Bulk acoustic wave driving structure and electronic device

Abstract

This invention discloses a bulk acoustic wave (BAW) driven structure and an electronic device. The BAW driven structure includes a cover plate assembly, a piezoelectric assembly, and a connecting assembly. The cover plate assembly has a receiving chamber. The piezoelectric assembly is disposed within the receiving chamber and includes a piezoelectric element whose thickness can vary. One end of the connecting assembly is connected to the piezoelectric assembly, and the other end is connected to the inner wall of the cover plate assembly. The connecting assembly and the piezoelectric assembly can divide the receiving chamber into a first chamber and a second chamber. The cover plate assembly has a first through hole, through which the first chamber and / or the second chamber communicate with the outside. Thus, pressure changes in the corresponding chamber can be driven by variations in the thickness of the piezoelectric element, thereby achieving the driving function.

Description

Technical Field

[0001] This invention relates to the field of bulk acoustic wave driving technology, and more specifically, to a bulk acoustic wave driving structure and electronic device. Background Technology

[0002] Due to its advantages such as fast response speed, compact structure and high energy density, piezoelectric drive has become the core driving mechanism for fluid generating devices such as liquid pumps, air pumps and miniature horns, and is widely used in fields such as medical liquid delivery, precision fluid control and consumer electronics.

[0003] Existing piezoelectric drive structures generally apply a driving voltage in the thickness direction of the piezoelectric layer, and use the in-plane strain difference between the piezoelectric layer and the elastic layer to generate bending deformation, thereby driving the actuator of the fluid generating device to move and realize the function of fluid transportation or sound generation.

[0004] However, since this driving method relies solely on the interlayer strain difference between the piezoelectric layer and the elastic layer, frictional damping inevitably occurs at the interlayer interface. This frictional damping reduces the mechanical Q value (quality factor) of the driving structure, thereby increasing driving energy loss and driving power consumption. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a new technology solution for a bulk acoustic wave driven structure and an electronic device.

[0006] According to one aspect of the present invention, a bulk acoustic wave driving structure is provided. The bulk acoustic wave driving structure includes: A cover assembly having a receiving chamber therein; A piezoelectric assembly, wherein the piezoelectric assembly is disposed within the receiving cavity, the piezoelectric assembly comprising a piezoelectric element, the thickness of which is capable of variation; A connecting component, one end of which is connected to the piezoelectric component, and the other end of which is connected to the inner wall of the cover plate assembly. The connecting component and the piezoelectric component can divide the receiving chamber into a first chamber and a second chamber. The cover plate assembly has a first through hole, through which the first chamber and / or the second chamber communicate with the outside.

[0007] Optionally, the piezoelectric component further includes a first electrode and a second electrode, which are respectively disposed on both sides of the piezoelectric element, and the pressure changes of the first chamber and the second chamber are the same.

[0008] Optionally, the connecting assembly includes a first connector and a second connector. The first connector is connected between the first surface of the piezoelectric component and the cover plate assembly, and the second connector is connected between the second surface of the piezoelectric component and the cover plate assembly. The second surface is the surface of the piezoelectric component opposite to the first surface, and the first connector, the second connector, the piezoelectric component, and the cover plate assembly form a third chamber.

[0009] Optionally, the first connector and / or the second connector is an annular plate, which partially overlaps with the piezoelectric component along the thickness direction of the bulk acoustic wave driven structure.

[0010] Optionally, the first connector and / or the second connector is a flat plate that covers the surface of the piezoelectric component.

[0011] Optionally, the first connector and / or the second connector are provided with a second through hole, and the cover plate assembly is also provided with a third through hole, and the third chamber is connected to the outside through the second through hole and the third through hole.

[0012] Optionally, the cover plate assembly includes a first cover plate, a second cover plate, and a third cover plate, the third cover plate being connected between the first cover plate and the second cover plate, and the connecting component, the piezoelectric component, and the first cover plate forming a first chamber, and the connecting component, the piezoelectric component, and the second cover plate forming a second chamber.

[0013] Optionally, the connecting assembly includes a third connector and a fourth connector. The third connector is connected between the first surface of the piezoelectric component and the third surface of the third cover plate, and the fourth connector is connected between the second surface of the piezoelectric component and the fourth surface of the third cover plate. The second surface is the surface of the piezoelectric component opposite to the first surface, and the fourth surface is the surface of the third cover plate opposite to the third surface. The third connector, the fourth connector, the piezoelectric component, and the third cover plate together form a third chamber.

[0014] Optionally, the connecting assembly further includes a first isolator connected between the surface of the piezoelectric assembly and the corresponding cover plate, the third connector and / or the fourth connector having a fifth through hole, the cover plate assembly having a sixth through hole, and the third chamber communicating with the outside through the fifth through hole and the sixth through hole.

[0015] Optionally, the connecting assembly includes a fifth connector and a sixth connector. The fifth connector is connected between the first surface of the piezoelectric assembly and the first cover plate, and the sixth connector is connected between the second surface of the piezoelectric assembly and the second cover plate. The second surface is the surface of the piezoelectric assembly opposite to the first surface, and the fifth connector, the sixth connector, the piezoelectric assembly, and the cover plate assembly form a third chamber.

[0016] Optionally, the third cover plate has a fourth through hole, through which the third chamber is connected to the outside.

[0017] Optionally, it also includes a movable member, which is connected to the fifth connector and has a gap between it and the first cover plate. The first cover plate has the first through hole, and the movable member can move to open or close the first through hole.

[0018] Optionally, the movable element is a perforated baffle, which can vibrate and open or close the first through hole.

[0019] Optionally, the connecting assembly further includes a second isolator and a third isolator, the second isolator being connected between the first surface of the piezoelectric component and the cover plate assembly, and the third isolator being connected between the second surface of the piezoelectric component and the cover plate assembly, the second surface being the surface of the piezoelectric component opposite to the first surface, and the second isolator, the third isolator, the piezoelectric component and the cover plate assembly forming a third chamber.

[0020] Optionally, the second and / or the third spacer includes a spacer gasket and two adhesive members, the spacer gasket being connected between the two adhesive members, and the side of the adhesive members away from the spacer gasket being connected to the cover plate assembly.

[0021] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising a housing and the aforementioned bulk acoustic wave driving structure, the bulk acoustic wave driving structure being disposed within the housing, the housing having an opening, and a first through hole facing the opening.

[0022] One technical advantage of this invention is that: The bulk acoustic wave driving structure provided by this invention can drive pressure changes in a corresponding chamber by varying the thickness of a piezoelectric element, thereby achieving a driving function. When a specific electric field is applied to the piezoelectric element, it can rapidly and accurately convert electrical energy into mechanical vibration. This vibration conversion process is based on the piezoelectric effect, exhibiting high sensitivity and rapid response. Furthermore, this bulk acoustic wave driving structure has a high mechanical Q value, which helps reduce its driving power consumption.

[0023] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which form part of this specification, illustrate embodiments of the invention and, together with the specification, serve to explain the principles of the invention.

[0025] Figure 1 This is a schematic diagram of the first type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the second type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the third type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the fourth type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the fifth type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the sixth type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the seventh type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the eighth type of bulk acoustic wave driving structure according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the ninth type of bulk acoustic wave driving structure according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures: 1. Cover plate assembly; 11. First chamber; 12. Second chamber; 13. Third chamber; 14. First through hole; 15. Third through hole; 16. First cover plate; 17. Second cover plate; 18. Third cover plate; 181. Fourth through hole; 19. Sixth through hole; 2. Piezoelectric assembly; 21. Piezoelectric element; 22. First electrode; 23. Second electrode; 3. Connecting assembly; 31. First connector; 32. Second connector; 321. Second through hole; 33. Third connector; 34. Fourth connector; 341. Fifth through hole; 35. First isolator; 36. Fifth connector; 37. Sixth connector; 38. Second isolator; 39. Third isolator; 4. Movable element. Detailed Implementation

[0027] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0028] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0029] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0030] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0032] According to one aspect of the present invention, a bulk acoustic wave drive structure is provided. This bulk acoustic wave drive structure can realize the driving function by utilizing the pressure change of the chamber through the thickness change of the piezoelectric element 21 and the supporting and separating effect of the connecting component 3. The structure is compact and has high driving efficiency.

[0033] like Figures 1 to 9 As shown, the bulk acoustic wave driving structure provided by the present invention includes: A cover assembly 1 having a receiving chamber therein; A piezoelectric component 2 is disposed in the receiving cavity, the piezoelectric component 2 includes a piezoelectric element 21, the thickness of which can vary; A connecting component 3 is provided, one end of which is connected to the piezoelectric component 2, and the other end of which is connected to the inner wall of the cover plate assembly 1. The connecting component 3 and the piezoelectric component 2 can divide the receiving chamber into a first chamber 11 and a second chamber 12. The cover plate assembly 1 is provided with a first through hole 14, through which the first chamber 11 and / or the second chamber 12 communicate with the outside.

[0034] Specifically, the cover plate assembly 1, as the load-bearing foundation of the entire drive structure, can be made of high-strength aluminum alloy or engineering plastic to provide excellent structural stability and wear resistance. The external dimensions of the cover plate assembly 1 can be adapted to the actual application scenario, preferably designed as a cuboid structure, with cylindrical or cuboid accommodating chambers opened along its thickness direction to provide sufficient installation and deformation space for the piezoelectric assembly 2 and the connecting assembly 3.

[0035] One, two, or even more first through holes 14 can be formed on the side or top wall of the cover plate assembly 1. The inner wall of the first through hole 14 is smoothed to avoid turbulence interference when airflow passes through. The first through hole 14 is used to connect the corresponding chamber to the external environment. For example, it can be set such that only the first chamber 11 is connected to the outside through the first through hole 14, only the second chamber 12 is connected to the outside through the first through hole 14, or the first chamber 11 and the second chamber 12 are connected to the outside through their respective first through holes 14, so as to improve the flexibility of chamber pressure regulation and thus realize different driving modes.

[0036] The piezoelectric element 21 can be made of piezoelectric ceramic sheet or piezoelectric polymer, which has excellent bulk acoustic wave response characteristics and high sensitivity to changes in thickness. The external dimensions of the piezoelectric element 21 are adapted to the cross-sectional dimensions of the accommodating chamber, and are preferably designed to be circular or square. Metal electrodes can be deposited on the upper and lower surfaces of the piezoelectric element 21 using a sputtering process. Electrode leads are connected to an external driving power supply, which outputs a sinusoidal alternating current, thereby driving the piezoelectric element 21 to produce periodic thickness changes.

[0037] The connecting component 3 can be made of an elastic sealing material, such as fluororubber or silicone rubber, to provide good elastic deformation capability and sealing performance. It can expand and contract synchronously when the thickness of the piezoelectric component 21 changes, thereby ensuring the sealed isolation between the first chamber 11 and the second chamber 12. The overall structure of the connecting component 3 can be an annular sealing ring or an annular elastic support, with its inner diameter matching the outer diameter of the piezoelectric component 2 and its outer diameter precisely matching the size of the positioning groove on the inner wall of the receiving chamber.

[0038] In one embodiment, one end of the connecting component 3 can be embedded into the positioning groove of the receiving chamber of the cover plate assembly 1 by interference fit, and UV-curing adhesive is used for fixation to ensure the connection strength between the connecting component 3 and the inner wall of the cover plate assembly 1; the other end of the connecting component 3 can be fixed to the edge of the piezoelectric component 2 by hot pressing or bonding.

[0039] Thus, through the separating effect of the connecting component 3, the accommodating chamber can be divided into a relatively independent first chamber 11 and a second chamber 12. The first chamber 11 is located on one side of the piezoelectric component 2, and the second chamber 12 is located on the other side of the piezoelectric component 2, so that the first chamber 11 and the second chamber 12 form independent pressure environments. This chamber division design allows the thickness change of the piezoelectric element 21 to cause periodic pressure changes in the two chambers, forming an effective bulk acoustic wave source.

[0040] The design of the first through-hole 14 provides a clear channel for the propagation of bulk sound waves. This design avoids reflection and interference of bulk sound waves inside the structure, reduces energy loss, and enables bulk sound waves to propagate outward more efficiently.

[0041] like Figures 1 to 9 As shown, the bulk acoustic wave driving structure provided by this invention can drive the corresponding chamber to generate pressure changes through the thickness change of the piezoelectric element 21, thereby realizing the driving function. When a specific electric field is applied to the piezoelectric element 21, the piezoelectric element 21 can quickly and accurately convert electrical energy into mechanical vibration. This vibration conversion process is based on the piezoelectric effect, which has the characteristics of high sensitivity and fast response. Moreover, this bulk acoustic wave driving structure has a high mechanical Q value (quality factor), which helps to reduce its driving power consumption. The specific process is as follows: Initial state: The piezoelectric element 21 is in its natural state, and the pressure in the first chamber 11 and the pressure in the second chamber 12 are the same as the external ambient pressure.

[0042] Drive phase: An external driving power supply outputs sinusoidal alternating current to the piezoelectric element 21. Under the action of the electric field, the piezoelectric element 21 undergoes periodic thickness expansion and contraction deformation. When the thickness of the piezoelectric element 21 increases, it compresses the space of the first chamber 11 and the second chamber 12, causing the pressure inside the chamber to rise. The high-pressure gas is discharged to the outside through the corresponding first through hole 14. When the thickness of the piezoelectric element 21 decreases, the space of the first chamber 11 and the second chamber 12 expands, creating a negative pressure inside the chamber. External gas is drawn into the corresponding chamber through the first through hole 14.

[0043] Thus, through the periodic thickness change of the piezoelectric element 21, continuous pressure alternation can be achieved in the first chamber 11 and the second chamber 12. The driving force is generated by the intake and exhaust of gas, which can be used to drive fluid flow, realize the function of a micro pump, or drive the movement of external actuators through pressure changes.

[0044] In one embodiment, a one-way valve, such as a duckbill one-way valve, can also be provided in the first through hole 14 to allow gas to flow only in a preset direction, such as entering the chamber in one direction when inhaled and exiting the chamber in one direction when discharged, so as to avoid gas backflow and thereby improve driving efficiency and stability.

[0045] The cover plate assembly 1 can have one or more first through holes 14, which can be used to connect the first chamber 11 and / or the second chamber 12 to the outside. When multiple first through holes 14 are provided, bulk sound waves can propagate simultaneously from multiple directions, expanding the propagation range and coverage area. Furthermore, the design of connecting different chambers through the first through holes 14 allows for adjustment of the frequency and intensity of the bulk sound waves. For example, by changing the size, number, and position of the first through holes 14, the airflow impedance within the corresponding chamber can be adjusted, thereby affecting the propagation characteristics of the bulk sound waves and meeting the diverse needs of different application scenarios.

[0046] Taking the application of this drive structure to a fluid pump as an example: the first through hole 14 can be opened only on the first cover plate 16 to connect the first chamber 11 and form a unilateral jet; the first through hole 14 can be opened only on the second cover plate 17 to connect the second chamber 12 and form a unilateral jet; the first through hole 14 can also be opened on the first cover plate 16 and the second cover plate 17 respectively to connect the first chamber 11 and the second chamber 12 and form a double-sided jet.

[0047] Furthermore, by changing the thickness and material properties of the piezoelectric element 21 in the piezoelectric component 2, or the frequency and intensity of the applied electric field, the vibration frequency of the piezoelectric component 2 can also be adjusted, thereby changing the frequency of the generated bulk acoustic wave. This frequency adjustability allows the drive structure to adapt to the frequency requirements of bulk acoustic waves in different application scenarios.

[0048] In one embodiment, the heights of the first chamber 11 and the second chamber 12 can be set to be integer multiples of the half-wavelength of ultrasound in the fluid, thereby achieving acoustic standing wave resonance at the same frequency and facilitating drive amplification, such as flow amplification.

[0049] Optionally, the piezoelectric component 2 further includes a first electrode 22 and a second electrode 23, the first electrode 22 and the second electrode 23 being respectively disposed on both sides of the piezoelectric component 21, and the pressure changes of the first chamber 11 and the second chamber 12 being the same.

[0050] like Figures 1 to 4 As shown, the upper and lower surfaces of the piezoelectric element 21 can be deposited with metal electrodes by sputtering process to form a first electrode 22 and a second electrode 23. The two electrodes are connected to an external driving power supply through wires. The driving power supply outputs sinusoidal alternating current, which can drive the piezoelectric element 21 to produce periodic thickness changes, thereby driving the first chamber 11 and the second chamber 12 to produce pressure changes, thus realizing the driving function.

[0051] In this way, the projected area of ​​the first electrode 22 and the second electrode 23 on the piezoelectric element 21 can be increased. For example, the projected area of ​​the first electrode 22 and the second electrode 23 on the piezoelectric element 21 can be set to be equal to the area of ​​the piezoelectric element 21, so as to improve the surface utilization rate of the piezoelectric element 21 and thus improve the driving efficiency.

[0052] The thickness or mass of the first electrode 22 and the second electrode 23 can be adjusted to change the resonant frequency of the drive structure, which helps to improve the consistency of electronic devices using the drive structure.

[0053] like Figures 1 to 9As shown, multiple first through holes 14 can be formed on the cover plate assembly 1. Some of the first through holes 14 connect the first chamber 11 to the outside, and other first through holes 14 connect the second chamber 12 to the outside. When the piezoelectric element 21 produces periodic thickness changes, the pressure in the first chamber 11 and the second chamber 12 changes synchronously, so as to realize the double-sided intake and exhaust of gas, thereby improving the driving force.

[0054] Optionally, the connecting component 3 includes a first connector 31 and a second connector 32. The first connector 31 is connected between the first surface of the piezoelectric component 2 and the cover plate component 1, and the second connector 32 is connected between the second surface of the piezoelectric component 2 and the cover plate component 1. The second surface is the surface of the piezoelectric component 2 opposite to the first surface, and the first connector 31, the second connector 32, the piezoelectric component 2 and the cover plate component 1 form a third chamber 13.

[0055] like Figures 1 to 4 As shown, the first surface of the piezoelectric component 2 can be its upper surface, and the second surface of the piezoelectric component 2 can be its lower surface. The upper surface of the piezoelectric component 2, the first connector 31, and the cover plate assembly 1 form a first chamber 11, the lower surface of the piezoelectric component 2, the second connector 32, and the cover plate assembly 1 form a second chamber 12, and the first connector 31, the second connector 32, the piezoelectric component 2, and the cover plate assembly 1 form a third chamber 13. The first chamber 11, the second chamber 12, and the third chamber 13 are not interconnected.

[0056] The thickness of the first connector 31 and the thickness of the second connector 32 are both less than the thickness of the piezoelectric component 2. The first connector 31 and the second connector 32 can be made of conductive materials such as metal, alloy plates or FPC flexible boards, so that they have a certain elasticity in the thickness direction, so as to maintain good sealing performance during the thickness change of the piezoelectric component 21.

[0057] Optionally, the first connector 31 and / or the second connector 32 are annular plates, and the annular plates partially overlap with the piezoelectric component 2 along the thickness direction of the bulk acoustic wave driven structure.

[0058] like Figure 1 As shown, at least one of the first connector 31 and the second connector 32 can be configured as an annular plate. The inner diameter of the annular plate is smaller than the size of the piezoelectric component 2, and the outer diameter of the annular plate is smaller than the size of the cover plate assembly, so as to facilitate the assembly of the annular plate and the independence and sealing of the three chambers formed.

[0059] Optionally, the first connector 31 and / or the second connector 32 are flat plates that cover the surface of the piezoelectric component 2.

[0060] like Figure 2 As shown, at least one of the first connector 31 and the second connector 32 can be a flat plate. The flat plate is directly connected to the inner wall of the cover plate assembly 1, and the flat plate can cover the corresponding surface of the piezoelectric assembly 2, so as to reduce the resonant frequency of the driving structure by utilizing a larger flat plate area.

[0061] Optionally, the first connector 31 and / or the second connector 32 are provided with a second through hole 321, and the cover plate assembly 1 is also provided with a third through hole 15. The third chamber 13 is connected to the outside through the second through hole 321 and the third through hole 15.

[0062] like Figure 3 As shown, a second through hole 321 can be opened on at least one of the first connector 31 and the second connector 32. A third through hole 15 is also opened on the cover plate assembly 1. One end of the third through hole 15 is connected to the second through hole 321, and the other end of the third through hole 15 is connected to the outside, so that the third chamber 13 can be connected to the outside through the second through hole 321 and the third through hole 15, thereby enhancing the driving capability of the drive structure by utilizing the third chamber 13.

[0063] The shape of the second through hole 321 includes, but is not limited to, a circle, an ellipse, and a rectangle, and the shape of the third through hole 15 includes, but is not limited to, a circle, an ellipse, and a rectangle.

[0064] Optionally, the cover plate assembly 1 includes a first cover plate 16, a second cover plate 17, and a third cover plate 18. The third cover plate 18 is connected between the first cover plate 16 and the second cover plate 17. The connecting assembly 3, the piezoelectric assembly 2, and the first cover plate 16 form the first chamber 11, and the connecting assembly 3, the piezoelectric assembly 2, and the second cover plate 17 form the second chamber 12.

[0065] like Figures 1 to 9 As shown, the first cover plate 16 can be an upper cover plate, the second cover plate 17 can be a lower cover plate, and the third cover plate 18 can be a middle frame connected between the upper cover plate and the lower cover plate. The upper surface of the piezoelectric component 2, the connecting component 3, and the upper cover plate form a first chamber 11, the lower surface of the piezoelectric component 2, the connecting component 3, and the lower cover plate form a second chamber 12, and the connecting component 3, the piezoelectric component 2, and the middle frame form a third chamber 13. The first chamber 11, the second chamber 12, and the third chamber 13 are not interconnected.

[0066] like Figures 1 to 9 As shown, a first through hole 14 can be opened on at least one of the first cover plate 16 and the second cover plate 17 to enable external communication of the corresponding chamber.

[0067] Optionally, the connecting component 3 includes a third connector 33 and a fourth connector 34. The third connector 33 is connected between the first surface of the piezoelectric component 2 and the third surface of the third cover plate 18. The fourth connector 34 is connected between the second surface of the piezoelectric component 2 and the fourth surface of the third cover plate 18. The second surface is the surface of the piezoelectric component 2 opposite to the first surface, and the fourth surface is the surface of the third cover plate 18 opposite to the third surface. The third connector 33, the fourth connector 34, the piezoelectric component 2, and the third cover plate 18 together form a third chamber 13.

[0068] like Figure 4 As shown, the first surface of the piezoelectric component 2 can be its upper surface, and the second surface of the piezoelectric component 2 can be its lower surface. The third surface of the third cover plate 18 can be its upper surface, and the fourth surface of the third cover plate 18 can be its lower surface.

[0069] The upper surface of the piezoelectric component 2, the third connector 33, and the first cover plate 16 form a first chamber 11. The lower surface of the piezoelectric component 2, the fourth connector 34, and the second cover plate 17 form a second chamber 12. The third connector 33, the fourth connector 34, the piezoelectric component 2, and the third cover plate 18 form a third chamber 13. The first chamber 11, the second chamber 12, and the third chamber 13 are not interconnected.

[0070] The thickness of the third connector 33 and the fourth connector 34 are both less than the thickness of the piezoelectric component 2. The third connector 33 and the fourth connector 34 can be made of conductive materials such as metal, alloy plate or FPC flexible board, so that they have a certain elasticity in the thickness direction, so as to maintain good sealing performance during the thickness change of the piezoelectric component 21.

[0071] Optionally, the connecting assembly 3 further includes a first isolator 35, which is connected between the surface of the piezoelectric assembly 2 and the corresponding cover plate. The third connecting member 33 and / or the fourth connecting member 34 are provided with a fifth through hole 341. The cover plate assembly 1 is also provided with a sixth through hole 19. The third chamber 13 is connected to the outside through the fifth through hole 341 and the sixth through hole 19.

[0072] like Figure 4 As shown, the first isolator 35 is connected between the surface of the piezoelectric component 2 and the corresponding cover plate to provide support in the thickness direction, which helps to enhance the mechanical reliability of the drive structure. The first isolator 35 can be an isolation gasket used to isolate the first chamber 11, the second chamber 12, and the third chamber 13. It can be made of low-elasticity, low-density silicone, polymers, etc., to reduce the impact on the resonant frequency and modes of the drive structure.

[0073] like Figure 4 As shown, a fifth through hole 341 can be formed on at least one of the third connector 33 and the fourth connector 34, and a sixth through hole 19 is also formed on the cover plate assembly 1. One end of the sixth through hole 19 is connected to the fifth through hole 341, and the other end of the sixth through hole 19 is connected to the outside, so that the third chamber 13 can be connected to the outside through the fifth through hole 341 and the sixth through hole 19, thereby enabling the third chamber 13 to enhance the driving capability of the drive structure.

[0074] The shape of the fifth through hole 341 includes, but is not limited to, a circle, an ellipse, and a rectangle, and the shape of the sixth through hole 19 includes, but is not limited to, a circle, an ellipse, and a rectangle.

[0075] Taking the application of this drive structure to a fluid pump as an example: When an external drive power source outputs sinusoidal alternating current to the piezoelectric element 21, under the action of the electric field, the piezoelectric element 21 undergoes periodic thickness expansion and contraction deformation. When the thickness of the piezoelectric element 21 increases, it compresses the space of the first chamber 11 and the second chamber 12, causing the pressure inside the chamber to rise. The high-pressure gas is discharged to the outside through the corresponding first through hole 14. At the same time, the radial dimension of the piezoelectric element 21 decreases, allowing external gas to enter the third chamber 13 through the sixth through hole 19 and the fifth through hole 341. When the thickness of the piezoelectric element 21 decreases, the space of the first chamber 11 and the second chamber 12 expands, creating a negative pressure inside the chamber. External gas is drawn into the corresponding chamber through the first through hole 14. At the same time, the radial dimension of the piezoelectric element 21 expands, allowing the high-pressure gas to be discharged to the outside through the corresponding fifth through hole 341 and the sixth through hole 19.

[0076] Thus, through the periodic thickness change of the piezoelectric element 21, the first chamber 11, the second chamber 12 and the third chamber 13 can achieve continuous alternating pressure changes, and the pressure changes of the first chamber 11 and the second chamber 12 are exactly opposite to the pressure changes of the third chamber 13. In this way, the corresponding driving force is generated by the intake and exhaust of gas, which can be used to drive fluid flow and realize the function of a micro pump.

[0077] Optionally, the connecting assembly 3 includes a fifth connector 36 and a sixth connector 37. The fifth connector 36 is connected between the first surface of the piezoelectric assembly 2 and the first cover plate 16, and the sixth connector 37 is connected between the second surface of the piezoelectric assembly 2 and the second cover plate 17. The second surface is the surface of the piezoelectric assembly 2 opposite to the first surface, and the fifth connector 36, the sixth connector 37, the piezoelectric assembly 2, and the cover plate assembly 1 form a third chamber 13.

[0078] like Figure 6 and Figure 7As shown, the first surface of the piezoelectric component 2 can be its upper surface, and the second surface of the piezoelectric component 2 can be its lower surface. The upper surface of the piezoelectric component 2, the fifth connector 36, and the first cover plate 16 form a first chamber 11, the lower surface of the piezoelectric component 2, the sixth connector 37, and the second cover plate 17 form a second chamber 12, and the fifth connector 36, the sixth connector 37, the piezoelectric component 2, and the cover plate assembly 1 form a third chamber 13. The first chamber 11, the second chamber 12, and the third chamber 13 are not interconnected.

[0079] The fifth connector 36 and the sixth connector 37 can be made of conductive materials such as metal, alloy plate or FPC flexible board, so that they have a certain elasticity in the thickness direction, so as to maintain good sealing performance during the thickness change of the piezoelectric component 21.

[0080] At least one of the fifth connector 36 and the sixth connector 37 can be a connecting ring or a support washer, so as to reduce the constraint on the piezoelectric component 2 while connecting the piezoelectric component 2 and the cover plate assembly 1 and separating the three chambers, thereby reducing the impact on the resonant frequency, mode, etc. of the driving structure.

[0081] Optionally, at least one of the first cover plate 16 and the second cover plate 17 is provided with a sixth through hole 19, through which the third chamber 13 is connected to the outside.

[0082] like Figure 8 As shown, a sixth through hole 19 can be formed on at least one of the first cover plate 16 and the second cover plate 17. One end of the sixth through hole 19 is connected to the third chamber 13, and the other end of the sixth through hole 19 is connected to the outside, so that the third chamber 13 can be connected to the outside through the sixth through hole 19, thereby enhancing the driving capability of the driving structure by utilizing the third chamber 13.

[0083] The shape of the sixth through hole 19 includes, but is not limited to, circles, ellipses, and rectangles.

[0084] Optionally, the third cover plate 18 has a fourth through hole 181, and the third chamber 13 is connected to the outside through the fourth through hole 181.

[0085] like Figure 1 and Figure 2 As shown, a fourth through hole 181 can be opened on the third cover plate 18. One end of the fourth through hole 181 is connected to the third chamber 13, and the other end of the fourth through hole 181 is connected to the outside, so that the third chamber 13 can be connected to the outside through the fourth through hole 181, thereby enhancing the driving capability of the driving structure by utilizing the third chamber 13.

[0086] The shape of the fourth through hole 181 includes, but is not limited to, circles, ellipses, and rectangles.

[0087] Thus, through the periodic thickness change of the piezoelectric element 21, the first chamber 11, the second chamber 12 and the third chamber 13 can achieve continuous alternating pressure changes, and the pressure changes of the first chamber 11 and the second chamber 12 are exactly opposite to the pressure changes of the third chamber 13. In this way, the corresponding driving force is generated by the intake and exhaust of gas, which can be used to drive fluid flow and realize the function of a micro pump.

[0088] Optionally, it also includes a movable member 4, which is connected to the fifth connector 36 and has a gap between it and the first cover plate 16. The first cover plate 16 has the first through hole 14, and the movable member 4 can move to open or close the first through hole 14.

[0089] like Figure 6 and Figure 7 As shown, the movable member 4 can be an elastic thin plate with a hollow area. This elastic thin plate can move under electrostatic, piezoelectric, electrothermal, electromagnetic or other driving methods to open or close the first through hole 14, so as to adjust the external communication state of the first chamber 11. In this way, this driving structure can be applied to products such as loudspeakers, and the movement of the movable member 4 can be used to open or close the first through hole 14 to facilitate the control and processing of sound signals.

[0090] Optionally, the movable member 4 is a hollow baffle, which can vibrate and open or close the first through hole 14.

[0091] Specifically, the movable part 4 can be a hollow baffle. The hollow baffle can vibrate under the drive of the drive source and reduce the gap between itself and the first cover plate 16 until the non-hollow area covers the first through hole 14, that is, close the first through hole 14, or vibrate and increase the gap between itself and the first cover plate 16 until the hollow area covers the first through hole 14, that is, open the first through hole 14, thereby adjusting the external communication state of the first chamber 11.

[0092] Optionally, the movable element 4 is a MEMS switch chip, which can vibrate to open or close the first through hole 14.

[0093] Specifically, the effective shielding area of ​​the movable diaphragm of the MEMS switch chip can be adapted to the aperture of the first through hole 14 so that the first through hole 14 can be opened or closed accordingly.

[0094] For example, when the external control module does not output a drive voltage to the MEMS switch chip, the movable diaphragm of the MEMS switch chip is in a naturally relaxed state, maintaining a gap with the first through hole 14. The first chamber 11 is normally connected to the outside through the first through hole 14, such as... Figure 7As shown; when it is necessary to close the first through-hole 14, the control module outputs the rated drive voltage to the MEMS switch chip, driving the movable diaphragm to vibrate in the direction of the first through-hole 14 and block the first through-hole 14, thereby isolating the first chamber 11 from the outside. Figure 6 As shown; after the control module stops outputting the drive voltage, the electrostatic attraction disappears, the movable diaphragm vibrates and resets in the opposite direction under its own elasticity, the first through hole 14 reopens, and the pressure in the first chamber 11 returns to equilibrium.

[0095] Optionally, the connecting assembly 3 further includes a second isolator 38 and a third isolator 39. The second isolator 38 is connected between the first surface of the piezoelectric assembly 2 and the cover plate assembly 1, and the third isolator 39 is connected between the second surface of the piezoelectric assembly 2 and the cover plate assembly 1. The second surface is the surface of the piezoelectric assembly 2 opposite to the first surface, and the second isolator 38, the third isolator 39, the piezoelectric assembly 2 and the cover plate assembly 1 form a third chamber 13.

[0096] like Figure 8 and Figure 9 As shown, the first surface of the piezoelectric component 2 can be its upper surface, and the second surface of the piezoelectric component 2 can be its lower surface. The upper surface of the piezoelectric component 2, the second isolator 38, and the cover plate assembly 1 form a first chamber 11; the lower surface of the piezoelectric component 2, the third isolator 39, and the cover plate assembly 1 form a second chamber 12; the second isolator 38, the third isolator 39, the piezoelectric component 2, and the cover plate assembly 1 form a third chamber 13; the first chamber 11, the second chamber 12, and the third chamber 13 are not interconnected.

[0097] The second isolation element 38 and the third isolation element 39 can be made of conductive materials such as metal, alloy plate or FPC flexible board, so that they have a certain elasticity in the thickness direction, so as to maintain good sealing performance during the thickness change of the piezoelectric element 21.

[0098] At least one of the second isolation member 38 and the third isolation member 39 can be a connecting ring or a support washer, so as to reduce the constraint on the piezoelectric component 2 while connecting the piezoelectric component 2 and the cover plate assembly 1 and separating the three chambers, thereby reducing the impact on the resonant frequency, mode, etc. of the driving structure.

[0099] In one embodiment, the height of the receiving chamber can be adjusted to an integer multiple of the half-wavelength of the carrier wave in the fluid, so that the first through-hole 14 can be located at the pressure antinode, which helps to enhance the driving efficiency.

[0100] Optionally, the second spacer 38 and / or the third spacer 39 include a spacer gasket and two adhesive members, the spacer gasket being connected between the two adhesive members, and the side of the adhesive members away from the spacer gasket being connected to the cover plate assembly 1.

[0101] Specifically, at least one of the second isolation member 38 and the third isolation member 39 can be provided, including a first adhesive member, an isolation gasket, and a second adhesive member. The first adhesive member and the second adhesive member are located on both sides of the isolation gasket, which facilitates the assembly of the second isolation member 38 and the third isolation member 39, and also facilitates the control of the height of the corresponding chambers. It can also reduce the constraint on the piezoelectric component 2, thereby reducing the impact on the resonant frequency, mode, etc. of the driving structure.

[0102] In addition, at least one of the second isolation member 38 and the third isolation member 39 includes an isolation gasket and two adhesive members to enhance the connection reliability of the respective isolation members, which helps to enhance the mechanical reliability of the drive structure.

[0103] According to another aspect of the present invention, an electronic device is provided, including a housing and the aforementioned bulk acoustic wave driving structure, the bulk acoustic wave driving structure being disposed within the housing, the housing having an opening, and a first through hole 14 facing the opening.

[0104] The electronic devices include, but are not limited to, fluid pumps and loudspeakers. When used as a fluid pump, jet air intake can be achieved through the first through-hole 14 and the opening; when used as a loudspeaker, sound signals can be output through the first through-hole 14 and the opening.

[0105] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0106] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A bulk acoustic wave driven structure, characterized in that, include: A cover plate assembly (1) having a receiving chamber therein; A piezoelectric assembly (2) is disposed in the receiving cavity, the piezoelectric assembly (2) includes a piezoelectric element (21), the thickness of which can vary; A connecting component (3) is provided, one end of which is connected to the piezoelectric component (2), and the other end of which is connected to the inner wall of the cover plate assembly (1). The connecting component (3) and the piezoelectric component (2) can divide the receiving chamber into a first chamber (11) and a second chamber (12) opposite to each other. The cover plate assembly (1) is provided with a first through hole (14), and the first chamber (11) and / or the second chamber (12) are connected to the outside through the first through hole (14).

2. The bulk acoustic wave driving structure according to claim 1, characterized in that, The piezoelectric component (2) further includes a first electrode (22) and a second electrode (23), the first electrode (22) and the second electrode (23) are respectively disposed on both sides of the piezoelectric component (21), and the pressure changes of the first chamber (11) and the second chamber (12) are the same.

3. The bulk acoustic wave driving structure according to claim 1, characterized in that, The connecting component (3) includes a first connector (31) and a second connector (32). The first connector (31) is connected between the first surface of the piezoelectric component (2) and the cover plate component (1). The second connector (32) is connected between the second surface of the piezoelectric component (2) and the cover plate component (1). The second surface is the surface of the piezoelectric component (2) opposite to the first surface. The first connector (31), the second connector (32), the piezoelectric component (2) and the cover plate component (1) form a third chamber (13).

4. The bulk acoustic wave driving structure according to claim 3, characterized in that, The first connector (31) and / or the second connector (32) are annular plates, and the annular plates partially overlap with the piezoelectric component (2) along the thickness direction of the bulk acoustic wave driven structure.

5. The bulk acoustic wave driving structure according to claim 3, characterized in that, The first connector (31) and / or the second connector (32) are flat plates that cover the surface of the piezoelectric component (2).

6. A bulk acoustic wave driving structure according to claim 4 or 5, characterized in that, The first connector (31) and / or the second connector (32) are provided with a second through hole (321), and the cover plate assembly (1) is also provided with a third through hole (15). The third chamber (13) is connected to the outside through the second through hole (321) and the third through hole (15).

7. The bulk acoustic wave driving structure according to claim 1, characterized in that, The cover plate assembly (1) includes a first cover plate (16), a second cover plate (17) and a third cover plate (18). The third cover plate (18) is connected between the first cover plate (16) and the second cover plate (17). The connecting component (3), the piezoelectric component (2) and the first cover plate (16) form the first chamber (11), and the connecting component (3), the piezoelectric component (2) and the second cover plate (17) form the second chamber (12).

8. The bulk acoustic wave driving structure according to claim 7, characterized in that, The connecting component (3) includes a third connector (33) and a fourth connector (34). The third connector (33) is connected between the first surface of the piezoelectric component (2) and the third surface of the third cover plate (18). The fourth connector (34) is connected between the second surface of the piezoelectric component (2) and the fourth surface of the third cover plate (18). The second surface is the surface of the piezoelectric component (2) opposite to the first surface, and the fourth surface is the surface of the third cover plate (18) opposite to the third surface. The third connector (33), the fourth connector (34), the piezoelectric component (2), and the third cover plate (18) together form a third chamber (13).

9. A bulk acoustic wave driving structure according to claim 8, characterized in that, The connecting assembly (3) further includes a first isolator (35), which is connected between the surface of the piezoelectric assembly (2) and the corresponding cover plate. The third connector (33) and / or the fourth connector (34) are provided with a fifth through hole (341). The cover plate assembly (1) is also provided with a sixth through hole (19). The third chamber (13) is connected to the outside through the fifth through hole (341) and the sixth through hole (19).

10. A bulk acoustic wave driving structure according to claim 7, characterized in that, The connecting assembly (3) includes a fifth connector (36) and a sixth connector (37). The fifth connector (36) is connected between the first surface of the piezoelectric assembly (2) and the first cover plate (16). The sixth connector (37) is connected between the second surface of the piezoelectric assembly (2) and the second cover plate (17). The second surface is the surface of the piezoelectric assembly (2) opposite to the first surface. The fifth connector (36), the sixth connector (37), the piezoelectric assembly (2), and the cover plate assembly (1) together form a third chamber (13).

11. A bulk acoustic wave driving structure according to claim 8 or 10, characterized in that, The third cover plate (18) has a fourth through hole (181), and the third chamber (13) is connected to the outside through the fourth through hole (181).

12. The bulk acoustic wave driving structure according to claim 10, characterized in that, It also includes a movable member (4), which is connected to the fifth connector (36) and has a gap with the first cover plate (16). The first cover plate (16) has the first through hole (14), and the movable member (4) can move and open or close the first through hole (14).

13. A bulk acoustic wave driving structure according to claim 12, characterized in that, The movable part (4) is a hollow baffle, which can vibrate and open or close the first through hole (14).

14. The bulk acoustic wave driving structure according to claim 1, characterized in that, The connecting assembly (3) further includes a second isolator (38) and a third isolator (39). The second isolator (38) is connected between the first surface of the piezoelectric assembly (2) and the cover plate assembly (1). The third isolator (39) is connected between the second surface of the piezoelectric assembly (2) and the cover plate assembly (1). The second surface is the surface of the piezoelectric assembly (2) opposite to the first surface. The second isolator (38), the third isolator (39), the piezoelectric assembly (2) and the cover plate assembly (1) form a third chamber (13).

15. A bulk acoustic wave driving structure according to claim 14, characterized in that, The second isolation member (38) and / or the third isolation member (39) includes an isolation gasket and two adhesive members, the isolation gasket being connected between the two adhesive members, and the side of the adhesive members away from the isolation gasket being connected to the cover plate assembly (1).

16. An electronic device, characterized in that, The device includes a housing and a bulk acoustic wave drive structure as described in any one of claims 1 to 15, the bulk acoustic wave drive structure being disposed within the housing, the housing having an opening, and the first through hole (14) facing the opening.

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