Novel MEMS piezoelectric air pump

Abstract

The invention relates to a novel MEMS piezoelectric air pump, and belongs to the technical field of semiconductor heat dissipation. Comprising a first flow channel outer frame; a driving electrode and a detection electrode are integrated on the surface of the controllable vibrator, and the controllable vibrator is mounted in the first flow channel outer frame; the second flow channel outer frame is installed on the first flow channel outer frame, a plurality of resistance reduction holes are formed in the second flow channel outer frame and are opposite to the controllable vibrator, and a negative pressure generation flow channel is formed between the second flow channel outer frame and the first flow channel outer frame. The method is used for solving the technical problems that in the prior art, the manufacturing precision requirement is high, vibrator structure sizes need to be guaranteed to be consistent, and otherwise accurate phase control between vibrators is difficult to achieve.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor heat dissipation, and in particular relates to a novel MEMS piezoelectric air pump. Background Art

[0002] The MEMS piezoelectric air pump manufactured using SOI technology drives airflow through ultrasonic piezoelectric vibrators and integrated flow channels to achieve efficient air intake and exhaust, enabling efficient air circulation in narrow spaces.

[0003] Announcement No. CN116146466B discloses a micro air pump comprising: a tube plate having an air inlet and an air outlet; a check valve plate arranged inside the tube plate, the check valve plate having a valve hole and a recessed space, and the valve hole is located at the center of the recessed space; a check baffle arranged on the check valve plate, the check baffle having a convex portion, and the convex portion convex toward the valve hole of the check valve plate; an insulating plate arranged on the check baffle; a conductive foam arranged on the convex portion of the check baffle; an actuator arranged on the insulating plate and in contact with the conductive foam, the actuator having a second pin and a piezoelectric plate, the piezoelectric plate of the actuator and the conductive foam are in contact with each other; and a cover plate arranged on the actuator and sealed with the tube plate.

[0004] The air pump represented by the above-mentioned prior art has at least the following problems during use:

[0005] High manufacturing precision is required, and the structural dimensions of the oscillators must be consistent; otherwise, it will be difficult to achieve precise phase control between the oscillators. Summary of the Invention

[0006] The present invention provides a novel MEMS piezoelectric air pump, which is used to solve the technical problem in the prior art that high manufacturing precision is required and the structural dimensions of the vibrators must be ensured to be consistent, otherwise it is difficult to achieve precise phase control between the vibrators.

[0007] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0008] A new MEMS piezoelectric air pump includes: a first flow channel outer frame; a controllable vibrator with a driving electrode and a detection electrode integrated on its surface, the controllable vibrator being installed in the first flow channel outer frame; a second flow channel outer frame being installed on the first flow channel outer frame, the second flow channel outer frame being provided with a plurality of drag-reducing pores, the plurality of drag-reducing pores being arranged opposite to the controllable vibrator, and a negative pressure generating flow channel being formed between the second flow channel outer frame and the first flow channel outer frame.

[0009] Furthermore, the driving electrodes include a first driving electrode, a second driving electrode, a third driving electrode, and corresponding driving electrode pins.

[0010] Furthermore, the detection electrodes include a first detection electrode, a second detection electrode, a third detection electrode, and corresponding detection electrode pins.

[0011] Furthermore, it also includes: a flow collecting channel outer frame, which is installed below the first flow channel outer frame, and the controllable oscillator divides the space between the flow collecting channel outer frame, the second flow channel outer frame and the first flow channel outer frame into a flow collecting channel air inlet cavity and a flow collecting channel exhaust cavity; and a windshield, which is arranged in the flow collecting channel outer frame.

[0012] Furthermore, two flow collecting channel inlets are formed between the flow collecting channel outer frame and the first flow channel outer frame, and the two flow collecting channel inlets are respectively arranged on both sides of the flow collecting channel outer frame.

[0013] Furthermore, the flow collecting duct outer frame and the wind shield divide the flow collecting duct exhaust cavity into two symmetrical parts, thereby forming two flow collecting duct outlets. The two flow collecting duct outlets are located on both sides of the wind shield, and the two flow collecting duct outlets are opened at the bottom of the flow collecting duct outer frame.

[0014] The present invention provides a novel MEMS piezoelectric air pump, which has the following beneficial effects:

[0015] The controllable oscillator can achieve low-voltage closed-loop resonant drive, effectively reducing the device's operating energy consumption; the drag-reducing pores and negative pressure-generating flow channels of the negative pressure generation technology are used to improve the intake and exhaust efficiency; the controllable oscillator is combined with the first flow channel frame and the second flow channel frame to make the device extremely small, thus meeting the active air circulation needs of the internal space of almost all mobile devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic structural diagram of a novel MEMS piezoelectric air pump provided in an embodiment of the present invention;

[0018] Figure 2 for Figure 1 An exploded diagram of a new MEMS piezoelectric air pump is provided;

[0019] Figure 3 A schematic diagram of the structure of a controllable oscillator and a PZT film provided in an embodiment of the present invention;

[0020] Figure 4 For Figure 1 A-A along the cutaway view;

[0021] Figure 5 For Figure 1 Structure diagram of air intake process of a new type of MEMS piezoelectric air pump provided by the application;

[0022] Figure 6 For Figure 1 Structure diagram of air exhaust process of a new type of MEMS piezoelectric air pump provided by the application;

[0023] Figure 7 For another structure diagram of a new type of MEMS piezoelectric air pump provided by the application;

[0024] Figure 8 For Figure 7 Exploded view of a new type of MEMS piezoelectric air pump provided by the application;

[0025] Figure 9 For Figure 7 B-B along the cutaway view;

[0026] Figure 10 For Figure 7 Structure diagram of air intake process of a new type of MEMS piezoelectric air pump provided by the application;

[0027] Figure 11 For Figure 7 Structure diagram of air exhaust process of a new type of MEMS piezoelectric air pump provided by the application.

[0028] In the figure: 11-first flow channel outer frame; 310-controllable vibrator; 320-PZT film; 21-second flow channel outer frame; 22-drag reduction aperture; 12-negative pressure generation flow channel; 321-first drive electrode; 322-second drive electrode; 323-third drive electrode; 324-drive electrode pin; 325-first detection electrode; 326-second detection electrode; 327-third detection electrode; 328-detection electrode pin; 41-gas collection flow channel outer frame; 42-gas collection flow channel air inlet cavity; 43-gas collection flow channel air outlet cavity; 44-windshield; 421-gas collection flow channel inlet; 431-gas collection flow channel outlet. DETAILED DESCRIPTION

[0029] The embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0030] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0031] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installation," "connection," and "connection" should be understood in a broad sense. For example, they can refer to welding, bolting, or riveting; fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0033] Example 1:

[0034] like Figures 1 to 6 As shown, this embodiment provides a new MEMS piezoelectric air pump, including: a first flow channel outer frame 11; a controllable vibrator 310 with a driving electrode and a detection electrode integrated on its surface, and the controllable vibrator 310 is installed in the first flow channel outer frame 11; a second flow channel outer frame 21 is installed on the first flow channel outer frame 11, and a plurality of drag reducing pores 22 are provided on the second flow channel outer frame 21, and the plurality of drag reducing pores 22 are arranged opposite to the controllable vibrator 310, and a negative pressure generating flow channel 12 is formed between the second flow channel outer frame 21 and the first flow channel outer frame 11.

[0035] Furthermore, the driving electrodes include a first driving electrode 321 , a second driving electrode 322 , a third driving electrode 323 , and corresponding driving electrode pins 324 .

[0036] Furthermore, the detection electrodes include a first detection electrode, a second detection electrode, a third detection electrode, and corresponding detection electrode pins.

[0037] In this embodiment, the piezoelectric air pump is a new type of MEMS piezoelectric air pump structure designed in this patent, with a size of 10 4 0.6mm, its structure is as follows Figure 1 and Figure 2 As shown, the piezoelectric air pump is based on a controllable vibrator 310 based on PZT film 320 technology. The controllable vibrator 310 is an SOI vibrator. Through the PZT film 320 technology, a PZT film 320 driving electrode and a PZT film 320 detection electrode are generated on the surface of the controllable vibrator 310 to achieve low-power driving and high-precision amplitude detection of the vibrator, and realize closed-loop control of the vibrator.

[0038] The piezoelectric air pump is composed of a controllable vibrator 310 and a PZT film 320. The controllable vibrator 310 based on the PZT film 320 technology and the integrated flow channel based on the negative pressure generation technology are composed of the flow channel outer frame, the negative pressure generation flow channel 12, and the drag reduction pores 22. When the piezoelectric air pump is working,

[0039] The specific implementation process is as follows: when the PZT film 320 drives the SOI vibrator through the inverse piezoelectric effect to achieve 21KHz resonance. When the piezoelectric air pump is working, when an alternating voltage signal of 3.3V or 5V is applied to the first drive electrode 321, the second drive electrode 322, and the third drive electrode 323 integrated on the surface of the controllable vibrator 310, the PZT film 320 produces periodic mechanical deformation due to the inverse piezoelectric effect. The deformation is transmitted to the vibrator structure through the interface coupling between the film and the SOI vibrator, causing the vibrator to produce bending vibration. By precisely controlling the frequency of the driving signal to make it close to the natural frequency of the vibrator 21KHz, the vibrator will produce a stable resonance with the maximum amplitude under the action of resonance. At the same time, the detection electrode monitors the vibration state of the vibrator in real time through the positive piezoelectric effect, converts the mechanical vibration into an electrical signal feedback, and forms a closed-loop control system to ensure that the vibrator always works at the optimal resonance point, achieving low power consumption and high efficiency stable drive. The intake and exhaust working state of the piezoelectric air pump is as follows Figure 4 、 Figure 5 shown.

[0040] Figure 5 This is the piezoelectric air pump's intake process. During the upward motion of the controllable oscillator 310, air flows upward from the upper negative pressure generating channel 12, while air flows downward from the lower negative pressure generating channel 12. Based on the core negative pressure zone, the upward motion of the controllable oscillator 310 reduces the air pressure below the edge of the controllable oscillator 310. The airflow on both sides flows in the direction of the main airflow shown in the figure, converging below the edge of the controllable oscillator 310 to achieve intake.

[0041] Figure 6This is the piezoelectric air pump exhaust process, during the downward motion of the controllable oscillator 310. Air flows downward from the upper negative pressure generating channel 12, while air flows upward from the lower negative pressure generating channel 12. Due to inertia, gas that collects below the edge of the controllable oscillator 310 during the intake process flows toward the center of the controllable oscillator 310. At this point, the downward motion of the controllable oscillator 310 pushes the gas that collected during the intake process downward, with the airflow following the main gas flow direction shown in the figure, achieving downward exhaust.

[0042] Example 2:

[0043] like Figures 7 to 11 As shown, this embodiment also provides a new MEMS piezoelectric air pump, including: a first flow channel outer frame 11; a controllable vibrator 310 with a driving electrode and a detection electrode integrated on its surface, and the controllable vibrator 310 is installed in the first flow channel outer frame 11; a second flow channel outer frame 21 is installed on the first flow channel outer frame 11, and a plurality of drag reducing pores 22 are provided on the second flow channel outer frame 21, and the plurality of drag reducing pores 22 are arranged opposite to the controllable vibrator 310, and a negative pressure generating flow channel 12 is formed between the second flow channel outer frame 21 and the first flow channel outer frame 11.

[0044] Furthermore, the driving electrodes include a first driving electrode 321 , a second driving electrode 322 , a third driving electrode 323 , and corresponding driving electrode pins 324 .

[0045] Furthermore, the detection electrodes include a first detection electrode, a second detection electrode, a third detection electrode, and corresponding detection electrode pins.

[0046] Furthermore, it also includes: a collecting channel outer frame, which is installed below the first channel outer frame 11, and a controllable oscillator 310 divides the space between the collecting channel outer frame, the second channel outer frame 21 and the first channel outer frame 11 into a collecting channel air inlet cavity and a collecting channel exhaust cavity; a windshield, which is arranged in the collecting channel outer frame.

[0047] Furthermore, two flow collecting channel inlets are formed between the flow collecting channel outer frame and the first flow channel outer frame 11 , and the two flow collecting channel inlets are respectively arranged on both sides of the flow collecting channel outer frame.

[0048] Furthermore, the manifold outer frame and the wind shield divide the manifold exhaust cavity into two symmetrical parts, thereby forming two manifold outlets. The two manifold outlets are located on both sides of the wind shield, and the two manifold outlets are opened at the bottom of the manifold outer frame.

[0049] In this embodiment, based on the piezoelectric air pump, Example 2 is proposed. Example 2 adds a collection channel on the basis of the piezoelectric air pump to isolate the intake and exhaust airflow and reduce the reverse flow of the airflow. The size of Example 2 is 10 4 2mm.

[0050] The controllable vibrator 310 based on the PZT film 320 technology used in Example 2 is the same as the piezoelectric air pump, such as Figure 5 As shown. Example 2 is a bilaterally symmetrical structure. Example 2 consists of two parts, namely, a controllable oscillator 310 based on PZT film 320 technology composed of a controllable oscillator 310 and a PZT film 320, and an integrated flow channel based on negative pressure generation technology composed of a flow channel outer frame, a flow channel outer frame, a negative pressure generating flow channel 12, and a drag reduction pore 22. When Example 2 is working, the controllable oscillator 310 resonates at around 21KHz under the drive and control of the PZT film 320, and the driving voltage is 3.3V or 5V. At this time, the edge of the controllable oscillator 310 flaps at high speed, causing the airflow at the upper and lower negative pressure generating flow channels 12 to flow at high speed, generating a core negative pressure area. The flow channel outer frame constitutes the flow channel of Example 2, through which the intake and exhaust airflows are isolated. At the same time, the flow channel adopts a one-way diffuser design to reduce the reverse flow of the airflow. The drag reduction pore 22 is used to further reduce the compression film damping between the oscillator and the flow channel outer frame to reduce the driving power consumption. Example 2 Intake and exhaust working conditions are as follows Figure 10 、 Figure 11 shown.

[0051] Figure 10 This is the intake process in Example 2. During the upward movement of controllable oscillator 310, air flows upward from the upper negative pressure generating channel 12, while air flows downward from the lower negative pressure generating channel 12. Based on the core negative pressure zone, the upward movement of controllable oscillator 310 reduces the air pressure below the edge of controllable oscillator 310. Due to the negative pressure, air flows from the two side flow channel inlets in the direction of the arrows into the flow channel intake cavity, completing the intake process.

[0052] Figure 11 This is the exhaust process in Example 2, during which the controllable oscillator 310 is moving downward. Air flows downward from the upper negative pressure generating channel 12, while air flows upward from the lower negative pressure generating channel 12. Due to inertia, the gas collected in the intake chamber of the collecting channel during the intake process will flow toward the exhaust chamber of the collecting channel. At this time, the downward movement of the controllable oscillator 310 pushes the gas collected during the intake process downward, and the airflow direction is in the direction of the arrow in the figure, achieving downward exhaust.

[0053] In summary, the oscillator drive and detection electrode integration based on the PZT film 320: the PZT film 320 drive electrode and the PZT film 320 detection electrode are integrated on the surface of the controllable oscillator 310 to form a piezoelectric oscillator structure that can be controlled in a closed loop; low voltage resonant drive, the PZT film 320 drive electrode can drive the controllable oscillator 310 to generate resonant motion at a specific frequency near 21KHz at a lower driving voltage of 3.3V or 5V; the integrated negative pressure generating channel 12 is designed, and an integrated flow channel structure including a negative pressure generating channel 12 and a drag reducing pore 22 is set around the oscillator; the negative pressure generating channel 12, the upper and lower negative pressure generating channel 12 ports use high-speed airflow to generate a core negative pressure area when the oscillator resonates; the drag reducing pore 22 is designed, and a drag reducing pore 22 is set in the flow channel structure 2. It is used to reduce the film damping between the vibrator and the flow channel outer frame, thereby reducing the driving power consumption; Symmetrical flow channel and airflow coordination mechanism: adopting a left-right symmetrical flow channel structure design, and utilizing the phase difference of the upward / downward movement of the vibrator, in conjunction with the core negative pressure area, to achieve directional flow of airflow gathered below the edge of the vibrator and pushed toward the center / bottom; the collection flow channel isolation design is unique to Example 2, adding a collection flow channel to the basic flow channel structure to physically isolate the intake airflow and the exhaust airflow, and reduce the reverse flow of the airflow, further improving the intake and exhaust efficiency; the combined structure of the controllable vibrator 310 and the stamping flow channel frame, the vibrator is manufactured by SOI process, and the flow channel outer frame is manufactured by stamping process, to achieve ultra-thin devices, such as the piezoelectric air pump thickness of 0.6mm and miniaturization, such as the piezoelectric air pump size 10 4 0.6mm; Based on the closed-loop resonance control of the detection electrode, the PZT film 320 detection electrode is used to monitor the oscillator amplitude in real time, realize the closed-loop control of the oscillator resonance state, and optimize the driving efficiency.

[0054] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope of the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A new MEMS piezoelectric air pump, characterized in that: include: First flow channel outer frame (11); a controllable vibrator (310), wherein a driving electrode and a detection electrode are integrated on the surface of the controllable vibrator (310), and the controllable vibrator (310) is installed in the first flow channel outer frame (11); The second flow channel outer frame (21) is mounted on the first flow channel outer frame (11), and a plurality of drag-reducing pores (22) are provided on the second flow channel outer frame (21). The plurality of drag-reducing pores (22) are arranged relative to the controllable oscillator (310), and a negative pressure generating flow channel (12) is formed between the second flow channel outer frame (21) and the first flow channel outer frame (11).

2. A novel MEMS piezoelectric air pump according to claim 1, characterized in that: The driving electrodes include a first driving electrode (321), a second driving electrode (322), a third driving electrode (323), and corresponding driving electrode pins (324).

3. A novel MEMS piezoelectric air pump according to claim 2, characterized in that: The detection electrodes include a first detection electrode, a second detection electrode, a third detection electrode, and corresponding detection electrode pins.

4. A novel MEMS piezoelectric air pump according to claim 3, characterized in that: Also includes: A flow channel outer frame is installed below the first flow channel outer frame (11), and the controllable oscillator (310) divides the space between the flow channel outer frame, the second flow channel outer frame (21), and the first flow channel outer frame (11) into a flow channel air inlet cavity and a flow channel exhaust cavity; A windshield is arranged in the outer frame of the air collecting channel.

5. A novel MEMS piezoelectric air pump according to claim 4, characterized in that: Two flow collecting channel inlets are formed between the flow collecting channel outer frame and the first flow channel outer frame (11), and the two flow collecting channel inlets are respectively arranged on both sides of the flow collecting channel outer frame.

6. A novel MEMS piezoelectric air pump according to claim 5, characterized in that: The flow collecting duct outer frame and the wind shield divide the flow collecting duct exhaust cavity into two symmetrical parts, thereby forming two flow collecting duct outlets. The two flow collecting duct outlets are located on both sides of the wind shield, and the two flow collecting duct outlets are opened at the bottom of the flow collecting duct outer frame.

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