CN214154837U

CN214154837U - Piezoelectric MEMS microphone

Info

Publication number: CN214154837U
Application number: CN202022826794.0U
Authority: CN
Inventors: 童贝; 石正雨; 沈宇; 段炼
Original assignee: Ruisheng Technology Nanjing Co Ltd
Current assignee: AAC Technologies Holdings Nanjing Co Ltd; Ruisheng Technology Nanjing Co Ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2021-09-07
Anticipated expiration: 2030-11-30
Also published as: WO2022110416A1

Abstract

The utility model provides a piezoelectric MEMS microphone, including at least one piezoelectric MEMS unit, piezoelectric MEMS unit includes the basement, the basement includes the annular perisporium that encloses into and accepts the chamber and locates the bearing structure in accepting the chamber, bearing structure, including the supporting part that sets up with the perisporium interval and extend to a plurality of extension arms of supporting part from the perisporium; the diaphragm structure, diaphragm structure as an organic whole structure, including fixed region and a plurality of movable part, fixed region includes anchoring portion and a plurality of anchor arm that forms from the edge radial extension of anchoring portion, anchoring portion is fixed in the supporting part, the anchor arm is fixed in the extension arm, every movable part encircle anchoring portion and set up with the anchor arm interval. The utility model discloses its diaphragm structure passes through anchoring portion and certainly a plurality of anchoring arm that the edge radial extension of anchoring portion formed is fixed in the basement, increases the area of contact of diaphragm structure and basement to effectively reduce the risk that the diaphragm structure peeled off from the basement.

Description

Piezoelectric MEMS microphone

[ technical field ] A method for producing a semiconductor device

The utility model relates to an acoustoelectric conversion technical field especially relates to a piezoelectricity MEMS microphone.

[ background of the invention ]

The existing piezoelectric MEMS unit includes a substrate, a support member, and a diaphragm structure, wherein the diaphragm structure is composed of four independent fan-shaped diaphragms, and a small portion of the middle of the diaphragm structure is fixed on the support column of the support member, while the support arm area located on the support member does not cover the diaphragm structure, i.e. only the vertex of each fan-shaped diaphragm is partially fixed on the support column of the support member, therefore, the diaphragm structure of the existing piezoelectric MEMS unit has a certain risk of peeling off, thereby affecting the reliability of the piezoelectric MEMS microphone.

[ Utility model ] content

An object of the utility model is to provide a prevent that diaphragm structure from peeling off piezoelectricity MEMS microphone.

In order to achieve the above object, the present invention provides a piezoelectric MEMS microphone, including at least one piezoelectric MEMS element, the piezoelectric MEMS element includes: the substrate comprises an annular peripheral wall and a supporting structure, wherein the annular peripheral wall surrounds a containing cavity, the supporting structure is arranged in the containing cavity, and the supporting structure comprises a supporting part and a plurality of extension arms, the supporting part is arranged at intervals with the peripheral wall, and the extension arms extend from the peripheral wall to the supporting part; the diaphragm structure, diaphragm structure as an organic whole structure, including fixed region and a plurality of movable part, fixed region include anchor portion and certainly a plurality of anchor arm that the edge radial extension of anchor portion formed, anchor portion is fixed in the supporting part, the anchor arm is fixed in the extension arm, every the movable part encircles anchor portion and with the anchor arm interval sets up.

Preferably, the membrane structure includes a first electrode layer, a first piezoelectric layer and a second electrode layer stacked in sequence along the vibration direction, and the first electrode layer is disposed on one side of the membrane structure close to the support structure.

Preferably, the diaphragm structure further includes a second piezoelectric layer stacked on a side of the second electrode layer away from the first piezoelectric layer, and a third electrode layer stacked on the second piezoelectric layer.

Preferably, the extension arm will accept the chamber and separate into a plurality of cavity, the movable part is followed the axial orthographic projection of basement falls into in the cavity.

Preferably, the number of extension arms is at least two.

Preferably, the base includes a first substrate, the accommodating cavity includes a first cavity formed in the first substrate, the peripheral wall includes a first peripheral wall enclosing the first cavity, the supporting portion includes a first supporting portion disposed in the first cavity and spaced apart from the first peripheral wall, and the plurality of extension arms include a plurality of first extension arms extending from the first peripheral wall to the first supporting portion.

Preferably, the base further includes an isolation layer disposed between the first substrate and the diaphragm structure, and a projection profile of the isolation layer along the vibration direction of the movable portion is the same as a projection profile of the first substrate along the vibration direction of the movable portion.

Preferably, the number of the piezoelectric MEMS units is multiple, and the multiple piezoelectric MEMS units are distributed in an array structure.

The beneficial effects of the utility model reside in that: the diaphragm structure of the piezoelectric MEMS microphone is fixed on a substrate through the anchoring part and a plurality of anchoring arms formed by radially extending from the edge of the anchoring part, so that the contact area between the diaphragm structure and the substrate is increased, and the risk of peeling off the diaphragm structure from the substrate is effectively reduced.

[ description of the drawings ]

FIG. 1 is a schematic structural diagram of a piezoelectric MEMS unit according to an embodiment of the present invention;

FIG. 2 is a front view of a piezoelectric MEMS unit of an embodiment of the present invention;

FIG. 3 is a perspective view of a piezoelectric MEMS unit of an embodiment of the present invention;

FIG. 4 is a bottom view of a piezoelectric MEMS element of an embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along A-A of FIG. 3;

FIG. 6 is a schematic structural diagram of a diaphragm structure according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a first electrode layer according to an embodiment of the invention;

fig. 8 is a schematic structural diagram of a first piezoelectric layer according to an embodiment of the invention;

FIG. 9 is a schematic structural diagram of a substrate according to an embodiment of the present invention;

FIG. 10 is a perspective view of a substrate of an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a first substrate according to an embodiment of the invention;

fig. 12 is a schematic structural diagram of an isolation layer according to an embodiment of the invention.

[ detailed description ] embodiments

The present invention will be further described with reference to the accompanying drawings and embodiments.

It should be noted that all the directional indicators (such as upper, lower, left, right, front, back, inner, outer, top, bottom … …) in the embodiments of the present invention are only used to explain the relative position between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

Referring to fig. 1 to 12, the present invention provides a piezoelectric MEMS microphone, which includes a plurality of piezoelectric MEMS elements 1, and the plurality of piezoelectric MEMS elements 1 are distributed in an array structure, in this embodiment, the number of the piezoelectric MEMS elements 1 is 1, and certainly, when a certain sensitivity or a signal-to-noise ratio is ensured, the piezoelectric MEMS elements 1 may also be distributed in a 2 × 2 array structure, or distributed in a 3 × 3 array structure or in more array structures.

Referring to fig. 1 to 5, a piezoelectric MEMS unit 1 includes a substrate 10 and a diaphragm structure 30, the square substrate 10 having a housing cavity 101; the diaphragm structure 30 is formed over the substrate 10.

The base 10 comprises an annular peripheral wall 102 enclosing a containing cavity 101 and a supporting structure arranged in the containing cavity 101; the supporting structure includes a supporting portion 103 spaced from the peripheral wall 102 and a plurality of extending arms 104 extending from the peripheral wall 102 to the supporting portion 103, wherein the supporting portion 103 is disposed at a center position of the accommodating cavity 101.

The diaphragm structure 30 is a structure, and includes fixed region 301 and a plurality of movable part 302, fixed region 301 includes anchor portion 303 and the anchor arm 304 that a plurality of interval set up, each anchor arm 304 certainly the edge radial extension of anchor portion 303 forms, anchor portion 303 is fixed in the supporting part 103, anchor arm 304 is fixed in extension arm 104, every movable part 302 encircle anchor portion 303, and with anchor arm 304 interval sets up.

The diaphragm structure 30 of the piezoelectric MEMS unit 1 is fixed on the supporting structure of the substrate 10 through the anchoring portion 303 and a plurality of anchoring arms 304 formed by radially extending from the edge of the anchoring portion 303, so that the contact area between the diaphragm structure 30 and the substrate 10 is increased, and the risk of peeling off the diaphragm structure 30 from the substrate 10 is effectively reduced.

In this embodiment, one end of the extension arm 104 is connected to the support portion 103, the other end of the extension arm 104 is connected to the peripheral wall 102 so as to divide the housing cavity 101 into a plurality of cavities 105 arranged at intervals along the circumferential direction of the extension arm 104, and the movable portion 302 falls into the cavity 105 along the orthogonal projection of the axial direction of the substrate 10. Specifically, one movable portion 302 is suspended above each cavity 105, and the projection contour of each movable portion 302 in the direction perpendicular to the diaphragm structure 30 is located within the projection contour of the corresponding cavity 105 in the direction perpendicular to the diaphragm structure 30.

In the present embodiment, the projection profile of the inner sidewall of the annular peripheral wall 102 in the direction perpendicular to the diaphragm structure 30 may be a circle or a polygon, and the number of the extension arms 104 may be set according to actual needs, specifically, the number of the extension arms is at least two, and as a more preferred embodiment, the number of the extension arms 104 is four.

In the present embodiment, the projection profiles of the inner sidewall of the annular peripheral wall 102 and the outer sidewall of the support 103 in the substrate 10 in the direction perpendicular to the diaphragm structure 30 are both circular; the projection contour of the anchoring part 303 in the direction vertical to the diaphragm structure 30 is circular, and the projection contour of the anchoring arm 304 in the direction vertical to the diaphragm structure 30 is strip-shaped; the projection profile of the single movable portion 302 in the direction perpendicular to the diaphragm structure 30 is a fan-ring shape.

The membrane structure 30 is formed by stacking at least three layers of materials. Alternatively, the membrane structure 30 includes a first electrode layer 31, a first piezoelectric layer 32, and a second electrode layer 33, which are sequentially stacked in the vibration direction; alternatively, the membrane structure 30 includes a first electrode layer 31, a first piezoelectric layer 32, a second electrode layer 33, a second piezoelectric layer 34, and a third electrode layer 35, which are sequentially stacked in the vibration direction; alternatively, any other membrane structure formed by stacking an electrode layer and a piezoelectric layer is also applicable to the present invention. Wherein the first electrode layer 31 is disposed on a side of the membrane structure 30 close to the support structure.

Referring to fig. 7, the first electrode layer 31 includes a first electrode sheet 311 located at the movable portion 302 and a second electrode sheet 312 located at the fixed region 301, and the first electrode sheet 311 and the second electrode sheet 312 are spaced apart. The second electrode layer 33 and the third electrode layer 35 have the same structure as the first electrode layer 31.

The second electrode layer 33 includes a third electrode sheet located at the movable portion 302 and a fourth electrode sheet located at the fixed region 301, and the third electrode sheet and the fourth electrode sheet are disposed at an interval.

The third electrode layer 35 includes a fifth electrode sheet located at the movable portion 302 and a sixth electrode sheet located at the fixed region 301, and the fifth electrode sheet and the sixth electrode sheet are disposed at an interval.

Referring to fig. 8, the first piezoelectric layer 32 includes a first movable portion 321 located at the movable portion 302 and a first fixed region 322 located at the fixed region 301, and the first movable portion 321 is connected to the first fixed region 322. The first piezoelectric layer 32 is integrally formed and has a circular structure as a whole, that is, the first movable portion 321 is connected to the first fixing area 322, so as to improve the reliability of the membrane structure 30. The second piezoelectric layer 34 is identical in structure to the first piezoelectric layer 32.

The second piezoelectric layer 34 includes a second movable portion located at the movable portion 302 and a second fixed region located at the fixed region 301, the second movable portion being connected to the second fixed region.

The first electrode sheet 311, the first movable portion 321, the third electrode sheet, the second movable portion, and the fifth electrode sheet are sequentially stacked to form the movable portion 302, and the second electrode sheet 312, the first fixed region 322, the fourth electrode sheet, the second fixed region, and the sixth electrode sheet are sequentially stacked to form the fixed region 301.

Referring to fig. 9 and 10, the base 10 includes a first substrate 11 and an isolation layer 12 disposed between the first substrate 11 and the diaphragm structure 30, and a projection profile of the isolation layer 12 in the vibration direction of the movable portion 302 has the same shape as a projection profile of the first substrate 11 in the vibration direction of the movable portion 302.

Referring to fig. 11, the first substrate 11 includes a first peripheral wall 112 enclosing a first cavity 111, a first supporting portion 113 disposed in the first cavity 111 and spaced apart from the first peripheral wall 112, and a first extension arm 114 extending from the first peripheral wall 112 to the first supporting portion 113, the first supporting portion 113 being disposed at a center position of the first cavity 111, wherein the first supporting portion 113 and the first extension arm 114 form a first supporting structure; one end of the first extension arm 114 is connected to the first support portion 113, and the other end of the first extension arm 114 is connected to the first peripheral wall 112, so as to divide the first cavity 111 into a plurality of first sub-cavities 115 arranged at intervals along the circumference of the first extension arm 114.

Referring to fig. 12, the isolation layer 12 includes a second peripheral wall 122 enclosing a second cavity 121, a second supporting portion 123 disposed in the second cavity 121 and spaced apart from the second peripheral wall 122, and a second extension arm 124 extending from the second peripheral wall 122 to the second supporting portion 123, where the second supporting portion 123 is disposed at a central position of the second cavity 121, and the second supporting portion 123 and the second extension arm 124 form a second supporting structure; one end of the second extension arm 124 is connected to the second support portion 123, and the other end of the second extension arm 124 is connected to the second peripheral wall 122 so as to divide the second cavity 121 into a plurality of second sub-cavities 125 arranged at intervals along the circumferential direction of the second extension arm 124.

Referring to fig. 9 and 10, the first cavity 111 is communicated with the second cavity 121 to form a containing cavity 101, and the first peripheral wall 112 and the second peripheral wall 122 enclose to form an annular peripheral wall 102; the first support part 113 and the second support part 123 are overlapped to form the support part 103 of the substrate 10, the first extension arm 114 and the second extension arm 124 form the extension arm 104 of the substrate 10, and the support part 103 and the extension arm 104 form a support structure; the first subchamber 115 communicates with the second subchamber 125 to form the chamber 105. The extension arms 104 may be used to provide some support protection to the diaphragm structure 30 when the diaphragm structure 30 is greatly deformed, thereby preventing the diaphragm structure 30 from breaking.

Specifically, the anchoring portion 303 and the anchoring arm 304 of the diaphragm structure 30 are respectively and correspondingly fixed on the supporting portion 103 and the extension arm 104, the movable portion 302 of the diaphragm structure 30 is suspended above the cavity 105, and the contact area between the diaphragm structure 30 and the supporting structure (the supporting portion 103 and the extension arm 104) is increased, so that the risk that the diaphragm structure 30 is peeled off from the substrate is effectively reduced.

The above embodiments of the present invention are only described, and it should be noted that, for those skilled in the art, modifications can be made without departing from the inventive concept, but these all fall into the protection scope of the present invention.

Claims

1. A piezoelectric MEMS microphone comprising at least one piezoelectric MEMS element, the piezoelectric MEMS element comprising:

the substrate comprises an annular peripheral wall and a supporting structure, wherein the annular peripheral wall surrounds a containing cavity, the supporting structure is arranged in the containing cavity, and the supporting structure comprises a supporting part and a plurality of extension arms, the supporting part is arranged at intervals with the peripheral wall, and the extension arms extend from the peripheral wall to the supporting part;

the diaphragm structure, diaphragm structure as an organic whole structure, including fixed region and a plurality of movable part, fixed region include anchor portion and certainly a plurality of anchor arm that the edge radial extension of anchor portion formed, anchor portion is fixed in the supporting part, the anchor arm is fixed in the extension arm, every the movable part encircles anchor portion and with the anchor arm interval sets up.

2. A piezoelectric MEMS microphone as defined in claim 1, wherein: the diaphragm structure is including the first electrode layer, first piezoelectric layer and the second electrode layer that stack gradually along the vibration direction, first electrode layer set up in the diaphragm structure is close to one side of bearing structure.

3. A piezoelectric MEMS microphone as defined in claim 2, wherein: the diaphragm structure further comprises a second piezoelectric layer and a third electrode layer, wherein the second piezoelectric layer is stacked on one side, far away from the first piezoelectric layer, of the second electrode layer, and the third electrode layer is stacked on the second piezoelectric layer.

4. A piezoelectric MEMS microphone as defined in claim 1, wherein: the extension arm will accept the chamber and separate into a plurality of cavity, the movable part is followed the axial orthographic projection of basement falls into in the cavity.

5. A piezoelectric MEMS microphone as claimed in claim 4, wherein: the number of extension arms is at least two.

6. A piezoelectric MEMS microphone as defined in claim 1, wherein: the basement includes first base plate, accept the chamber including form in the first cavity of first base plate, the perisporium is including enclosing into the first perisporium of first cavity, the supporting part including locate first cavity and with the first supporting part that first perisporium interval set up, a plurality of the extension arm includes certainly first circumference wall extends to a plurality of first extension arms of first supporting part.

7. A piezoelectric MEMS microphone as claimed in claim 6, wherein: the base further comprises an isolation layer arranged between the first substrate and the diaphragm structure, and the projection profile of the isolation layer along the vibration direction of the movable portion is the same as the projection profile of the first substrate along the vibration direction of the movable portion in shape.

8. Piezoelectric MEMS microphone according to claim 7, characterized in that: the piezoelectric MEMS unit is a plurality of, a plurality of piezoelectric MEMS unit is a distribution of array structure.