WO2022116288A1 - 压电麦克风 - Google Patents

压电麦克风 Download PDF

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Publication number
WO2022116288A1
WO2022116288A1 PCT/CN2020/137529 CN2020137529W WO2022116288A1 WO 2022116288 A1 WO2022116288 A1 WO 2022116288A1 CN 2020137529 W CN2020137529 W CN 2020137529W WO 2022116288 A1 WO2022116288 A1 WO 2022116288A1
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Prior art keywords
piezoelectric
diaphragm
microphone
unit
layer
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PCT/CN2020/137529
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English (en)
French (fr)
Inventor
童贝
石正雨
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AAC Technologies Holdings Shenzhen Co Ltd
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AAC Acoustic Technologies Shenzhen Co Ltd
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Publication of WO2022116288A1 publication Critical patent/WO2022116288A1/zh
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H04R17/02—Microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction

Definitions

  • the present application relates to the technical field of microphones, and in particular, to a piezoelectric microphone.
  • a second piezoelectric unit 13 with the same structure as the first piezoelectric unit 12 above the diaphragm 11 is mainly prepared under the diaphragm 11 , and then the second piezoelectric unit 13 is combined with the first piezoelectric unit 12 above the diaphragm 11 .
  • the first piezoelectric unit 12 is connected in parallel.
  • the piezoelectric microphone is difficult to realize in the process.
  • the middle part of the diaphragm will sink, that is, the lower surface of the diaphragm and the lower part of the second piezoelectric unit will sink.
  • the surfaces are in the same plane, which reduces the sensitivity of the device.
  • the purpose of the present application is to provide a piezoelectric microphone with low process difficulty and high sensitivity.
  • the present application provides a piezoelectric microphone, comprising at least one piezoelectric component, the piezoelectric component includes a substrate with a back cavity, a vibrating membrane and a piezoelectric unit, the vibrating membrane is fixedly connected to the On the base, a piezoelectric hole is arranged on the vibrating film, and the piezoelectric unit is embedded in the piezoelectric hole.
  • the piezoelectric holes penetrate through both side surfaces of the vibrating membrane along the vibration direction of the vibrating membrane.
  • the piezoelectric unit includes a plurality of stacked electrode layers, and a piezoelectric layer is spaced between two adjacent electrode layers.
  • the piezoelectric unit includes a first electrode layer, a piezoelectric layer and a second electrode layer stacked in sequence along the vibration direction of the diaphragm.
  • the piezoelectric unit further includes a second piezoelectric layer stacked on the second electrode sheet and a third electrode sheet stacked on the second piezoelectric layer.
  • the thickness of the piezoelectric unit is greater than half of the thickness of the diaphragm.
  • the projection of the piezoelectric unit along the vibration direction of the diaphragm is a square, a rectangle, a star or a circle.
  • the piezoelectric component further includes an oxide layer disposed between the substrate and the diaphragm.
  • the piezoelectric microphone includes a plurality of the piezoelectric components, and the plurality of the piezoelectric components are assembled into the piezoelectric microphone.
  • a plurality of the piezoelectric components are distributed in an array structure.
  • the beneficial effect of the present application is that a piezoelectric microphone with low technological difficulty and high sensitivity is provided, and the piezoelectric unit is embedded in the piezoelectric hole by arranging the piezoelectric hole on the vibrating membrane.
  • the difficulty of the preparation process can be significantly reduced; on the other hand, since the piezoelectric unit is embedded in the piezoelectric hole of the diaphragm, under the same sound pressure, the piezoelectric unit will be more affected by the elastic extrusion of the diaphragm.
  • the stress of the piezoelectric microphone improves the sensitivity; in addition, since the piezoelectric microphone eliminates the elastic area of the diaphragm part (the position of the diaphragm corresponding to the piezoelectric hole), the resonance frequency of the piezoelectric microphone can be increased.
  • FIG. 1 is a schematic structural diagram of a piezoelectric microphone in the prior art
  • FIG. 2 is a schematic structural diagram of the piezoelectric microphone of the present application.
  • the present application provides a piezoelectric microphone including at least one piezoelectric component 20 .
  • the piezoelectric microphone includes a plurality of piezoelectric components 20, the piezoelectric microphone can be formed by splicing the plurality of piezoelectric components 20, and the plurality of piezoelectric components 20 are distributed in an array structure.
  • the piezoelectric component 20 can also be designed to be distributed in a 4*4 array structure or more array structures.
  • the piezoelectric component 20 includes a substrate 21 having a back cavity, a diaphragm 22 , a piezoelectric unit 23 and an oxide layer 24 , the diaphragm 22 is fixedly connected on the substrate 21 , and the oxide layer 24 is disposed between the base 21 and the vibrating film 22, the vibrating film 22 is formed with piezoelectric holes 221 penetrating both sides of the vibrating film 22 along the vibration direction of the vibrating film 22, the The piezoelectric unit 23 is embedded in the piezoelectric hole 221 .
  • the piezoelectric holes 221 may be formed by etching the formed vibrating membrane 22 after the vibrating membrane 22 is formed.
  • the piezoelectric unit 23 may be deposited to be embedded in the piezoelectric hole 221 of the diaphragm 22 .
  • the piezoelectric unit 23 can be embedded in the parts of the diaphragm 22 where the displacement or deformation is relatively large.
  • the piezoelectric unit 23 includes a plurality of electrode layers 231 , and a piezoelectric layer 232 is spaced between two adjacent electrode layers 231 .
  • the piezoelectric unit 23 includes two electrode layers 231 , and the two electrode layers 231 are marked as a first electrode layer 231 a and a second electrode layer 231 b respectively.
  • the two electrode layers 231b are separated by a piezoelectric layer 232 .
  • the piezoelectric unit 23 includes a first electrode layer 231 a , a piezoelectric layer 232 and a second electrode layer 231 b that are stacked in sequence along the vibration direction of the diaphragm 33 .
  • the piezoelectric unit may further include a second piezoelectric layer stacked on the second electrode layer and a second piezoelectric layer stacked on the second piezoelectric layer
  • the third electrode layer, at this time, the piezoelectric unit includes three electrode layers.
  • the thickness of the piezoelectric unit 23 is greater than half of the thickness of the diaphragm 22 .
  • the projection of the piezoelectric unit 23 along the vibration direction of the diaphragm is rectangular.
  • the projected shape of the piezoelectric unit along the vibration direction of the diaphragm may also be other shapes, such as a square, a rectangle, a star, or a circle.
  • the present application provides a piezoelectric microphone 20 .
  • the piezoelectric unit 23 is embedded in the piezoelectric hole 221 .
  • the difficulty of the manufacturing process can be significantly reduced; on the other hand, since the piezoelectric unit 23 is embedded in the piezoelectric hole 221 of the vibrating membrane, under the same sound pressure, the piezoelectric unit 23 is due to the elastic pressing action of the vibrating membrane 22.
  • the resonant frequency of the piezoelectric microphone 20 can be increased.
  • the technical solution of embedding the piezoelectric unit 23 into the vibrating membrane 22 proposed in the present application can provide more choices in the structural design of other piezoelectric MEMS (Micro-Electro-Mechanical System, Micro-Electro-Mechanical System) devices.
  • piezoelectric MEMS Micro-Electro-Mechanical System, Micro-Electro-Mechanical System

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)

Abstract

本申请提供了一种压电麦克风，包括至少一个压电组件，所述压电组件包括具有背腔的基底、振膜以及压电单元，所述振膜固定连接在所述基底上，所述振膜上设置有压电孔，所述压电单元嵌入在所述压电孔内。本申请通过在振膜上设置压电孔，使压电单元嵌入在压电孔内，一方面可以降低制备工艺的难度，另一方面可使灵敏度得到提升，此外，还可提高压电麦克风的谐振频率。

Description

压电麦克风 技术领域
本申请涉及麦克风技术领域，尤其涉及一种压电麦克风。
 背景技术
目前压电麦克风，如图1所示，主要在振膜11的下方制备与振膜11上方的第一压电单元12结构相同的第二压电单元13，然后将第二压电单元13与第一压电单元12进行并联连接，该设计方法虽会小幅降低灵敏度，但是由于并联后电容增加了一倍，使其噪声会大幅度减小，因此，总的SNR（SIGNAL NOISE RATIO，信噪比）会有可观的提升。
但是，该压电麦克风在工艺实现上有较大的难度，其原因在于：在实际制备完成后，振膜的中间部位会有下沉，即振膜的下表面与第二压电单元的下表面处于同一平面，这样会削弱器件的灵敏度。
因此，有必要提供一种新的压电麦克风来解决上述技术问题。
 技术问题
本申请的目的在于提供了一种工艺难度低且灵敏度高的压电麦克风。
 技术解决方案
为达到上述目的，本申请提供了一种压电麦克风，包括至少一个压电组件，所述压电组件包括具有背腔的基底、振膜以及压电单元，所述振膜固定连接在所述基底上，所述振膜上设置有压电孔，所述压电单元嵌入在所述压电孔内。
优选的，所述压电孔沿所述振膜的振动方向贯穿所述振膜的两侧表面。
优选的，所述压电单元包括多个层叠的电极层，相邻两个所述电极层之间通过一压电层间隔设置。
优选的，所述压电单元沿所述振膜的振动方向包括依次层叠的第一电极层、压电层以及第二电极层。
优选的，所述压电单元还包括叠设在所述第二电极片上的第二压电层以及叠设在所述第二压电层上的第三电极片。
优选的，所述压电单元的厚度大于所述振膜的厚度的一半。
优选的，所述压电单元沿所述振膜的振动方向的投影呈正方形、矩形、星形或圆形。
优选的，所述压电组件还包括设置所述基底与所述振膜之间的氧化层。
优选的，所述压电麦克风包括多个所述压电组件，多个所述压电组件拼接成所述压电麦克风。
优选的，多个所述压电组件呈阵列结构分布。
 有益效果
本申请的有益效果在于：提供了一种工艺难度低且灵敏度高的压电麦克风，通过在振膜上设置压电孔，使压电单元嵌入在压电孔内。一方面可以显著降低制备工艺的难度；另一方面，由于压电单元嵌入在振膜的压电孔中，在相同声压作用下，压电单元由于振膜的弹性挤压作用将受到更大的应力，使灵敏度得到提升；此外，由于该压电麦克风消减了振膜的部分的弹性区域（振膜的对应压电孔的位置），可提高压电麦克风的谐振频率。
 附图说明
图1为现有技术的压电麦克风的结构示意图；
图2为本申请的压电麦克风的结构示意图。
 本发明的实施方式
下面结合附图和实施方式对本申请作进一步说明。
需要说明的是，本申请实施例中所有方向性指示（诸如上、下、左、右、前、后、内、外、顶部、底部……）仅用于解释在某一特定姿态（如附图所示）下各部件之间的相对位置关系等，如果该特定姿态发生改变时，则该方向性指示也相应地随之改变。
还需要说明的是，当元件被称为“固定于”或“设置于”另一个元件上时，该元件可以直接在另一个元件上或者可能同时存在居中元件。当一个元件被称为“连接”另一个元件，它可以是直接连接另一个元件或者可能同时存在居中元件。
请参考图2，本申请提供了一种压电麦克风，包括至少一个压电组件20。若压电麦克风包括多个压电组件20，则可将多个所述压电组件20拼接形成所述压电麦克风，而且多个压电组件20呈阵列结构分布。在本实施中，压电组件20设有4个，其呈2*2阵列结构分布。当然了，在保证一定的灵敏度或信噪比的前提下，压电组件20也可设计成4*4阵列结构分布或者更多阵列式结构。
请参考图2，所述压电组件20包括具有背腔的基底21、振膜22、压电单元23以及氧化层24，所述振膜22固定连接在所述基底21上，所述氧化层24设置所述基底21与所述振膜22之间，所述振膜22上形成有沿所述振膜22的振动方向贯穿所述振膜22的两侧表面的压电孔221，所述压电单元23嵌入在所述压电孔221内。具体地，所述压电孔221可在振膜22形成后，通过对形成的振膜22进行刻蚀处理形成。之后，可沉积所述压电单元23，以嵌入所述振膜22的压电孔221中。优选的，振膜22位移较大或变形较大的部位均可嵌入压电单元23。
请参考图2，所述压电单元23包括多个电极层231，相邻两个所述电极层231之间通过一压电层232间隔设置。
优选的，请参考图2，所述压电单元23包括两个电极层231，两个电极层231分别标记为第一电极层231a及第二电极层231b，所述第一电极层231a与第二电极层231b之间通过压电层232间隔。具体地，所述压电单元23沿所述振膜33的振动方向包括依次层叠的第一电极层231a、压电层232以及第二电极层231b。
另一较佳实施例（图未示出）中，所述压电单元还可包括叠设在所述第二电极层上的第二压电层以及叠设在所述第二压电层上的第三电极层，此时，所述压电单元包括三个电极层。
优选的，请参考图2，所述压电单元23的厚度大于所述振膜22的厚度的一半。所述压电单元23沿所述振膜的振动方向的投影呈矩形。图未示出的其他实施例中，所述压电单元沿所述振膜的振动方向的投影的形状也可以为其他形状，如正方形、矩形、星形或圆形等。
本申请提供了一种压电麦克风20，通过在振膜22上设置压电孔221，使压电单元23嵌入在压电孔221内。一方面可以显著降低制备工艺的难度；另一方面，由于压电单元23嵌入在振膜的压电孔221中，在相同声压作用下，压电单元23由于振膜22的弹性挤压作用将受到更大的应力，使灵敏度得到提升；此外，由于消减了振膜22的部分的弹性区域（振膜22的对应压电孔221的位置），可提高压电麦克风20的谐振频率。
本申请提出的将压电单元23嵌入振膜22的技术方案可为其他压电MEMS（Micro-Electro-Mechanical System，微机电系统）器件在结构设计上提供更多的选择。
以上所述的仅是本申请的实施方式，在此应当指出，对于本领域的普通技术人员来说，在不脱离本申请创造构思的前提下，还可以做出改进，但这些均属于本申请的保护范围。

Claims (10)

1、一种压电麦克风，包括至少一个压电组件，所述压电组件包括具有背腔的基底、振膜以及压电单元，所述振膜固定连接在所述基底上，其特征在于：所述振膜上形成有压电孔，所述压电单元嵌入在所述压电孔内。
2、根据权利要求1所述的压电麦克风，其特征在于：所述压电孔沿所述振膜的振动方向贯穿所述振膜的两侧表面。
3、根据权利要求1所述的压电麦克风，其特征在于：所述压电单元包括多个层叠的电极层，相邻两个所述电极层之间通过一压电层间隔设置。
4、根据权利要求3所述的压电麦克风，其特征在于：所述压电单元沿所述振膜的振动方向包括依次层叠的第一电极层、第一压电层以及第二电极层。
5、根据权利要求4所述的压电麦克风，其特征在于：所述压电单元还包括叠设在所述第二电极层上的第二压电层以及叠设在所述第二压电层上的第三电极层。
6、根据权利要求1所述的压电麦克风，其特征在于：所述压电单元的厚度大于所述振膜的厚度的一半。
7、根据权利要求1所述的压电麦克风，其特征在于：所述压电单元沿所述振膜的振动方向的投影呈正方形、矩形、星形或圆形。
8、根据权利要求1所述的压电麦克风，其特征在于：所述压电组件还包括设置所述基底与所述振膜之间的氧化层。
9、根据权利要求1所述的压电麦克风，其特征在于：所述压电麦克风包括多个所述压电组件，多个所述压电组件拼接成所述压电麦克风。
10、根据权利要求9所述的压电麦克风，其特征在于：多个所述压电组件呈阵列结构分布。
PCT/CN2020/137529 2020-12-01 2020-12-18 压电麦克风 Ceased WO2022116288A1 (zh)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4079213A (en) * 1977-04-21 1978-03-14 Essex Group, Inc. Piezoelectric transducer having improved low frequency response
CN101336562A (zh) * 2005-12-27 2008-12-31 日本电气株式会社 压电致动器及电子装置
CN102111703A (zh) * 2009-12-28 2011-06-29 精拓丽音科技（北京）有限公司 一种振膜打孔型压电平板扬声器
CN102460938A (zh) * 2009-05-11 2012-05-16 日本电气株式会社 压电致动器和音频部件
CN102668598A (zh) * 2009-12-15 2012-09-12 日本电气株式会社 致动器、压电致动器、电子装置，和用于衰减振动并且转换振动方向的方法
CN111669690A (zh) * 2020-07-10 2020-09-15 瑞声科技（南京）有限公司 一种压电式麦克风及其制备工艺

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4079213A (en) * 1977-04-21 1978-03-14 Essex Group, Inc. Piezoelectric transducer having improved low frequency response
CN101336562A (zh) * 2005-12-27 2008-12-31 日本电气株式会社 压电致动器及电子装置
CN102460938A (zh) * 2009-05-11 2012-05-16 日本电气株式会社 压电致动器和音频部件
CN102668598A (zh) * 2009-12-15 2012-09-12 日本电气株式会社 致动器、压电致动器、电子装置，和用于衰减振动并且转换振动方向的方法
CN102111703A (zh) * 2009-12-28 2011-06-29 精拓丽音科技（北京）有限公司 一种振膜打孔型压电平板扬声器
CN111669690A (zh) * 2020-07-10 2020-09-15 瑞声科技（南京）有限公司 一种压电式麦克风及其制备工艺

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