CN101568054B

CN101568054B - Silicone base capacitance microphone

Info

Publication number: CN101568054B
Application number: CN200910106510A
Authority: CN
Inventors: 储着明; 葛舟; 张睿
Original assignee: Ruisheng Acoustic Technology Changzhou Co ltd; AAC Acoustic Technologies Shenzhen Co Ltd
Current assignee: Ruisheng Acoustic Technology Changzhou Co ltd; AAC Technologies Holdings Shenzhen Co Ltd
Priority date: 2009-04-03
Filing date: 2009-04-03
Publication date: 2012-08-29
Anticipated expiration: 2029-04-03
Also published as: CN101568054A

Abstract

The invention provides a silicone base capacitance microphone, comprising a base, a back plate, a diaphragm opposite to the back plate in a certain distance from the back plate, wherein the diaphragm comprises a vibration main body in the center position and a plurality of T shaped supporting arms extending from the peripheral side of the vibration main body and an abdication base depressing inwards from the inner wall of the cavity is set mounted in the right inferior of a supporting arm in the base and the supporting arm is connected with the upper surface of the base through the relative two ends on the T shape and suspended above the abdication base. Compared with the prior technique, the lateral length of the supporting arm is increased without reducing the vibration main body size and increasing the radial length of the supporting arm, thus the turning arm of the diaphragm is prolonged, therefore the diaphragm vibration amplitude is increased and the product sensitivity is increased.

Description

Silica-based condenser microphone

[technical field]

The present invention relates to a kind of MEMS silica-based condenser microphone.

[background technology]

Use more microphone at present and comprise traditional electret microphone and emerging MEMS condenser microphone (Micro-Electro-Mechanical-System Microphone; Be called for short the MEMS microphone); The MEMS microphone is based on silicon-based semiconductor material and processes, so claim silica-based condenser microphone again.Its encapsulation volume is littler than traditional electret microphone, and performance is also good.Thereby in recent years, silica-based MEMS microphone had been obtained very big development space.

As shown in Figure 1; Cross-sectional schematic for relevant MEMS silica-based condenser microphone 2; It comprises the center be provided with the substrate 20 of cavity 200, be contained in back pole plate 21 in the cavity, with back pole plate relatively and the vibrating diaphragm 22 that keeps at a certain distance away; Vibrating diaphragm comprises vibration main body 220 that is positioned at middle position and a plurality of support arms 221 that extended by vibration main body outer circumferential side, and vibrating diaphragm links to each other with substrate through support arm.When the sound air-flow was delivered on the vibrating diaphragm, the vibration main body was to rotate the arm of force with the support arm, and up-down vibration is to produce displacement.But such microphone is because vibration main body outer circumferential side near the inwall 201 of substrate cavity 20, is pretended to the coverage of the support arm that rotates the arm of force very short, and the amplitude that causes vibrating main body is limited.In order to address this problem; The size that has scheme will vibrate main body reduces; Let the vibration main body increase, thereby the coverage as the support arm that rotates the arm of force is increased, though can improve the amplitude of vibration main body so effectively from the distance of substrate cavity inwall; But the size of vibration main body reduces, and the sensitivity meeting of product descends to some extent.

Thereby, be necessary to study a kind of new solution the coverage of support arm is increased, do not reduce to vibrate simultaneously the size of main body again.

[summary of the invention]

The technical problem that the present invention need solve provides a kind of highly sensitive silicone base capacitance microphone.

According to the above-mentioned technical problem that needs solution; The present invention has designed a kind of silicone base capacitance microphone; Comprise the center be provided with the substrate of cavity, be contained in back pole plate in the cavity, with back pole plate relatively and the vibrating diaphragm that keeps at a certain distance away; Substrate comprises upper surface, and said vibrating diaphragm comprises vibration main body that is positioned at middle position and a plurality of support arms that extended by vibration main body outer circumferential side, and said support arm is " T " font; Comprise the first arm that extends by vibration main body outer circumferential side and second arm of vertical the first arm; Second arm comprises relative two ends, and said substrate is provided with below support arm from cavity inner wall to the slot to make way away from cavity center depression, and the two ends of support arm through second arm link to each other with upper surface of substrate and are suspended on the slot to make way.

Further improve as the present invention, the shape of the said cross section of stepping down and support arm coupling are " T " font.

Further improve as the present invention, the length in said slot to make way cross section is greater than the length of said support arm.

Further improve as the present invention, the degree of depth self-supporting arm of said slot to make way extends to back pole plate.

Further improve as the present invention, said a plurality of support arms are symmetrical about the central point of vibration main body.

Further improve as the present invention, the first arm of said a plurality of support arms is positioned on the straight line with the central point that vibrates main body respectively.

Further improve as the present invention, said support arm is at least 4.

Compared with prior art; The present invention " T " font support arm is suspended on the slot to make way; The first arm links to each other with the vibration main body, and the second arm two ends link to each other with upper surface of substrate, and this structure is equivalent to the equivalent arm of force of the lateral length of second arm for the vibration main body; According to the lateral length of adjustment support arm second arm, can realize adjusting the length that the vibration main body is rotated the arm of force.Making the vibration size of main body not reduce and not increase under the situation of support arm radical length, increase the lateral length of support arm second arm, can make the rotation arm of force of vibrating diaphragm obtain prolonging, thereby strengthen the vibrating diaphragm Oscillation Amplitude, improved the sensitivity of product.

[description of drawings]

Fig. 1 is the cross-sectional schematic of relevant MEMS silica-based condenser microphone;

Fig. 2 is the schematic perspective view of silica-based condenser microphone of the present invention;

Fig. 3 is a sketch map of getting rid of vibrating diaphragm among Fig. 2;

Fig. 4 be Fig. 2 partly cut open structural representation;

Fig. 5 is the enlarged drawing at A place among Fig. 4.

[embodiment]

Below in conjunction with accompanying drawing and execution mode the present invention is described further.

To shown in Figure 4, silica-based condenser microphone 1 of the present invention comprises substrate 10, back pole plate 11, vibrating diaphragm 12 like Fig. 2.Substrate 10 comprises upper surface 101, and the center is provided with cavity 100, and cavity comprises inwall 1000.Back pole plate 11 is provided with gas port 110, and it is contained in the cavity 100.

Vibrating diaphragm 12 is relative with back pole plate 11, and keeps at a certain distance away, and also is contained in the cavity 100.Vibrating diaphragm 12 comprises the vibration main body 120 that is positioned at middle position and a plurality of support arms 121 that extended by vibration main body outer circumferential side, and the quantity of support arm is more than at least 4, and the support arm quantity of present embodiment is 8, also can be 6,12 or the like certainly.These 8 support arms 121 are " T " font, comprise the first arm 121a that extended by vibration main body outer circumferential side and the second arm 121b of vertical the first arm, and second arm comprises relative two ends.The first arm of these 8 support arms 121 is positioned on the straight line with the central point that vibrates main body respectively, that is, the first arm of these 8 support arms is the outer circumferential side that emitting shape is distributed in the vibration main body with the center of vibration main body.These 8 support arms evenly distribute, and symmetrical about the central point of vibration main body.

Substrate 10 is provided with the slot to make way 102 that caves inward from cavity inner wall 1000 below support arm.Like Fig. 3 and shown in Figure 5, the shape of present embodiment slot to make way 102 and the form fit of support arm also are " T " font, comprise from inside first groove 102a of cavity inner wall and the second groove 102b of vertical first groove.Whole slot to make way radical length L1 is greater than the radical length L2 of support arm; Wherein, The transverse width L3 of first groove is greater than the transverse width L4 of the first arm; The transverse width L5 of second groove is less than the transverse width L6 of second arm, and like this, the two ends of support arm through second arm link to each other with upper surface of substrate and are suspended on the slot to make way.The shape of slot to make way of the present invention is not limited to " T " shape, promptly satisfies for abdicating the space in the support arm below, is suspended on the slot to make way, also can like bar shaped, circle, ellipse or the like and let the two ends of support arm through second arm link to each other with upper surface of substrate.In the present embodiment, the degree of depth of slot to make way extends on the back pole plate from upper surface of substrate.

Product of the present invention is when using, and when the sound air-flow was delivered on the vibrating diaphragm, the vibration main body was the rotation arm of force of equivalence with second arm of support arm, and up-down vibration forms capacity effect to produce displacement with back pole plate.The change of capacitance makes the output of capacitor produce corresponding alternating electric field, forms the signal of telecommunication corresponding with acoustic signals, thereby accomplishes the function of acoustic-electric conversion.

Above-described only is execution mode of the present invention, should be pointed out that for the person of ordinary skill of the art at this, under the prerequisite that does not break away from the invention design, can also make improvement, but these all belongs to protection scope of the present invention.

Claims

1. silica-based condenser microphone; Comprise the center be provided with the substrate of cavity, be contained in back pole plate in the cavity, with back pole plate relatively and the vibrating diaphragm that keeps at a certain distance away; Substrate comprises upper surface; Said vibrating diaphragm comprises vibration main body that is positioned at middle position and a plurality of support arms that extended by vibration main body outer circumferential side; It is characterized in that: said support arm is " T " font, comprises the first arm that extended by vibration main body outer circumferential side and second arm of vertical the first arm, and second arm comprises relative two ends; Said substrate is provided with below support arm from cavity inner wall to the slot to make way away from cavity center depression, and the two ends of support arm through second arm link to each other with upper surface of substrate and are suspended on the slot to make way.

2. silica-based condenser microphone according to claim 1 is characterized in that: the shape of said slot to make way and support arm coupling are " T " font.

3. silica-based condenser microphone according to claim 1 is characterized in that: the radical length of said slot to make way is greater than the radical length of said support arm.

4. silica-based condenser microphone according to claim 1 is characterized in that: the degree of depth of said slot to make way extends to back pole plate from the upper surface of substrate.

5. according to claim 1,2,3 or 4 described silica-based condenser microphones, it is characterized in that: said a plurality of support arms are symmetrical about the central point of vibration main body.

6. according to claim 1,2,3 or 4 described silica-based condenser microphones, it is characterized in that: the first arm of said a plurality of support arms is positioned on the straight line with the central point that vibrates main body respectively.

7. according to claim 1,2,3 or 4 described silica-based condenser microphones, it is characterized in that: said support arm is at least 4.