with the acoustic holes area, form the distributed capacitor system, help the adjusting of backboard and vibrating diaphragm pick-up voltage, owing between vibrating diaphragm and backboard insulation layer supports is arranged, unsettled area reduces, to avoid the subsiding of vibrating diaphragm and backboard, adhesion, improved the sensitivity of vibrating diaphragm, help the raising of microphone reliability.

[description of drawings]

Fig. 1 is the utility model perspective view;

Fig. 2 is a front view of the present utility model;

Fig. 3 is along the cross-sectional view of A-A among Fig. 2;

Fig. 4 is a blast structural representation of the present utility model.

[embodiment]

Below in conjunction with accompanying drawing, the utility model MEMS microphone is elaborated.

The utility model MEMS microphone is mainly used on the mobile phone, accepts sound and sound is converted into the signal of telecommunication, and the utility model is to reach the effect that improves Electret Condencer Microphone sensitivity by changing diaphragm structure.

The utility model MEMS microphone 100 comprises substrate, and referring to shown in Figure 1, what link to each other with the substrate (not shown) has a backboard 40, and backboard is provided with insulating barrier 30, and insulating barrier 30 is provided with vibrating diaphragm 20 and is connected electrode layer 10 on the vibrating diaphragm 20, altogether four-layer structure.

Referring to shown in Figure 2, described electrode layer 10 is provided with the entity electrode unit 11 of a plurality of array arrangements, offers mesopore 12 between each electrode unit 11, so just avoids increasing the thickness of vibrating diaphragm 20.

See shown in Fig. 3,4, offer the acoustic holes 41 of array arrangement on the backboard 40, described acoustic holes 41 single monnolithic cases are polygon, are hexagon in the present embodiment; Each acoustic holes 41 is arranged by a plurality of slots hole 411 and is constituted.Offer the manhole 31 overlapping with acoustic holes 41 areas on the described insulating barrier 30, vibrating diaphragm 20 is covered in through hole 31 and forms the distributed capacitor system like this.The equivalence on circuit of this structure is a lot of electric capacity parallel connections, the capacitance of supposing each junior unit is C0, total capacitance then is n*C0, n is the quantity of junior unit, when the capacitance variations of junior unit dC, then total capacitance changes the sensitivity of visible vibrating diaphragm 20 integral body of n*dC. and the sensitivity of each junior unit is the same.Vibrating diaphragm 20 is provided with electrode layer 10, and its electrode unit 11 is overlapping with through hole 31 areas on the insulating barrier 30.In the time of in working order, deformation takes place in vibrating diaphragm 20 under the effect of acoustic pressure, the capacitance of electric field changes between vibrating diaphragm 20 and the backboard 40, and the capacitance variations value reflects the size of acoustic pressure, because deformation can not take place in backboard 40, so the size of vibrating diaphragm 20 deformation directly influences capacitance.Capacitance is to calculate like this: between capacitance and vibrating diaphragm 20 and the backboard 40 is that the area of through hole 31 is directly proportional over against area, and the distance between vibrating diaphragm 20 and the backboard 40 is that the degree of depth of through hole 31 is inversely proportional to, i.e. C=k ε 0 ε rS/d, and k is a constant, ε 0 is a constant, and ε r is a constant.After Electret Condencer Microphone was made, the value of ε 0 ε r was also just fixing, S be between two electroplaxs of electric capacity over against area, d is two distances between the electroplax, so the sensitivity of vibrating diaphragm 20 is most important.

The utility model MEMS microphone, the distributed capacitor system that constitutes, help the adjusting of backboard 40 and vibrating diaphragm 20 pick-up voltages, because vibrating

diaphragm

20 and 40 of backboards have insulating barrier 30 to support, unsettled area reduces, to avoid the subsiding of vibrating diaphragm 20 and backboard 40, adhesion, improved the sensitivity of vibrating diaphragm 20, if the sub-vibrating diaphragm on the single through hole 31 damages, other sub-vibrating diaphragms can also operate as normal, do not influence the use of microphone, help the raising of microphone reliability.

The above only is a better embodiment of the present utility model; protection range of the present utility model does not exceed with above-mentioned execution mode; as long as the equivalence that those of ordinary skills do according to the utility model institute disclosure is modified or changed, all should include in the protection range of putting down in writing in claims.

Claims

1. MEMS microphone, it is characterized in that: comprise the backboard that has acoustic holes, be provided with insulating barrier, vibrating diaphragm and electrode layer on the backboard successively, wherein said acoustic holes is arranged in array, and offers the through hole overlapping with the acoustic holes area on the insulating barrier.

2. MEMS microphone according to claim 1 is characterized in that: described electrode layer is provided with a plurality of mesopores, and the entity between the mesopore is the electrode unit of array arrangement, and the via area on electrode unit and the insulating barrier is overlapping.

3. MEMS microphone according to claim 1 is characterized in that: the single monnolithic case of described acoustic holes is polygon, and each acoustic holes is arranged by a plurality of slots hole and constituted.

4. MEMS microphone according to claim 3 is characterized in that: the single monnolithic case of described acoustic holes is hexagon.

5. MEMS microphone according to claim 1 is characterized in that: the through hole on the described insulating barrier is a manhole.