WO2023245789A1 - 一种mems压电扬声器 - Google Patents

一种mems压电扬声器 Download PDF

Info

Publication number
WO2023245789A1
WO2023245789A1 PCT/CN2022/106847 CN2022106847W WO2023245789A1 WO 2023245789 A1 WO2023245789 A1 WO 2023245789A1 CN 2022106847 W CN2022106847 W CN 2022106847W WO 2023245789 A1 WO2023245789 A1 WO 2023245789A1
Authority
WO
WIPO (PCT)
Prior art keywords
piezoelectric
diaphragm
electrode layer
mems
suspended
Prior art date
Application number
PCT/CN2022/106847
Other languages
English (en)
French (fr)
Inventor
沈宇
周一苇
但强
李杨
Original Assignee
瑞声开泰科技(武汉)有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 瑞声开泰科技(武汉)有限公司 filed Critical 瑞声开泰科技(武汉)有限公司
Publication of WO2023245789A1 publication Critical patent/WO2023245789A1/zh

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/02—Microstructural systems; Auxiliary parts of microstructural devices or systems containing distinct electrical or optical devices of particular relevance for their function, e.g. microelectro-mechanical systems [MEMS]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R19/00—Electrostatic transducers
    • H04R19/02—Loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/16—Mounting or tensioning of diaphragms or cones

Definitions

  • the utility model belongs to the technical field of speakers, and in particular relates to a MEMS piezoelectric speaker.
  • MEMS(Micro ⁇ Electro ⁇ Mechanical System) piezoelectric actuators can be used as one of the main components of mobile terminals such as mobile phones. They are mainly used to convert electrical signals into sound signals and are the key to realizing human-computer interaction interfaces.
  • MEMS piezoelectric actuators usually include a base, a diaphragm fixed on the base, and a piezoelectric functional layer placed on the diaphragm.
  • the piezoelectric functional layer deforms after being energized, and the charged diaphragm vibrates and produces sound.
  • the diaphragm of the MEMS piezoelectric speaker in the related art is limited by the deformation ability of the driver, resulting in the inability to further improve the acoustic performance of the MEMS piezoelectric speaker.
  • the purpose of this utility model is to provide a MEMS piezoelectric speaker that can solve the problem in related technologies that the MEMS piezoelectric speaker diaphragm is limited by the deformation ability of the driver, resulting in the inability to further improve the acoustic performance of the MEMS piezoelectric speaker.
  • a MEMS piezoelectric speaker including a base with a back cavity, a diaphragm fixed on the base, and a capacitive system fixed on the side of the diaphragm away from the base.
  • the membrane includes a fixed end fixed to the base, and a plurality of suspended ends extending from the fixed end and suspended above the back cavity. Slits are formed at least partially between adjacent suspended ends. The end of the suspended end away from the fixed end is spaced apart to form a receiving space connected to the slit.
  • the suspended end includes a support section connected to the fixed end and a support section connected to the support section away from the slit.
  • the piezoelectric segment on the fixed end side, the capacitive system includes a plurality of piezoelectric structures corresponding to the suspended end, each of the piezoelectric structures includes a piezoelectric structure that is stacked on the diaphragm in sequence and at least completely covers the piezoelectric
  • the first electrode layer, piezoelectric layer and second electrode layer of the segment, the projection of the second electrode layer along the thickness direction of the MEMS piezoelectric speaker only covers the piezoelectric segment of the diaphragm, the third An electrode layer and the overlapped portion of the piezoelectric layer and the second electrode layer along the thickness direction of the MEMS piezoelectric speaker together form a piezoelectric functional area.
  • the MEMS piezoelectric speaker also includes a device disposed far away from the capacitor system.
  • a flexible film on one side of the back cavity and at least completely covering the slit, the flexible film and the diaphragm are located on different planes, and the flexible film and the diaphragm are in the thickness direction of the MEMS piezoelectric speaker.
  • the membrane is at least partially spaced apart and the flexible membrane is spaced apart from the substrate.
  • the projections of the first electrode layer and the piezoelectric layer along the thickness direction of the MEMS piezoelectric speaker only cover the piezoelectric segment of the diaphragm; or the first electrode layer and the piezoelectric layer
  • the projection of the piezoelectric layer along the thickness direction of the MEMS piezoelectric speaker simultaneously covers the fixed end and the suspended end of the diaphragm; or the first electrode layer extends along the thickness direction of the MEMS piezoelectric speaker.
  • the projection in the thickness direction covers the fixed end and the suspended end of the diaphragm, and the projection of the piezoelectric layer and the second electrode layer in the thickness direction of the MEMS piezoelectric speaker only covers the diaphragm.
  • the slit is only formed on the adjacent piezoelectric segment.
  • the support sections adjacent to each suspended end are connected to each other to form an integrated structure as a support area to connect the piezoelectric functional area and the substrate.
  • the projections of the first electrode layer and the piezoelectric layer along the thickness direction of the MEMS piezoelectric speaker both cover the fixed end and the suspended end of the diaphragm
  • the projection of the first electrode layer along the thickness direction of the MEMS piezoelectric speaker covers the fixed end and the suspended end of the diaphragm
  • the piezoelectric layer extends along the thickness of the MEMS piezoelectric speaker.
  • the projection of the direction covers only the piezoelectric segment of the diaphragm
  • the slit extends to the inner circumference of the substrate and is completely spaced adjacent the suspended end.
  • the diaphragm further includes a connecting end connected to each of the suspended ends, the connecting end is received in the accommodation space, the connecting end includes a first connecting piece connected to each of the suspended ends, each The suspended end is arranged around the first connecting member.
  • the connecting end further includes a second connecting piece with one end connected to the suspended end and the other end connected to the first connecting piece, and there is a gap between each hanging end and the first connecting piece. At least one second connecting piece is provided.
  • the MEMS piezoelectric speaker further includes a mass fixed on the first connecting member and received in the back cavity.
  • the Young's modulus of the flexible membrane is smaller than the Young's modulus of the diaphragm.
  • the MEMS piezoelectric speaker further includes a connection component fixed on the side of the connection end away from the base, and the connection component includes a number of sub-connectors stacked sequentially along the thickness direction of the MEMS piezoelectric speaker.
  • the sub-connector includes a first sub-connector connecting the first electrode layers of a plurality of piezoelectric structures, a second sub-connector connecting the piezoelectric layers and a third sub-connector connecting the second electrode layer.
  • the first sub-connector is integrally formed with the first electrode layer
  • the second sub-connector is integrally formed with the piezoelectric layer
  • the third sub-connector is integrally formed with the second electrode layer.
  • the beneficial effects of the utility model are: after the piezoelectric structure is energized, it drives the diaphragm to vibrate, realizing the sound generation of the MEMS piezoelectric speaker; because the projection of the second electrode layer along the thickness direction of the MEMS piezoelectric speaker only covers the piezoelectric segment of the diaphragm, And the overlapping portions of the first electrode layer, the piezoelectric layer and the second electrode layer along the thickness direction of the MEMS piezoelectric speaker together form a piezoelectric functional area.
  • the deformation of the piezoelectric structure drives the piezoelectric segment below it to vibrate, and at the same time drives the The support section vibrates, and the support section is passively driven, so compared with speakers in the prior art, this design can significantly improve the mid- and high-frequency sound pressure level of the MEMS piezoelectric speaker, thereby improving the acoustic performance of the MEMS piezoelectric speaker.
  • Figure 1 is an exploded view of a first embodiment of a MEMS piezoelectric speaker of the present invention
  • Figure 2 is a top view of a first embodiment of a MEMS piezoelectric speaker of the present invention
  • Figure 3 is a cross-sectional view along line A-A in Figure 2;
  • Figure 4 is an exploded view of a second embodiment of a MEMS piezoelectric speaker of the present invention.
  • Figure 5 is a top view of a second embodiment of a MEMS piezoelectric speaker of the present invention.
  • Figure 6 is a cross-sectional view along B-B in Figure 5;
  • Figure 7 is an exploded view of a third embodiment of a MEMS piezoelectric speaker of the present invention.
  • Figure 8 is a top view of a third embodiment of a MEMS piezoelectric speaker of the present invention.
  • Fig. 9 is a cross-sectional view along line C-C in Fig. 8 .
  • This embodiment provides a MEMS piezoelectric speaker, including a substrate 1 with a back cavity 11, a diaphragm 2 fixed on the substrate 1, and a capacitor fixed on the side of the diaphragm 2 away from the substrate 1 System, the diaphragm 2 includes a fixed end 21 fixed on the base 1, a plurality of suspended ends 22 extending from the fixed end 21 and suspended above the back cavity 11, and a connecting end 23 connecting each suspended end 22. Adjacent suspensions The ends 22 are at least partially spaced apart to form slits 4. The ends of a number of suspended ends 22 away from the fixed end 21 are spaced apart to form an accommodating space 24 connected with the slits 4.
  • the connecting end 23 is accommodated in the accommodating space 24, and the suspended ends 22 includes a support section a connected to the fixed end 21 and a piezoelectric section b connected to the support section a on the side away from the fixed end 21.
  • the capacitive system includes a plurality of piezoelectric structures 3 corresponding to the suspended end 22.
  • Each piezoelectric structure 3 includes a first electrode layer 31, a piezoelectric layer 32 and a second electrode layer 33 that are sequentially stacked on the diaphragm 2 and at least completely cover the piezoelectric segment b.
  • the projection of the second electrode layer 33 along the thickness direction of the MEMS piezoelectric speaker Only the piezoelectric segment b covering the diaphragm 2, the overlapping portions of the first electrode layer 31, the piezoelectric layer 32 and the second electrode layer 33 along the thickness direction of the MEMS piezoelectric speaker together form a piezoelectric functional area.
  • the piezoelectric structure 3 drives the diaphragm 2 to vibrate, thereby realizing the sound generation of the MEMS piezoelectric speaker; since the projection of the second electrode layer 33 along the thickness direction of the MEMS piezoelectric speaker only covers the piezoelectric segment b of the diaphragm 2 , and the overlapping portions of the first electrode layer 31, the piezoelectric layer 32 and the second electrode layer 33 along the thickness direction of the MEMS piezoelectric speaker together form a piezoelectric functional area. Therefore, the deformation of the piezoelectric structure 3 drives the piezoelectric segment below it. b vibrates, and at the same time drives the support section a to vibrate. The support section a is passively driven. Compared with the speakers in the prior art, this design can significantly improve the mid- and high-frequency sound pressure level of the MEMS piezoelectric speaker, thereby improving the MEMS Acoustic performance of piezoelectric loudspeakers.
  • the base 1 can be a rectangular block with a rectangular back cavity 11.
  • the fixed end 21 of the diaphragm 2 can be stacked and fixed on the four sides of the base 1. Each side of the fixed end 21 is connected to a
  • the four suspended ends 22 are connected to the connecting end 23, and the four suspended ends 22 are arranged at equal angular intervals around the connecting end 23 as the center.
  • Each suspended end 22 is provided with a piezoelectric structure 3 , so that the vibration of the diaphragm 2 after being driven by the piezoelectric structure 3 is more stable.
  • the first electrode layer 31 and the piezoelectric layer 32 in the piezoelectric structure 3 are arranged in different ways on the diaphragm 2, and the corresponding positions of the slits 4 formed are also different.
  • the projection of the first electrode layer 31 along the thickness direction of the MEMS piezoelectric speaker covers the fixed end 21 and the suspended end 22 of the diaphragm 2.
  • the projections of the piezoelectric layer 32 and the second electrode layer along the thickness direction of the MEMS piezoelectric speaker only cover the piezoelectric segment b of the diaphragm 2, and the slit 4 is only formed between adjacent piezoelectric segments b, and each suspension
  • the adjacent support sections a of the end 22 are connected to each other to form an integrated structure as a support area to connect the piezoelectric functional area and the substrate 1;
  • the flexible film 6 is provided on the side of the capacitive system away from the substrate 1, and the flexible film 6 covers the diaphragm 2 and
  • the piezoelectric structure 3 is spaced apart from the substrate 1 .
  • the shape and area of the piezoelectric layer 32 and the second electrode layer 33 are the same as the shape and area of the piezoelectric segment b, and the piezoelectric layer 32 and the second electrode layer 33 cover part of the upper area of the back cavity 11.
  • An electrode layer 31 covers the entire upper area of the back cavity 11 .
  • the support section is passively driven, so that the vibration of the support section is not limited by the deformation capacity of the piezoelectric structure 3, and there is This is beneficial to further improving the vibration effect of the diaphragm 2 and improving the acoustic performance of the MEMS piezoelectric speaker.
  • the support sections a are connected to each other to form an integrated structure as a support area to connect the piezoelectric functional area and the substrate 1 .
  • the flexible film 6 is stacked on the side of the capacitive system facing away from the substrate 1, and the area of the flexible film 6 corresponding to the piezoelectric layer 32 and the second electrode layer 33 protrudes toward the side of the capacitive system facing away from the substrate 1 to form a cavity, and the piezoelectric layer 32 and the second electrode layer 33 are located in the cavity, which not only ensures that the flexible film 6 can completely cover the piezoelectric structure 3 and the diaphragm 2, but also ensures that the flexible film 6 will not affect the piezoelectric layer 32 and the second electrode layer 33. Deformation causes interference.
  • all the first electrode layers 31 in each piezoelectric structure 3 are connected to be integrated, the piezoelectric layer 32 and the second electrode layer 33 in each piezoelectric structure 3 are independently arranged, and the middle part of the flexible film 6 faces
  • the base 1 extends to form a block, and the block extends into the middle space of the piezoelectric structure 3, which is beneficial to improving the acoustic performance of the MEMS piezoelectric speaker.
  • the projections of the first electrode layer 31 and the piezoelectric layer 32 along the thickness direction of the MEMS piezoelectric speaker both cover the fixed position of the diaphragm 2 at the same time.
  • the slit 4 extends to the inner periphery of the substrate 1 and completely separates the adjacent suspended end 22;
  • the flexible film 6 is disposed on the side of the capacitive system away from the substrate 1, and the flexible film 6 covers the diaphragm 2 and Piezoelectric structures3.
  • the shape and area of the first electrode layer 31 and the piezoelectric layer 32 are the same as the shape and area of the diaphragm 2, and the shape and area of the second electrode layer 33 are the same as the shape and area of the piezoelectric segment b of the suspended end 22.
  • the area is the same.
  • the piezoelectric structure 3 is supported by the fixed end 21 of the diaphragm 2, which can increase the support strength provided by the diaphragm 2 to the piezoelectric structure 3, thereby improving the vibration stability of the piezoelectric structure 3, thereby ensuring that the diaphragm 2 Vibration stability.
  • the slit 4 extends to the inner periphery of the substrate 1 and completely separates the adjacent suspended ends 22 , and the first electrode layer 31 , the piezoelectric layer 32 and the second electrode layer 33 in each piezoelectric structure 3 are connected to form an integrated arrangement. , no rectangular block is provided in the cavity of the flexible membrane 6 . It should be understood that the remaining aspects of this embodiment are the same as the first embodiment and will not be discussed here.
  • the projections of the first electrode layer 31 and the piezoelectric layer 32 along the thickness direction of the MEMS piezoelectric speaker only cover the pressure of the diaphragm 2.
  • Electrical section b, the slit 4 is only formed between adjacent piezoelectric sections b, and the adjacent support sections a of each suspended end 22 are connected to each other to form an integrated structure as a support area to connect the piezoelectric functional area and the substrate 1;
  • the flexible film 6 is disposed on the side of the capacitive system facing away from the substrate 1 , and the flexible film 6 only covers the piezoelectric section b of the suspended end 22 , the accommodating space 24 and the slit 4 . It should be understood that the remaining aspects of this embodiment are the same as the second embodiment and will not be discussed here.
  • the main material of the flexible membrane 6 is piezoelectric material, such as PZT (lead zirconate titanate piezoelectric ceramic), polymer (polyvinylidene fluoride and vinylidene fluoride-trifluoroethylene copolymer, etc.);
  • the main materials of the piezoelectric structure 3 are AlN (aluminum nitride), PZT (lead zirconate titanate piezoelectric ceramic) and ZnO (zinc oxide).
  • the Young's modulus of the flexible film 6 is smaller than the Young's modulus of the capacitive system, so that the flexible film 6 will not adversely affect the deformation of the piezoelectric structure 3; the flexible film 6 and the piezoelectric structure 3 are not in the same plane, so that the piezoelectric function
  • the area of the area will not be limited by the flexible membrane 6, which is beneficial to increasing the effective vibration area of the diaphragm 2 and improving the acoustic performance of the speaker; the flexible membrane 6 completely covers the slit 4, which can seal the air flow so that there is no air leakage area in the speaker. Ensure good acoustic performance of the speaker.
  • the connecting end 23 includes a first connecting member 231 connected to each suspended end 22 , and each suspended end 22 is arranged around the first connecting member 231 .
  • the first connecting member 231 can be a circular plate, and the first connecting member 231 is flush with the plate surface of the suspended end 22; since each suspended end 22 is connected to the first connecting member 231, each suspended end 22 The vibration frequency is consistent, which is beneficial to improving the vibration stability of the diaphragm 2; the first connecting member 231 is located in the middle of the accommodation space 24, and each suspended end 22 is arranged at equal angular intervals around the first connecting member 231 as the center, so that each The suspended ends 22 are arranged symmetrically, and the distribution of the suspended ends 22 in the back cavity 11 is more balanced, which is beneficial to improving the sound effect of the MEMS piezoelectric speaker.
  • the shape of the connecting end 23 can be square, hexagonal, etc.; the first connecting member 231 can be composed of a piezoelectric structure 3, which can be deformed according to the voltage applied to the area, or the piezoelectric structure 3 can be engraved. corrosion, not driven by voltage, or formed from other materials.
  • the connecting end 23 also includes a second connecting member 232 with one end connected to the suspended end 22 and the other end connected to the first connecting member 231.
  • Each suspended end 22 At least one second connecting piece 232 is provided between the first connecting piece 231 and the first connecting piece 231 .
  • the second connecting member 232 can be a connecting beam.
  • the second connecting member 232 can not only improve the connection strength between the first connecting member 231 and the suspended end 22, but also make the connection between the first connecting member 231 and the suspended end 22 There is a certain gap to prevent the vibration amplitude from being reduced after each suspended end 22 is connected to the first connecting member 231 .
  • the number of second connecting members 232 between each suspended end 22 and the first connecting member 231 can be multiple, such as two or three; by rationally designing the shape of the second connecting member 232 and Size, such as U-shaped beams or S-shaped beams, can effectively reduce the THD (Total Harmonic Distortion) of the device and improve the acoustic performance and reliability of MEMS piezoelectric speakers.
  • THD Total Harmonic Distortion
  • the MEMS piezoelectric speaker also includes a mass block 5 fixed on the first connecting member 231 and received in the back cavity 11.
  • the mass block 5 can lower the MEMS piezoelectric speaker.
  • the resonant frequency of the MEMS piezoelectric speaker can be flexibly adjusted to increase the available sound frequency range and reduce the THD of the device.
  • the material of the mass 5 is the same as the material of the substrate 1 .
  • the shape of the mass block 5 can be a ring, a frame, or other polygons.
  • the MEMS piezoelectric speaker also includes a connection component 7 fixed on the side of the connection end 23 away from the substrate 1.
  • the connection component 7 includes components stacked sequentially along the thickness direction of the MEMS piezoelectric speaker.
  • a number of sub-connectors, the sub-connectors include a first sub-connector 71 connected to the first electrode layers 31 of several piezoelectric structures 3, a second sub-connector 72 connected to the piezoelectric layer 32 and a second sub-connector 72 connected to the second electrode layer 33.
  • the third sub-connector 73 is stacked sequentially along the thickness direction of the MEMS piezoelectric speaker.
  • the shape and area of the first sub-connector 71 , the second sub-connector 72 and the third sub-connector 73 are the same as the shape and area of the connecting end 23 , ensuring that the first electrode layer 31 can be closely attached to the diaphragm. 2, the piezoelectric layer 32 is closely attached to the first electrode layer 31, and the second electrode layer 33 is closely attached to the piezoelectric layer 32; as an implementation manner, the first sub-connector 71 is integrated with the first electrode layer 31 By forming, the second sub-connector 72 and the piezoelectric layer 32 are integrally formed, and the third sub-connector 73 and the second electrode layer 33 are integrally formed, thereby reducing processing steps.

Landscapes

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

Abstract

本实用新型提供了一种MEMS压电扬声器，包括具有背腔的基底、振膜、电容系统以及柔性膜，振膜包括固定端、悬置端，相邻悬置端之间至少部分间隔设置形成狭缝，悬置端包括支撑段和压电段，电容系统包括与悬置端对应的若干压电结构，每一压电结构包括第一电极层、压电层以及第二电极层，第二电极层沿MEMS压电扬声器的厚度方向的投影仅覆盖振膜的压电段，第一电极层和压电层与第二电极层沿MEMS压电扬声器厚度方向重叠的部分共同形成压电功能区，柔性膜与振膜位于不同的平面，沿MEMS压电扬声器的厚度方向柔性膜与振膜至少部分间隔设置且所述柔性膜与所述基底间隔设置。本实用新型可以提升MEMS压电扬声器的中高频的声压级，提升MEMS压电扬声器的声学性能。

Description

一种MEMS压电扬声器 技术领域
本实用新型属于扬声器技术领域，尤其涉及一种MEMS压电扬声器。
 背景技术
MEMS(Micro‑Electro‑Mechanical System)压电执行器尤其是MEMS压电扬声器可作为手机等移动终端的主要元器件之一，其主要是用于将电信号转换成声音信号，是实现人机交互接口的关键。
相关的MEMS压电执行器通常包括基底、固定在基底上的振膜及置于振膜上的压电功能层，压电功能层通电后产生形变，带电振膜振动发声。相关技术中的MEMS压电扬声器振膜受驱动器变形能力的限制，导致MEMS压电扬声器的声学性能无法进一步提升。
因此，有必要提供一种新的MEMS压电扬声器解决上述技术问题。
 技术问题
本实用新型的目的在于提供一种MEMS压电扬声器，能够解决相关技术中的MEMS压电扬声器振膜受驱动器变形能力的限制，导致MEMS压电扬声器的声学性能无法进一步提升的问题。
 技术解决方案
本实用新型的技术方案如下：一种MEMS压电扬声器，包括具有背腔的基底、固定于所述基底的振膜以及固定于所述振膜远离所述基底一侧的电容系统，所述振膜包括固定于所述基底的固定端、自所述固定端延伸并悬置于所述背腔上方的若干悬置端，相邻所述悬置端之间至少部分间隔设置形成狭缝，若干所述悬置端远离所述固定端的端部间隔形成与所述狭缝连通的容纳空间，所述悬置端包括与所述固定端相连的支撑段和连接于所述支撑段的远离所述固定端侧的压电段，所述电容系统包括与所述悬置端对应的若干压电结构，每一所述压电结构包括依次叠设于所述振膜并至少完全覆盖所述压电段的第一电极层、压电层以及第二电极层，所述第二电极层沿所述MEMS压电扬声器的厚度方向的投影仅覆盖所述振膜的所述压电段，所述第一电极层和所述压电层与所述第二电极层沿所述MEMS压电扬声器厚度方向重叠的部分共同形成压电功能区，所述MEMS压电扬声器还包括设置于所述电容系统远离所述背腔一侧且至少完全覆盖所述狭缝的柔性膜，所述柔性膜与所述振膜位于不同的平面，沿所述MEMS压电扬声器的厚度方向所述柔性膜与所述振膜至少部分间隔设置且所述柔性膜与所述基底间隔设置。
优选地，所述第一电极层和所述压电层沿所述MEMS压电扬声器的厚度方向的投影均仅覆盖所述振膜的所述压电段；或者所述第一电极层和所述压电层沿所述MEMS压电扬声器的厚度方向的投影均同时覆盖所述振膜的所述固定端和所述悬置端；或者所述第一电极层沿所述MEMS压电扬声器的厚度方向的投影覆盖所述振膜的所述固定端和所述悬置端，所述压电层和所述第二电极层沿所述MEMS压电扬声器的厚度方向的投影仅覆盖所述振膜的所述压电段。
优选地，当所述压电层沿所述MEMS压电扬声器的厚度方向的投影仅覆盖所述振膜的所述压电段时，所述狭缝仅形成于相邻的所述压电段之间，各所述悬置端相邻的所述支撑段之间相互连接形成一体结构作为支撑区连接所述压电功能区和所述基底。
优选地，当所述第一电极层和所述压电层沿所述MEMS压电扬声器的厚度方向的投影均同时覆盖所述振膜的所述固定端和所述悬置端时，以及当所述第一电极层沿所述MEMS压电扬声器的厚度方向的投影覆盖所述振膜的所述固定端和所述悬置端、且所述压电层沿所述MEMS压电扬声器的厚度方向的投影仅覆盖所述振膜的所述压电段时时，所述狭缝延伸至所述基底的内周缘并完全间隔相邻所述悬置端。
优选地，所述振膜还包括连接各所述悬置端的连接端，所述连接端收容于所述容纳空间内，所述连接端包括连接于各所述悬置端的第一连接件，各所述悬置端环绕所述第一连接件设置。
优选地，所述连接端还包括一端连接于所述悬置端且另一端连接于所述第一连接件的第二连接件，每一所述悬置端和所述第一连接件之间设有至少一个所述第二连接件。
优选地，所述MEMS压电扬声器还包括固定于所述第一连接件且收容于所述背腔的质量块。
优选地，所述柔性膜的杨氏模量小于所述振膜的杨氏模量。
优选地，所述MEMS压电扬声器还包括固定于所述连接端远离所述基底一侧的连接组件，所述连接组件包括沿所述MEMS压电扬声器的厚度方向依次叠设的若干子连接件，所述子连接件包括连接若干所述压电结构的所述第一电极层的第一子连接件，连接所述压电层的第二子连接件以及连接所述第二电极层的第三子连接件。
优选地，所述第一子连接件与所述第一电极层一体成型，所述第二子连接件与所述压电层一体成型，所述第三子连接件与所述第二电极层一体成型。
 有益效果
本实用新型的有益效果在于：压电结构通电后带动振膜振动，实现MEMS压电扬声器的发声；由于第二电极层沿MEMS压电扬声器的厚度方向的投影仅覆盖振膜的压电段，且第一电极层和压电层与第二电极层沿MEMS压电扬声器厚度方向重叠的部分共同形成压电功能区，因此，压电结构的形变带动其下方的压电段振动，并同时带动支撑段振动，支撑段属于被动被驱动，使得与现有技术中的扬声器相比，本设计可以显著提升MEMS压电扬声器的中高频的声压级，进而提升MEMS压电扬声器的声学性能。
 附图说明
图1为本实用新型一种MEMS压电扬声器第一实施方式的爆炸图；
图2为本实用新型一种MEMS压电扬声器第一实施方式的俯视图；
图3为图2中的A-A向剖视图；
图4为本实用新型一种MEMS压电扬声器第二实施方式的爆炸图；
图5为本实用新型一种MEMS压电扬声器第二实施方式的俯视图；
图6为图5中的B-B向剖视图；
图7为本实用新型一种MEMS压电扬声器第三实施方式的爆炸图；
图8为本实用新型一种MEMS压电扬声器第三实施方式的俯视图；
图9为图8中的C-C向剖视图。
 本发明的实施方式
下面将结合本实用新型实施例中的附图，对本实用新型实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅是本实用新型的一部分实施例，而不是全部的实施例。基于本实用新型中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其它实施例，都属于本实用新型保护的范围。
请参阅图1至图9，本实施例提供了一种MEMS压电扬声器，包括具有背腔11的基底1、固定于基底1的振膜2以及固定于振膜2远离基底1一侧的电容系统，振膜2包括固定于基底1的固定端21、自固定端21延伸并悬置于背腔11上方的若干悬置端22以及连接各悬置端22的连接端23，相邻悬置端22之间至少部分间隔设置形成狭缝4，若干悬置端22远离固定端21的端部间隔形成与狭缝4连通的容纳空间24，连接端23收容于容纳空间24内，悬置端22包括与固定端21相连的支撑段a和连接于支撑段a的远离固定端21侧的压电段b，电容系统包括与悬置端22对应的若干压电结构3，每一压电结构3包括依次叠设于振膜2并至少完全覆盖压电段b的第一电极层31、压电层32以及第二电极层33，第二电极层33沿MEMS压电扬声器的厚度方向的投影仅覆盖振膜2的压电段b，第一电极层31和压电层32与第二电极层33沿MEMS压电扬声器厚度方向重叠的部分共同形成压电功能区。
可以理解的，压电结构3通电后带动振膜2振动，实现MEMS压电扬声器的发声；由于第二电极层33沿MEMS压电扬声器的厚度方向的投影仅覆盖振膜2的压电段b，且第一电极层31和压电层32与第二电极层33沿MEMS压电扬声器厚度方向重叠的部分共同形成压电功能区，因此，压电结构3的形变带动其下方的压电段b振动，并同时带动支撑段a振动，支撑段a属于被动被驱动，使得与现有技术中的扬声器相比，本设计可以显著提升MEMS压电扬声器的中高频的声压级，进而提升MEMS压电扬声器的声学性能。
请参阅图1，在本实施例中，基底1可以为具有矩形背腔11的矩形块，振膜2的固定端21可以叠设固定在基底1的四边，固定端21的每一边连接有一个悬置端22，四个悬置端22均与连接端23相连，且四个悬置端22以连接端23为中心等角度间隔环绕设置，每个悬置端22设有一个压电结构3，使得在振膜2受到压电结构3的驱动后的振动更加稳定。应当理解，压电结构3中第一电极层31和压电层32在振膜2上设置方式不同，对应形成的狭缝4的位置也不相同。
请参阅图1、图2以及图3，在本实施例的第一实施方式中，第一电极层31沿MEMS压电扬声器的厚度方向的投影覆盖振膜2的固定端21和悬置端22，压电层32和第二电极层沿MEMS压电扬声器的厚度方向的投影均仅覆盖振膜2的压电段b，狭缝4仅形成于相邻的压电段b之间，各悬置端22相邻的支撑段a之间相互连接形成一体结构作为支撑区连接压电功能区和基底1；柔性膜6设置于电容系统的背离基底1侧，且柔性膜6覆盖振膜2和压电结构3并与基底1间隔设置。
具体的，压电层32和第二电极层33的形状和面积均与压电段b的形状和面积相同，且压电层32和第二电极层33覆盖部分背腔11的上方区域，第一电极层31覆盖整个背腔11的上方区域。第一电极层31和第二电极层33通电后压电结构3会产生形变，带动压电结构3下方悬置端22的压电段b振动，悬置端22的压电段b带动悬置端22的支撑段a振动，使得各支撑段a之间相互连接形成一体结构的支撑区振动，支撑区属于被动被驱动，从而使得支撑区的振动不受压电结构3形变能力的限制，有利于进一步提升振膜2的振动效果，提升MEMS压电扬声器的声学性能。狭缝4共设有四条，狭缝4的一端连通容纳空间24，另一端与基底1的内周缘具有一定距离，此时狭缝4在背腔11内，保证各悬置端22相邻的支撑段a之间相互连接形成一体结构作为支撑区连接压电功能区和基底1。柔性膜6叠设于电容系统背离基底1的一侧，且柔性膜6对应于压电层32和第二电极层33的区域朝电容系统的背离基底1侧凸起形成凹腔，压电层32和第二电极层33位于凹腔内，既能保证柔性膜6可以完全覆盖压电结构3和振膜2，也能保证柔性膜6不会对压电层32和第二电极层33的形变产生干扰。优选地，各压电结构3中的所有第一电极层31连接成一体化设置，各压电结构3中的压电层32和第二电极层33均独立设置，且柔性膜6的中部朝基底1延伸形成块部，块部伸入至压电结构3的中部空间，有利于提升MEMS压电扬声器的声学性能。
请参阅图4、图5以及图6，在本实施例的第二实施方式中，第一电极层31和压电层32沿MEMS压电扬声器的厚度方向的投影均同时覆盖振膜2的固定端21和悬置端22，狭缝4延伸至基底1的内周缘并完全间隔相邻悬置端22；柔性膜6设置于电容系统的背离基底1侧，且柔性膜6覆盖振膜2和压电结构3。
具体的，第一电极层31和压电层32的形状和面积均与振膜2的形状和面积相同，第二电极层33的形状和面积与悬置端22的压电段b的形状和面积相同，此时压电结构3被振膜2的固定端21支撑，可以提升振膜2向压电结构3提供的支撑强度，从而提升压电结构3振动的稳定性，进而保证振膜2振动的稳定性。此外，狭缝4延伸至基底1的内周缘并完全间隔相邻悬置端22，各压电结构3中的第一电极层31、压电层32和第二电极层33连接成一体化设置，柔性膜6的凹腔内未设置矩形块。应当理解，本实施方式中其余方面与第一实施方式相同，在此不进行论述。
请参阅图7、图8以及图9，在本实施例的第三实施方式中，第一电极层31和压电层32沿MEMS压电扬声器的厚度方向的投影均仅覆盖振膜2的压电段b，狭缝4仅形成于相邻的压电段b之间，各悬置端22相邻的支撑段a之间相互连接形成一体结构作为支撑区连接压电功能区和基底1；柔性膜6设置于电容系统的背离基底1侧，且柔性膜6仅覆盖悬置端22的压电段b、容纳空间24和狭缝4。应当理解，本实施方式中其余方面与第二实施方式相同，在此不进行论述。
在本实施例中，柔性膜6的主要材料为压电材料，如PZT（锆钛酸铅压电陶瓷）,高聚物（聚偏氟乙烯和偏氟乙烯一三氟乙烯共聚物等）；压电结构3的主要材料为AlN（氮化铝）、PZT（锆钛酸铅压电陶瓷）和ZnO（氧化锌）等。柔性膜6的杨氏模量小于电容系统的杨氏模量，使得柔性膜6不会对压电结构3的形变产生不利影响；柔性膜6与压电结构3不在同一平面，使得压电功能区的面积不会受到柔性膜6的限制，有利于提升振膜2的有效振动面积，改善扬声器的声学性能；柔性膜6完全覆盖狭缝4，可以封闭气流，使得扬声器不存在漏气区域，保证扬声器的良好声学性能。
请参阅图2、图5以及图8，在本实施例中，连接端23包括连接于各悬置端22的第一连接件231，各悬置端22环绕第一连接件231设置。具体的，第一连接件231可以为圆板，第一连接件231与悬置端22的板面相齐平；由于各悬置端22均连接于第一连接件231，使得各悬置端22的振动频率一致，有利于提升振膜2的振动稳定性；第一连接件231位于容纳空间24的中部，且各悬置端22以第一连接件231为中心等角度间隔环绕设置，使得各悬置端22对称设置，悬置端22在背腔11内的分布更加均衡，有利于提升MEMS压电扬声器的发声效果。根据实际需要，连接端23的形状可以为方形和六边形等；第一连接件231可以由压电结构3组成，可以根据施加到该区域的电压而变形，也可以将压电结构3刻蚀，不受电压驱动，或者由其他材料形成。
请参阅图2、图5以及图8，较佳地，连接端23还包括一端连接于悬置端22且另一端连接于第一连接件231的第二连接件232，每一悬置端22和第一连接件231之间设有至少一个第二连接件232。具体的，第二连接件232可以为连接梁，第二连接件232既能提升第一连接件231和悬置端22的连接强度，也能使第一连接件231和悬置端22之间具有一定的间隙，避免各悬置端22连接于第一连接件231后振动幅度降低。根据实际需要，每一个悬置端22和第一连接件231之间的第二连接件232的数量可以设置多个，如两个或三个等；通过合理设计第二连接件232的形状及大小，如U形梁或S形梁等，可以有效降低器件THD（Total Harmonic Distortion 总谐波失真），提升MEMS压电扬声器的声学性能及可靠性。
请参阅图2、图6以及图8，在本实施例中，MEMS压电扬声器还包括固定于第一连接件231且收容于背腔11的质量块5，质量块5可以降低MEMS压电扬声器的谐振频率，灵活调整MEMS压电扬声器的第一谐振频率，增加可用的发声频率范围和降低器件的THD。优选地，质量块5的材料与基底1的材料相同。根据实际需要，质量块5的形状可以为环形、框架以及其他多边形等。
请参阅图4和图7，在本实施例中，MEMS压电扬声器还包括固定于连接端23远离基底1一侧的连接组件7，连接组件7包括沿MEMS压电扬声器的厚度方向依次叠设的若干子连接件，子连接件包括连接若干压电结构3的第一电极层31的第一子连接件71，连接压电层32的第二子连接件72以及连接第二电极层33的第三子连接件73。具体的，第一子连接件71、第二子连接件72以及第三子连接件73的形状和面积与连接端23的形状和面积相同，保证第一电极层31能够紧密贴合在振膜2上，压电层32紧密贴合在第一电极层31，第二电极层33紧密贴合在压电层32；作为一种实施方式，第一子连接件71与第一电极层31一体成型，第二子连接件72与压电层32一体成型，第三子连接件73与第二电极层33一体成型，减少加工工序。
以上所述的仅是本实用新型的实施方式，在此应当指出，对于本领域的普通技术人员来说，在不脱离本实用新型创造构思的前提下，还可以做出改进，但这些均属于本实用新型的保护范围。

Claims (10)

  1. 一种MEMS压电扬声器，包括具有背腔的基底、固定于所述基底的振膜以及固定于所述振膜远离所述基底一侧的电容系统，所述振膜包括固定于所述基底的固定端、自所述固定端延伸并悬置于所述背腔上方的若干悬置端，相邻所述悬置端之间至少部分间隔设置形成狭缝，若干所述悬置端远离所述固定端的端部间隔形成与所述狭缝连通的容纳空间，其特征在于，所述悬置端包括与所述固定端相连的支撑段和连接于所述支撑段的远离所述固定端侧的压电段，所述电容系统包括与所述悬置端对应的若干压电结构，每一所述压电结构包括依次叠设于所述振膜并至少完全覆盖所述压电段的第一电极层、压电层以及第二电极层，所述第二电极层沿所述MEMS压电扬声器的厚度方向的投影仅覆盖所述振膜的所述压电段，所述第一电极层和所述压电层与所述第二电极层沿所述MEMS压电扬声器厚度方向重叠的部分共同形成压电功能区，所述MEMS压电扬声器还包括设置于所述电容系统远离所述背腔一侧且至少完全覆盖所述狭缝的柔性膜，所述柔性膜与所述振膜位于不同的平面，沿所述MEMS压电扬声器的厚度方向所述柔性膜与所述振膜至少部分间隔设置且所述柔性膜与所述基底间隔设置。
  2. 根据权利要求1所述的MEMS压电扬声器，其特征在于，所述第一电极层和所述压电层沿所述MEMS压电扬声器的厚度方向的投影均仅覆盖所述振膜的所述压电段；或者所述第一电极层和所述压电层沿所述MEMS压电扬声器的厚度方向的投影均同时覆盖所述振膜的所述固定端和所述悬置端；或者所述第一电极层沿所述MEMS压电扬声器的厚度方向的投影覆盖所述振膜的所述固定端和所述悬置端，所述压电层和所述第二电极层沿所述MEMS压电扬声器的厚度方向的投影仅覆盖所述振膜的所述压电段。
  3. 根据权利要求2所述的MEMS压电扬声器，其特征在于，当所述压电层沿所述MEMS压电扬声器的厚度方向的投影仅覆盖所述振膜的所述压电段时，所述狭缝仅形成于相邻的所述压电段之间，各所述悬置端相邻的所述支撑段之间相互连接形成一体结构作为支撑区连接所述压电功能区和所述基底。
  4. 根据权利要求2所述的MEMS压电扬声器，其特征在于，当所述第一电极层和所述压电层沿所述MEMS压电扬声器的厚度方向的投影均同时覆盖所述振膜的所述固定端和所述悬置端时，所述狭缝延伸至所述基底的内周缘并完全间隔相邻所述悬置端。
  5. 根据权利要求1所述的MEMS压电扬声器，其特征在于，所述振膜还包括连接各所述悬置端的连接端，所述连接端收容于所述容纳空间内，所述连接端包括连接于各所述悬置端的第一连接件，各所述悬置端环绕所述第一连接件设置。
  6. 根据权利要求5所述的MEMS压电扬声器，其特征在于，所述连接端还包括一端连接于所述悬置端且另一端连接于所述第一连接件的第二连接件，每一所述悬置端和所述第一连接件之间设有至少一个所述第二连接件。
  7. 根据权利要求5所述的MEMS压电扬声器，其特征在于，所述MEMS压电扬声器还包括固定于所述第一连接件且收容于所述背腔的质量块。
  8. 根据权利要求1所述的MEMS压电扬声器，其特征在于，所述柔性膜的杨氏模量小于所述振膜的杨氏模量。
  9. 根据权利要求5所述的MEMS压电扬声器，其特征在于，所述MEMS压电扬声器还包括固定于所述连接端远离所述基底一侧的连接组件，所述连接组件包括沿所述MEMS压电扬声器的厚度方向依次叠设的若干子连接件，所述子连接件包括连接若干所述压电结构的所述第一电极层的第一子连接件，连接所述压电层的第二子连接件以及连接所述第二电极层的第三子连接件。
  10. 根据权利要求9所述的MEMS压电扬声器，其特征在于，所述第一子连接件与所述第一电极层一体成型，所述第二子连接件与所述压电层一体成型，所述第三子连接件与所述第二电极层一体成型。
PCT/CN2022/106847 2022-06-21 2022-07-20 一种mems压电扬声器 WO2023245789A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202221574278.6 2022-06-21
CN202221574278.6U CN217985406U (zh) 2022-06-21 2022-06-21 一种mems压电扬声器

Publications (1)

Publication Number Publication Date
WO2023245789A1 true WO2023245789A1 (zh) 2023-12-28

Family

ID=84273571

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/106847 WO2023245789A1 (zh) 2022-06-21 2022-07-20 一种mems压电扬声器

Country Status (2)

Country Link
CN (1) CN217985406U (zh)
WO (1) WO2023245789A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117880726A (zh) * 2024-01-15 2024-04-12 山东博华电子科技发展有限公司 微机电系统压电换能器及其制作方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN217693709U (zh) * 2022-06-20 2022-10-28 瑞声开泰科技(武汉)有限公司 Mems扬声器
US20240284119A1 (en) * 2023-02-16 2024-08-22 AAC Technologies Pte. Ltd. Acoustic transducer and method for manufacturing acoustic transducer
CN118540642A (zh) * 2023-02-22 2024-08-23 天津大学 具有应力释放缝隙的mems扬声器

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200177996A1 (en) * 2018-11-30 2020-06-04 Merry Electronics (Shenzhen) Co., Ltd. Speaker
CN113365196A (zh) * 2021-07-05 2021-09-07 瑞声开泰科技(武汉)有限公司 Mems扬声器及mems扬声器制造方法
CN215581695U (zh) * 2021-06-28 2022-01-18 瑞声开泰科技(武汉)有限公司 Mems声传感器
WO2022048810A1 (en) * 2020-09-07 2022-03-10 Pss Belgium Nv Dipole loudspeaker assembly

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200177996A1 (en) * 2018-11-30 2020-06-04 Merry Electronics (Shenzhen) Co., Ltd. Speaker
WO2022048810A1 (en) * 2020-09-07 2022-03-10 Pss Belgium Nv Dipole loudspeaker assembly
CN215581695U (zh) * 2021-06-28 2022-01-18 瑞声开泰科技(武汉)有限公司 Mems声传感器
CN113365196A (zh) * 2021-07-05 2021-09-07 瑞声开泰科技(武汉)有限公司 Mems扬声器及mems扬声器制造方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117880726A (zh) * 2024-01-15 2024-04-12 山东博华电子科技发展有限公司 微机电系统压电换能器及其制作方法

Also Published As

Publication number Publication date
CN217985406U (zh) 2022-12-06

Similar Documents

Publication Publication Date Title
WO2023245789A1 (zh) 一种mems压电扬声器
US20200100033A1 (en) Micromechanical sound transducer
JP5478406B2 (ja) リング状の振動膜を有する圧電型マイクロスピーカ及びその製造方法
CN111294715B (zh) 压电mems麦克风
CN112601169B (zh) 一种宽频带高灵敏度谐振式压电mems麦克风
KR101630353B1 (ko) 질량체를 가진 압전 스피커 및 그 제조 방법
CN109803217B (zh) 压电式麦克风
US20220417671A1 (en) MEMS Acoustic Sensor
CN113365196B (zh) Mems扬声器及mems扬声器制造方法
CN215453273U (zh) 一种麦克风组件及电子设备
WO2023202417A1 (zh) 一种麦克风组件及电子设备
US11950070B2 (en) Sound production device
US20230192473A1 (en) Mems microphone
WO2023130914A1 (zh) 电子设备及声学换能器
EP2369855B1 (en) Electronic device with electret electro-acoustic transducer
WO2024139029A1 (zh) Mems麦克风
WO2021134308A1 (zh) 电容式麦克风
WO2023051372A1 (zh) 扬声器及电子设备
CN211744726U (zh) 一种mems扬声器
KR101495090B1 (ko) 압전 스피커
WO2021134667A1 (zh) 一种mems扬声器
WO2022007016A1 (zh) 一种压电式麦克风及其制备工艺
WO2024138923A1 (zh) Mems麦克风
US20240114795A1 (en) Mems piezoelectric speaker
WO2024065905A1 (zh) Mems 压电扬声器

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22947536

Country of ref document: EP

Kind code of ref document: A1