Piezoelectric modules and electronic devices

Abstract

The present application discloses a piezoelectric module and an electronic device, belonging to the field of piezoelectric technology. The piezoelectric module is used to drive the driven surface to move, and the piezoelectric module includes a piezoelectric layer, an intermediate layer, and a driving trace. Among them, the intermediate layer is located between the piezoelectric layer and the driven surface, and the intermediate layer is used to fix the piezoelectric layer to the driven surface. The driving trace is electrically connected to the piezoelectric layer, and the driving trace is used to receive an input signal and drive the piezoelectric layer to move. In the piezoelectric module, the driving trace is located in the accommodation space of the intermediate layer, which can achieve the thinning of the piezoelectric module.

Description

Technical Field

[0001] The present application belongs to the field of piezoelectric technology, and in particular relates to a piezoelectric module and an electronic device. Background Art

[0002] A piezoelectric module is a device that uses the inverse piezoelectric effect to produce mechanical deformation under the action of an electric field, thereby generating linear motion. It is widely used in electronic devices (such as mobile phones). For example, it is used as the sound-emitting component of a mobile phone, producing sound by vibrating in the mobile phone.

[0003] Certain usage scenarios of piezoelectric modules have requirements on the thickness of the piezoelectric modules. For example, piezoelectric modules stacked in the thickness direction of an electronic device will occupy the space of the electronic device in the thickness direction. This makes the thickness of the piezoelectric module affect the thickness of the electronic device. In electronic devices that pursue ultra-thin size, excessive thickness of the piezoelectric module will make the thickness of the electronic device too large, thereby failing to meet the thickness requirements. Therefore, the thickness of the electronic device can be reduced by reducing the thickness of the piezoelectric module. Based on this, a solution for thinning the piezoelectric module is urgently needed. Summary of the invention

[0004] The present application provides a piezoelectric module and an electronic device, which can achieve thinning of the piezoelectric module while retaining the function of the piezoelectric module.

[0005] In a first aspect, an embodiment of the present application provides a piezoelectric module for driving a driven surface to move. The piezoelectric module includes a piezoelectric layer, an intermediate layer, and a driving trace. The driving trace is electrically connected to the piezoelectric layer. The driving trace is located in the accommodation space of the intermediate layer. The intermediate layer is located between the piezoelectric layer and the driven surface of the electronic device, and the intermediate layer is used to fix the piezoelectric layer to the driven surface. The driving trace is used to receive an input signal and drive the piezoelectric layer to move.

[0006] It should be understood that the piezoelectric layer is a component in the piezoelectric module that is used to convert the input signal into mechanical motion (such as mechanical vibration). In order to use the piezoelectric layer to drive the driven surface to move, it is necessary to set an intermediate layer between the piezoelectric layer and the driven surface, and use the intermediate layer to fix the piezoelectric layer to the driven surface. It can be seen that in order to use the piezoelectric module to drive the driven surface to move, the setting of the intermediate layer is necessary and inevitable. The setting of the intermediate layer itself will occupy the space in the thickness direction of the piezoelectric module. In this embodiment, the drive wiring is located in the accommodation space opened in the intermediate layer, and the space occupied by the intermediate layer in the thickness direction of the piezoelectric module is reused. Therefore, the drive wiring does not occupy additional space in the thickness direction of the piezoelectric module.

[0007] In the related art, the driving wire, the piezoelectric layer and the middle layer are stacked, and the driving wire will occupy additional space in the thickness direction of the piezoelectric module. Obviously, compared with the location setting of the driving wire in the related art, this embodiment sets the driving wire in the accommodation space of the middle layer so that it does not occupy additional space in the thickness direction of the piezoelectric module, thereby achieving the purpose of reducing the thickness of the piezoelectric module.

[0008] Optionally, the drive line extends through the accommodation space toward the direction of the side of the middle layer, and bends and extends toward the piezoelectric layer on the side of the middle layer. The drive line includes a first area, a second area, and a third area. The first area is the portion of the drive line located in the accommodation space; the second area is the portion of the drive line located on the side of the middle layer; the third area is the portion of the drive line located on the side of the piezoelectric layer; the drive line is electrically connected to the side of the piezoelectric layer through the third area.

[0009] It should be noted that the piezoelectric layer has a first surface and a second surface that are arranged opposite to each other along the thickness direction of the piezoelectric module, and the side surface of the piezoelectric layer is a surface sandwiched between the first surface and the second surface of the piezoelectric layer, and the side surface usually extends along the thickness direction of the piezoelectric module. The thickness direction of the piezoelectric module can be understood as the movement direction of the piezoelectric module (such as the vibration direction), which is also the movement direction of the piezoelectric layer.

[0010] In this embodiment, the first area of ​​the driving line is located in the accommodating space. According to the content of the previous embodiment, the first area reuses the space occupied by the intermediate layer in the thickness direction of the piezoelectric module, and does not occupy additional space in the thickness direction of the piezoelectric module. The second area of ​​the driving line is located on the side of the intermediate layer. The second area also reuses the space occupied by the intermediate layer in the thickness direction of the piezoelectric module, and does not occupy additional space in the thickness direction of the piezoelectric module. The third area of ​​the driving line is located on the side facing the side of the piezoelectric layer. It should be understood that in order to use the piezoelectric module to drive the driven surface to move, the provision of the piezoelectric layer is also necessary and inevitable. The provision of the piezoelectric layer itself will occupy the space in the thickness direction of the piezoelectric module. Therefore, the third area of ​​the driving line reuses the space occupied by the piezoelectric layer in the thickness direction of the piezoelectric module, and does not occupy additional space in the thickness direction of the piezoelectric module.

[0011] It should be understood that in this embodiment, the drive line is electrically connected to the side of the piezoelectric layer after passing through the accommodation space of the middle layer. In this case, the structure for realizing the electrical connection between the drive line and the piezoelectric layer is also located on the side of the piezoelectric layer. Therefore, the space occupied by the structure for electrically connecting the drive line and the second surface of the piezoelectric layer in the thickness direction of the piezoelectric module can be saved. Moreover, in this embodiment, the drive line is electrically connected to the side of the piezoelectric layer after passing through the accommodation space of the middle layer. The accommodation space of the middle layer is conducive to preventing the movement of the drive line, thereby reducing the risk of the position where the drive line is electrically connected to the piezoelectric layer falling off, which is conducive to the connection reliability of the drive line.

[0012] In some embodiments of the present application, the intermediate layer includes a support layer, a first fixed layer, and a second fixed layer. The support layer is located between the piezoelectric layer and the driven surface, and is used to support the piezoelectric layer. The support layer is fixed to the driven surface through the second fixed layer, and the support layer is connected to the piezoelectric layer through the first fixed layer, so that the piezoelectric layer is fixed to the driven surface. In this embodiment, by providing the support layer in the intermediate layer, the risk of the piezoelectric layer breaking can be reduced and the crack resistance of the piezoelectric layer can be improved.

[0013] Optionally, the first fixed layer has a storage space. In this embodiment, the drive line is located in the storage space provided by the first fixed layer, reusing the space occupied by the first fixed layer in the thickness direction, thereby not occupying additional space of the piezoelectric module in the thickness direction, thereby achieving thinning of the piezoelectric module.

[0014] Optionally, both the first fixed layer and the support layer are provided with a receiving space. In this embodiment, the drive line is located in the receiving space provided by the first fixed layer and the support layer, and the space occupied by the first fixed layer and the support layer in the thickness direction is reused, so that no additional space in the thickness direction of the piezoelectric module is occupied, thereby achieving the thinning of the piezoelectric module.

[0015] Optionally, the first fixed layer, the support layer, and the second fixed layer are all provided with accommodation spaces. In this embodiment, the drive wiring is located in the accommodation spaces provided by the first fixed layer, the support layer, and the second fixed layer, and the space occupied by the first fixed layer, the support layer, and the second fixed layer in the thickness direction is reused, so that no additional space in the thickness direction of the piezoelectric module is occupied, thereby achieving the thinning of the piezoelectric module.

[0016] In the above-mentioned embodiments, the driving wiring located in the accommodation space may be a flexible printed circuit (FPC) or a printed wiring, such as a metal wiring.

[0017] Exemplarily, the drive line can be printed on a partial area of ​​the first surface of the support layer, and the first fixed layer is located on the remaining partial area of ​​the first surface of the support layer. The first surface of the support layer is the side of the support layer facing the piezoelectric layer. The accommodation space is opened at the position corresponding to the partial area of ​​the first fixed layer, so that the drive line can be accommodated in the accommodation space opened by the first fixed layer, so that the space occupied by the first fixed layer in the thickness direction can be reused.

[0018] In this example, the drive line is printed on a partial area of ​​the first surface of the support layer, and the first fixed layer is located on the remaining area of ​​the first surface of the support layer. It can be seen that the area occupied by the drive line and the area occupied by the first fixed layer do not overlap, and the first fixed layer completely avoids the drive line. In this way, the drive line can be located on the same layer as the first fixed layer, thereby reusing the space occupied by the first fixed layer in the thickness direction, so as not to occupy additional space in the thickness direction of the piezoelectric module, thereby achieving thinning of the piezoelectric module. Moreover, in this example, the drive line is attached to the hard attachment surface of the first surface of the support layer. Compared with the solution of attaching it to the soft attachment surface, it is not easy to be impacted and broken under the action of external force, thereby improving the reliability of the piezoelectric module.

[0019] In some other embodiments of the present application, the middle layer is a first fixed layer, and the piezoelectric layer is fixed to the driven surface through the first fixed layer. The first fixed layer is provided with a storage space. In this embodiment, the drive wiring is located in the storage space provided by the first fixed layer, and the space occupied by the first fixed layer in the thickness direction is reused, so that the space of the piezoelectric module in the thickness direction is not additionally occupied, thereby achieving the thinning of the piezoelectric module.

[0020] In some other embodiments of the present application, the intermediate layer includes a supporting layer and a second fixed layer; the supporting layer is used to support the piezoelectric layer; and the supporting layer is fixed to the driven surface through the second fixed layer. In this case, the accommodation space of the intermediate layer is the side to which the first surface of the supporting layer faces. The driving trace is printed on the first surface of the supporting layer, and is located in the accommodation space of the intermediate layer. The piezoelectric layer is fixedly connected to the driven surface through the driving trace; the first surface of the supporting layer is the side of the supporting layer facing the piezoelectric layer.

[0021] In this embodiment, the driving wiring is used to fix the piezoelectric layer and realize the electrical connection with the piezoelectric layer. It should be noted that the use of other structures (such as the aforementioned first fixed layer) to fix the piezoelectric layer itself needs to occupy a certain space in the thickness direction of the piezoelectric module. Obviously, in this embodiment, the driving wiring originally used for electrical connection with the piezoelectric layer is reused to fix the piezoelectric layer, and the driving wiring only occupies the space originally occupied by other structures used to fix the piezoelectric layer in the thickness direction, and does not occupy additional space in the thickness direction of the piezoelectric module, thereby achieving thinning of the piezoelectric module.

[0022] The piezoelectric module reuses the driving wiring, which, on the one hand, saves the cost of fixing the piezoelectric layer by using other structures; on the other hand, by welding the driving wiring and the piezoelectric layer in one step, the fixing function and electrical connection function that originally required multiple steps to complete are achieved, thereby improving the processing efficiency.

[0023] In addition, in this embodiment, by providing a support layer in the middle layer, the risk of the piezoelectric layer breaking can be reduced and the crack resistance of the piezoelectric layer can be improved. Moreover, the provision of the support layer provides a hard attachment surface for the drive wiring, which is less likely to be impacted and broken under the action of external forces compared to the solution of attaching to a soft attachment surface, thereby improving the reliability of the piezoelectric module.

[0024] It should be noted that in the above embodiments, the driving wiring can be printed on the first surface of the support surface by using surface mounted technology (SMT), and the electrical connection process has a higher assembly efficiency.

[0025] In other embodiments of the present application, when the material of the support layer is a metal material, the first surface of the support layer has an insulating layer, and the insulating layer is located between the driving trace and the first surface of the support layer. In other words, the driving trace is printed on the insulating layer provided on the first surface of the support layer. In this case, the current of the metal trace is insulated by the insulating layer and cannot flow to the support layer, thereby improving the current driving capability of the piezoelectric layer and improving the reliability of the line connection.

[0026] In some other embodiments of the present application, the piezoelectric layer includes a plurality of piezoelectric units, each of which is electrically connected to the driving wiring layer. The plurality of piezoelectric units are distributed in an array, and the plurality of piezoelectric units are in the same plane in a static state.

[0027] It should be noted that the piezoelectric unit here can be regarded as an independent piezoelectric element, which can move independently under the drive of the input signal. Therefore, multiple piezoelectric units can move under the drive of the same or different input signals to meet the operating requirements of different usage scenarios. Here, the audio output scenario is used as an example. The frequency of the piezoelectric unit vibration is related to the frequency of the input signal that drives its vibration, the amplitude of the vibration is related to the amplitude of the input signal that drives its vibration, and the phase of the vibration is related to the phase of the input signal that drives its vibration. Therefore, the vibration generated by the piezoelectric unit is related to the frequency, amplitude, and phase of the input signal that drives its vibration. It should be understood that the vibration of the piezoelectric unit driven by the same input signal (frequency, amplitude, and phase are all the same) is synchronized, and the sound waves generated by different piezoelectric units are the same due to the same phase, so that the amplitude of the synthesized sound waves is enhanced, thereby increasing the driving ability of the piezoelectric module. The vibration of the piezoelectric unit driven by different input signals (such as any one or more of the frequency, amplitude, and phase are different) is not synchronized, so that a rich vibration state can be generated to serve the vibration needs in different scenarios. For example, the vibration frequencies of the piezoelectric units driven by input signals of different frequencies are different, which makes the synthesized sound waves contain multiple frequency components, thus producing rich audio effects.

[0028] In this embodiment, the piezoelectric layer is split into a plurality of piezoelectric units spaced apart in the same plane. It should be understood that, compared with a large, intact, unsplit piezoelectric layer, the area of ​​a single piezoelectric unit (the area of ​​the orthographic projection in the thickness direction) is smaller when the piezoelectric layer is split into a plurality of piezoelectric units. The smaller the area of ​​the piezoelectric unit, the less likely the piezoelectric unit is to break, that is, the risk of the piezoelectric unit breaking is lower; and, the easier it is to control the flatness of the piezoelectric unit during the production process, the higher the process yield of the piezoelectric unit. In this way, the crack resistance of the piezoelectric layer can be improved, and the flatness can be improved (that is, the flatness is reduced).

[0029] In a second aspect, an embodiment of the present application provides an electronic device. The electronic device includes a piezoelectric module as in the first aspect and any possible design thereof, and also includes a driven surface. Exemplarily, the driven surface may be the back of the display screen or the back of the rear shell of the electronic device. The back of the display screen of the electronic device refers to a surface arranged opposite to the display surface of the display screen, such as the surface of the touch screen close to the rear shell. The rear shell of the electronic device refers to a shell used for protection and decoration in the electronic device, which is arranged opposite to the display screen and can be seen or touched by the user in daily use. The back of the rear shell refers to a surface arranged opposite to the appearance surface of the rear shell (the surface that the user can see or touch in daily use), such as the surface of the rear shell facing the touch screen. Among them, the piezoelectric module is used to receive an input signal and move under the drive of the input signal. The driven surface is fixed to the piezoelectric module and is used to move under the drive of the piezoelectric module.

[0030] It can be understood that the beneficial effects that can be achieved by the technical solution of the second aspect can refer to the beneficial effects of the electronic device in the first aspect and any possible design thereof, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0032] Figure 2 for Figure 1 A schematic diagram of the exploded structure of the electronic device shown;

[0033] Figure 3 A schematic diagram of the structure of a piezoelectric module provided in an embodiment of the present application;

[0034] Figure 4 A cross-sectional schematic diagram of a piezoelectric module provided in an embodiment of the present application;

[0035] Figure 5 for Figure 4 A bottom view of the piezoelectric module shown;

[0036] Figure 6 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application;

[0037] Figure 7 A schematic diagram of a piezoelectric layer fracture and warping provided in an embodiment of the present application;

[0038] Figure 8 A schematic diagram of a planar structure of a piezoelectric layer provided in an embodiment of the present application;

[0039] Fig. 9 A schematic diagram of the internal structure of a piezoelectric unit provided in an embodiment of the present application;

[0040] Fig.10 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application;

[0041] Fig.11 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application;

[0042] Fig.12 for Fig.11 A bottom view of the piezoelectric layer is shown;

[0043] Fig.13 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application;

[0044] Fig.14 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application;

[0045] Fig.15A A side view schematic diagram of a piezoelectric module provided in an embodiment of the present application;

[0046] Fig. 15B For along Fig.15A The cross-sectional view obtained by cutting along the cutting line BB in FIG. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0048] It should be noted that when a component is referred to as being "disposed on" another component, it may be directly on the other component or indirectly on the other component. The term "electrical connection" involved in the embodiments of the present application may be a direct electrical connection or an indirect electrical connection through an intermediate medium.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0050] It should be noted that in the embodiments of the present application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplarily" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific way.

[0051] It should be noted that, in the embodiments of the present application, the term "and / or" used herein refers to and covers any and all possible combinations of one or more items in the associated listed items. The term "and / or" is a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone.

[0052] It should be noted that in the embodiments of the present application, "fixed" means that there is no relative movement between the two connected parts. It should be understood that fixation can be a non-detachable or detachable connection, as long as the two parts do not move relative to each other after being connected.

[0053] An embodiment of the present application provides a piezoelectric module for driving the driven surface of a driven part to move. The piezoelectric module includes a piezoelectric layer, an intermediate layer, and a driving trace. The piezoelectric layer is a component in the piezoelectric module used to convert an input signal into mechanical motion (such as mechanical vibration). The intermediate layer is a component in the piezoelectric module used to fix the piezoelectric layer on the driven surface. The driving trace is a component in the piezoelectric module used to receive an input signal and drive the piezoelectric layer to move. The driven surface is a surface driven by the piezoelectric module to achieve motion-related functions (such as audio output functions). The piezoelectric layer is fixed to the driven surface through the intermediate layer; the driving trace is electrically connected to the piezoelectric layer, and the piezoelectric module receives the input signal through the driving trace, and transmits it to the piezoelectric layer to drive the piezoelectric layer to move, thereby driving the driven surface to move.

[0054] It can be seen that in order to use the piezoelectric module to drive the driven surface to move, the setting of the intermediate layer is necessary and inevitable. The setting of the intermediate layer itself will occupy the space in the thickness direction of the piezoelectric module. In this piezoelectric module, the driving wiring is set in the accommodation space of the intermediate layer, and the space occupied by the intermediate layer in the thickness direction of the piezoelectric module is reused. In this way, the driving wiring will not occupy additional space in the thickness direction (that is, the movement direction) of the piezoelectric module, thereby reducing the thickness of the piezoelectric module.

[0055] The piezoelectric module provided in the embodiment of the present application can be applied to electronic devices that convert input signals into mechanical motions to drive the driven surface of the electronic device to move, thereby realizing motion-related functions, such as audio output functions. It should be understood that when the piezoelectric module is applied to electronic devices and stacked in the thickness direction of the electronic devices, it can play a role in reducing the thickness of the electronic devices.

[0056] Exemplarily, the electronic device in the embodiments of the present application may be a headset, a speaker, a mobile phone, a tablet computer, a desktop, a laptop, a handheld computer, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook, and a cellular phone, a personal digital assistant (PDA), an augmented reality (AR) and a virtual reality (VR) device, etc., which have an audio output function. Specifically, the piezoelectric module can be used as the main sound-generating component of an electronic device with an audio output function, converting the audio input signal into mechanical vibration to drive the driven surface fixed to it to vibrate, thereby driving the surrounding air to vibrate to achieve audio output. The subsequent embodiments are described by taking the piezoelectric module as an example of a sound-generating component for achieving audio output.

[0057] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0058] Taking a mobile phone as an example, the electronic device includes a touch screen 100, a housing assembly 200, and a rear cover 300 (sometimes also referred to as a battery cover). The touch screen 100 is located on one side of the housing assembly 200, and the touch screen 100 is used to implement a touch detection function and a display function. The rear cover 300 is located on the other side of the housing assembly 200, and plays a role in protecting and decorating the electronic device.

[0059] Please refer to Figure 2 , Figure 2 for Figure 1 Schematic diagram of the exploded structure of the electronic device shown.

[0060] Depend on Figure 2 It can be seen that the electronic device may further include a piezoelectric module 400 , a circuit board 500 and a battery 600 . In addition, the housing assembly 200 may include a front housing 210 and a middle frame 220 .

[0061] The front shell 210 can be used to carry and fix the touch display screen 100. Specifically, the touch display screen 100 is fixed on a side of the front shell 210 away from the rear shell 300.

[0062] The middle frame 220 is located between the front shell 210 and the rear shell 300, and can be used to connect the front shell 210 and the rear shell 300. The middle frame 220 can further include a frame 221 and a middle plate 222. The frame 221 surrounds the middle plate 222 and can be understood as the visible part of the housing assembly 200. Figure 1 The housing assembly 200 shown is essentially the frame 221 of the housing assembly 200. The middle plate 222 is a non-visible portion of the housing assembly 200, located between the rear housing 300 and the front housing 210, and is used to carry and fix components such as the circuit board 500 and the battery 600.

[0063] The piezoelectric module 400 is disposed on a side of the touch display screen 100 close to the rear housing 300, and is attached and fixed to a surface 100a of the touch display screen 100 close to the rear housing 300. In this case, the surface 100a of the touch display screen 100 close to the rear housing 300 is used as a driven surface, which is used to vibrate under the drive of the piezoelectric module 400, thereby driving the surrounding air to vibrate and realize audio output.

[0064] The circuit board 500 is used to carry and electrically connect the functional modules of the electronic device. For example, the circuit board 500 can carry and electrically connect functional modules such as a processor, an audio driver module, and a power amplifier (PA). It should be understood that functional modules not provided on the circuit board 500 can also be electrically connected to functional modules on the circuit board 500. For example, the piezoelectric module 400 can be electrically connected to the PA on the circuit board 500 through its drive trace 450.

[0065] During the specific implementation, based on the product layout requirements, the circuit board 500 may include a main board 510 and a sub-board 520, and the main board 510 and the sub-board 520 respectively carry and electrically connect different functional modules of the electronic device. The main board 510 may be arranged in area 1 222a of the middle board 222, and the sub-board 520 may be arranged in area 222b of the middle board 222. The main board 510 and the sub-board 520 may be electrically connected through a flexible circuit board to achieve signal transmission.

[0066] The processor may include one or more processing units, for example, the processor may include an application processor (AP), a modem processor, a controller, a memory, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors. For example, the processor may be an application processor AP. Alternatively, the processor may be integrated into a system on chip (SOC). Alternatively, the processor may be integrated into an IC chip. The processor may include an analog front end (AFE) and a microcontroller unit (MCU) in an IC chip.

[0067] Among them, the audio driving module is used to convert the digital audio input signal from the processor into an analog audio input signal output, and is also used to convert the analog audio input signal into a digital audio input signal. In some embodiments, the audio driving module can be set in the processor, or some functional units of the audio driving module can be set in the processor. PA is used to amplify the analog audio input signal output by the audio driving module and output it to the piezoelectric module 400 to drive the piezoelectric module 400 to mechanically vibrate, thereby driving the driven surface to vibrate and achieve sound.

[0068] The battery 600 is used to supply power to each functional module of the electronic device. The battery 600 can be embedded in the opening 222c of the middle plate 222. It should be understood that the electronic device can also include other functional devices such as a camera, which is not limited in the embodiment of the present application.

[0069] It should be noted that Figure 1 and Figure 2 The electronic device shown is described with the surface 100a of the touch display screen 100 close to the rear housing 300 as the driven surface. It should be understood that in other embodiments, other planes in the electronic device can also be used as the driven surface, such as the surface of the rear housing 300 facing the touch display screen 100, which is not limited in the present embodiment.

[0070] Depend on Figure 2 It can be seen that the piezoelectric module 400 is stacked in the thickness direction of the electronic device (the direction perpendicular to the touch screen 100), which will occupy the space of the electronic device in the thickness direction. It can be seen that the piezoelectric module 400 will affect the thickness of the electronic device. In an electronic device with thickness requirements, the thickness of the electronic device can be reduced by reducing the thickness of the piezoelectric module 400, thereby meeting the thickness requirements of the electronic device.

[0071] In addition, in order to pursue a good audio speaker experience, the piezoelectric module 400 is usually set in the center of the whole device, which is opposite to the battery 600 in the thickness direction of the electronic device. In other words, the piezoelectric module 400 and the battery 600 are stacked. In order to ensure the stacking, the piezoelectric module 400 should be made as thin as possible.

[0072] Based on this, it is necessary to study how to reduce the thickness of the piezoelectric module 400. Figures 3 to 15B , the solution for thinning the piezoelectric module 400 in the embodiment of the present application is described.

[0073] For example, please refer to Figure 3 , Figure 3 A schematic diagram of the structure of a piezoelectric module provided in an embodiment of the present application. Figure 3 The piezoelectric module 400 shown can be understood as Figure 2 A piezoelectric module 400 is shown in an electronic device.

[0074] Among them, the piezoelectric module 400 includes a driving line 450. The driving line 450 is used to be electrically connected to a functional module that provides an input signal (such as the above-mentioned PA) to receive an input signal (such as the amplified analog audio input signal output by the above-mentioned PA). A pad 451 can be set at one end of the driving line 450 that is electrically connected to the functional module that provides the input signal, and the pad 451 is welded to the functional module that provides the input signal to achieve electrical connection. The piezoelectric module 400 is used to be fitted and fixed on the driven surface, and vibrates under the drive of the input signal, thereby driving the driven surface to vibrate and achieve sound.

[0075] For example, please refer to Figure 4 , Figure 4 A cross-sectional schematic diagram of a piezoelectric module provided in an embodiment of the present application.

[0076] Figure 4 The piezoelectric module 400 shown can be understood as Figure 3 The piezoelectric module 400 is a cross-sectional view obtained by cutting along the section line AA. For ease of understanding and explanation, in addition to illustrating the structure of the piezoelectric module 400 itself, the figure also illustrates the driven surface 101 used in conjunction with the piezoelectric module 400. The driven surface 101 can be understood as Figure 2 The touch screen 100 shown is close to the surface 100a of the rear housing 300. The piezoelectric module 400 is used to be attached and fixed on the driven surface 101, and vibrates under the drive of the input signal (such as the amplified analog audio input signal output by the PA), thereby driving the driven surface 101 to vibrate and produce sound.

[0077] Figure 4 The piezoelectric module 400 shown may include a piezoelectric layer 410 and an intermediate layer 401 stacked in sequence along the direction of the Z axis shown in the figure. The intermediate layer 401 includes a first fixed layer 420, a support layer 430, and a second fixed layer 440 stacked in sequence along the direction of the Z axis shown in the figure. The direction of the Z axis shown in the figure is the thickness direction of the piezoelectric module 400, and is also the vibration direction of the piezoelectric module 400 (i.e., the movement direction of the piezoelectric module 400).

[0078] The piezoelectric layer 410 is a component in the piezoelectric module 400 for converting an input signal (in the audio output scenario, the input signal is an AC signal) into mechanical vibration. Specifically, the piezoelectric layer 410 can be a structure with an inverse piezoelectric effect, such as a piezoelectric ceramic. It should be understood that in order to achieve the purpose of thinning and vibration, the piezoelectric layer 410 is usually constructed as a thin sheet structure, which makes the piezoelectric layer 410 easy to break.

[0079] The support layer 430 is a component, such as a support sheet, used to support the piezoelectric layer 410 in the piezoelectric module 400. Specifically, the support layer 430 may be a hard structure made of a metal material or a non-metal material, for example, the support layer 430 is a steel sheet.

[0080] Specifically, the piezoelectric layer 410 includes an upper surface (i.e., a first surface) and a lower surface (i.e., a second surface) that are relatively arranged along the Z direction; the support layer 430 also includes an upper surface (i.e., a first surface) and a lower surface (i.e., a second surface) that are relatively arranged along the Z direction. The lower surface of the piezoelectric layer 410 is fixed by the first fixed layer 420 and the upper surface of the support layer 430. In this way, the support layer 430 can support the piezoelectric layer 410. Exemplarily, the first fixed layer 420 can be implemented with a sticky glue layer. In the embodiment of the present application, the structure in which the first fixed layer 420 is implemented by the glue layer is called piezoelectric glue. In this case, the lower surface of the piezoelectric layer 410 is fixed by bonding the first fixed layer 420 and the upper surface of the support layer 430. Of course, in other embodiments, the piezoelectric layer 410 can also be fixed on the support layer 430 by other fixing methods other than bonding, so that the support layer 430 can support the piezoelectric layer 410, and the embodiment of the present application does not specifically limit this.

[0081] It should be noted that the piezoelectric layer 410 with a thin sheet structure is prone to fracture under stress. In this embodiment, the support layer 430 is provided to support the piezoelectric layer 410 to disperse the stress on the piezoelectric layer 410, thereby reducing the risk of the piezoelectric layer 410 fracture, thereby enhancing the crack resistance of the piezoelectric layer 410. Of course, in other embodiments, the support layer 430 may not be provided. For example, when the piezoelectric layer 410 has good crack resistance, the support layer 430 may not be provided. Figure 7 The piezoelectric module 400 shown is not provided with a support layer 430 .

[0082] The lower surface of the support layer 430 is also fixed by the second fixing layer 440 and the driven surface 101, so that the piezoelectric module 400 is attached and fixed on the driven surface 101. It should be understood that when the piezoelectric layer 410 vibrates under the drive of the input signal, it can drive the driven surface 101 attached and fixed thereto to vibrate synchronously, thereby achieving sound generation.

[0083] Exemplarily, the second fixed layer 440 can be implemented with a sticky adhesive layer, such as adhesive backing. In the embodiment of the present application, the structure in which the second fixed layer 440 is implemented by adhesive backing is referred to as support sheet adhesive backing. In this way, when the piezoelectric module 400 needs to be used, the isolation film of the adhesive backing is peeled off, and the piezoelectric module 400 is bonded to the driven surface 101 using the remaining sticky film of the adhesive backing. Of course, in other embodiments, the piezoelectric module 400 can also be fixed to the driven surface 101 by other fixing methods other than bonding, and the embodiment of the present application does not specifically limit this.

[0084] In addition, the piezoelectric module 400 further includes a driving trace 450 , which is a component in the piezoelectric module 400 for receiving an input signal and transmitting it to the piezoelectric layer 410 to drive the piezoelectric layer 410 to vibrate.

[0085] Figure 4 The driving trace 450 in the embodiment is FPC450a, one end of which is electrically connected to a functional module (such as the above-mentioned PA) that provides an input signal to receive the input signal; the other end of FPC450a is electrically connected to the piezoelectric layer 410, specifically to the lower surface of the piezoelectric layer 410, to transmit the received input signal to the piezoelectric layer 410. The electrical connection between FPC450a and the piezoelectric layer 410 may be, but is not limited to, anisotropic conductive film (ACF) glue, solder, conductive cloth, etc.

[0086] The FPC 450a is located between the piezoelectric layer 410 and the second fixed layer 440, that is, between the first fixed layer 420 and the support layer 430. Specifically, Figure 4 In the embodiment, the first fixing layer 420 and the supporting layer 430 define a receiving space 401 a , and the FPC 450 a is located in the receiving space 401 a , and thus located between the first fixing layer 420 and the supporting layer 430 .

[0087] Depend on Figure 4 visible, Figure 4 The accommodation space 401a in the first fixing layer 420 passes through the upper surface of the first fixing layer 420 and the lower surface of the supporting layer 430. Accordingly, the FPC 450a is distributed in the entire space occupied by the first fixing layer 420 and the supporting layer 430 in the direction of the Z axis. In this case, Figure 4 The penetrating accommodation space 401 a can be realized by opening holes in the first fixing layer 420 and the supporting layer 430 .

[0088] Of course, in other embodiments, Figure 4The accommodation space 401a in the support layer 430 may not penetrate the lower surface of the support layer 430. Accordingly, the FPC 450a is distributed in the space occupied by the first fixing layer 420 and the support layer 430 in the direction of the Z axis. In this case, Figure 4 The accommodation space 401 a can be realized by opening a hole in the first fixing layer 420 and making a groove on the supporting layer 430 .

[0089] In addition, in other embodiments, the opening position of the accommodation space 401a may not be in the first fixed layer 420 and the support layer 430. For example, the first fixed layer 420 is provided with an accommodation space 401a. In this case, the FPC 450a is distributed in the entire or partial space occupied by the first fixed layer 420 in the direction where the Z axis is located. For another example, the first fixed layer 420, the support layer 430 and the second fixed layer 440 are provided with an accommodation space 401a. In this case, the FPC 450a is distributed in the entire or partial space occupied by the first fixed layer 420, the support layer 430 and the second fixed layer 440 in the direction where the Z axis is located.

[0090] Combine the following Figure 5 ,right Figure 4 How the FPC 450a is distributed on the first fixing layer 420 and the supporting layer 430 is described.

[0091] Please refer to Figure 5 , Figure 5 for Figure 4 In order to facilitate the display of the positional relationship between the FPC 450a and the support layer 430, Figure 5 The second fixing layer 440 of the piezoelectric module 400 is not shown.

[0092] Figure 5 The middle support layer 430 avoids the FPC 450a. Figure 5 It can be seen that the area where the FPC 450a is located and the area where the support layer 430 is located do not overlap each other, thereby achieving avoidance. It should be understood that when the support layer 430 avoids the FPC 450a, the FPC 450a can be laid in other areas of the same layer outside the area where the support layer 430 is located. In this way, a part of the FPC 450a is distributed in the layer where the support layer 430 is located (the other part of the FPC 450a is distributed in the layer where the first fixed layer 420 is located), and no additional space of the piezoelectric module 400 in the direction of the Z axis is occupied.

[0093] It should be noted that Figure 5 Only the positional relationship between FPC450a and support layer 430 is shown. Due to the shading of support layer 430, Figure 5The first fixing layer 420 is not shown, and the positional relationship between the FPC 450a and the first fixing layer 420 cannot be shown. Figure 4 It can be understood that the positional relationship between the FPC 450a and the first fixing layer 420 is Figure 5 The positional relationship between FPC450a and the supporting layer 430 is similar, that is, the first fixed layer 420 avoids FPC450a, and the area occupied by FPC450a and the area occupied by the first fixed layer 420 do not overlap with each other. FPC450a can be laid in other areas of the same layer outside the area occupied by the first fixed layer 420. In this way, another part of FPC450a is distributed in the first fixed layer 420, and will not occupy additional space of the piezoelectric module 400 in the direction of the Z axis.

[0094] Please continue to refer to Figure 4 , Figure 4 In the piezoelectric module 400 shown, the first fixed layer 420, the supporting layer 430 and the second fixed layer 440 are components of the intermediate layer 401. Therefore, the accommodation space 401a of the first fixed layer 420 and the supporting layer 430 is also the accommodation space 401a of the intermediate layer 401. The FPC 450a is located in the accommodation space 401a of the first fixed layer 420 and the supporting layer 430, and naturally is also located in the accommodation space 401a of the intermediate layer 401.

[0095] In related technologies, such as Figure 6 As shown, FPC450a is located on the upper surface of piezoelectric layer 410. In the embodiment of the present application, FPC450a is located in the middle layer 401. Obviously, compared with Figure 6 As for the scheme shown, FPC450a is set in the accommodating space 401a of the first fixed layer 420 and the supporting layer 430, which is equivalent to reusing the space occupied by the first fixed layer 420 and the supporting layer 430 in the direction of the Z axis, and will not occupy additional space of the piezoelectric module 400 in the direction of the Z axis, thereby reducing the thickness of the piezoelectric module 400.

[0096] It should be noted that, due to the need for audio output effects, the size of the piezoelectric layer 410 (which can be measured by the orthographic projection area of ​​the piezoelectric layer 410 in the direction of the Z axis) is required to be large enough. A large and thin piezoelectric layer 410 faces problems such as easy breakage and poor flatness.

[0097] Combination Figure 7 As can be seen from (a), Figure 7 (a) in the figure shows the situation that the piezoelectric layer 410 is broken. For the sake of easy understanding, other components of the piezoelectric module 400 except the piezoelectric layer 410 are not shown in the figure, and the piezoelectric layer 410 is directly attached and fixed on the driven surface 101.

[0098] Among them, the region S1 of the piezoelectric layer 410 continues to vibrate under the drive of the input signal after the break, and the region S2 of the piezoelectric layer 410 cannot receive the input signal after the break, and thus stops vibrating. It can be seen that compared with the vibration of the entire piezoelectric layer 410, when the piezoelectric layer 410 is broken, a part of the piezoelectric layer 410 vibrates. That is to say, when the piezoelectric layer 410 is broken, the effective area (i.e., the area of ​​the piezoelectric layer 410 that can vibrate) on the piezoelectric layer 410 is reduced. Figure 7 (a) is the positive projection area of ​​region S1 along the direction of the Z axis) is greatly reduced, so the effective area on the driven surface 101 that can vibrate is also reduced, thereby reducing the audio output effect.

[0099] Combination Figure 7 As can be seen from (b), Figure 7 (b) in the figure shows that the edge of the piezoelectric layer 410 is warped while the middle is flat. Among them, area S3 of the piezoelectric layer 410 is a flat area without warping, and the rest of the area is a warping area. It should be understood that the flatness of the piezoelectric layer 410 refers to the flatness of the surface of the piezoelectric layer 410. The warping of the edge of the piezoelectric layer 410 is a manifestation of poor flatness of the piezoelectric layer 410. The flatness of the piezoelectric layer 410 is reflected by the flatness value. The larger the flatness value, the worse the flatness of the piezoelectric layer 410; the smaller the flatness value, the better the flatness of the piezoelectric layer 410.

[0100] Compared with the case where the edge of the piezoelectric layer 410 is not warped, the edge of the piezoelectric layer 410 cannot be bonded to the driven surface 101 due to the warping of the edge of the piezoelectric layer 410, and the bonding area between the piezoelectric layer 410 and the driven surface 101 is reduced to the illustrated area S3. In this way, the effective area ( Figure 7 (b) in the figure is the area of ​​the positive projection of region S3 along the direction of the Z axis) which is reduced, thereby reducing the audio output effect.

[0101] Based on this, in order to reduce the risk of reduced audio output effect caused by the piezoelectric layer 410 being broken or having very poor flatness, in some embodiments, Figure 3 The illustrated piezoelectric layer 410 may be provided as a structure having a plurality of piezoelectric units.

[0102] For details, please refer to Figure 8 , Figure 8 This is a schematic diagram of a planar structure of a piezoelectric layer provided in an embodiment of the present application. This diagram can be understood as Figure 3 The bottom view of the piezoelectric layer 410 shown can also be understood as Figure 3 A schematic diagram of the lower surface of the piezoelectric layer 410 is shown.

[0103] Depend on Figure 8It can be seen that the piezoelectric layer 410 includes four piezoelectric units 411, namely, piezoelectric unit 411a, piezoelectric unit 411b, piezoelectric unit 411c and piezoelectric unit 411d. Among them, the four piezoelectric units 411 are spaced apart in the same plane parallel or substantially parallel to the driven surface 101. Each piezoelectric unit 411 includes an upper surface (i.e., a first surface) and a lower surface (i.e., a second surface) arranged relatively along the direction where the Z axis is located. In a stationary state (i.e., not driven to move), the upper surface or the lower surface of each piezoelectric unit 411 is in the same plane.

[0104] Figure 8 In the figure, four piezoelectric units 411 are spaced apart in a 2×2 array, and the shape of the orthographic projection of the piezoelectric unit 411 along the direction of the Z axis (hereinafter referred to as the shape of the piezoelectric unit 411) is a rectangle. It should be understood that in other embodiments, the piezoelectric layer 410 may also include a greater or lesser number of piezoelectric units 411, and the plurality of piezoelectric units 411 may not be spaced apart in an array, for example, they may be distributed in a disorderly manner. The shape of the piezoelectric unit 411 may also be a circle, a triangle, or other shapes. The embodiments of the present application are not limited to this.

[0105] It should be understood that, compared to the unsplit piezoelectric layer 410, the area of ​​a single piezoelectric unit 411 (the area of ​​the orthographic projection in the direction of the Z axis) is smaller. The smaller the area of ​​the piezoelectric unit 411, the less likely the piezoelectric unit 411 is to break, and the easier it is to control the flatness of the piezoelectric unit 411 during the production process. Therefore, compared to the unsplit piezoelectric layer 410, by splitting the piezoelectric layer 410 into four piezoelectric units 411, the risk of fracture and flatness difference of the piezoelectric layer 410 can be reduced, the crack resistance and flatness of the piezoelectric layer 410 can be improved, and the audio output effect can be improved.

[0106] It should be noted that Figure 8 Each piezoelectric unit 411 can be understood as a piezoelectric element that can vibrate independently and can vibrate independently under the drive of an input signal.

[0107] Specifically, the piezoelectric unit 411 may include at least two electrodes with opposite electrical properties (a positive electrode and a negative electrode, respectively), and a piezoelectric body sandwiched between the positive electrode and the negative electrode. The piezoelectric body is made of a piezoelectric material, such as piezoelectric ceramics, and the electrodes are made of a metal material. Fig. 9 , Fig. 9 A schematic diagram of the internal structure of a possible piezoelectric unit is shown. Fig. 9 It can be understood as Figure 8 A cross-sectional view of the piezoelectric unit 411a in FIG. 4 is obtained by cutting along the direction of the Z axis.

[0108] pass Fig. 9It can be seen that the piezoelectric unit 411 includes positive electrodes + and negative electrodes alternately stacked from top to bottom along the direction of the Z axis; and also includes a piezoelectric body 4111 sandwiched between each pair of positive electrodes and negative electrodes.

[0109] In order to facilitate electrical connection with the FPC 450a to receive input signals, the piezoelectric unit 411 further includes a first metal layer 4112 and a second metal layer 4113 coated on the surface. Figure 3 As for the piezoelectric module 400 shown, since the FPC 450a is located on the lower surface of the piezoelectric layer 410, the first metal layer 4112 and the second metal layer 4113 can be coated on the lower surface of the piezoelectric unit 411 to facilitate electrical connection with the FPC 450a located below.

[0110] Among them, the first metal layer 4112 and the second metal layer 4113 can be realized by a silver layer, a copper layer, etc. The first metal layer 4112 is electrically connected to all positive electrodes for leading out the positive electrodes; the second metal layer 4113 is electrically connected to all negative electrodes for leading out the negative electrodes. FPC450a can be electrically connected to the first metal layer 4112 and the second metal layer 4113 respectively to achieve electrical connection between the positive electrode and the negative electrode. In this way, FPC450a can transmit the received input signal to the piezoelectric unit 411, and the input signal applies an alternating electric field to the positive electrode and the negative electrode through the first metal layer 4112 and the second metal layer 4113. The piezoelectric body 4111 sandwiched between the positive electrode and the negative electrode is excited by the inverse piezoelectric effect, and moves back and forth along the direction of the Z axis under the action of the alternating electric field, generating mechanical vibration. It should be noted that, in the embodiment of the present application, the specific implementation of the electrical connection between the drive wiring 450 (such as FPC450a or the metal wiring 450b mentioned later) and the piezoelectric unit 411 can be described here. In addition, in the case where the piezoelectric layer 410 is not split into multiple piezoelectric units 411, the piezoelectric layer 410 is equivalent to one piezoelectric unit 411 here, and the specific implementation of the electrical connection between the drive wiring 450 (such as FPC450a or the metal wiring 450b mentioned later) and the piezoelectric layer 410 can be described here. How the drive wiring 450 is specifically electrically connected to the piezoelectric unit 411 or the piezoelectric layer 410 will not be described later.

[0111] In a specific implementation process, the first metal layer 4112 and the two positive electrodes can be regarded as a positive electrode as a whole, and the second metal layer 4113 and the two negative electrodes can be regarded as a negative electrode as a whole, without distinction.

[0112] It should be noted that Fig. 9 The piezoelectric unit 411 is merely a schematic diagram. In the specific implementation process, the piezoelectric unit 411 may also have other structures, which will not be described in detail in the embodiment of the present application.

[0113] Please continue to refer to Figure 8 , Figure 8 The piezoelectric layer 410 shown includes four piezoelectric units 411, which are equivalent to four piezoelectric elements. The input signals received by the four piezoelectric units 411 at the same time can be the same or different. In other words, the four piezoelectric units 411 can be driven by the same input signal or by different input signals. Figure 8 The driving method of the four piezoelectric units 411 is illustrated by way of example.

[0114] For example, among the four piezoelectric units 411 , the piezoelectric unit 411 a is driven by one input signal, the piezoelectric unit 411 b is driven by one input signal, the piezoelectric unit 411 c is driven by one input signal, and the piezoelectric unit 411 d is driven by one input signal.

[0115] For another example, any two of the four piezoelectric units 411 (such as piezoelectric unit 411a and piezoelectric unit 411b) are driven by one input signal, any one of the remaining two piezoelectric units 411 (such as piezoelectric unit 411c) is driven by one input signal, and the other of the remaining two piezoelectric units 411 (such as piezoelectric unit 411d) is driven by one input signal.

[0116] For another example, any two piezoelectric units 411 (such as piezoelectric unit 411a and piezoelectric unit 411b) among the four piezoelectric units 411 are driven by one input signal, and the remaining two piezoelectric units 411 (such as piezoelectric unit 411c and piezoelectric unit 411d) can be driven by another input signal through different piezoelectric units 411.

[0117] For another example, any three piezoelectric units 411 (such as piezoelectric unit 411a, piezoelectric unit 411b and piezoelectric unit 411c) among the four piezoelectric units 411 are driven by one input signal, and the remaining piezoelectric unit 411 (such as piezoelectric unit 411d) can be driven by another input signal through a different piezoelectric unit 411.

[0118] For another example, the four piezoelectric units 411 are all driven by one input signal.

[0119] It should be noted that the frequency of the vibration of the piezoelectric unit 411 is related to the frequency of the input signal driving its vibration, the amplitude of the vibration is related to the amplitude of the input signal driving its vibration, and the phase of the vibration is related to the phase of the input signal driving its vibration. Therefore, the sound wave generated by the piezoelectric unit 411 is related to the frequency, amplitude, and phase of the input signal driving its vibration. It should be understood that the vibration of the piezoelectric unit 411 driven by the same input signal (frequency, amplitude, and phase are all the same) is synchronized, and the sound waves generated by different piezoelectric units 411 are the same due to the same phase, so that the amplitude of the synthesized sound wave is enhanced, thereby increasing the driving ability of the piezoelectric module 400. The vibration of the piezoelectric unit 411 driven by different input signals (such as any one or more of the frequency, amplitude, and phase are different) is not synchronized, so that a rich vibration state can be generated to serve the vibration needs in different scenarios. For example, the vibration frequencies of the piezoelectric unit 411 driven by input signals of different frequencies are different, which makes the synthesized sound wave contain multiple frequency components, so that a rich audio effect can be produced.

[0120] It should be understood that Figure 8 The driving modes of the four piezoelectric units 411 may be fixed or not. The electrical connection modes between the FPC 450a and the piezoelectric units 411 in these two cases are described below.

[0121] exist Figure 8 When the driving mode of the four piezoelectric units 411 remains unchanged, the piezoelectric units 411 driven by the same input signal can be connected in series, and FPC450a can be electrically connected to the piezoelectric units 411 at the ends of the piezoelectric units 411 connected in series. In this way, the input signal transmitted by FPC450a is fed into the piezoelectric units 411 connected in series in sequence, so that the piezoelectric units 411 connected in series are driven by the same input signal. In this case, the input signal driving the piezoelectric units 411 connected in series can be transmitted through one line in FPC450a without occupying multiple lines. Figure 8 When the driving mode of the four piezoelectric units 411 is fixed, each piezoelectric unit 411 driven by a different input signal is electrically connected to the FPC450a, so that each input signal transmitted by the FPC450a is fed into each piezoelectric unit 411 to achieve driving with different input signals. Of course, when the driving mode is fixed, the piezoelectric units 411 driven by the same input signal can also be electrically connected to the FPC450a, in which case the input signals of each piezoelectric unit 411 are transmitted through different lines in the FPC450a.

[0122] exist Figure 8When the driving modes of the four piezoelectric units 411 are not fixed, FPC450a can be electrically connected to the four piezoelectric units 411 respectively. In this way, when the driving modes of the four piezoelectric units 411 need to be changed, the driving mode can be changed by changing the input signal input by FPC450a to each piezoelectric unit 411. This connection method enables the piezoelectric module 400 to support changes in the driving mode, making it suitable for a wider range of scenarios. In this case, the input signals that drive the four piezoelectric units 411 are transmitted to the four piezoelectric units 411 through different lines in FPC450a.

[0123] For example, please refer to Fig.10 , Fig.10 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application.

[0124] Different from Figure 4 The piezoelectric module 400 shown, Fig.10 In the piezoelectric module 400 shown, the intermediate layer 401 no longer includes the support layer 430 and the second fixed layer 440, and only includes the first fixed layer 420. The piezoelectric layer 410 is directly fixed on the driven surface 101 through the first fixed layer 420. In this case, the first fixed layer 420 can be implemented by the above-mentioned adhesive. In this way, when the piezoelectric module 400 needs to be used, the isolation film of the adhesive is peeled off, and the piezoelectric module 400 is bonded to the driven surface 101 using the remaining adhesive film of the adhesive.

[0125] Fig.10 In the illustrated piezoelectric module 400 , the FPC 450 a is located between the piezoelectric layer 410 and the driven surface 101 , and is located on the first fixed layer 420 .

[0126] Specifically, Fig.10 In the embodiment, the first fixing layer 420 is provided with a receiving space 401 a , and the FPC 450 a is located in the receiving space 401 a , and thus is located on the first fixing layer 420 . Fig.10 The accommodation space 401a in the first fixed layer 420 passes through the upper surface and the lower surface, and accordingly, the FPC 450a is distributed in the entire space occupied by the first fixed layer 420 in the direction where the Z axis is located. It should be understood that in other embodiments, the accommodation space 401a may not pass through the lower surface of the first fixed layer 420, and accordingly, the FPC 450a is distributed in a part of the space occupied by the first fixed layer 420 in the direction where the Z axis is located.

[0127] It should be noted that the positional relationship between the FPC 450a and the first fixing layer 420 and Figure 5The positional relationship between FPC450a and the supporting layer 430 is similar, that is, the first fixed layer 420 avoids FPC450a, and the area occupied by FPC450a and the area occupied by the first fixed layer 420 do not overlap with each other. FPC450a can be laid in other areas of the same layer outside the area occupied by the first fixed layer 420. In this way, FPC450a is located in the first fixed layer 420 and will not occupy additional space of the piezoelectric module 400 in the direction of the Z axis.

[0128] Fig.10 In the piezoelectric module 400 shown, the first fixed layer 420 forms the middle layer 401 of the piezoelectric module 400. Therefore, the accommodation space 401a of the first fixed layer 420 is also the accommodation space 401a of the middle layer 401. The FPC 450a is located in the accommodation space 401a of the first fixed layer 420, and naturally is also located in the accommodation space 401a of the middle layer 401. It should be understood that, without contradiction, Figure 4 The technical solution and corresponding technical effects of the piezoelectric module 400 shown are also applicable to Fig.10 The piezoelectric module 400 can be adapted to refer to the embodiments and will not be described in detail here.

[0129] For example, please refer to Fig.11 , Fig.11 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application.

[0130] Different from Figure 4 The piezoelectric module 400 shown, Fig.11 The driving trace 450 in the piezoelectric module 400 is no longer FPC 450a, but a metal trace 450b printed on the upper surface of the support layer 430. In other words, Fig.11 In the illustrated piezoelectric module 400, a metal trace 450b is used as a driving trace 450 to be electrically connected to the piezoelectric layer 410. Specifically, the metal trace 450b is electrically connected to the lower surface of the piezoelectric layer 410. It should be understood that in other embodiments, the metal trace 450b can also be implemented by other non-metal conductor traces that can be printed.

[0131] It should be noted that the metal trace 450b is electrically connected to the piezoelectric layer 410, and the piezoelectric layer 410 and the metal trace 450b can be welded by SMT, so as to realize the electrical connection between the piezoelectric layer 410 and the metal trace 450b. Compared with the solution of using the FPC 450a and the piezoelectric layer 410 to be electrically connected, the electrical connection process assembly efficiency is higher by using the SMT method.

[0132] When the piezoelectric layer 410 is divided into a plurality of piezoelectric units, Fig.11 The electrical connection relationship between the metal trace 450b and the plurality of piezoelectric units can be adaptively referred to Figure 8 The electrical connection method between FPC450a and piezoelectric unit 411 is described in detail in the following. Fig.12 , taking the piezoelectric layer 410 including four piezoelectric units 411 and the four piezoelectric units 411 driven by the same input signal as an example, Fig.11 The line distribution of the metal routing 450b is exemplified.

[0133] Please refer to Fig.12 , Fig.12 for Fig.11 A bottom view of the piezoelectric layer 410 is shown. Fig.12 It can also be understood as Fig.11 Schematic diagram of the lower surface of the piezoelectric layer 410 shown. In order to facilitate the display of the line distribution of the metal trace 450b, Fig.12 Metal trace 450b is also shown by a dotted line.

[0134] Depend on Fig.12 It can be seen that one of the metal traces 450b passes through the first metal layer 4112 of the piezoelectric unit 411a, the first metal layer 4112 of the piezoelectric unit 411b, the first metal layer 4112 of the piezoelectric unit 411c, and the first metal layer 4112 of the piezoelectric unit 411d in sequence, and the SMT technology can be used to weld the line to the first metal layer 4112 of each piezoelectric unit 411. Another line of the metal trace 450b passes through the second metal layer 4113 of the piezoelectric unit 411a, the second metal layer 4113 of the piezoelectric unit 411b, the second metal layer 4113 of the piezoelectric unit 411c, and the second metal layer 4113 of the piezoelectric unit 411d in sequence, and the SMT technology can be used to weld the line to the second metal layer 4113 of each piezoelectric unit 411.

[0135] In this way, the metal routing 450b can transmit the same input signal to the first metal layer 4112 of each piezoelectric unit 411 and the second metal layer 4113 of the piezoelectric unit 411d in sequence through two lines. The input signal applies an alternating electric field to the positive electrode and the negative electrode of each piezoelectric unit 411 through the first metal layer 4112 and the second metal layer 4113, and the four piezoelectric units 411 vibrate synchronously under the action of the electric field of the same input signal.

[0136] Please continue to refer to Fig.11 , Fig.11 In the illustrated piezoelectric module 400 , the first fixed layer 420 defines a receiving space 401 a , and the metal trace 450 b is located in the receiving space 401 a , and thus is located in the first fixed layer 420 . Fig.11The accommodation space 401a in the first fixed layer 420 passes through the upper surface and the lower surface, and accordingly, the metal traces 450b are distributed in the entire space occupied by the first fixed layer 420 in the direction where the Z axis is located.

[0137] Specifically, Fig.11 In the embodiment, the metal trace 450b is printed on a partial area of ​​the upper surface of the support layer 430, and the first fixed layer 420 is located on the remaining area of ​​the upper surface of the support layer 430. The accommodation space 401a is opened at a position of the partial area of ​​the first fixed layer 420 corresponding to the location of the metal trace 450b, so that the metal trace 450b protruding from the upper surface of the support layer 430 can be accommodated in the accommodation space 401a.

[0138] Fig.11 In the piezoelectric module 400 shown, the metal trace 450b and the first fixed layer 420 are located in different areas on the upper surface of the support layer 430. It can be seen that the area occupied by the metal trace 450b and the area occupied by the first fixed layer 420 do not overlap, and the first fixed layer 420 completely avoids the metal trace 450b. In this way, the area occupied by the metal trace 450b and the first fixed layer 420 can be located in the same layer. In this way, the metal trace 450b is distributed in the space occupied by the first fixed layer 420 in the direction of the Z axis, and will not occupy additional space of the piezoelectric module 400 in the direction of the Z axis. It should be noted that the positional relationship between the metal trace 450b and the first fixed layer 420 can be seen in Figure 5 The positional relationship between FPC450a and the supporting layer 430.

[0139] also, Fig.11 In the illustrated piezoelectric module 400, the metal trace 450b is printed on the upper surface of the support layer 430. Since the support layer 430 is a hard structure, the metal trace 450b printed on the upper surface of the support layer 430 is attached to the hard attachment surface of the upper surface of the support layer 430. Compared with the solution of attaching to the soft attachment surface, it is not easy to be impacted and broken under the action of external force, thereby improving the reliability of the piezoelectric module 400.

[0140] Fig.11 In the illustrated piezoelectric module 400, the first fixed layer 420, the support layer 430, and the second fixed layer 440 form the middle layer 401 of the piezoelectric module 400. It can be seen that the first fixed layer 420 is a component of the middle layer 401, and the accommodation space 401a of the first fixed layer 420 is also the accommodation space 401a of the middle layer 401. Therefore, the metal trace 450b is located in the accommodation space 401a of the first fixed layer 420, and naturally the metal trace 450b is located in the accommodation space 401a of the middle layer 401.

[0141] It should be noted that Fig.11 In the illustrated piezoelectric module 400, when the support layer 430 is made of metal, an insulating layer is required to be provided on the upper surface of the support layer 430, and the insulating layer is located between the metal trace 450b and the upper surface of the support layer 430, that is, the metal trace 450b is printed on the insulating layer provided on the upper surface of the support layer 430. In this case, the current of the metal trace 450b is insulated by the insulating layer and cannot flow to the support layer 430, thereby improving the current driving capability of the piezoelectric layer 410 and improving the reliability of the line connection.

[0142] In addition, it should be noted that, under the premise of no contradiction, the technical solutions and corresponding technical effects of the piezoelectric module 400 shown in the above embodiments are also applicable to Fig.11 The piezoelectric module 400 can be adapted to refer to the embodiments and will not be described in detail here.

[0143] For example, please refer to Fig.13 , Fig.13 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application.

[0144] Fig.13 The piezoelectric module 400 shown in FIG. Fig.11 The support layer 430 and the second fixing layer 440 are removed from the piezoelectric module 400 , and the piezoelectric layer 410 is directly fixed to the driven surface 101 through the first fixing layer 420 .

[0145] In this case, the metal trace 450b can be directly printed on the driven surface 101. Specifically, the metal trace 450b is printed on a partial area of ​​the driven surface 101, and the first fixed layer 420 is located in the remaining area of ​​the driven surface 101. The accommodation space 401a is opened at a position of the partial area of ​​the first fixed layer 420 corresponding to the metal trace 450b, so that the metal trace 450b protruding from the driven surface 101 is accommodated in the accommodation space 401a.

[0146] Fig.13 In the piezoelectric module 400 shown, the metal trace 450b and the first fixed layer 420 are located in different areas of the driven surface 101. It can be seen that the area occupied by the metal trace 450b and the area occupied by the first fixed layer 420 do not overlap, and the first fixed layer 420 completely avoids the metal trace 450b. In this way, the area occupied by the metal trace 450b and the first fixed layer 420 can be located in the same layer. In this way, the metal trace 450b is distributed in the space occupied by the first fixed layer 420 in the direction of the Z axis, and will not occupy additional space of the piezoelectric module 400 in the direction of the Z axis. It should be noted that the positional relationship between the metal trace 450b and the first fixed layer 420 can be seen in Figure 5The positional relationship between FPC450a and the supporting layer 430.

[0147] Fig.13 In the piezoelectric module 400 shown, the first fixed layer 420 forms the middle layer 401 of the piezoelectric module 400. Therefore, the accommodation space 401a of the first fixed layer 420 is also the accommodation space 401a of the middle layer 401. The metal trace 450b is located in the accommodation space 401a of the first fixed layer 420, and naturally is also located in the accommodation space 401a of the middle layer 401.

[0148] It should be noted that Fig.13 In the illustrated piezoelectric module 400, when the driven component providing the driven surface 101 is made of a metal surface, the driven surface 101 has an insulating layer. The insulating layer is located between the metal trace 450b and the driven surface 101, that is, the metal trace 450b is printed on the insulating layer of the driven surface 101 to prevent the current of the metal trace 450b from flowing to the driven surface 101 when transmitting a signal, thereby preventing the piezoelectric layer 410 from being driven, thereby improving the reliability of the line connection.

[0149] In addition, it should be noted that, under the premise of no contradiction, the technical solutions and corresponding technical effects of the piezoelectric module 400 shown in the above embodiments are also applicable to Fig.13 The piezoelectric module 400 is not described in detail here.

[0150] For example, please refer to Fig.14 , Fig.14 A cross-sectional schematic diagram of another piezoelectric module provided in an embodiment of the present application.

[0151] Different from Fig.11 The piezoelectric module 400 shown, Fig.14 In the illustrated piezoelectric module 400, the intermediate layer 401 no longer includes the first fixed layer 420, but the first fixed layer 420 is replaced by a metal trace 450b to fix the piezoelectric layer 410. In other words, the metal trace 450b is used to both achieve electrical connection with the piezoelectric layer 410 and to fix the piezoelectric layer 410 on the upper surface of the support layer 430.

[0152] Specifically, the metal trace 450b is printed on the upper surface of the support layer 430, and the piezoelectric layer 410 is fixedly connected to the upper surface of the support layer 430 by the metal trace 450b printed on the upper surface of the support layer 430. Here, the metal trace 450b can be fixedly connected to the upper surface of the support layer 430 by welding, such as SMT welding. It can be seen that in this embodiment, the metal trace 450b not only realizes the electrical connection between the piezoelectric layer 410 and the metal trace 450b, but also realizes the bonding and fixing between the piezoelectric layer 410 and the support layer 430. The reuse of the metal trace 450b by the piezoelectric module 400 saves the cost required for bonding and fixing by using the first fixed layer 420 on the one hand; on the other hand, by welding the metal trace 450b and the piezoelectric layer 410, the bonding and fixing function and the electrical connection function that originally required multiple steps to complete are realized, and the processing efficiency is higher. It should be noted that, except for the case where the metal wiring 450 b is required to be separated for signal transmission, the metal wiring 450 b is spread over the upper surface of the support layer 430 as much as possible to play a transmission role.

[0153] Fig.14 In the piezoelectric module 400 shown, the side to which the upper surface of the support layer 430 faces can be understood as the accommodation space 401a of the intermediate layer 401, and the metal trace 450b is printed on the upper surface of the support layer 430, and is located in the accommodation space 401a. It should be noted that the accommodation space 401a was originally used to set the first fixed layer 420. Here, since the metal trace 450b is reused as the function of the first fixed layer 420, the metal trace 450b is located in the accommodation space 401a. It should be understood that in this case, the metal trace 450b also only occupies the space originally occupied by the first fixed layer 420 for bonding and fixing the piezoelectric layer 410 in the thickness direction, and does not occupy additional space in the thickness direction of the piezoelectric module 400, so that the piezoelectric module 400 can be thinned.

[0154] It should be understood that Fig.14 When the support layer 430 in the piezoelectric module 400 shown is made of metal, the upper surface of the support layer 430 has an insulating layer to prevent the current of the metal trace 450b from flowing to the support layer 430 when transmitting signals, resulting in the inability to drive the piezoelectric layer 410, thereby improving the reliability of the line connection.

[0155] In addition, it should be noted that, under the premise of no contradiction, the technical solutions and corresponding technical effects of the piezoelectric module 400 shown in the above embodiments are also applicable to Fig.14 The piezoelectric module 400 is not described in detail here. Fig.14 The technical solution of using metal wiring 450b to fix the piezoelectric layer 410 and the support layer 430 can also be used in Fig.13 The piezoelectric module 400 is shown as an example. In this case, the metal trace 450 b is printed on the driven surface 101 , which will not be described in detail herein.

[0156] For example, please refer to Fig.15A and Fig. 15B , Fig.15A A side view of a piezoelectric module provided in an embodiment of the present application is shown in FIG. Fig. 15B For along Fig.15A The cross-sectional view obtained by cutting along the BB cutting line in FIG.

[0157] It should be understood that Fig.15A For along Figure 3 Schematic diagram of the side surface 402 of the piezoelectric module 400 obtained from the perspective shown in the X direction shown. It should be noted that the side surface of the piezoelectric module 400 is a surface sandwiched between the upper surface and the lower surface of the piezoelectric module 400 that are oppositely arranged along the direction where the Z axis is located. The side surface of the piezoelectric module 400 includes two side surfaces passed through by the FPC 450a, and the side surface 402 shown in the figure is the side surface of the two side surfaces passed through by the FPC 450a, which is closer to the end of the FPC 450a that is electrically connected to the functional module that provides the input signal.

[0158] Different from Figure 4 The piezoelectric module 400 shown, Fig. 15B In the piezoelectric module 400 shown, the FPC 450a extends through the accommodation space 401a opened by the first fixing layer 420 and the supporting layer 430 to the direction of the side of the first fixing layer 420 and the side of the supporting layer 430, and then bends and extends toward the piezoelectric layer 410 at the side of the first fixing layer 420 and the side of the supporting layer 430, and is electrically connected to the side of the piezoelectric layer 410. In this embodiment, the FPC 450a includes a first area 4501, a second area 4502 and a third area 4503. Fig. 15B The areas are divided by dotted lines, wherein the second area 4502 and the third area 4503 can be Fig.15A The first area 4501 is the portion of the FPC 450a located in the accommodation space 401a opened by the first fixed layer 420 and the support layer 430, that is, the portion passing through the accommodation space 401a opened by the first fixed layer 420 and the support layer 430; the second area 4502 is the portion of the FPC 450a located on the side of the first fixed layer 420 and the side of the support layer 430, that is, the portion extending out of the accommodation space 401a opened by the first fixed layer 420 and the support layer 430; the third area 4503 is the portion of the FPC 450a located on the side of the piezoelectric layer 410, that is, the portion of the FPC 450a bent toward the side of the piezoelectric layer 410. The FPC 450a is electrically connected to the side of the piezoelectric layer 410 through the third area 4503. It should be understood that for Fig. 15BFor the piezoelectric module 400 shown, Fig. 9 The first metal layer 4112 and the second metal layer 4113 shown may be transferred to the side of the piezoelectric layer 410 to facilitate electrical connection with the third region 4503 of the FPC 450 a located on the side of the piezoelectric layer 410 .

[0159] It should be noted that the meanings of the side surface of the piezoelectric layer 410 , the side surface of the first fixed layer 420 , and the side surface of the support layer 430 may refer to the meaning of the side surface 402 of the piezoelectric module 400 .

[0160] It should be understood that the third area 4503 of the FPC 450a is located on the side of the piezoelectric layer 410, that is, distributed in the space occupied by the piezoelectric layer 410 in the direction of the Z axis, and does not occupy additional space of the piezoelectric module 400 in the direction of the Z axis, thereby reducing the thickness of the piezoelectric module 400. Fig. 15B The third area 4503 of FPC450a is distributed in the partial space occupied by the piezoelectric layer 410 in the direction of the Z axis, but in the specific implementation process, FPC450a can also be distributed in the entire space occupied by the piezoelectric layer 410 in the direction of the Z axis, and the embodiment of the present application is not limited to this.

[0161] It should be noted that Fig. 15B The technical solution of setting the FPC 450a on the side of the piezoelectric layer 410 and the accommodation space 401a of the middle layer 401 can also be applied to the piezoelectric module 400 shown in other embodiments, and will not be repeated here. It should be understood that when the driving wiring 450 is a metal wiring 450b, a non-metallic attachment surface needs to be provided for attaching the metal wiring 450b.

[0162] In addition, it should be noted that, under the premise of no contradiction, the technical solutions and corresponding technical effects of the piezoelectric module 400 shown in the above embodiments are also applicable to Fig. 15B The piezoelectric module 400 is not described in detail here.

[0163] It should be noted that Figures 4 to 14 In the piezoelectric module 400 shown, the driving trace 450 (i.e., FPC 450a or metal trace 450b) is located on the lower surface of the piezoelectric layer 410 and distributed in the accommodation space 401a of the middle layer 401; Fig. 15B In the illustrated piezoelectric module 400, the driving trace 450 (i.e., FPC 450a or metal trace 450b) is located on the side of the piezoelectric layer 410 and the accommodation space 401a of the intermediate layer 401. In other embodiments, the driving trace 450 (i.e., FPC 450a or metal trace 450b) in the piezoelectric module 400 may also be located only on the side of the piezoelectric layer 410.

[0164] The following table is combined with Figure 6 The piezoelectric module 400 shown (the piezoelectric layer 410 is not divided into four piezoelectric units 411), Figure 4 The piezoelectric module 400 (the piezoelectric layer 410 is divided into four piezoelectric units 411) and Fig.11 The piezoelectric module 400 (the piezoelectric layer 410 is divided into four piezoelectric units 411) is shown for comparison, wherein the size of the piezoelectric layer 410 is 25*20*0.3 mm, and the size of the piezoelectric unit 411 is 12.35*9.85*0.3 mm.

[0165]

[0166] It can be seen from the above table that the intermediate layers of the above three piezoelectric modules all include three layers of piezoelectric glue, support sheet and support sheet backing glue. Figure 4 and Fig.11 In the piezoelectric module shown, since the drive wiring is set in the middle layer, the overall thickness of the piezoelectric module gains the same size as the thickness of the FPC, that is, 0.15mm. In addition, Figure 4 and Fig.11 The piezoelectric module shown in the figure makes the piezoelectric layer 410 more flat and reduces the risk of breakage by splitting the piezoelectric layer 410 into four piezoelectric units 411. Fig.11 The piezoelectric module shown uses SMT to achieve the welding of metal traces, and the assembly efficiency of the electrical connection process is improved.

[0167] In the above embodiments, the description of each embodiment has its own emphasis. For the part that is not described or recorded in detail in a certain embodiment, please refer to the relevant description of other embodiments. The above embodiments are only used to illustrate the technical solution of the present application, not to limit it; although the present application is described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features therein by equivalent; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present application, and should be included in the protection scope of the present application.

Claims

1. A piezoelectric module, characterized in that: The piezoelectric module comprises: Piezoelectric layer; An intermediate layer; the intermediate layer is located between the piezoelectric layer and the driven surface of the electronic device in the thickness direction of the piezoelectric module, and the intermediate layer is used to fix the piezoelectric layer to the driven surface; A driving line is electrically connected to the piezoelectric layer; wherein the driving line is located in the accommodation space of the middle layer; the driving line is used to receive an input signal and drive the piezoelectric layer to move, so as to drive the driven surface to vibrate.

2. The piezoelectric module according to claim 1, characterized in that: The driving line extends through the accommodation space toward the direction of the side surface of the intermediate layer, and bends and extends toward the piezoelectric layer at the side surface of the intermediate layer; The driving line includes a first area, a second area and a third area; wherein the first area is the portion of the driving line located in the accommodating space; the second area is the portion of the driving line located on the side of the middle layer; the third area is the portion of the driving line located on the side of the piezoelectric layer; the driving line is electrically connected to the side of the piezoelectric layer through the third area.

3. The piezoelectric module according to claim 1 or 2, characterized in that: The intermediate layer includes a supporting layer, a first fixing layer and a second fixing layer; The support layer is used to support the piezoelectric layer, and the support layer is located between the piezoelectric layer and the driven surface; the support layer is fixed to the driven surface through the second fixing layer, and the support layer is connected to the piezoelectric layer through the first fixing layer.

4. The piezoelectric module according to claim 3, characterized in that: The first fixing layer is provided with the accommodation space.

5. The piezoelectric module according to claim 3, characterized in that: The supporting layer and the first fixing layer define the accommodation space.

6. The piezoelectric module according to claim 3, characterized in that: The first fixing layer, the supporting layer and the second fixing layer define the accommodation space.

7. The piezoelectric module according to claim 3, characterized in that: The driving trace is printed on a partial area of ​​the first surface of the supporting layer, and the first fixed layer is located on the remaining area of ​​the first surface of the supporting layer; the first surface of the supporting layer is a side of the supporting layer facing the piezoelectric layer; The accommodating space is opened at a position of the first fixing layer corresponding to the partial area.

8. The piezoelectric module according to claim 1 or 2, characterized in that: The intermediate layer is a first fixing layer; the first fixing layer is used to fix the piezoelectric layer to the driven surface; The first fixing layer is provided with a receiving space.

9. The piezoelectric module according to claim 1 or 2, characterized in that: The intermediate layer includes a supporting layer and a second fixing layer; the supporting layer is used to support the piezoelectric layer; the supporting layer is fixed to the driven surface through the second fixing layer; The driving trace is printed on the first surface of the supporting layer; The piezoelectric layer is fixedly connected to the supporting layer through the driving wiring; the first surface of the supporting layer is a side of the supporting layer facing the piezoelectric layer.

10. The piezoelectric module according to claim 7 or 9, characterized in that: The driving wiring is printed on the first surface of the supporting layer by using surface mounting technology (SMT).

11. The piezoelectric module according to any one of claims 7, 9 to 10, characterized in that: When the material of the support layer is a metal material, the first surface of the support layer has an insulating layer; The insulating layer is located between the driving wiring and the first surface of the supporting layer.

12. The piezoelectric module according to any one of claims 1 to 11, characterized in that: The piezoelectric layer includes a plurality of piezoelectric units, each of which is electrically connected to the driving wiring; The plurality of piezoelectric units are distributed in an array, and the plurality of piezoelectric units are located in the same plane in a static state.

13. An electronic device, characterized in that: include: The piezoelectric module according to any one of claims 1 to 12, wherein the piezoelectric module is used to receive an input signal and move under the drive of the input signal; The driven surface is fixed to the piezoelectric module, and the driven surface is used to move under the drive of the piezoelectric module.

14. The electronic device according to claim 13, characterized in that: The driven surface is the back of the screen or the back of the rear shell of the electronic device.

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