CN217011187U

CN217011187U - Speaker unit, speaker module and electronic equipment

Info

Publication number: CN217011187U
Application number: CN202122670896.2U
Authority: CN
Inventors: 野村幸治; 吴华; 中野阳介; 李贤胜; 董泳江; 角田直隆; 文晙赫
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-11-03
Filing date: 2021-11-03
Publication date: 2022-07-19
Anticipated expiration: 2031-11-03

Abstract

The application provides a speaker unit, a speaker module and an electronic device. The loudspeaker unit has the double-cantilever structure which is opposite to and spaced from each other by arranging the double-diaphragm actuating structure, so that the actuating performance of the loudspeaker unit is greatly improved, and the output power of the loudspeaker unit can be improved. In addition, the loudspeaker unit of this application still sets up organic membrane, prevents that the acoustic pressure from reducing under the prerequisite that does not influence dual-diaphragm actuating action. Thus, it is advantageous to minimize the size of the speaker unit and maximize the sound pressure in a limited space by the above structural design. Therefore, the speaker unit of the present application can achieve both miniaturization and improvement in output power, and a speaker module and an electronic device including the speaker unit also have the same effects.

Description

Speaker unit, speaker module and electronic equipment

Technical Field

The present application relates to the field of speakers, and in particular, to a speaker unit, a speaker module including the speaker unit, and an electronic device including the speaker module.

Background

In recent years, various electronic devices have been increasingly miniaturized, and speaker modules have become a standard configuration for miniaturized electronic devices having a voice function, such as earphones or hearing aids.

At present, a piezoelectric speaker module is a commonly used speaker module, and is manufactured by using the principle that a piezoelectric material deforms under the action of an electric field. Specifically, a diaphragm comprising a piezoelectric element is placed in an electric field formed by an audio current signal, and the diaphragm is driven to produce sound by utilizing the inverse piezoelectric effect of the piezoelectric element. However, the conventional piezoelectric speaker module is miniaturized and has an adverse effect on output power, so that insufficient sound pressure is generated, and the voice function of electronic equipment is affected. Accordingly, there is a need for a speaker module that can ensure sufficient power while achieving miniaturization.

SUMMERY OF THE UTILITY MODEL

In view of the above, a novel speaker unit is proposed, which can minimize the size and maximize the sound pressure in a limited space, i.e., which can achieve both miniaturization and improvement of output power. A speaker module including the speaker unit and an electronic device including the speaker module are also provided.

Therefore, the following technical scheme is adopted in the application.

In a first aspect, embodiments of the present application provide a speaker unit configured to have a multilayer structure in a thickness direction thereof, the speaker unit including:

a base layer configured to have a bezel structure, the base layer being formed at a central portion thereof with a first through hole penetrating in the thickness direction;

the first diaphragm is arranged on the base layer and is positioned on one side of the base layer in the thickness direction, and the first diaphragm is provided with a first cantilever part extending from the frame structure towards the first through hole;

a second diaphragm disposed on the base layer and located on the one side of the base layer in the thickness direction, the second diaphragm having a second cantilever portion extending from the bezel structure toward the first through hole, the second cantilever portion extending opposite to the first cantilever portion and being spaced apart from the first cantilever portion; and

the organic membrane, the organic membrane set up in first vibrating diaphragm, the second vibrating diaphragm with on the basic unit, the organic membrane totally closed first through-hole.

By adopting the technical scheme, on one hand, the loudspeaker unit has a double-cantilever structure which is opposite to and spaced from each other by arranging the double-diaphragm actuating structure, so that the actuating performance of the loudspeaker unit is greatly improved, and the output power of the loudspeaker unit can be improved; on the other hand, an organic film which completely seals the first through hole is further arranged, so that the sound pressure is prevented from being reduced on the premise of not influencing the actuating action of the double-diaphragm. Thus, it is advantageous to minimize the size of the speaker unit and maximize the sound pressure in a limited space by the above structural design. Therefore, the loudspeaker unit of the present application can both achieve miniaturization and increase output power, and can also meet the performance requirements of active noise reduction.

In one possible embodiment according to the first aspect, the first cantilever portion is formed so as to gradually decrease in width as it extends towards the second cantilever portion, and

the second cantilever portion is formed to have a width gradually decreasing as it extends toward the first cantilever portion.

By adopting the technical scheme, the shapes of the first cantilever part and the second cantilever part are limited, so that the actuating performance of the diaphragm is improved.

In one possible embodiment according to the first aspect, the first cantilever portion and the second cantilever portion are each formed as an isosceles trapezoid.

By adopting the technical scheme, the shapes of the first cantilever part and the second cantilever part are more specifically limited, so that the actuating performance of the diaphragm is further improved.

In one possible embodiment according to the first aspect, there is a reference line in a plane perpendicular to the thickness direction, and the first diaphragm and the second diaphragm are arranged symmetrically with respect to the reference line.

Through adopting above-mentioned technical scheme, through making double diaphragm have the structure of symmetrical arrangement, be favorable to double diaphragm actuating action to keep unanimous to improve the actuating performance of diaphragm and guarantee the tone quality of speaker unit sound production.

In one possible embodiment according to the first aspect, the speaker unit has a symmetrical structure with respect to a reference plane that passes through the reference line and extends in the thickness direction.

By adopting the technical scheme, the structure of the loudspeaker unit is easier to realize, and the loudspeaker unit is beneficial to large-scale industrial production.

In one possible embodiment according to the first aspect, the organic film is made of polyimide, and the first diaphragm and the second diaphragm include layers made of a single-crystal piezoelectric ceramic material.

By adopting the technical scheme, the preferable manufacturing materials of the organic film and the vibrating diaphragm are provided, and the power consumption of the loudspeaker unit can be reduced and the long-endurance performance can be realized by utilizing the single-crystal piezoelectric ceramic material.

In a second aspect, an embodiment of the present application provides a speaker module including a speaker unit according to any one of the above technical solutions and a shield cover fixed to the speaker unit.

Through adopting above-mentioned technical scheme, under the condition of being integrated as a module with speaker unit and shield cover, the shield cover can play the shielding effect in order to guarantee the sound production effect of the speaker unit in the speaker module, provides the protection to the speaker unit simultaneously.

In one possible embodiment according to the second aspect, one of the speaker units corresponds to one of the shield shells, the shield shell is fixed to a circuit substrate of the speaker unit, and the shield shell covers the speaker unit from one side in a thickness direction of the speaker unit.

Through adopting above-mentioned technical scheme, through adopting above-mentioned scheme, when being convenient for realize that the installation between shield cover and the speaker unit is fixed, guarantee that the shield cover can exert its due shielding and guard action.

In one possible embodiment according to the second aspect, the speaker module comprises a plurality of the speaker units, the plurality of the speaker units being arranged in pairs,

in a pair of speaker units, circuit substrates of the two speaker units are fixed to each other so that the two speaker units surround to form a cavity, and a hole is formed between the circuit substrates of the two speaker units, the hole communicating the cavity with the outside of the speaker module.

Through adopting above-mentioned technical scheme, through pair pile speaker unit in speaker module, can improve speaker module's output to improve tone quality.

In one possible embodiment according to the second aspect, in the pair of speaker units, each of the speaker units forms a sound outlet with the corresponding shield.

By adopting the above technical solution, the structure for guiding sound emission is constructed with a simple structure.

In a possible embodiment according to the second aspect, in any cross-section of the loudspeaker module, a straight-line distance between any two points on the cross-sectional contour line is not more than 3 mm.

Through adopting above-mentioned technical scheme, guarantee that the size of speaker module is enough little to miniaturized electronic equipment such as adaptation earphone or audiphone.

In a third aspect, an embodiment of the present application provides an electronic device, where the electronic device includes the speaker module according to any one of the above technical aspects.

Through adopting above-mentioned technical scheme, a speaker module's application for field has been injectd.

In one possible embodiment according to the third aspect, the electronic device is an earphone or a hearing aid.

Through adopting above-mentioned technical scheme, limited the suitable application scene of speaker module.

These and other aspects of the present application will be more readily apparent from the following description of the embodiment(s).

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments, features, and aspects of the application and, together with the description, serve to explain the principles of the application.

Fig. 1A is a schematic perspective view showing a structure of a speaker unit according to an embodiment of the present application.

Fig. 1B is another perspective view showing the structure of the speaker unit in fig. 1A.

Fig. 1C is a schematic sectional view showing the structure of the speaker unit in fig. 1A.

Fig. 2A to 2I are schematic views for explaining a manufacturing process of the speaker unit in fig. 1A.

Fig. 3A is a perspective view illustrating a speaker module according to the present application, which includes speaker units as shown in fig. 1A arranged in pairs.

Fig. 3B is another perspective view illustrating the speaker module of fig. 3A.

Fig. 3C is a schematic sectional view showing the speaker module in fig. 3A.

Fig. 3D is another cross-sectional schematic view illustrating the speaker module of fig. 3A.

Fig. 4 is a schematic cross-sectional view showing an electronic device according to the present application, including the speaker module shown in fig. 3A.

Description of the reference numerals

SU loudspeaker unit 1 base layer 2 first diaphragm 21 first cantilever part 3 second diaphragm 31 second cantilever part 4 organic film 5 circuit substrate L datum line

L1 first electrode layer L2 piezoelectric layer L3 second electrode layer L4 first silicon base layer L5 silicon oxide base layer L6 second silicon base layer L7 passivation layer MC metal contact T thickness direction

The SM speaker module SH shielding cover H1 sound outlet H2 hole P goes out the sound channel.

Detailed Description

Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

In addition, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present application. It will be understood by those skilled in the art that the present application may be practiced without some of these specific details. In some instances, methods, means, elements well known to those skilled in the art have not been described in detail so as not to obscure the present application.

In the present application, unless otherwise specified, "thickness direction" refers to the thickness direction of the speaker unit according to the present application, and "one side in the thickness direction" refers to the upper side in fig. 2A to 2I.

The technical idea of the present application is explained below. The speaker unit of this application includes basic unit, first vibrating diaphragm, second vibrating diaphragm and the organic membrane of integration together. The double vibrating diaphragms are arranged on the base layer and located on one side of the base layer in the thickness direction, and parts of the double vibrating diaphragms extend into the first through holes of the frame structure of the base layer to form double cantilever portions which are opposite to each other and spaced. In addition, the organic film is disposed on the dual diaphragm and the base layer, and completely closes the first through hole. Therefore, the double-diaphragm actuating structure is arranged, so that the actuating performance is improved, and the output power of the loudspeaker unit is improved; the organic film completely seals the first through hole, and sound pressure is prevented from being reduced on the premise of not influencing the actuating action of the double vibrating diaphragms.

A speaker unit according to an embodiment of the present application is explained below.

As shown in fig. 1A to 1C, the speaker unit SU according to an embodiment of the present application is configured to have a multilayer structure in its thickness direction T. The speaker unit SU includes a base 1, a first diaphragm 2, a second diaphragm 3, an organic film 4, and a circuit substrate 5 which are integrated together.

In the present embodiment, as shown in fig. 1A to 1C, the base layer 1 is configured to have a frame structure. The frame has four sides extending in a straight line, and the four sides are connected end to end in sequence, so that a rectangular frame structure is formed. With this frame structure, the base layer 1 is formed at its central portion with a first through hole penetrating in the thickness direction T.

In this embodiment, as shown in fig. 1A to 1C, the first diaphragm 2 is disposed on the frame structure of the base layer 1 and is located on one side of the base layer 1 in the thickness direction T. The first diaphragm 2 has a first cantilever portion 21 that protrudes from the frame structure toward the first through hole. The second diaphragm 3 is disposed on the frame structure of the base layer 1 and located on one side of the base layer 1 in the thickness direction T, and the second diaphragm 3 includes a second cantilever portion 31 extending from the frame structure toward the first through hole. The second cantilever portions 31 extend opposite to and spaced apart from the first cantilever portion 21. In a plan view seen in the thickness direction T, the first cantilever portion 21 and the second cantilever portion 31 are each formed in an isosceles trapezoid shape such that the first cantilever portion 21 is formed to gradually decrease in width as it extends toward the second cantilever portion 31 and the second cantilever portion 31 is formed to gradually decrease in width as it extends toward the first cantilever portion 21. It is understood that the longer bases of the isosceles trapezoids of the first cantilever portion 21 and the second cantilever portion 31 are connected to the frame structure of the substrate 1, and the shorter bases of the isosceles trapezoids of the first cantilever portion 21 and the second cantilever portion 31 are parallel to and opposite to each other. The

cantilever portions

21, 31 having the above-described specific shapes can greatly improve the actuation performance of the speaker unit SU because one end is suspended.

In this embodiment, as shown in fig. 1A to 1C, the organic film 4 is disposed on the first diaphragm 2, the second diaphragm 3 and the base layer 1, and the organic film 4 is mainly located on one side of the first diaphragm 2 and the second diaphragm 3 in the thickness direction T. The organic film 4 completely closes the first through hole so that the speaker unit SU forms a so-called "seamless" configuration, that is, both sides in the thickness direction of the speaker unit SU are not communicated.

In this embodiment, as shown in fig. 1A to 1C, the circuit board 5 is electrically connected to the first diaphragm 2 and the second diaphragm 3, and can control the first diaphragm 2 and the second diaphragm 3 to perform an actuating action by using a reverse piezoelectric effect to generate sound. The circuit substrate 5 is configured to have a frame structure having four linearly extending sides that are sequentially connected end to end, thereby constituting a rectangular-shaped frame structure. With this frame structure, the circuit board 5 is formed with a second through hole penetrating in the thickness direction T in the central portion thereof. The base layer 1 is provided on the circuit substrate 5 and is located on one side of the circuit substrate 5 in the thickness direction T. After the base layer 1 and the circuit substrate 5 are mounted in place, the first through hole communicates with the second through hole. It is understood that the speaker unit SU cannot be conducted on both sides in the thickness direction through the first through hole and the second through hole due to the presence of the organic film 4.

The following describes a manufacturing process of the speaker unit SU described above with reference to the drawings of the specification.

The first diaphragm 2 and the second diaphragm 3 were prepared based on the electrode layers L1, L3 and the piezoelectric layer L2 provided on the base layer 1 (including the first silicon base layer L4, the silicon oxide base layer L5 and the second silicon base layer L6). First, a multilayer structure as shown in fig. 2A, which includes, in order from one side toward the other side in the thickness direction T, a first electrode layer L1 (which may also be referred to as a top electrode layer, which may be made of platinum or titanium), a piezoelectric layer L2 (which may be made of a single-crystal piezoelectric ceramic, and may be about 2 μm to 4 μm thick), and a second electrode layer L3 (which may also be referred to as a bottom electrode layer, and may be made of platinum or titanium), a first silicon-based layer L4 (which is made of silicon and is about 8 μm thick), a silicon oxide layer (which is made of silicon dioxide and is about 1 μm thick), and a second silicon-based layer L6 (which is made of silicon and is about 600 μm thick), may be produced by a radio frequency magnetron Sputtering method (RF Sputtering) or a Sol-Gel deposition method. Subsequently, based on the multilayer structure shown in fig. 2A, a device shape can be made mainly by patterning by a mask etching process, thereby manufacturing a speaker unit SU having a complete MEMS (Micro-Electro-Mechanical System, which may also be referred to as a Micro Electro Mechanical System). The mask etching process can obtain layers having different patterns on the multi-layered structure shown in fig. 2A by etching using different masks, eight masks being required in the entire manufacturing process for manufacturing the speaker unit SU.

Specifically, based on the multilayer structure shown in fig. 2A, the shape of the first electrode layer L1 is processed using a first mask, and a part of the structure of the first electrode layer L1 is removed to form a structure shown in fig. 2B.

Further, the shape of the piezoelectric layer L2 is processed using a second mask, and a part of the structure of the piezoelectric layer L2 is removed to form a structure shown in fig. 2C.

Further, the shape of the second electrode layer L3 is processed by using a third mask, and a part of the structure of the second electrode layer L3 is removed, so as to form the structure shown in fig. 2D.

Further, a passivation layer L7 is formed using a fourth mask, and a passivation layer L7 is mainly formed on one side of the first electrode layer L1 in the thickness direction T to form the structure shown in fig. 2E. The passivation layer L7 may be made of iridium, iridium dioxide, or iridium oxide.

Further, a metal contact MC is formed using a fifth mask, and the metal contact MC is electrically connected to the first electrode layer L1 and the second electrode layer L3 and penetrates through the passivation layer L7 to form the structure shown in fig. 2F.

Further, the passivation layer L7 and the first silicon base layer L4 were processed using a sixth mask, and a portion of the structure of the passivation layer L7 and the first silicon base layer L4 was removed to form the structure shown in fig. 2G.

Further, the organic film 4 is formed using a seventh mask and may be formed by a spin coating process, the organic film 4 being mainly located on one side of the passivation layer L7 in the thickness direction T to form the structure shown in fig. 2H. The organic film 4 may be made of polyimide.

Further, the silicon oxide based layer L5 and the second silicon based layer L6 were processed using an eighth mask, and a part of the structures of the silicon oxide based layer L5 and the second silicon based layer L6 were removed to form the structure shown in fig. 2I.

Finally, the structure shown in fig. 2I may be fixed to the circuit substrate 5 by a dispensing process, and then electrically connected (signal conduction) to the circuit substrate 5 through a connecting wire, thereby manufacturing the speaker unit SU according to the present application.

In the speaker unit SU produced through the above processing steps, the second diaphragm 3 has the same multilayer structure as the first diaphragm 2 in the thickness direction T, and the multilayer structure of the

diaphragms

2, 3 in the thickness direction T will be described below by taking the first diaphragm 2 as an example. As shown in fig. 2I, the first diaphragm 2 includes a first electrode layer L1, a piezoelectric layer L2, and a second electrode layer L3, which are stacked in the thickness direction T. The piezoelectric layer L2 is located between the first electrode layer L1 and the second electrode layer L3, and the second electrode layer L3 is directly disposed on the base layer 1. Further, as shown in fig. 2I, the passivation layer L7 is mainly disposed on the first electrode layer L1, and the passivation layer L7 is located on one side of the first electrode layer L1 in the thickness direction T. Different metal contacts MC are connected to the first electrode layer L1 and the second electrode layer L3, respectively, each of which penetrates the passivation layer L7 and is partially located on one side of the passivation layer L7 in the thickness direction T. In addition, as shown in fig. 1A, there is a reference line L in a plane perpendicular to the thickness direction T, the reference line L being parallel to the bases of the trapezoidal shapes of the two

diaphragms

2, 3, and not only the first diaphragm 2 and the second diaphragm 3 are arranged symmetrically with respect to the reference line L, but also the speaker unit SU has a structure that is mirror-symmetrical with respect to a reference plane that passes through the reference line L and extends in the thickness direction T.

Thus, on the one hand, by providing the dual diaphragm actuating structure such that the speaker units SU have the dual cantilever configuration opposed to and spaced apart from each other, the output power of the speaker units SU can be increased; on the other hand, by providing the organic film 4 that completely closes the first through hole, the sound pressure is prevented from being reduced without affecting the actuation action of the dual diaphragm. Thus, it is advantageous to minimize the size of the speaker unit SU and maximize the sound pressure in a limited space by the above structural design. Therefore, the speaker unit SU of the present application can achieve both miniaturization and improvement of output power, and can satisfy the performance requirement of active noise reduction.

In the present application, the structure of the speaker module SM according to the present application can be constructed by realizing a modular structure using the above-described speaker unit SU and the shield cover SH.

As shown in fig. 3A to 3D, the speaker module SM according to the present application includes two speaker units SU arranged in pairs. One speaker unit SU corresponds to one shield cover SH, and the shield cover SH is fixed to the circuit board 5 of the speaker unit SU. The shield case SH bulges toward one side in the thickness direction T of the corresponding speaker unit SU to cover the base layer 1, the first diaphragm 2, the second diaphragm 3, and the organic film 4 of the speaker unit SU. Thus, the shield SH can ensure the sound-producing effect of the speaker unit SU in the speaker module SM, while providing protection to the speaker unit SU.

In this speaker module SM, as shown in fig. 3A and 3B, the circuit substrates 5 of the two speaker units SU of the speaker units SU arranged in pairs are fixed to each other so that the two speaker units SU surround to form a cavity, and the connection portion between the circuit substrates 5 of the two speaker units SU is separately provided with a hole H2 that communicates the cavity with the outside of the speaker module SM, the hole H2 allowing air to circulate between the cavity and the outside of the speaker module SM during actuation of the two diaphragms. The axially one-side end wall of the shield SH also forms a sound outlet H1 with the corresponding speaker unit SU, and the sound outlet H1 and the above-mentioned hole H2 are located on both sides of the entire speaker module SM. The sound outlet H1 is not in communication with the cavity formed between the two speaker units SU, but rather in communication with the side of the corresponding speaker unit SU facing away from the cavity. The sound outlet H1 allows the sound of the two speaker units SU to be transmitted out through the sound outlet H1. Since the speaker module SM encapsulates the paired speaker units SU, the sound quality of sound can be ensured.

In order to be able to install the speaker module SM having the above-described structure into a miniaturized electronic apparatus, in any cross section of the speaker module SM according to the present application, a straight-line distance between any two points on a cross-sectional contour line is not more than 3mm, thus ensuring that the size of the speaker module SM is small enough to fit into a miniaturized electronic apparatus such as an earphone or a hearing aid.

The speaker module SM according to this application can be applied to various electronic equipment for electronic equipment has the speech function. In particular, the electronic device may be an earphone or a hearing aid or the like. As shown in fig. 4, the speaker module SM according to the present application is housed in the sound outlet channel P of the electronic device (e.g., a headphone), so that the speaker module SM can emit sound through the sound outlet channel P. Since the speaker module SM has a very small size, it can be integrated into subminiaturized electronic devices, which is advantageous for ensuring the wearing comfort of the subminiaturized electronic devices.

The foregoing has outlined exemplary embodiments of the detailed description of the present application and related modifications, as well as additional descriptions that follow.

i. It is to be understood that the speaker module SM according to the present application is not limited to including a pair of speaker units SU, and a plurality of pairs of speaker units SU may be provided in one speaker module SM. The loudspeaker module SM with the loudspeaker units SU arranged in pairs covers a very wide audio band and simplifies the assembly requirements compared to existing loudspeaker modules.

In fact, only one speaker unit SU and the corresponding shield cover SH may be provided in the speaker module SM of the present application. That is, the number of the speaker units SU in the speaker module SM according to the present application can be appropriately adjusted as needed.

The dielectric constant of the common polycrystalline piezoceramic material is about 1500, while the dielectric constant of the single-crystal piezoceramic material can reach below 500, and by enabling the piezoelectric layer L2 of the

diaphragms

2 and 3 of the loudspeaker unit SU according to the application to comprise the single-crystal piezoceramic material with the lower dielectric constant, the overall input capacitance of the loudspeaker module SM can be controlled below 30nF @20kHz, so that the power consumption of the loudspeaker unit SU is reduced, and the long-endurance performance can be realized. The single-crystal piezoelectric ceramic material may be a lead zirconate titanate-based piezoelectric ceramic material.

The loudspeaker unit SU according to the present application is capable of enabling full frequency applications covering commonly used wireless headsets and may reach a sound pressure level of 120dB @20 kHz.

While the present application has been described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The foregoing description of the embodiments of the present application has been presented for purposes of illustration and description and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A speaker unit characterized by being configured to have a multilayer structure in a thickness direction thereof, comprising:

and the organic film is arranged on the first vibrating diaphragm, the second vibrating diaphragm and the base layer, and the organic film completely seals the first through hole.

2. The speaker unit of claim 1,

the first cantilever portion is formed to have a width gradually reduced in a process of extending toward the second cantilever portion, and

3. The speaker unit of claim 2, wherein the first cantilever portion and the second cantilever portion are each formed as an isosceles trapezoid.

4. The speaker unit according to any one of claims 1 to 3, wherein there is a reference line in a plane perpendicular to the thickness direction, and the first diaphragm and the second diaphragm are arranged symmetrically with respect to the reference line.

5. The speaker unit according to claim 4, wherein the speaker unit has a symmetrical structure with respect to a reference plane that passes through the reference line and extends in the thickness direction.

6. A loudspeaker unit according to any one of claims 1 to 3, wherein the organic membrane is made of polyimide, and the first diaphragm and the second diaphragm comprise layers made of a single-crystal piezoceramic material.

7. A loudspeaker module comprising a speaker unit according to any one of claims 1 to 6 and a shield cover, the shield cover being secured to the speaker unit.

8. The speaker module according to claim 7, wherein one of the speaker units corresponds to one of the shield shells, the shield shell is fixed to a circuit substrate of the speaker unit, and the shield shell covers the speaker unit from one side in a thickness direction of the speaker unit.

9. The speaker module as claimed in claim 8, wherein the speaker module comprises a plurality of the speaker units, the plurality of speaker units being arranged in pairs,

10. A loudspeaker module according to claim 9, wherein in the pair of loudspeaker units, each loudspeaker unit forms a sound outlet with the corresponding shield.

11. A loudspeaker module according to any one of claims 7 to 10, wherein in any cross-section of the loudspeaker module, the straight line distance between any two points on the cross-sectional profile is no greater than 3 mm.

12. An electronic device characterized in that the electronic device comprises the speaker module of any one of claims 7 to 11.

13. The electronic device of claim 12, wherein the electronic device is an earphone or a hearing aid.