MEMS (Micro Electro Mechanical System) fan, manufacturing method thereof, equipment and medium

Abstract

The invention discloses an MEMS fan, a manufacturing method thereof, equipment and a medium. According to the MEMS fan scheme, the top layer of a cantilever beam structure is covered with an organic film to form a closed layer, an edge silicon cantilever beam is arranged on the edge of a cantilever beam, and an island-shaped silicon wafer is arranged in the center of the cantilever beam, so that the vibration amplitude of the organic film is increased, and the air outlet amount is increased.

Description

Technical Field

[0001] This application belongs to the field of MEMS fans, and in particular relates to a MEMS fan and its manufacturing method, equipment and medium. Background Technology

[0002] As electronic products rapidly evolve towards miniaturization and high integration, the heat density of their internal components increases significantly, making heat dissipation a key bottleneck restricting product performance and reliability. Traditional heat dissipation solutions, such as using large fans or passive cooling modules, often fail to meet the stringent requirements of ultra-thin, compact electronic devices for heat dissipation space, noise, and efficiency.

[0003] Currently, the mainstream heat dissipation technologies for electronic devices mainly include the following: Active fan cooling: Traditional rotary fans generate airflow to remove heat by rotating blades. However, these fans have drawbacks such as large size, high power consumption, high noise, and short lifespan due to mechanical wear, making them unsuitable for the heat dissipation needs of ultra-thin, quiet products such as smartphones and wearable devices. Furthermore, due to their structure, traditional fans struggle to achieve precise, localized heat dissipation.

[0004] Passive cooling (such as heat sinks and heat pipes): Passive cooling relies on the heat conduction and convection of materials and has no moving parts, so it is noiseless and wear-free. However, its heat dissipation efficiency is relatively low, especially in applications with limited space or high heat flux density, where its heat dissipation capacity is often insufficient to meet the requirements.

[0005] To overcome the limitations of traditional heat dissipation solutions, MEMS fans have emerged. MEMS technology integrates micron-sized mechanical components and electronic circuits onto a single chip. MEMS devices are characterized by small size, low power consumption, high integration, and low mass production costs. The piezoelectric effect refers to the mechanical deformation of certain materials when an electric field is applied. MEMS fans utilize MEMS micromachining technology to precisely construct piezoelectric drive units, using the high-frequency vibration of piezoelectric materials to convert air into directional, high-speed microjets, thereby achieving precise and efficient cooling of the heat source.

[0006] The inventors discovered that common MEMS fan designs typically involve pairs of opposing silicon cantilever arms. Applying a voltage to the piezoelectric material on these arms causes them to vibrate up and down, generating airflow. The gap between the opposing cantilever arms must be as small as a few micrometers; otherwise, air will leak downwards, failing to increase air pressure. Furthermore, to ensure quiet operation, the resonant frequency of the cantilever pair needs to be increased to make the fan noise inaudible. However, achieving such a high resonant frequency requires the silicon cantilever arms to be designed to be relatively small, which in turn increases the gap between the arms, reduces the airflow per minute, and lowers the jet velocity. These designs struggle to meet the requirements of both high-efficiency and quiet operation. Therefore, a solution for efficient, quiet, and well-directional airflow is needed. Summary of the Invention

[0007] To address the challenge of improving the design of MEMS fans in existing technologies, thereby meeting the demands for enhanced airflow efficiency and quiet operation, the technical solution proposed in this application is as follows: On the one hand, a MEMS fan is provided, comprising: The top is a rectangular enclosure with an air outlet in the center of the top and an air inlet at the bottom or side edge. The encapsulation housing has a cantilever beam structure with a quadrilateral top. Two edge silicon cantilever arms of the same shape and size extend from the left and right sides of the cantilever beam toward the center, and an island silicon wafer is set in the center of the cantilever beam. A piezoelectric thin film layer is set on a part of the edge silicon cantilever arms, but no piezoelectric thin film layer is set on the island silicon wafer. The top layer of the cantilever beam structure is covered with an organic film to form a sealing layer. When a voltage is applied to the piezoelectric thin film layer, the edge silicon cantilever vibrates up and down, which in turn causes the organic film of the sealing layer and the island silicon wafer to vibrate up and down, so that the airflow is guided from the air inlet of the package shell to the air outlet and ejected from the air outlet.

[0008] In some embodiments, the resonant frequency of the edge silicon cantilever is above 20 kHz.

[0009] In some embodiments, the piezoelectric thin film layer includes a PZT thin film layer.

[0010] In some embodiments, the area of ​​a single edge silicon cantilever is smaller than the area of ​​the gap between the edge silicon cantilever and the island silicon wafer.

[0011] In some embodiments, the encapsulation housing has multiple cantilever beam structures with rectangular tops inside, and the long sides of the cantilever beam structures are joined together in pairs so that the multiple cantilever beam structures are arranged in a row. The encapsulation housing has a slit-shaped air outlet at the center of the top of each cantilever beam structure. Among them, the two long sides of the cantilever beam extend towards the center to form two edge silicon cantilever arms of the same shape and size, and the shape, size and position of the island silicon wafer are adapted to the slit-shaped air outlet.

[0012] In some embodiments, the encapsulation housing has multiple cantilever beam structures with square tops inside, and the multiple cantilever beam structures are fitted together so that the multiple cantilever beam structures are arranged in a square. The encapsulation housing has a circular air outlet at the center of the top of each cantilever beam structure. Among them, the cantilever beam structure has four edge silicon cantilever arms of the same shape and size extending from each side toward the center, and the shape, size and position of the island silicon wafers are adapted to the round hole-shaped air outlet.

[0013] In some embodiments, the organic film is made of polyimide. In another aspect, a method for manufacturing the above-mentioned MEMS fan is provided, comprising the steps of: A piezoelectric film including upper and lower electrodes is fabricated on an SOI substrate using a sputtering process. The piezoelectric film, including the upper and lower electrodes, is patterned, i.e., etched after the shape of the insulating layer is formed. The shape of edge silicon cantilever and island silicon wafers is formed through the Si etching process; Thermal polymerization is achieved by coating the upper surface of the edge silicon cantilever, the upper surface of the island silicon wafer, the gap between them, and the upper surface of the piezoelectric thin film layer with an organic film. After reverse etching of the Si substrate, the SiO2 layer is removed from the back side by etching. Make the packaging shell.

[0014] In some embodiments, the organic film is made of polyimide, and etching is performed using the DRIE method.

[0015] On another front, a MEMS fan fabrication apparatus is provided, comprising a memory and a processor coupled to each other, wherein the processor is used to execute program instructions stored in the memory to implement the aforementioned MEMS fan fabrication method.

[0016] On another front, a computer-readable storage medium is provided, on which program instructions are stored, which, when executed by a processor, implement the aforementioned method for manufacturing a MEMS fan.

[0017] The beneficial effects of this application are as follows: A MEMS fan is provided, comprising: a rectangular top enclosure with an air outlet at the center of the top and an air inlet at the bottom or side edge; an internal cantilever beam structure with a quadrilateral top, with two identical edge silicon cantilever arms extending from the left and right sides of the cantilever beam towards the center, and an island-shaped silicon wafer at the center of the cantilever beam; a portion of the edge silicon cantilever arms is provided with a piezoelectric thin film layer, while the island-shaped silicon wafer is not provided with a piezoelectric thin film layer; the top layer of the cantilever beam structure is covered with an organic film to form a sealing layer; when a voltage is applied to the piezoelectric thin film layer, the edge silicon cantilever arms vibrate up and down, causing the organic film of the sealing layer and the island-shaped silicon wafer to vibrate up and down, so that airflow is guided from the air inlet of the enclosure to the air outlet and ejected from the air outlet. This application's solution, by covering the top layer of the cantilever beam structure with an organic film to form a sealing layer, and by providing edge silicon cantilever arms at the edge of the cantilever beam and an island-shaped silicon wafer at the center of the cantilever beam, increases the vibration amplitude of the organic film, thereby increasing the amount of air discharged. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a frame of an embodiment of a cantilever beam structure in the prior art; Figure 2 This is a schematic cross-sectional view of the frame of an embodiment of a MEMS fan in the prior art; Figure 3 This is a perspective view of a frame of an embodiment of the cantilever beam structure of this application; Figure 4 This is a schematic cross-sectional view of the frame of an embodiment of the MEMS fan of this application; Figure 5 This is a perspective view of the frame of another embodiment of the cantilever beam structure of this application; Figure 6 This is a perspective view of a frame of one embodiment of a cantilever beam structure according to this application; Figure 7 This is a cross-sectional schematic diagram of the frame of another embodiment of the MEMS fan in this application; Figure 8A This is a perspective view of a frame of another embodiment of a cantilever beam structure according to this application; Figure 8B This is a cross-sectional schematic diagram of the frame of another embodiment of the MEMS fan in this application; Figure 9 These are a perspective view and a cross-sectional view of a frame, representing another embodiment of a cantilever beam structure according to this application. Figure 10 This is a schematic diagram of the fabrication process of an embodiment of the MEMS fan of this application; Figure 11A This is a cross-sectional schematic diagram showing the structural changes of an embodiment of the MEMS fan fabrication method of this application; Figure 11BThis is a cross-sectional schematic diagram showing the structural changes in an embodiment of the fabrication method of the cantilever beam structure in the MEMS fan of this application; Figure 11C This is a cross-sectional schematic diagram showing the structural changes in an embodiment of the fabrication method of the cantilever beam structure in the MEMS fan of this application; Figure 11D This is a cross-sectional schematic diagram showing the structural changes in an embodiment of the fabrication method of the cantilever beam structure in the MEMS fan of this application; Figure 11E This is a cross-sectional schematic diagram showing the structural changes in an embodiment of the fabrication method of the cantilever beam structure in the MEMS fan of this application; Figure 12 This is a schematic diagram of the frame of an embodiment of the MEMS fan fabrication equipment of this application; Figure 13 This is a schematic diagram of a framework of an embodiment of the computer-readable storage medium of this application.

[0019] The attached figures are labeled as follows: 1. Cantilever beam structure; 10. Gap section; 11. Cantilever beam; 12. Piezoelectric thin film layer; 131. Edge silicon cantilever; 132. Island silicon wafer; 133. Edge silicon hammer; 134. Island silicon hammer; 135. Silicon cantilever; 14. Organic film; 21. Encapsulation shell; 22. Air outlet; 23. Air inlet. Detailed Implementation

[0020] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0021] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application.

[0022] The following are the definitions of the technical terms used in the embodiments of this application: MEMS: Micro-Electro-Mechanical Systems SOI: Silicon on Insulator Silicon cantilever: A fundamental microstructure in the field of microelectromechanical systems (MEMS). It is usually made of silicon, a semiconductor material, with one end fixed to a substrate and the other end suspended freely, hence the name "cantilever".

[0023] The specific contents of this application will be described in detail below with reference to specific embodiments.

[0024] This application relates to the structural design and fabrication of a MEMS fan.

[0025] With the increasing miniaturization and high integration of electronic devices, localized heat dissipation has become an increasingly prominent issue. Traditional cooling fans have the following limitations: Size limitations: Traditional fans are difficult to shrink further, making them unable to meet the heat dissipation needs of ultra-thin devices (such as smartphones and tablets).

[0026] Noise issue: Traditional fans generate noise during operation, which affects the user experience.

[0027] Wear and tear on moving parts: Traditional fans have rotating parts that are prone to wear and tear, have a short lifespan, and easily accumulate dust.

[0028] Efficiency and Directionality: Traditional plate piezoelectric fans are insufficient in terms of air volume and directionality, making it difficult to meet the precise cooling needs of specific directions.

[0029] To address the shortcomings of traditional piezoelectric fans, the technological development of MEMS fans mainly focuses on the following aspects: Miniaturization and integration: By utilizing MEMS microfabrication technology, the size of the fan can be further reduced and it can be tightly integrated with the heat source, or even directly integrated into the chip package.

[0030] Optimize airflow patterns: Break free from the limitations of traditional fan blades and generate high-speed, directional microjet streams through the vibration of piezoelectric elements to more effectively remove heat. For example, Frore Systems' AirJet technology converts air into high-speed jets through a micro piezoelectric vibrating diaphragm.

[0031] For details, please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of a frame of an embodiment of a cantilever beam structure in the prior art. Figure 2 This is a schematic cross-sectional view of the frame of an embodiment of a MEMS fan in the prior art.

[0032] The inventors discovered through research that, for example Figure 1 and Figure 2In the existing technology shown, the traditional MEMS fan structure is as follows: an air outlet and an air inlet are set on the package shell, and a rectangular cantilever beam structure is set inside the package shell. Two cantilever arms extend from the left and right sides of the cantilever beam towards the center. The gap between the cantilever arms is very small. A piezoelectric thin film layer is set on each cantilever arm, causing the cantilever arm to vibrate up and down and generate compressed air, which is then guided from the air inlet of the package shell to the air outlet and ejected. With the development of technology and the times, smart devices are being designed to be thinner and thinner, posing an increasing challenge to MEMS jet fans as heat dissipation devices. There is a desire for thinner fans with a larger air volume. Therefore, improvements to traditional MEMS fans are needed. Through in-depth research, the inventors believe that the following issues require improvement: 1. The gap between the cantilever arms needs to be set to a range of a few micrometers; otherwise, air will leak and the air pressure will not increase.

[0033] 2. In order to make the vibration frequency of the cantilever reach 20KHz or higher and ensure that the sound of the fan is inaudible to the human ear, the cantilever needs to be designed to be relatively small or thick. This results in the gap between the cantilever becoming larger when it vibrates up and down, and the air compression effect is not good. This not only reduces the exhaust volume per minute, but also reduces the jet wind speed.

[0034] 3. Each cantilever is only connected and supported at one end, making it prone to breakage due to long-term high-frequency vibration.

[0035] In view of this, this application provides a MEMS fan, including: a rectangular package 21, an air outlet 22 is provided at the center of the top of the package 21, and an air inlet 23 is provided at the bottom or side edge of the package 21. The encapsulation housing 21 has a cantilever beam structure 1 with a quadrilateral top. Two edge silicon cantilever arms 131 of the same shape and size extend from the left and right sides of the cantilever beam 11 towards the center. An island silicon wafer 132 is set at the center of the cantilever beam 11. A piezoelectric thin film layer 12 is set on a part of the edge silicon cantilever arm 131, but no piezoelectric thin film layer 12 is set on the island silicon wafer 132. The top layer of the cantilever beam structure 1 is covered with an organic film 14 to form a sealing layer. When a voltage is applied to the piezoelectric thin film layer 12, the edge silicon cantilever 131 vibrates up and down, which in turn causes the organic film 14 of the sealing layer and the island silicon wafer 132 to vibrate up and down, so that the airflow is guided from the air inlet 23 of the package shell 21 to the air outlet 22, and the airflow is ejected from the air outlet 22.

[0036] In some embodiments, the resonant frequency of the edge silicon cantilever 131 is above 20 kHz.

[0037] In some embodiments, reference Figure 3 and Figure 4 , Figure 3 This is a perspective view of a frame of an embodiment of the cantilever beam structure 1 of this application; Figure 4 This is a schematic cross-sectional view of the frame of an embodiment of the MEMS fan of this application. Figure 3 As shown, the cantilever beam structure 1 is square. The cantilever beams 11 on the left and right sides extend towards the center to form two trapezoidal edge silicon cantilever arms 131 of the same shape and size. Each edge silicon cantilever arm 131 is provided with a piezoelectric thin film layer 12. Alternatively, edge silicon cantilever arms 131 can extend towards the center from each of the four sides of the cantilever beam 11. There will be more than one edge silicon cantilever arm 131. They will appear in pairs, and all edge silicon cantilever arms 131 will have the same shape and size. There is a rectangular island silicon wafer 132 in the center of the cantilever beam 11. The island silicon wafer 132 does not have a piezoelectric thin film layer 12. An organic film 14 is covered on the top layer of the cantilever beam structure 1 to form a sealing layer. The island silicon wafer 132 is connected to the cantilever beam 11 through the organic film 14. Figure 3 It is a partial perspective view, such as Figure 4 As shown, the organic film 14 actually completely covers the piezoelectric thin film layer 12, the edge silicon cantilever 131, and the island silicon wafer 132 to form a sealing layer, rather than simply filling the gaps. The sealing layer is a thin film, typically 1 to 3 micrometers thick, manufactured using advanced technology. When a voltage is applied to the piezoelectric thin film layer 12, the edge silicon cantilever 131 vibrates up and down, causing the organic film 14 and the island silicon wafer 132 to vibrate up and down, thereby generating compressed air. By adjusting the driving voltage of the piezoelectric thin film layer 12 to match the natural frequency of the edge silicon cantilever 131, designing the shape of the edge silicon cantilever 131, and increasing the thickness of the piezoelectric thin film layer 12, the resonant frequency of the edge silicon cantilever 131 can reach above 20 kHz, which is the ultrasonic frequency band, exceeding the upper limit of human hearing and achieving a silent effect.

[0038] like Figure 4As shown, the cantilever beam structure 1 is disposed inside the package housing 21. The top of the package housing 21 is rectangular, with an air outlet 22 at the center of the top and an air inlet 23 at the bottom edge of the package housing 21. Alternatively, the air inlet 23 can also be disposed at the side edge of the package housing. The package housing 21 is disposed between the cantilever beam structure 1 and the heat-generating component, such as a CPU. In the cantilever beam structure 1, in order from top to bottom, the organic film 14 sealing layer is the first layer, the piezoelectric film layer 12 is the second layer, and the edge silicon cantilever 131, the island silicon wafer 132, and the cantilever beam structure 1 are the third layer. When a voltage is applied to the piezoelectric film layer 12, the edge silicon cantilever 131 vibrates, causing the organic film 14 of the sealing layer and the island silicon wafer 132 to vibrate up and down. This generates compressed air and directs the airflow from the air inlet 23 of the package housing 21 to the air outlet 22. Air is drawn in from the air inlet 23 at the bottom of the package housing 21 and then ejected from the air outlet 22 at the top of the package housing 21, thereby reducing the temperature of the heat-generating component. When the air inlet 23 is located on the side of the package, air can be drawn in from the air inlet 23 and expelled from the air outlet 22, which can also reduce the temperature of the heat-generating components.

[0039] and Figure 2 Compared to traditional MEMS fans, the organic film 14 forms a sealing layer that encloses the gap, preventing air leakage and increasing air pressure. Furthermore, while traditional silicon cantilever 135 vibrates vertically around its connected cantilever beam 11, forming a fan-shaped trajectory, in this application, multiple edge silicon cantilever 131 vibrate simultaneously, driving the organic film 14 to vibrate vertically. By incorporating island-shaped silicon wafers 132, the amplitude at the center of the organic film 14 is increased, resulting in a parabolic vibration mode throughout the entire organic film 14, leading to better air compression. In addition, traditional MEMS fans require the silicon cantilever 135 to be designed to be relatively thick in order to raise the resonant frequency of the silicon cantilever 135 to above 20kHz and ensure that the sound of the fan is inaudible to the human ear. This also results in a smaller exhaust volume. However, the cantilever beam structure 1 provided in this application does not need to consider the thickness of the edge silicon cantilever 131 due to the sealing layer. It is easier to raise the resonant frequency of the edge silicon cantilever 131 to above 20kHz. Furthermore, the edge silicon cantilever 131 can be designed to be small and thin, so that it can generate a larger vibration displacement, increase the air ejection volume, and make the entire MEMS fan thinner, occupying less space in ultra-thin electronic devices.

[0040] In some embodiments, the shape and size of the edge silicon cantilever 131, the island silicon wafer 132, and the gap 10 between them can be freely designed in order to improve the resonant frequency.

[0041] In some embodiments, reference Figure 5 , Figure 5This is a perspective view of the frame of another embodiment of the cantilever beam structure 1 of this application. The cantilever beam structure 1 is rectangular, with two trapezoidal edge silicon cantilever 131 of the same shape and size extending from the cantilever beams 11 on the left and right sides towards the center. A circular island-shaped silicon wafer 132 is set at the center of the cantilever beam 11. Since the organic film 14 forms a closed layer covering the entire cantilever beam structure 1, it is not necessary to consider the shape and size of the two edge silicon cantilevers 131, the island silicon wafers 132 and the gap 10 between them. The shape and size of the edge silicon cantilevers 131 and the island silicon wafers 132 can also be freely designed. Different shapes result in different inherent vibration frequencies. By freely designing the shape and size of the edge silicon cantilevers 131 and the island silicon wafers 132, it is easier to improve the resonant frequency of the entire cantilever beam structure 1. Different shapes of island silicon wafers 132 cause the organic film 14 to produce different vibration deformations, thereby forming the rotation of airflow. In addition, even if the resonant frequency deviates, the compressed air will not leak because the organic film 14 forms a closed layer. Therefore, the generated air discharge is not easy to fluctuate and a stable air outlet effect can be produced.

[0042] In some embodiments, the area of ​​a single edge silicon cantilever 131 is smaller than the area of ​​the gap 10 between the edge silicon cantilever 131 and the island silicon wafer 132.

[0043] In traditional MEMS fans, it is difficult to design the silicon cantilever 135 to be small in order to minimize the gap 10 between the silicon cantilever 135. However, in this application, reference... Figure 5 , Figure 5 This is a perspective view of the frame of another embodiment of the cantilever beam structure 1 of this application. By design, the area of ​​each edge silicon cantilever 131 is smaller than the area of ​​the gap 10. A portion of the edge silicon cantilever 131 is provided with a piezoelectric thin film layer 12, so the piezoelectric thin film layer 12 is also relatively small. Since the piezoelectric thin film layer 12 can drive the edge silicon cantilever 131 and the organic film 14 of the sealing layer to vibrate up and down after applying voltage, while ensuring the air outlet effect, the capacitance is reduced and the current consumption is reduced accordingly after the piezoelectric thin film layer 12 is designed to be smaller.

[0044] In some embodiments, the encapsulation housing 21 has multiple cantilever beam structures 1 with rectangular tops inside, and the long sides of the cantilever beam structures 1 are attached to each other so that the multiple cantilever beam structures 1 are arranged in a row. The encapsulation housing 21 has a slit-shaped air outlet 22 at the center of the top of each cantilever beam structure 1. Among them, the two long sides of the cantilever beam 11 extend towards the center to form two edge silicon cantilever 131 with the same shape and size, and the shape, size and position of the island silicon wafer 132 are adapted to the slit-shaped air outlet 22.

[0045] In some embodiments, reference Figure 6 and Figure 7 , Figure 6 This is a perspective view of a frame of one embodiment of a cantilever beam structure 1 in this application; Figure 7 This is a cross-sectional schematic diagram of a MEMS fan embodiment of this application. Multiple cantilever beam structures 1 are integrated within the internal cavity of the package housing 21. Each cantilever beam structure 1 has a rectangular top, with two long sides extending towards the center to form a trapezoidal edge silicon cantilever 131. The two trapezoidal edge silicon cantilever 131 are of the same size. A rectangular island-shaped silicon wafer 132 is positioned at the center of each cantilever beam structure 1. Each cantilever beam structure 1 is 8 mm long and 2.5 mm wide. The long sides of the four cantilever beam structures 1 are adjacent and closely arranged to form a rectangle with a top length of 10 mm and a width of 8 mm. Four slit-shaped air outlets 22 are provided on the top of the package housing 21, each corresponding to a position of one of the island-shaped silicon wafers 132 in one of the four cantilever beam structures 1. In this embodiment, a rectangular island-shaped silicon wafer 132 is provided in the cantilever beam structure 1 to match the slit-shaped air outlet 22. The area of ​​the island-shaped silicon wafer 132 is larger than the area of ​​the slit-shaped air outlet 22, so that when the organic film 14 vibrates up and down, a larger amplitude is generated at the island-shaped silicon wafer 132, increasing the airflow speed and creating the effect of airflow being ejected from the air outlet 22. The MEMS fan composed of four cantilever beam structures 1 covers a component to be cooled, such as a CPU or GPU. This design allows the airflow generated by the vibration of the cantilever beam structure 1 to be concentrated and discharged from the corresponding slit-shaped air outlet 22.

[0046] The size and combination of the cantilever beam structure 1 are designed according to the size of the cooling components. In traditional MEMS fans, in order to achieve a vibration frequency of over 20kHz, the width of the silicon cantilever 135 cannot be too large. At the same time, the gaps between the silicon cantilever 135s must be small enough, otherwise the air compression effect will be poor. The width of the entire cantilever beam structure 1 generally cannot exceed 1.5 mm. However, the MEMS fan of this application, due to the covering of the organic film 14 and the setting of island silicon wafers 132 corresponding to the air outlet 22, improves the air compression and air delivery effect. It does not need to consider the width of the gaps, and has a higher degree of design freedom for the size of the edge silicon cantilever 131. The width of a cantilever beam structure 1 can be designed to be 2.5 mm, and a vibration frequency of over 20kHz and an air volume can be achieved.

[0047] In some embodiments, the encapsulation housing 21 has a plurality of cantilever beam structures 1 with square tops inside, the plurality of cantilever beam structures 1 are fitted together so that the plurality of cantilever beam structures 1 are arranged in a square, and the encapsulation housing 21 has a circular air outlet 22 at the center of the top of each cantilever beam structure 1. Among them, four edge silicon cantilever 131 of the same shape and size extend from each side of the cantilever beam structure 1 towards the center, and the shape, size and position of the island silicon wafer 132 are adapted to the circular air outlet 22.

[0048] In some embodiments, reference Figure 8A and Figure 8B , Figure 8A This is a perspective view of the frame of another embodiment of a cantilever beam structure 1 in this application; Figure 8B This is a cross-sectional view of another embodiment of the MEMS fan in this application. Multiple cantilever beam structures 1 are integrated within the internal cavity of the encapsulation housing 21. Each cantilever beam structure 1 has a square top and four trapezoidal edge silicon cantilever 131 extending from each side towards the center. The four trapezoidal edge silicon cantilever 131 are of the same size. A square island-shaped silicon wafer 132 is positioned at the center of each cantilever beam structure 1. The four cantilever beam structures 1 are closely fitted together, forming a square top shape, and can be bonded together using epoxy resin or other adhesives. Four circular air outlets 22 are provided on the top of the encapsulation housing 21, each corresponding to the position of the island-shaped silicon wafer 132 in one of the four cantilever beam structures 1. In this embodiment, the square island-shaped silicon wafer 132 in the cantilever beam structure 1 matches the circular air outlet 22. Alternatively, the island-shaped silicon wafer 132 can be circular; preferably, the island-shaped silicon wafer 132 is larger than the air outlet 22. When the organic film 14 vibrates up and down, it generates a larger amplitude at the island silicon wafer 132, resulting in a better compressed air effect and allowing the airflow to rise at high speed and be ejected from the air outlet 22. At the same time, a large amount of air can also be drawn in at the air inlet 23 of the encapsulation housing 21.

[0049] To improve the quietness of the MEMS jet fan, the vibration frequency of the silicon cantilever 135 needs to reach above 20kHz. Therefore, the width of the silicon cantilever 135 needs to be designed to be shorter. However, if the side connecting the silicon cantilever 135 and the cantilever beam 11 is relatively long, its unstable resonance may result in noise below 20kHz. (Reference) Figure 8A The square cantilever beam structure 1 is designed such that each side of the cantilever beam 11 is connected to an edge silicon cantilever 131. Since the organic film 14 forms a closed layer, there is no need to consider the gap between the edge silicon cantilever 131. The connecting side and the vibrating side of each edge silicon cantilever 131 can be designed to be relatively short, resulting in a more stable resonance effect and making it easier to reach frequencies above 20kHz. At the same time, the four edge silicon cantilever 131 drive the organic film 14 to vibrate up and down from four sides, and generate a larger displacement at the island silicon wafer 132, resulting in better overall airflow.

[0050] In some embodiments, reference Figure 9 , Figure 9 This is a perspective view and a cross-sectional view of another embodiment of the cantilever beam structure 1 of this application. The top of the cantilever beam structure 1 is square, and each of its four sides extends towards the center as a trapezoidal edge silicon cantilever 131. The four trapezoidal edge silicon cantilever 131 are of the same size. The lower base of the trapezoidal edge silicon cantilever 131 is connected to the cantilever beam 11, and its upper base is thicker, forming a cuboid edge silicon hammer 133 in the direction away from the organic film 14. A square island-shaped silicon hammer 134 is set at the center of the cantilever beam structure 1. The edge silicon hammer 133 includes an edge edge silicon hammer 133 and an island-shaped silicon hammer 134. Preferably, the height of the edge silicon hammer 133 does not exceed the height of the cantilever beam structure 1. For ease of processing and manufacturing, the height of the edge silicon hammer 133 can be designed to be the same as the height of the cantilever beam structure 1. The edge silicon cantilever 131 vibrates while simultaneously causing the organic membrane 14 to vibrate. By setting the edge silicon hammer 133 and the island-shaped silicon hammer 134, the mass of the central part of the organic membrane 14 is increased, causing the organic membrane 14 to generate a larger vibrational displacement in the central part, thereby generating a larger airflow. The edge silicon hammer 133 and the island-shaped silicon hammer 134 can be set simultaneously or individually.

[0051] In some embodiments, the organic membrane 14 is made of polyimide.

[0052] Polyimide is a high-performance thermoplastic engineering plastic with excellent stretchability. Its thickness can be manufactured to range from 1 micrometer to 3 micrometers. The organic film 14 made of polyimide can be integrated with the edge silicon cantilever 131 and the island silicon wafer 132, enabling synchronized vibration and increasing the overall amplitude, especially at the island silicon wafer 132. This efficiently generates a large amount of compressed air, increasing the air ejection volume. Furthermore, in traditional MEMS fans, each cantilever is only connected and supported at one end, making it prone to breakage due to long-term high-frequency vibration. In the MEMS fan of this application, the organic film 14 made of polyimide can protect the edge silicon cantilever 131 and the island silicon wafer 132.

[0053] In some embodiments, the piezoelectric thin film layer includes a PZT thin film layer.

[0054] PZT (lead zirconate titanate) possesses characteristics such as high piezoelectric coefficient, tunability, and a high Curie temperature. When applied in MEMS actuators, it can generate large strain with a relatively small voltage, resulting in high electromechanical conversion efficiency. Furthermore, its piezoelectric properties can be finely controlled by changing the ratio of zirconium to titanium. By placing a PZT thin film layer on the edge silicon cantilever 131 and applying a voltage to it, a larger displacement can be achieved in the edge silicon cantilever 131. The high Curie temperature characteristic ensures high stability and reliability of the piezoelectric properties of PZT material under normal operating conditions. Additionally, the fabrication process for PZT thin films is relatively mature, making it easier to produce high-quality PZT thin films.

[0055] In some embodiments, the piezoelectric thin film layer can also be made of lead-free materials such as AlN (aluminum nitride) or ZnO (zinc oxide). Lead-free materials are more in line with environmental protection requirements. AlN has high purity, good insulation properties, and is widely used in silicon-based MEMS processes.

[0056] on the other hand, Figure 10 This is a schematic diagram illustrating the fabrication process of an embodiment of the MEMS fan of this application, as shown below. Figure 10 As shown, this application provides a method for manufacturing the above-mentioned product, including the following steps: S11: Fabricate a piezoelectric film including upper and lower electrodes on an SOI substrate using a sputtering process; S12: A patterning process is performed on the piezoelectric film including the upper and lower electrodes, i.e., etching is performed after the shape of the insulating layer is formed; S13: The shape of edge silicon cantilever 131 and island silicon wafer 132 is formed by Si etching process; S14: The upper surface of the piezoelectric thin film layer 12, the upper surface of the edge silicon cantilever 131, the upper surface of the island silicon wafer 132, and the gap 10 therebetween are covered by coating with an organic film 14, thereby achieving thermal polymerization. S15: After reverse etching of the Si substrate, the SiO2 layer is removed from the back side by etching; S16: Fabricate the packaging shell 21.

[0057] In some embodiments, the above steps further include forming a silicon hammer-shaped cantilever by a Si etching process. refer to Figures 11A to 11E As shown, 11A to Figure 11E This is a cross-sectional schematic diagram showing the structural changes of an embodiment of the fabrication method of the cantilever beam structure 1 in the MEMS fan of this application. First, please refer to... Figure 11A A piezoelectric film, including upper and lower electrodes, is fabricated on an SOI substrate using a sputtering process; then, please refer to... Figure 11B The piezoelectric film, including the upper and lower electrodes, undergoes a patterning process, i.e., etching is performed after the shape of the insulating layer is formed; then, please refer to... Figure 11C The edge silicon cantilever 131 and island silicon wafer 132 are formed through a Si etching process; then, please refer to... Figure 11D An organic film 14 is coated onto the upper surface of the edge silicon cantilever 131, the upper surface of the island silicon wafer 132, the gap 10 between them, and the upper surface of the piezoelectric thin film layer 12 to achieve thermal polymerization. The organic film 14 forms a sealing layer on the top layer, and the two layers below it are the piezoelectric thin film layer 12, the edge silicon cantilever 131, and the island silicon wafer 132, respectively. Finally, please refer to... Figure 11E After reverse etching the Si substrate, the SiO2 layer is removed from the back side by etching. The cantilever beam structure 1 is attached to the base plate of the package shell 21, and then a cover with an air outlet 22 is attached to the base plate; the air outlet 22 can be a slit or a round hole, etc., and the air inlet 23 can be on the base plate or on the cover; the adhesive can be epoxy resin, etc. The package shell 21 is made of stainless steel or resin. The manufacturing process of MEMS fans is already very mature. Since the MEMS fan of this application does not need to make the gap between the edge silicon cantilever 131 and the island silicon wafer 132 very small, and the shapes of the edge silicon cantilever 131 and the island silicon wafer 132 can be freely designed, the manufacturing difficulty is reduced.

[0058] In some embodiments, the organic film 14 is made of polyimide, and etching is performed using the DRIE method. DRIE (Deep Reactive Ion Etching) is a high-precision etching technique used in microelectronics, MEMS, and other fields. This method utilizes the anisotropy of silicon to etch through chemical and physical processes. The method offers strong process controllability and good etching selectivity, effectively protecting the materials and improving etching accuracy by addressing significant differences in etching rates for various materials, including the Si substrate, the piezoelectric thin film layer 12, and the organic film 14.

[0059] Polyimide is characterized by its high-temperature imidization reaction, resulting in high heat resistance and strength, while also exhibiting flexibility. The patterning process for polyimide is also relatively simple. For the material selection of the organic film 14, other resin materials with similar characteristics can also be chosen. For example, parylene, silicone, epoxy resin, acrylic acid, and polydimethylsiloxane can be considered.

[0060] In another aspect, this application also provides a MEMS fan fabrication apparatus, including a memory and a processor coupled to each other, wherein the processor is used to execute program instructions stored in the memory to implement the above-described MEMS fan fabrication method.

[0061] Specifically, please refer to Figure 12The MEMS fan fabrication equipment 200 of this application may specifically include a processor 210 and a memory 220. The memory 220 is coupled to the processor 210.

[0062] Processor 210 is used for the operation of MEMS fan fabrication equipment 200. Processor 210 can also be referred to as CPU (Central Processing Unit). Processor 210 may be an integrated circuit chip with signal processing capabilities. Processor 210 can also be a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component. The general-purpose processor can be a microprocessor, or processor 210 can be any conventional processor.

[0063] The memory 220 is used to store computer programs and may be RAM, ROM, or other types of storage devices. Specifically, the memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory is used to store at least one line of program code.

[0064] The processor 210 is used to execute computer programs stored in the memory 220 to implement the methods described in the various method embodiments of this application.

[0065] In some embodiments, the MEMS fan fabrication apparatus 200 may further include a peripheral device interface 230 and at least one peripheral device. The processor 210, memory 220, and peripheral device interface 230 can be connected via a bus or signal line. Each peripheral device can be connected to the peripheral device interface 230 via a bus, signal line, or circuit board. Specifically, the peripheral device includes at least one of a radio frequency circuit 240, a display screen 250, an audio circuit 260, and a power supply 270.

[0066] Peripheral device interface 230 can be used to connect at least one I / O (Input / output) related peripheral device to processor 210 and memory 220. In some embodiments, processor 210, memory 220 and peripheral device interface 230 are integrated on the same chip or circuit board; in some other embodiments, any one or two of processor 210, memory 220 and peripheral device interface 230 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0067] The radio frequency (RF) circuit 240 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The RF circuit 240 communicates with communication networks and other communication devices via electromagnetic signals; it is the communication circuit of the MEMS fan fabrication device 200. The RF circuit 240 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals back into electrical signals. Optionally, the RF circuit 240 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, etc. The RF circuit 240 can communicate with other terminals via at least one wireless communication protocol. This wireless communication protocol includes, but is not limited to: the World Wide Web, metropolitan area networks, intranets, various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks, and / or WiFi (Wireless Fidelity) networks. In some embodiments, the RF circuit 240 may also include circuitry related to NFC (Near Field Communication), which is not limited in this application.

[0068] Display screen 250 is used to display a UI (User Interface). This UI may include graphics, text, icons, videos, and any combination thereof. When display screen 250 is a touch display, it also has the ability to collect touch signals on or above its surface. These touch signals can be input as control signals to processor 210 for processing. In this case, display screen 250 can also be used to provide virtual buttons and / or a virtual keyboard, also known as soft buttons and / or a soft keyboard. In some embodiments, there may be one display screen 250, disposed on the front panel of the MEMS fan fabrication device 200; in other embodiments, there may be at least two display screens, disposed on different surfaces of the MEMS fan fabrication device 200 or in a folded design; in still other embodiments, display screen 250 may be a flexible display screen, disposed on a curved or folded surface of the MEMS fan fabrication device 200. Furthermore, display screen 250 may even be configured as a non-rectangular, irregular shape, i.e., a non-rectangular screen. The display screen 250 can be made of materials such as LCD (Liquid Crystal Display) and OLED (Organic Light-Emitting Diode).

[0069] The audio circuit 260 may include a microphone and a speaker. The microphone is used to collect sound waves from the user and the environment, converting them into electrical signals that are input to the processor 210 for processing, or to the radio frequency circuit 240 for voice communication. For stereo sound acquisition or noise reduction purposes, multiple microphones may be used, each positioned at a different location within the MEMS fan fabrication device 200. The microphone may also be an array microphone or an omnidirectional microphone. The speaker is used to convert electrical signals from the processor 210 or the radio frequency circuit 240 into sound waves. The speaker may be a conventional thin-film speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can convert electrical signals not only into audible sound waves but also into inaudible sound waves for purposes such as distance measurement. In some embodiments, the audio circuit 260 may also include a headphone jack.

[0070] Power supply 270 is used to power the various components in the MEMS fan fabrication equipment 200. Power supply 270 can be AC ​​power, DC power, a disposable battery, or a rechargeable battery. When power supply 270 includes a rechargeable battery, the rechargeable battery can be a wired rechargeable battery or a wireless rechargeable battery. A wired rechargeable battery is a battery that is charged via a wired line, while a wireless rechargeable battery is a battery that is charged via a wireless coil. The rechargeable battery can also be used to support fast charging technology.

[0071] For a detailed description of the functions and execution processes of each functional module or component in the embodiments of the intelligent control platform of this application, please refer to the descriptions in the above-mentioned method embodiments of this application, which will not be repeated here.

[0072] In the embodiments provided in this application, it should be understood that the disclosed intelligent control platform and method can be implemented in other ways. For example, the embodiments of the intelligent control platform described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0073] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0074] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0075] In another aspect, this application provides a computer-readable storage medium storing a computer program that can be executed by a processor to implement any of the methods described above.

[0076] Please see Figure 13 If the integrated units described above are implemented as software functional units and sold or used as independent products, they can be stored in computer-readable storage medium 300. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions / computer programs to cause an intelligent control platform (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of various embodiments of this application. The aforementioned storage medium includes various media such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks, as well as electronic devices such as computers, mobile phones, laptops, tablets, and cameras that have the aforementioned storage media.

[0077] The execution process of program data in a computer-readable storage medium can be described with reference to the above-described method embodiments of this application, and will not be repeated here.

[0078] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

[0079] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0080] In summary, this application has the following beneficial effects: By covering the top layer of the cantilever beam structure with an organic film to form a closed layer, and designing the opposing edge silicon cantilevers to raise the resonant frequency to a level inaudible to the human ear (above 20kHz), by applying voltage to the piezoelectric thin film layer to make the edge silicon cantilevers drive the organic film to vibrate up and down together, and by setting island-shaped silicon wafers to make the organic film generate a larger amplitude at the island silicon wafers, a large amount of compressed air is generated and the airflow is ejected from the air outlet opened on the package shell. This achieves the effect of drawing in air from the surroundings of the package shell and then ejecting a large amount of air at high speed while maintaining a better noise reduction effect.

[0081] Furthermore, by freely designing the size and shape of the edge silicon cantilever, the island silicon wafer, and the gap between them, the resonant frequency can be increased. The simultaneous vibration of multiple edges drives the organic film and the island silicon wafer to vibrate up and down together, forming a vibration curve similar to a parabola, resulting in a better air compression effect.

[0082] Furthermore, by reducing the edge silicon cantilever and the area of ​​the piezoelectric thin film layer, power consumption is further reduced while ensuring heat dissipation.

[0083] Furthermore, by matching the design of the cantilever beam structure, the composition of multiple cantilever beam structures, and the design of the island silicon wafer and the air outlet of the package shell, a MEMS fan is matched with a heat-generating component, driving airflow to be ejected from multiple air outlets more quickly, achieving a better cooling effect.

[0084] Furthermore, organic films made of polyimide can protect edge silicon cantilevers and island silicon wafers, enabling MEMS fans to offer higher reliability and longer service life.

Claims

1. A MEMS fan, characterized in that, include: The top is a rectangular enclosure, with an air outlet at the center of the top and an air inlet at the bottom or side edge of the enclosure. The encapsulation shell has an internal cantilever beam structure with a quadrilateral top. Two edge silicon cantilever arms of the same shape and size extend from the left and right sides of the cantilever beam toward the center, and an island-shaped silicon wafer is set at the center of the cantilever beam. A piezoelectric thin film layer is set on a portion of the edge silicon cantilever arms, but no piezoelectric thin film layer is set on the island-shaped silicon wafer. The top layer of the cantilever beam structure is covered with an organic film to form a sealing layer. When a voltage is applied to the piezoelectric thin film layer, the edge silicon cantilever vibrates up and down, causing the organic film of the sealing layer and the island silicon wafer to vibrate up and down, so that the airflow is guided from the air inlet of the package shell to the air outlet, and the airflow is ejected from the air outlet.

2. The MEMS fan according to claim 1, characterized in that, The resonant frequency of the edge silicon cantilever is above 20kHz.

3. The MEMS fan according to claim 1, characterized in that, The piezoelectric thin film layer includes a PZT thin film layer.

4. The MEMS fan according to claim 1, characterized in that, The area of ​​a single edge silicon cantilever is smaller than the area of ​​the gap between the edge silicon cantilever and the island silicon wafer.

5. The MEMS fan according to claim 1, characterized in that, The encapsulation shell has multiple cantilever beam structures with rectangular tops inside. The long sides of the cantilever beam structures are joined together in pairs so that the multiple cantilever beam structures are arranged in a row. The encapsulation shell has a slit-shaped air outlet at the center of the top of each cantilever beam structure. The cantilever beam has two long sides that extend towards the center to form two edge silicon cantilever arms of the same shape and size, and the shape, size and position of the island-shaped silicon wafer are adapted to the slit-shaped air outlet.

6. The MEMS fan according to claim 1, characterized in that, The encapsulation shell has multiple cantilever beam structures with square tops inside. The multiple cantilever beam structures are fitted together so that they are arranged in a square. The encapsulation shell has a circular air outlet at the center of the top of each of the cantilever beam structures. The cantilever beam structure has four edge silicon cantilever arms of the same shape and size extending from each side toward the center, and the shape, size and position of the island-shaped silicon wafer are adapted to the circular air outlet.

7. The MEMS fan according to claim 1, characterized in that, The organic membrane is made of polyimide.

8. A method for manufacturing a MEMS fan as described in claim 1, characterized in that, Including the following steps: A piezoelectric film including upper and lower electrodes is fabricated on an SOI substrate using a sputtering process. The piezoelectric film, including the upper and lower electrodes, is patterned, i.e., etched after the shape of the insulating layer is formed. The shape of edge silicon cantilever and island silicon wafers is formed through the Si etching process; Thermal polymerization is achieved by coating the upper surface of the edge silicon cantilever, the upper surface of the island silicon wafer, the gap between them, and the upper surface of the piezoelectric thin film layer with an organic film. After reverse etching of the Si substrate, the SiO2 layer is removed from the back side by etching. Make the packaging shell.

9. The manufacturing method according to claim 8, characterized in that, The organic film is made of polyimide, and the etching is performed using the DRIE method.

10. A MEMS fan fabrication device, characterized in that, It includes a memory and a processor coupled to each other, the processor being used to execute program instructions stored in the memory to implement the method for manufacturing a MEMS fan according to any one of claims 8-9.

11. A computer-readable storage medium having program instructions stored thereon, characterized in that, When the program instructions are executed by the processor, the method for manufacturing the MEMS fan according to any one of claims 8-9 is implemented.

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