Piezoelectric refrigeration fan and electronic equipment

Abstract

The invention relates to the technical field of heat dissipation, and discloses a piezoelectric refrigeration fan and electronic equipment. The piezoelectric refrigeration fan comprises a shell and a piezoelectric vibration assembly, wherein the shell is provided with a cavity; the piezoelectric vibration assembly is arranged in the cavity and divides the cavity in the first direction. The piezoelectric vibration assembly comprises at least two piezoelectric vibration units which are arranged at intervals in the first direction, and the interval between every two adjacent piezoelectric vibration units in the at least two piezoelectric vibration units forms an air guide channel. The piezoelectric vibration unit comprises a vibrating diaphragm and a piezoelectric diaphragm arranged on at least one side of the vibrating diaphragm in the first direction, part of the periphery of the vibrating diaphragm is fixed to the shell, and the vibrating diaphragm is made of organic polymers. The piezoelectric film drives the vibrating diaphragm to vibrate along a first direction and compress air in the cavity; in the first direction, the shell is provided with an air channel communicated with the cavity on at least one side of the piezoelectric vibration assembly. According to the piezoelectric refrigeration fan, the size can be reduced, the occupied space of the piezoelectric refrigeration fan in electronic equipment is reduced, the airflow direction is accurately controlled, noise is lowered, and the service life is prolonged.

Description

Technical Field

[0001] This application relates to the field of heat dissipation technology, and in particular to a piezoelectric cooling fan and electronic device. Background Technology

[0002] In the field of electronic device heat dissipation, traditional impeller fans have long relied on rotating mechanical structures to drive airflow. Their technological limitations are no longer compatible with the development trends of high heat flux density in modern chips and miniaturization of devices. The motor and bearing components in the impeller structure typically occupy more than 10 millimeters of axial space, severely restricting the design and development of ultra-thin electronic products. More significantly, the noise generated by the high-speed cutting of airflow by the blades can reach over 40 decibels, causing noticeable noise pollution in quiet office environments. From a thermodynamic performance perspective, the turbulence generated by such fans results in severe energy dissipation, insufficient effective airflow for chip surface cooling, and localized temperature anomalies caused by heat dissipation blind spots, leading to significant performance losses in semiconductor devices. Furthermore, the inherent defects of the mechanical structure make it difficult for the lifespan to exceed the 30,000-hour threshold. Summary of the Invention

[0003] This application discloses a piezoelectric cooling fan and electronic device. The piezoelectric cooling fan can reduce its size, reduce the space it occupies in the electronic device, and accurately control the airflow direction, reduce noise, and extend its service life.

[0004] To achieve the above objectives, this application provides the following technical solution: In a first aspect, this application provides a piezoelectric cooling fan, comprising: a housing and a piezoelectric vibration assembly, wherein the housing has a cavity; the piezoelectric vibration assembly is disposed within the cavity and separates the cavity along a first direction; the piezoelectric vibration assembly includes at least two piezoelectric vibration units spaced apart around the first direction, and the interval between adjacent piezoelectric vibration units of the at least two piezoelectric vibration units forms an air guiding channel; each piezoelectric vibration unit includes a diaphragm and a piezoelectric film disposed on at least one side of the diaphragm along the first direction, a portion of the periphery of the diaphragm is fixed to the housing, and the diaphragm is made of an organic polymer material; the piezoelectric film is capable of driving the diaphragm to vibrate along the first direction and compressing the air in the cavity; Along the first direction, the housing has an air channel on at least one side of the piezoelectric vibration assembly, the air channel connecting the cavity to the external environment.

[0005] In some embodiments, the diaphragm is made of polyethylene terephthalate or polyimide.

[0006] In some embodiments, along the first direction, the housing is provided with air channels on both sides of the piezoelectric vibration unit; and along the first direction, the air channel on one side of the piezoelectric vibration unit forms an air inlet channel, and the air channel on the other side of the piezoelectric vibration unit forms an air outlet channel.

[0007] In some embodiments, along the first direction, a piezoelectric film is provided on the side of the diaphragm facing the air outlet channel; the piezoelectric film includes a first electrode layer, a first substrate layer and a second electrode layer arranged sequentially along the first direction, and the second electrode layer is located on the side of the first substrate layer facing the diaphragm; the second electrode layer and the first electrode layer are configured to be applied with different voltages, and the piezoelectric film is configured to contract when energized.

[0008] In some embodiments, along the first direction, another piezoelectric film is provided on the side of the diaphragm opposite to the air outlet channel; the other piezoelectric film includes a third electrode layer, a second substrate layer and a fourth electrode layer arranged sequentially along the first direction, and the fourth electrode layer is located on the side of the second substrate layer facing the diaphragm; the second substrate layer has the same polarization direction as the first substrate layer, the third electrode layer and the first electrode layer are configured to be applied with the same voltage, the fourth electrode layer and the second electrode layer are configured to be applied with the same voltage, and the other piezoelectric film is configured to expand when energized.

[0009] In some embodiments, the piezoelectric vibration assembly includes two piezoelectric vibration units, and the two piezoelectric vibration units are arranged symmetrically.

[0010] In some embodiments, the piezoelectric cooling fan further includes a power supply unit, which is electrically connected to the piezoelectric film and is used to form an electric field within the piezoelectric film; the power supply unit is configured to output an adjustable sinusoidal alternating current of 0kV~2kV with a frequency range greater than 200 Hz.

[0011] In some embodiments, the housing includes a first part and a second part, the second part fastening the first part to form the cavity; the diaphragm in the piezoelectric vibration unit is fixed to the fastening portion of the first part and the second part.

[0012] Secondly, this application also provides an electronic device, including an electronic component and a piezoelectric cooling fan as provided in any of the technical solutions in the first aspect above, wherein the electronic component is located on one side of the piezoelectric cooling fan and is located within the air outlet path of the air channel of the piezoelectric cooling fan.

[0013] In some embodiments, the electronic device further includes a power supply unit comprising a DC power supply and an inverter. The inverter is connected between the DC power supply and the piezoelectric diaphragm of the piezoelectric cooling fan and is configured to convert the DC power output by the DC power supply into adjustable sinusoidal AC power for use by the piezoelectric diaphragm.

[0014] One embodiment of this application described above has at least the following advantages or beneficial effects: It should be noted that the piezoelectric cooling fan provided in this application utilizes the inverse piezoelectric effect of the material selected for the piezoelectric film to directly convert electrical energy into the vibration of the film, thereby eliminating the rotating parts in the fan. When using the piezoelectric cooling fan provided in this application, the piezoelectric film acts as a driving source, converting the input electrical signal into deformation of the film itself. The frequency and direction of the deformation are consistent with the input electrical signal, and the amplitude of the deformation is proportional to the amplitude of the input electrical signal. The diaphragm's function is to change the deformation direction of the piezoelectric film, converting the stretching / contraction deformation of the piezoelectric film into bending deformation of the diaphragm, thereby compressing the air in the cavity to form an airflow discharged from the air channel to dissipate heat from the electronic components. This achieves directional air pressure output within a micro-millimeter amplitude while maintaining the structural reliability of the device.

[0015] Meanwhile, in the piezoelectric vibration unit, the diaphragm is made of a highly deformable organic polymer material. Under the same driving force of the piezoelectric diaphragm, the diaphragm made of organic polymer material can produce greater deformation than the diaphragm made of metal parts. This allows it to better match the structural design of the cavity and air channel, optimize the vibration effect, increase the airflow rate and velocity, and enhance the heat dissipation effect on electronic components. Furthermore, a portion of the diaphragm is fixed to the housing, while the remaining portion acts as a free end, vibrating along a first direction under the drive of the piezoelectric diaphragm. This constraint method reduces vibration losses under the drive of the piezoelectric diaphragm, which is beneficial for further optimizing the airflow jet performance.

[0016] Furthermore, the piezoelectric cooling fan provided in this application has at least two piezoelectric vibration units spaced apart inside the housing, and the gap between adjacent units forms an air guide channel, allowing the air in the cavity to flow through both sides, thereby supplementing and compensating the airflow discharged from the air channel.

[0017] Accordingly, the piezoelectric cooling fan provided in this application drives the diaphragm to vibrate and compress the cavity to generate airflow, thereby directly generating high-speed directional laminar airflow. This enables active targeted heat dissipation inside electronic devices, which not only solves the problem of heat dissipation blind spots caused by the diffusion of airflow in hot areas of high-power chips due to traditional fans, but also reduces the operating noise to below the human ear perception threshold through low-frequency resonance regulation, eliminating mechanical wear and friction noise problems, and thus extending the service life. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of the electronic device provided in an embodiment of this application is shown; Figure 2 A schematic diagram of a piezoelectric cooling fan provided in an embodiment of this application is shown; Figure 3 A schematic diagram of another structure of the piezoelectric cooling fan provided in an embodiment of this application is shown; Figure 4 It shows Figure 3 A schematic diagram of a medium-voltage electric refrigeration fan from another angle; Figure 5 It shows Figure 3 Schematic diagram of the structure of a medium-voltage electric vibration unit; Figure 6 A schematic diagram of another structure of the piezoelectric cooling fan provided in an embodiment of this application is shown; Figure 7 It shows Figure 6 Schematic diagram of the structure of a medium-voltage electric vibration unit; Figure 8 It shows Figure 6 A schematic diagram of the structure of a medium-voltage electric refrigeration fan during use; Figure 9 This illustration shows another structural schematic diagram of the piezoelectric cooling fan provided in an embodiment of this application; Figure 10 It shows Figure 7 A comparative diagram showing the relationship between the curvature of the diaphragm and the ratio of the piezoelectric film thickness to the diaphragm thickness within the medium-sized piezoelectric resonator unit; Figure 11 The temperature curves of active heat dissipation and passive heat dissipation of copper sheet for the piezoelectric cooling fan provided in the embodiments of this application are shown. Figure 12 The wind speed test data of the piezoelectric cooling fan provided in the embodiment of this application are shown; Reference numerals: 1. Electronic device; 10. Piezoelectric cooling fan; 100. Housing; 110. First part; 120. Second part; 101. Cavity; 102. Air channel; 200. Piezoelectric vibration assembly; 210. Piezoelectric vibration unit; 211. Diaphragm; 212. Piezoelectric film; 2121. First substrate layer; 2122. First electrode layer; 2123. Second electrode layer; 2124. Second substrate layer; 2125. Third electrode layer; 2126. Fourth electrode layer; 300. Power supply unit; 20. Electronic component; A. Air guide channel. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application. In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships, for example, A and / or B can represent: A alone, A and B at the same time, and B alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0020] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0021] This application provides an electronic device. This electronic device can be an ultra-thin laptop, a micro-server, or a mobile terminal, etc. The heat dissipation requirements of the electronic components inside the device, such as the CPU (Central Processing Unit), are crucial. As the electronic components operate, the concentrated heat flux density continuously increases. If the heat cannot be dissipated in time, it will cause a sharp rise in chip temperature, leading to performance degradation, instability, or even permanent damage. Therefore, the heat dissipation structure in the electronic device must have the ability to quickly dissipate localized high heat to maintain stable operation of the components within a safe temperature range and ensure the long-term reliability and energy efficiency of the device.

[0022] This application provides an electronic device that uses a fan to actively cool electronic components. While fans offer advantages in heat dissipation efficiency, they also bring several significant drawbacks. In terms of spatial layout, the fan and its associated airflow structure occupy internal space, forcing the device to either increase in size or reduce the density of other components, limiting the design of thinner and more compact devices. Furthermore, the airflow from the fan can create heat dissipation blind spots, affecting the cooling effect on electronic components. Regarding noise pollution, the air turbulence and mechanical friction noise generated by the high-speed rotation of the fan create continuous background noise, especially when the load increases, as the fan speed increases significantly, severely impacting the user experience, particularly in environments requiring quiet or noise-sensitive applications. In terms of lifespan, as a mechanical moving part, the fan's bearings wear down over time, and dust accumulation accelerates performance degradation and increases the risk of failure, ultimately leading to decreased heat dissipation efficiency or fan failure. This becomes a weak point in the overall reliability of the device and may indirectly affect the long-term stability and lifespan of the electronic components due to insufficient heat dissipation.

[0023] Based on this, in order to address the problems of bulky size, high-frequency noise generated by mechanical rotation, inefficient heat dissipation due to airflow dispersion, and difficulty in accurately controlling the local airflow direction, this application provides an electronic device including a piezoelectric cooling fan. The piezoelectric cooling fan reduces its size, reduces its space occupation within the electronic device, and accurately controls the airflow direction, reduces noise, and extends its service life.

[0024] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown. Figure 1 As shown, this application embodiment provides an electronic device 1, which includes a piezoelectric cooling fan 10 and an electronic component 20, with the electronic component 20 located on one side of the piezoelectric cooling fan 10. It should be understood that the placement of the piezoelectric cooling fan 10 and the electronic component 20 within the electronic device 1 is not limited to... Figure 1 As shown, this is only an illustrative illustration, and the specific placement can be changed according to requirements. When arranging the piezoelectric cooling fan 10 and the electronic component 20, it is only necessary to ensure that the airflow output by the piezoelectric cooling fan 10 can effectively flow to the electronic component 20 to remove the heat from the surface of the electronic component 20 and dissipate it.

[0025] It should be understood that the piezoelectric cooling fan 10 is protected not only as part of the electronic device 1 provided in the embodiments of this application, but also separately protected by the embodiments of this application.

[0026] Figure 2 A schematic diagram of a piezoelectric cooling fan 10 provided in an embodiment of this application is shown. Figure 2As shown, the piezoelectric cooling fan 10 includes a housing 100 and a piezoelectric vibration assembly 200. The housing 100 has a cavity 101. The piezoelectric vibration assembly 200 is placed inside the cavity 101 and separates the cavity 101 along a first direction. It should be understood that the separation position of the piezoelectric vibration assembly 200 from the cavity 101 along the first direction is not limited to... Figure 1 As shown, the specific settings can be customized according to your needs.

[0027] Figure 3 This paper shows another structural schematic diagram of the piezoelectric cooling fan 10 provided in an embodiment of this application; Figure 4 It shows Figure 3 A structural schematic diagram of the medium-voltage electric cooling fan 10 from another angle. Please refer to... Figure 3 and Figure 4 refer to Figure 2 The structure shown indicates that the piezoelectric vibration assembly 200 includes two piezoelectric vibration units 210 spaced apart around a first direction, and the interval between adjacent piezoelectric vibration units 210 forms an air guiding channel A. It should be understood that the piezoelectric vibration assembly 200 contains at least two piezoelectric vibration units 210. Figure 3 and Figure 4 Only two are shown in the figure, but it is not limited to this. The piezoelectric vibration assembly 200 may also include three, four or more piezoelectric vibration units 210, which will not be described in detail here.

[0028] like Figure 3 and Figure 4 As shown, the piezoelectric vibration unit 210 includes a diaphragm 211 and a piezoelectric membrane 212 disposed on one side of the diaphragm 211 along a first direction. A portion of the periphery of the diaphragm 211 is fixed to the housing 100, and the diaphragm 211 is made of an organic polymer material to provide higher frequency and amplitude. The piezoelectric membrane 212 can drive the diaphragm 211 to vibrate along the first direction and compress the air in the cavity 101. Along the first direction, the housing 100 has an air channel 102 on at least one side of the piezoelectric vibration assembly 200, and the air channel 102 connects the cavity 101 to the external environment. Figure 1 The electronic component 20 shown is located as follows Figure 4 The piezoelectric cooling fan 10 is positioned within the air outlet path of the air channel 102, so that the airflow output from the air channel 102 can effectively remove heat from the location of the electronic component 20. It should be understood that the piezoelectric diaphragm 212 in the piezoelectric vibration unit 210 is disposed along a first direction on at least one side of the diaphragm 211. Figure 3 The piezoelectric film 212 is shown only on one side of the diaphragm 211, but is not limited thereto.

[0029] It should be noted that the piezoelectric cooling fan 10 provided in this embodiment utilizes the inverse piezoelectric effect of the material selected for the piezoelectric film 212 to directly convert electrical energy into the vibration of the film, thereby eliminating the rotating parts in the fan. When applying the piezoelectric cooling fan 10 provided in this embodiment, the piezoelectric film 212 acts as a driving source, converting the input electrical signal into the deformation of the film itself. The frequency and direction of the deformation are consistent with the input electrical signal, and the amplitude of the deformation is proportional to the amplitude of the input electrical signal. The function of the diaphragm 211 is to change the deformation direction of the piezoelectric film, converting the stretching / contraction deformation of the piezoelectric film into the bending deformation of the diaphragm 211, thereby compressing the air in the cavity 101 to form an airflow discharged from the air channel 102 to dissipate heat from the electronic component 20. This achieves directional air pressure output within a micro-millimeter amplitude while maintaining the structural reliability of the device.

[0030] Meanwhile, in the piezoelectric vibration unit 210, the diaphragm 211 is made of a highly deformable organic polymer material. Under the same driving force of the piezoelectric membrane 212, the diaphragm 211 made of organic polymer material can produce greater deformation than a diaphragm made of metal, thus better matching the structural design of the cavity 101 and the air channel 102, optimizing the vibration effect, increasing the airflow rate and velocity, and enhancing the heat dissipation effect on the electronic components 20. Furthermore, a portion of the diaphragm 211 is fixed to the housing 100, while the remaining portion serves as a free end, allowing it to vibrate along a first direction under the drive of the piezoelectric membrane 212. This constraint method reduces vibration losses under the drive of the piezoelectric membrane 212, which is beneficial for further optimizing the airflow jet performance.

[0031] Furthermore, the piezoelectric cooling fan 10 provided in this application embodiment has at least two piezoelectric vibration units 210 spaced apart inside the housing 100. The gap between adjacent units forms an air guide channel A, allowing the air in the cavity 101 to flow through both sides, thereby supplementing and compensating the airflow discharged from the air channel 102.

[0032] Accordingly, the piezoelectric cooling fan 10 provided in this application generates airflow by driving the piezoelectric thin diaphragm 211 to vibrate and compress the cavity 101, thereby directly generating high-speed directional laminar airflow. This achieves active targeted heat dissipation inside the electronic device 1, which not only solves the problem of heat dissipation blind spots caused by the diffusion of airflow in the hot spots of high-power chips due to traditional fans, but also reduces the operating noise to below the human ear perception threshold through low-frequency resonance regulation, eliminating mechanical wear and friction noise problems, and thus extending the service life.

[0033] It is worth noting that you should continue to refer to [the relevant information]. Figure 1The piezoelectric cooling fan 10 provided in this embodiment is particularly suitable for the dense heat dissipation needs of chipsets in electronic devices 1 such as ultra-thin laptops, micro servers, or mobile terminals. For example, the piezoelectric cooling fan 10 can be used in miniaturized package structures with a thickness of less than 3 mm to dissipate heat from internal electronic components 20, while completely eliminating mechanical friction noise sources. By adjusting the resonant frequency of the thin film in the low-frequency range, the operating noise is controlled below the human hearing perception threshold.

[0034] In some embodiments, the diaphragm 211 can be made of polyethylene terephthalate or polyimide. Of course, the diaphragm 211 can also be made of other organic polymer materials, which will not be elaborated here.

[0035] When specifically configuring the piezoelectric cooling fan 10 provided in this application embodiment, the housing 100 can be configured to form an air channel 102 only on one side of the piezoelectric vibration unit 210. In this case, the air channel 102 serves as both an air inlet channel and an air outlet channel. Alternatively, as... Figure 3 As shown, in some embodiments, the housing 100 is provided with air channels 102 on both sides of the piezoelectric vibration unit 210 along the first direction; and along the first direction, the air channel 102 on one side of the piezoelectric vibration unit 210 forms an air inlet channel, and the air channel 102 on the other side of the piezoelectric vibration unit 210 forms an air outlet channel.

[0036] It is worth noting that, such as Figure 3 As shown, an air inlet channel and an air outlet channel are respectively arranged on both sides of the piezoelectric vibration unit 210 along the first direction, which can realize the physical separation and unidirectional guidance of the airflow path. This separate design of the air inlet and outlet channels can effectively avoid the mixing and short-circuiting of the inlet and outlet airflows within the cavity 101, reduce flow interference and pressure loss, thereby improving the directionality of the airflow driven by the piezoelectric diaphragm 211 and the overall ventilation efficiency. At the same time, the separate channel layout is conducive to establishing a stable and continuous "intake-exhaust" airflow, enhancing the airflow coverage intensity and heat exchange effect on the heat dissipation target area, and ultimately achieving a more concentrated and controllable targeted heat dissipation capability.

[0037] When specifically designing air inlet and outlet channels, their structures and arrangements can be the same or different. For example... Figure 3 There are multiple air outlet ducts and multiple air inlet ducts, with the number of inlet ducts being less than the number of outlet ducts. Alternatively, there can be only one outlet duct and one inlet duct; the specific configuration can be determined according to requirements and will not be elaborated upon here. Furthermore, the location of the outlet ducts and inlet ducts within the housing 100 is not limited to their relative positions in the first direction; they may also be unrelated.

[0038] When specifically setting up the piezoelectric vibration unit 210, there are multiple possibilities for the arrangement of the piezoelectric film 212 on the surface of the diaphragm 211, which can be one of the following structural forms.

[0039] Figure 5 It shows Figure 3 A structural schematic diagram of the medium-voltage electric vibration unit 210. Please refer to... Figure 3 refer to Figure 5 In some embodiments of the structure shown, a piezoelectric film 212 is provided on the side of the diaphragm 211 facing the air outlet duct along the first direction. The piezoelectric film 212 includes a first electrode layer 2122, a first substrate layer 2121, and a second electrode layer 2123 arranged sequentially along the first direction, with the second electrode layer 2123 located on the side of the first substrate layer 2121 facing the diaphragm 211. The second electrode layer 2123 and the first electrode layer 2122 are configured to be subjected to different voltages, and the piezoelectric film 212 is configured to contract when energized. It should be understood that the contraction of the piezoelectric film 212 when energized means that the voltage direction applied to the first electrode layer 2122 and the second electrode layer 2123 is opposite to the polarization direction.

[0040] The materials used to prepare the first substrate layer 2121 include, but are not limited to, piezoelectric polymers such as poly(L-lactic acid), poly(D-lactic acid), or polyvinylidene fluoride, to ensure sufficient amplitude and frequency. The electrode materials selected for the first electrode layer 2122 and the second electrode layer 2123 include, but are not limited to, gold, silver, copper, aluminum, indium tin oxide, etc.

[0041] It should be noted that, in this embodiment, the piezoelectric cooling fan 10, by placing the piezoelectric diaphragm 212 on the side of the diaphragm 211 facing the air outlet channel, can directly and efficiently drive the diaphragm 211 to vibrate towards the air outlet channel through the energized contraction of the piezoelectric diaphragm 212 when different voltages are applied. This layout and electrical configuration can convert electrical energy into directional mechanical deformation, enhancing the driving effect of the diaphragm 211 on the airflow, thereby improving the concentration and air pressure of the airflow output, which is beneficial for achieving more precise and efficient directional heat dissipation.

[0042] Furthermore, along the first direction, the piezoelectric film 212 can also be disposed on the side of the diaphragm 211 facing away from the air outlet channel. In this case, the placement of the piezoelectric film 212 is relatively... Figure 5 Located on the opposite side of the diaphragm 211 in the first direction, the piezoelectric membrane 212 is configured to expand when energized, thereby driving the diaphragm 211 to vibrate. It should be understood that the piezoelectric membrane 212 expands when energized, meaning the voltage applied to the first electrode layer 2122 and the second electrode layer 2123 is in the same direction as the polarization direction. However, this structure requires a large deformation of the piezoelectric membrane 212 to achieve the desired effect. Figure 5 The piezoelectric film 212 shown can produce the same vibration effect as the diaphragm 211.

[0043] Figure 6 A schematic diagram of another structure of the piezoelectric cooling fan 10 provided in an embodiment of this application is shown; Figure 7 It shows Figure 6 A structural schematic diagram of the medium-voltage electric vibration unit 210. Please refer to... Figure 7 refer to Figure 6 In some embodiments of the structure shown, along the first direction, another piezoelectric film 212 is provided on the side of the diaphragm 211 facing away from the air outlet channel; this other piezoelectric film 212 includes a third electrode layer 2125, a second substrate layer 2124, and a fourth electrode layer 2126 arranged sequentially along the first direction, and the fourth electrode layer 2126 is located on the side of the second substrate layer 2124 facing the diaphragm 211; the polarization direction of the second substrate layer 2124 is the same as that of the first substrate layer 2121, the third electrode layer 2125 and the first electrode layer 2122 are configured to be subjected to the same voltage, the fourth electrode layer 2126 and the second electrode layer 2123 are configured to be subjected to the same voltage, and the other piezoelectric film 212 is configured to expand when energized. It should be understood that... Figure 7 The polarization direction is illustrated by arrows in the example. The materials used to prepare the second substrate layer 2124 include, but are not limited to, piezoelectric polymers such as poly(L-lactic acid), poly(D-lactic acid), or polyvinylidene fluoride, to ensure sufficient amplitude and frequency. The electrode materials selected for the third electrode layer 2125 and the fourth electrode layer 2126 include, but are not limited to, gold, silver, copper, aluminum, and indium tin oxide.

[0044] In this embodiment, the piezoelectric cooling fan 10 has piezoelectric films 212 on both sides of the inner diaphragm 211 in the first direction. This structure is different from... Figure 5 The structure shown is equivalent to adding another piezoelectric film 212. For example... Figure 7 As shown, in the piezoelectric vibration unit provided in this application embodiment, the piezoelectric films 212 on both sides of the position diaphragm 211 have the same polarization direction, except that they are subjected to opposite voltages.

[0045] Figure 8 It shows Figure 6 A structural diagram of the medium-voltage electric refrigeration fan 10 during use. Please refer to... Figure 6 refer to Figure 8 In the illustrated structure, along the first direction, the piezoelectric membrane 212 located on the side of the diaphragm 211 opposite to the air outlet channel can expand and deform when energized, thereby forming a cooperative drive for the diaphragm 211 together with the contracting piezoelectric membrane 212 on the other side. Exemplarily, the diaphragm 211 can be driven by the cooperative action of the piezoelectric membranes 212 on both sides. Figure 6 Vibration at the indicated position Figure 8 The position shown; the piezoelectric film 212 is to recover its deformation, and the diaphragm 211 can be formed by... Figure 8 The position shown has been restored to Figure 6 The location shown.

[0046] It should be noted that the collaborative driving mechanism in this embodiment can enhance the overall amplitude and vibration energy of the diaphragm 211, effectively improve the efficiency and wind pressure of air jet, and make the diaphragm 211 more evenly stressed and more stable in motion, which is conducive to achieving higher performance and more reliable unidirectional airflow output.

[0047] When setting up the piezoelectric cooling fan 10, the number or arrangement of the piezoelectric vibration units 210 within the piezoelectric vibration assembly 200 can be configured according to requirements. In one embodiment, such as Figure 3 , Figure 4 and Figure 6 As shown, the piezoelectric vibration assembly 200 includes two piezoelectric vibration units 210, and Figure 4 The inner diaphragm 211 of the medium-voltage electric vibration unit 210 is shown in a rectangular form as an example.

[0048] In some embodiments, such as Figure 6 As shown, the piezoelectric vibration assembly 200 includes two piezoelectric vibration units 210, which are symmetrically arranged. This structural arrangement enables a dynamic balance between mechanical vibration and airflow drive, effectively counteracting the asymmetric stress or deflection load that may be generated when a single piezoelectric vibration unit 210 is working, thereby improving the stability and reliability of the overall structure. Simultaneously, the symmetrical layout facilitates the directional injection of high-frequency pulsed airflow, enhancing the superposition and guiding effect of airflow output within the cavity 101. This allows for the generation of higher flow rates or air pressures under the same power consumption, significantly improving heat dissipation efficiency and temperature uniformity, and reducing noise and device fatigue caused by vibration imbalance.

[0049] Figure 9 This paper shows another structural schematic diagram of the piezoelectric cooling fan 10 provided in an embodiment of this application, as shown below. Figure 9 As shown, in another embodiment, the piezoelectric vibration assembly 200 includes four piezoelectric vibration units 210, and Figure 9 The inner diaphragm 211 of the piezoelectric vibrating unit 210 is exemplary shown in a quarter-circle. It is worth noting that the different piezoelectric vibrating units 210 in the piezoelectric vibrating assembly 200 may be arranged in the same or different ways.

[0050] It is worth noting that the thickness and shape of the diaphragm 211 can be customized according to requirements. For example, as Figure 4 The rectangle shown, or, as Figure 9 The quarter circle shown.

[0051] When the piezoelectric film 212 is arranged on the surface of the diaphragm 211, the size and shape of the piezoelectric film 212 can be set according to requirements. For example, when the piezoelectric film 212 is arranged on the surface of the diaphragm 211, the diaphragm 211 can be covered by the piezoelectric film 212 as much as possible, except for the periphery fixed to the housing 100. Furthermore, the piezoelectric film 212 covering the same side of the diaphragm 211 can be multiple pieces or a single piece. As an example, such as... Figure 6 As shown, the piezoelectric membranes 212 located on both sides of the diaphragm 211 in the piezoelectric vibration unit 210 correspond to each other in order to enhance the driving effect of the piezoelectric membranes 212 on the diaphragm 211.

[0052] In some embodiments, such as Figure 2 As shown, the piezoelectric cooling fan 10 also includes a power supply unit 300, which is electrically connected to the piezoelectric film 212, such as by a wire, to form an electric field within the piezoelectric film 212. It should be understood that the power supply unit 300 can be a high-frequency voltage source. In this embodiment, the power supply unit 300 is an integral part of the piezoelectric cooling fan 10. The high-frequency voltage source can be a miniaturized integrated circuit manufactured using microelectromechanical systems (MEMS) technology. The power supply unit 300 is configured to output an adjustable sinusoidal alternating current of 0kV to 2kV with a frequency range greater than 200 Hz.

[0053] It is worth noting that when piezoelectric membranes 212 are provided on both sides of the diaphragm 211 in the first direction in the piezoelectric vibration unit 210, the two piezoelectric membranes 212 corresponding to the same diaphragm 211 can be controlled by the same high-frequency voltage source, except that the wires are reversed, so as to precisely control the phase difference between the two to 180° and realize the reverse deformation synchronization of the two piezoelectric membranes 212.

[0054] like Figure 7 As shown, in the piezoelectric vibration unit 210, the second electrode layer 2123 and the fourth electrode layer 2126 are shown carrying the same potential to avoid the difference in potential on both sides of the diaphragm 211, which would cause it to be broken down by high voltage, thereby improving the service life of the diaphragm 211.

[0055] In other embodiments, the power supply unit 300 can be integrated with the piezoelectric cooling fan 10 into a portable electronic device 1, powering the piezoelectric cooling fan 10 by converting the DC power provided by the portable electronic device into high-frequency AC power. In the embodiments of this application, the power supply unit 300 can be a high-frequency voltage source, which and the piezoelectric cooling fan 10 are two independent devices connected by wires.

[0056] As an example, the power supply unit 300 includes a DC power supply and an inverter connected between the DC power supply and the piezoelectric diaphragm 212, and is configured to convert the DC power output from the DC power supply into adjustable sinusoidal AC power for use by the piezoelectric diaphragm.

[0057] In some embodiments, such as Figure 6 As shown, the housing 100 includes a first part 110 and a second part 120, with the second part 120 engaging with the first part 110 to form a cavity 101. The diaphragm 211 in the piezoelectric vibration unit 210 is fixed to the engaging portion of the first part 110 and the second part 120. It should be understood that the periphery of the diaphragm 211 may be partially located within the engaging area of ​​the first part 110 and the second part 120 for fixation by the assembled housing 100. Of course, the diaphragm 211 can also be fixed to the housing 100 by means of adhesive bonding, etc., which will not be elaborated further.

[0058] Furthermore, the packaging form of the housing 100 is not limited to the aforementioned snap-fit ​​connection, and can be configured in other ways as needed; the material and shape of the housing 100 can also be configured as needed, and are not limited to... Figure 4 The rectangle shown, or Figure 9 The shape is circular as shown. Furthermore, the shape and size of the cavity 101 within the housing 100 are not limited to... Figure 6 As shown, you can configure it according to your needs.

[0059] In the piezoelectric cooling fan 10 provided in this application embodiment, the formula for calculating the curvature of the diaphragm 211 is as follows:

[0060] in: This indicates the curvature of diaphragm 211; A represents the radius of curvature; B represents the ratio of the Young's modulus of the piezoelectric film 212 and the diaphragm 211; C represents the ratio of the thickness of the piezoelectric film 212 and the diaphragm 211. S represents the thickness of the diaphragm 211 in the first direction; S represents the deformation of the piezoelectric film 212.

[0061] It is worth noting that Young's modulus is an inherent property of a material. Once the material is selected, the Young's modulus of that material is also a constant. The larger the electric field, the greater the deformation of the piezoelectric film 212, which is positively correlated with the electric field. Moreover, the deformation varies between different materials.

[0062] As an example Figure 10 It shows Figure 7 A comparison diagram showing the curvature of the diaphragm 211 within the piezoelectric vibrating unit 210 and the thickness ratio of the piezoelectric film 212 to the diaphragm 211. The piezoelectric film 212 can be made of PVDF (polyvinylidene fluoride); the diaphragm 211 can be made of PET (polyethylene terephthalate); S is preset to 3%. This indicates the thickness of the piezoelectric film 212 in the first direction. For example... Figure 10As shown, when the thickness ratio of PVDF to PET is 0.5, the diaphragm 211 vibrates at its maximum amplitude.

[0063] Of course, when the internal space of the electronic device 1 is limited, the size of the piezoelectric cooling fan 10 will also be compressed, and consequently, the thickness of the piezoelectric vibration unit 210 in the first direction may be only a few millimeters.

[0064] A heat dissipation test was conducted using the piezoelectric cooling fan 10 based on the piezoelectric film 212 provided in the embodiments of this application. The temperature curves for passive heat dissipation of the copper sheet and active heat dissipation using the piezoelectric cooling fan 10 are shown below. Figure 11 As shown. Figure 11 In the diagram, curve a represents the active cooling curve, and curve b represents the passive cooling curve. Curves a and b are referenced on the horizontal and left vertical axes, respectively. Curve c represents the temperature difference between the two cooling methods, referenced on the horizontal and right vertical axes. Compared to passive cooling, active cooling has already generated a temperature difference of 3°C by the 200th second. Therefore, this piezoelectric cooling fan 10 can be used for cooling the CPU in portable electronic devices.

[0065] The piezoelectric cooling fan 10 based on the piezoelectric film 212 provided in this application embodiment was used to conduct wind speed tests. The wind speed data plotted based on the data measured by the thermal anemometer is as follows: Figure 12 As shown in the data, the maximum wind speed can reach 1.89 m / s at the resonant frequency, indicating that the piezoelectric cooling fan 10 has a strong heat dissipation capacity.

[0066] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A piezoelectric cooling fan, characterized in that, include: A housing and a piezoelectric vibration assembly are provided. The housing has a cavity. The piezoelectric vibration assembly is placed inside the cavity and separates the cavity along a first direction. The piezoelectric vibration assembly includes at least two piezoelectric vibration units spaced apart around the first direction, and the interval between adjacent piezoelectric vibration units forms an air guiding channel. Each piezoelectric vibration unit includes a diaphragm and a piezoelectric membrane disposed on at least one side of the diaphragm along the first direction. A portion of the periphery of the diaphragm is fixed to the housing, and the diaphragm is made of an organic polymer material. The piezoelectric membrane can drive the diaphragm to vibrate along the first direction and compress the air inside the cavity. Along the first direction, the housing has an air channel on at least one side of the piezoelectric vibration assembly, the air channel connecting the cavity to the external environment.

2. The piezoelectric cooling fan according to claim 1, characterized in that, The diaphragm is made of polyethylene terephthalate or polyimide.

3. The piezoelectric cooling fan according to claim 1, characterized in that, Along the first direction, the housing is provided with air channels on both sides of the piezoelectric vibration unit; and along the first direction, the air channel on one side of the piezoelectric vibration unit forms an air inlet channel, and the air channel on the other side of the piezoelectric vibration unit forms an air outlet channel.

4. The piezoelectric cooling fan according to claim 3, characterized in that, Along the first direction, a piezoelectric film is provided on the side of the diaphragm facing the air outlet channel; the piezoelectric film includes a first electrode layer, a first substrate layer and a second electrode layer arranged sequentially along the first direction, and the second electrode layer is located on the side of the first substrate layer facing the diaphragm; the second electrode layer and the first electrode layer are configured to be applied with different voltages, and the piezoelectric film is configured to contract when energized.

5. The piezoelectric cooling fan according to claim 4, characterized in that, Along the first direction, another piezoelectric film is provided on the side of the diaphragm away from the air outlet channel; the other piezoelectric film includes a third electrode layer, a second substrate layer and a fourth electrode layer arranged sequentially along the first direction, and the fourth electrode layer is located on the side of the second substrate layer facing the diaphragm; the second substrate layer has the same polarization direction as the first substrate layer, the third electrode layer and the first electrode layer are configured to be applied with the same voltage, the fourth electrode layer and the second electrode layer are configured to be applied with the same voltage, and the other piezoelectric film is configured to expand when energized.

6. The piezoelectric cooling fan according to any one of claims 1-5, characterized in that, The piezoelectric vibration assembly includes two piezoelectric vibration units, and the two piezoelectric vibration units are arranged symmetrically.

7. The piezoelectric cooling fan according to any one of claims 1-5, characterized in that, The piezoelectric cooling fan also includes a power supply unit, which is electrically connected to the piezoelectric film and is used to form an electric field within the piezoelectric film. The power supply unit is configured to output an adjustable sinusoidal alternating current of 0kV to 2kV with a frequency range greater than 200 Hz.

8. The piezoelectric cooling fan according to any one of claims 1-5, characterized in that, The housing includes a first part and a second part, the second part being fastened to the first part to form the cavity; the diaphragm in the piezoelectric vibration unit is fixed to the fastening part of the first part and the second part.

9. An electronic device, characterized in that, Includes electronic components and a piezoelectric cooling fan as described in any one of claims 1-8, wherein the electronic components are located on one side of the piezoelectric cooling fan and within the air outlet path of the air passage of the piezoelectric cooling fan.

10. The electronic device according to claim 9, characterized in that, The electronic device further includes a power supply unit, which includes a DC power supply and an inverter. The inverter is connected between the DC power supply and the piezoelectric diaphragm of the piezoelectric cooling fan and is configured to convert the DC power output by the DC power supply into adjustable sinusoidal AC power for use by the piezoelectric diaphragm.

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