A piezoelectric pump with a tesla valve and venturi coordinated rectification for chip heat dissipation

Abstract

The application discloses a piezoelectric pump with Tesla valve and Venturi coordinated rectification for chip heat dissipation, which comprises a pump body, a piezoelectric driver, a circular pump cavity on a lower cover plate and a fluid processing unit; the circular pump cavity is arranged opposite to the piezoelectric driver; a first inlet and a second inlet are symmetrically arranged on opposite sides of the pump body, and an outlet is arranged on the other end side of the pump body; the fluid processing unit comprises a first Tesla valve, a second Tesla valve and a collecting channel. The piezoelectric pump utilizes the geometric asymmetry of the two-stage series Tesla valve to provide low flow resistance in the forward direction and high flow resistance through vortex in the reverse direction, effectively inhibits backflow and improves the net output flow; the contraction section of the Venturi structure is combined to accelerate, the throat is combined to increase flow and the diffusion section is combined to stabilize flow, so that the outlet flow velocity distribution is significantly improved and energy loss is reduced; the piezoelectric driver is driven by a multilayer composite structure of a trapezoidal wave with smooth edges, so that the response speed and deformation stability are considered, and instantaneous impact and fluid fluctuation are eliminated.

Description

Technical Field

[0001] This invention relates to the fields of heat dissipation of electronic devices, microfluidic transport and piezoelectric drive technology, and in particular to a piezoelectric pump for chip heat dissipation that uses a Tesla valve and a Venturi rectifier for coordinated flow. Background Technology

[0002] A piezoelectric pump is a miniature pump that utilizes the periodic deformation of a piezoelectric material under the influence of an electrical signal to change the volume of the pump chamber and thus achieve fluid transport. Piezoelectric pumps have advantages such as compact structure, fast response speed, low energy consumption, ease of miniaturization, and convenient integration, and have broad application prospects in microfluidic transport, electronic device heat dissipation, precision instruments, and biomedicine. However, existing piezoelectric pumps have the following technical shortcomings in practical applications:

[0003] First, backflow leads to a decrease in net output flow rate. Existing piezoelectric pumps typically rely on the reciprocating vibration of a piezoelectric actuator to achieve the suction and discharge processes. Due to the periodic pressure changes between the pump chamber, inlet, and outlet, backflow is easily generated during the suction and discharge processes, resulting in a significant decrease in net output flow rate and limiting the fluid delivery efficiency of the piezoelectric pump.

[0004] Second, the reliability of mechanical valve plate check structures is insufficient. To suppress backflow, some existing piezoelectric pumps use mechanical valve plates for check. However, mechanical valve plates may experience wear, fatigue fracture, or jamming deformation during long-term high-frequency reciprocating operation, seriously affecting the operational reliability and service life of the piezoelectric pump.

[0005] Third, the simple outlet flow channel structure leads to poor output stability. The outlet flow channel structure of existing piezoelectric pumps is usually relatively simple. After the fluid is discharged from the pump chamber, it is prone to local energy loss and uneven flow velocity distribution, resulting in large output flow pulsation and poor stability, which makes it difficult to meet the application requirements of precision fluid transportation.

[0006] Fourth, there is a contradiction between response speed and stability in the drive waveform. The selection of drive waveform for existing piezoelectric pumps faces a dilemma: although the commonly used sinusoidal drive waveform has a smooth transition, it reaches the peak displacement slowly, resulting in a limited drive response speed and a low rate of change of pump cavity volume; although the ideal square wave drive waveform has a fast response speed, its edge abrupt change is large, which can easily cause instantaneous impact on the piezoelectric actuator and fluid fluctuations in the pump cavity, and long-term operation can easily lead to fatigue failure of piezoelectric materials.

[0007] In summary, it is necessary to provide a miniature planar piezoelectric pump that combines flow channel rectification, outlet acceleration, and smooth transition of drive waveform to reduce backflow, improve outlet flow conditions, and enhance fluid delivery efficiency and output stability. Summary of the Invention

[0008] This invention provides a piezoelectric pump that uses a Tesla valve and a Venturi rectifier for chip heat dissipation, in order to solve the technical problems of existing piezoelectric pumps, such as reduced delivery efficiency due to reverse backflow, large energy loss and poor flow stability in the outlet flow channel, and difficulty in balancing the response speed and stability of the drive waveform.

[0009] In view of the above technical problems, the present invention provides a piezoelectric pump for chip heat dissipation with Tesla valve and Venturi coordinated rectification, including a pump body, a piezoelectric actuator disposed on the upper cover plate of the pump body, and a circular pump cavity built into the lower cover plate of the pump body; the circular pump cavity and the piezoelectric actuator are arranged facing each other; a first inlet and a second inlet are symmetrically arranged on opposite sides of the pump body, and an outlet is provided on the other end of the pump body on the perpendicular bisector of the line connecting the first inlet and the second inlet;

[0010] A fluid processing unit is provided between the circular pump chamber, the first inlet, the second inlet, and the outlet;

[0011] The fluid processing unit includes a first Tesla valve connected to the first inlet, a second Tesla valve connected to the second inlet, a manifold connecting the first Tesla valve and the second Tesla valve, and a Venturi structure connecting the manifold and the circular pump chamber; the manifold is connected to the outlet, and the front end of the Venturi structure and the rear end of the first Tesla valve and the rear end of the second Tesla valve are all connected to the manifold port, which is the starting end of the manifold and located between the Venturi structure and the manifold;

[0012] The piezoelectric actuator is used to vibrate under the action of a driving electrical signal, causing the volume of the circular pump chamber to change periodically, thereby driving the fluid to enter through the first inlet and the second inlet, be rectified by the first Tesla valve and the second Tesla valve and then flow into the confluence port, and then be discharged from the outlet after passing through the Venturi structure; the driving waveform of the driving electrical signal is a trapezoidal wave with smooth edges.

[0013] Optionally, the first Tesla valve and the second Tesla valve have the same structure and are arranged in a mirror image. Each includes a first-stage Tesla valve unit and a second-stage Tesla valve unit connected in series along the fluid flow direction. The first-stage Tesla valve unit and the second-stage Tesla valve unit are configured to provide a low flow resistance path when the fluid flows in the forward direction, and generate vortices through flow channel bifurcation when the fluid flows in the reverse direction to form a high flow resistance, thereby achieving rectification and suppressing backflow.

[0014] Optionally, the direction from the circular pump chamber to the manifold is defined as the pumping direction. The Venturi structure includes a contraction section, a throat, and a diffusion section connected sequentially from the pumping direction. The cross-sectional area of ​​the channel in the contraction section gradually decreases from the pumping direction. The throat is the position of the smallest cross-section of the Venturi structure. The cross-sectional area of ​​the channel in the diffusion section gradually increases from the pumping direction. The fluid accelerates when passing through the contraction section, reaches its maximum flow velocity at the throat, and then diffuses and stabilizes through the diffusion section before being discharged through the manifold.

[0015] Optionally, the piezoelectric actuator is a multilayer composite structure, including a piezoelectric ceramic sheet, an upper copper sheet, a polyimide film, a lower copper sheet, and an aluminum alloy metal reflective layer connected sequentially along the thickness direction; the piezoelectric ceramic sheet is used to generate electro-effect deformation under the action of the driving electrical signal, and the upper copper sheet and the lower copper sheet are used for conductive connection.

[0016] Optionally, the upper cover plate and the lower cover plate are connected to form the pump body. The lower cover plate is made of copper and is used to directly contact and adhere to the heating surface of the chip to absorb the heat generated by the chip.

[0017] Optionally, the smooth-edge trapezoidal wave includes a rising segment, a positive flat-top segment, a falling segment, and a negative flat-top segment within one cycle; the smooth-edge trapezoidal wave is used to reduce the instantaneous impact of the piezoelectric actuator, thereby improving the stability of the suction and discharge process of the circular pump chamber.

[0018] Optionally, the first inlet and the second inlet are arranged in a mirror-symmetric manner with respect to the central axis of the circular pump chamber, and the axis of the outlet is perpendicular to the line connecting the first inlet and the second inlet, so as to balance the pressure distribution within the circular pump chamber.

[0019] In this invention, by symmetrically arranging a first inlet and a second inlet on both sides of a circular pump chamber, and respectively arranging a first Tesla valve and a second Tesla valve on their rear sides, the asymmetrical flow channel structure of the first-stage and second-stage Tesla valve units generates a difference in forward and reverse flow resistance. This provides a low-resistance path for forward flow and creates vortices through flow channel bifurcation to form high flow resistance for reverse flow. This achieves rectification and suppresses backflow without mechanical valve plates, improves the unidirectional flow guidance capability of the flow channel, and reduces backflow, avoiding the wear, fatigue, or jamming problems of mechanical valve plates. The two-way fluid is merged through the manifold, and the outlet flow state is improved through a Venturi structure including a contraction section, throat, and diffuser section, allowing the fluid to accelerate and diffuse smoothly, improving output stability. The lower cover plate is made of copper, which improves the heat conduction efficiency between the pump body and the chip, and enhances the chip's heat dissipation effect in conjunction with periodic airflow. A trapezoidal wave drive with smooth edges is used, which balances response speed and displacement stability, reduces the instantaneous impact of the piezoelectric actuator, and improves the stability of the suction and discharge process of the circular pump chamber, thereby improving the overall performance of the micro planar piezoelectric pump. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of a piezoelectric pump that uses a Tesla valve for chip heat dissipation and a Venturi-assisted rectification for piezoelectric pump in one embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of a piezoelectric actuator in one embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of a fluid processing unit in one embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of the second Tesla valve in one embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the Venturi structure in one embodiment of the present invention;

[0026] Figure 6 This is an optimized driving waveform diagram in one embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of the integrated heat dissipation of the piezoelectric heat pump and the chip stack in one embodiment of the present invention.

[0028] The reference numerals in the accompanying drawings are as follows:

[0029] 1-Pump body, 11-Upper cover plate, 12-Lower cover plate, 2-Piezoelectric actuator, 21-Piezoelectric ceramic sheet, 22-Upper copper sheet, 23-Polyimide film, 24-Lower copper sheet, 25-Metal reflective layer, 3-Circular pump chamber, 4-First inlet, 5-Second inlet, 6-Outlet, 7-First Tesla valve, 8-Second Tesla valve, 81-First-stage Tesla valve unit, 82-Second-stage Tesla valve unit, 9-Manifold, 91-Manifold port, 10-Venturi structure, 1001-Contraction section, 1002-Throat, 1003-Diffusion section, 13-Chip body. Detailed Implementation

[0030] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] In the description of this invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0033] like Figures 1 to 5As shown, an embodiment of the present invention provides a piezoelectric pump for chip heat dissipation using a Tesla valve and a Venturi rectifier, including a pump body 1, a piezoelectric actuator 2 disposed on an upper cover plate 11 of the pump body 1, and a circular pump chamber 3 built into a lower cover plate 12 of the pump body 1; the circular pump chamber 3 is arranged opposite to the piezoelectric actuator 2; a first inlet 4 and a second inlet 5 are symmetrically arranged on opposite sides of the pump body 1, and an outlet 6 is provided on the other end of the pump body 1 on the perpendicular bisector of the line connecting the first inlet 4 and the second inlet 5.

[0034] A fluid processing unit is disposed between the circular pump chamber 3, the first inlet 4, the second inlet 5, and the outlet 6. The fluid processing unit includes a first Tesla valve 7 connecting the first inlet 4, a second Tesla valve 8 connecting the second inlet 5, a manifold 9 connecting the first Tesla valve 7 and the second Tesla valve 8, and a Venturi structure 10 connecting the manifold 9 and the circular pump chamber 3. The manifold 9 is connected to the outlet 6. The front end of the Venturi structure 10 and the rear ends of the first Tesla valve 7 and the second Tesla valve 8 are all connected to a manifold port 91. The manifold port 91 is the starting end of the manifold 9 and is located between the Venturi structure 10 and the manifold 9.

[0035] The piezoelectric actuator 2 is used to vibrate under the action of the driving electrical signal, causing the volume of the circular pump chamber 3 to change periodically, thereby driving the fluid to enter through the first inlet 4 and the second inlet 5, be rectified by the first Tesla valve 7 and the second Tesla valve 8 and then flow into the manifold 91, and then be discharged through the outlet 6 after passing through the Venturi structure 10; the driving waveform of the driving electrical signal is a trapezoidal wave with smooth edges.

[0036] Understandably, by means of the rear side of the first inlet 4 and the second inlet 5 (e.g. Figure 3 The first Tesla valve 7 and the second Tesla valve 8 are respectively installed in the directions shown. The asymmetrical structure of the flow channel generates a difference in flow resistance in both directions, resulting in lower resistance when the fluid flows in the forward direction and higher resistance when flowing in the reverse direction. This achieves rectification and suppresses backflow without mechanical valve plates, improving the unidirectional flow guidance capability of the flow channel and reducing backflow. It also avoids the wear, fatigue, or jamming problems that may occur with mechanical valve plates during long-term operation. A manifold 91 is provided so that the fluid from the first inlet 4 and the second inlet 5 merges and enters the manifold 9. The Venturi structure 10 accelerates and stabilizes the fluid as it passes through, thereby improving the outlet flow state and increasing output stability. The use of a trapezoidal wave drive with smooth edges balances drive response speed and displacement change smoothness, reducing the instantaneous impact of the piezoelectric actuator 2 and improving the stability of the suction and discharge processes of the circular pump chamber 3, thus improving the overall performance of the micro planar piezoelectric pump.

[0037] In one embodiment, such as Figure 3 As shown, the first Tesla valve 7 and the second Tesla valve 8 have the same structure and are arranged in a mirror image. Both include a first-stage Tesla valve unit 81 and a second-stage Tesla valve unit 82 connected in series along the fluid flow direction. The first-stage Tesla valve unit 81 and the second-stage Tesla valve unit 82 are configured to provide a low flow resistance path when the fluid flows in the forward direction, and generate vortices through flow channel bifurcation when the fluid flows in the reverse direction to form a high flow resistance, thereby achieving rectification and suppressing backflow.

[0038] Understandably, by setting the first Tesla valve 7 and the second Tesla valve 8 to have the same structure and be arranged in a mirror image, both including a first-stage Tesla valve unit 81 and a second-stage Tesla valve unit 82 connected in series along the fluid flow direction, the flow channels of the first-stage Tesla valve unit 81 and the second-stage Tesla valve unit 82 are asymmetrical. The asymmetrical structure of the flow channels generates a difference in forward and reverse flow resistance, providing a low flow resistance path when the fluid flows in the forward direction (such as from the second inlet 5 to the manifold 91), and generating vortices through flow channel bifurcation to form high flow resistance when flowing in the reverse direction (such as from the manifold 91 to the second inlet 5). This achieves rectification and suppression of backflow without mechanical valve plates, improves the unidirectional flow guidance capability of the flow channel and reduces backflow, and avoids the wear, fatigue or jamming problems that may occur with mechanical valve plates during long-term operation. At the same time, the rectification effect is exponentially enhanced by the two-stage series arrangement, ensuring that backflow can still be effectively suppressed under the high-frequency operation conditions of the piezoelectric pump.

[0039] In one embodiment, such as Figure 3 and Figure 5 As shown, the direction from the circular pump chamber 3 to the manifold 91 is defined as the pumping direction. The Venturi structure 10 includes a contraction section 1001, a throat 1002, and a diffuser section 1003 connected sequentially from the pumping direction. The cross-sectional area of ​​the channel of the contraction section 1001 gradually decreases from the pumping direction. The throat 1002 is the position of the smallest cross-section of the Venturi structure 10. The cross-sectional area of ​​the channel of the diffuser section 1003 gradually increases from the pumping direction. The fluid accelerates when passing through the contraction section 1001, reaches the highest flow velocity at the throat 1002, and then diffuses and stabilizes through the diffuser section 1003 before being discharged through the manifold 91.

[0040] Understandably, by utilizing the gradual change in cross-sectional area of ​​the Venturi structure 10, the fluid accelerates in the contraction section 1001 and reaches its maximum flow velocity in the throat 1002, significantly enhancing the fluid's heat carrying capacity and output kinetic energy. Subsequently, it smoothly expands in the diffusion section 1003, efficiently converting dynamic pressure energy into static pressure energy. This effectively reduces local energy loss and jet turbulence at the outlet 6, solving the problems of uneven outlet velocity distribution and large pressure fluctuations in existing piezoelectric pumps, and greatly improving the stability and delivery efficiency of fluid output.

[0041] In one embodiment, such as Figure 1 and Figure 2 As shown, the piezoelectric actuator 2 is a multi-layer composite structure, including a piezoelectric ceramic sheet 21, an upper copper sheet 22, a polyimide film 23, a lower copper sheet 24, and an aluminum alloy metal reflective layer 25 connected sequentially along the thickness direction. The piezoelectric ceramic sheet 21 is used to generate electro-effect deformation under the action of the driving electrical signal, and the upper copper sheet 22 and the lower copper sheet 24 are used for conductive connection. Understandably, while ensuring that the piezoelectric ceramic sheet 21 efficiently generates electro-induced deformation, the polyimide film 23 provides the necessary flexible support and insulation performance, and the upper copper sheet 22 and the lower copper sheet 24 ensure the stability of the conductive path. In particular, the addition of the aluminum alloy metal reflective layer 25 not only enhances the overall structural rigidity, but also effectively reflects the vibration wave energy. Combined with the trapezoidal wave drive with smooth edges, it eliminates the instantaneous mechanical impact during the driving process, significantly improving the response speed, deformation stability, and long-term working reliability of the piezoelectric actuator 2.

[0042] In one embodiment, such as Figure 1 and Figure 2 As shown, the upper cover plate 11 and the lower cover plate 12 are connected to form the pump body 1. The lower cover plate 12 is made of copper and is used to directly contact and adhere to the heating surface of the chip to absorb the heat generated by the chip. Understandably, the lower cover plate 12 is made of copper to utilize the high thermal conductivity of copper, thereby improving the heat transfer efficiency between the pump body and the high-performance chip. This facilitates the rapid transfer of heat from the chip to the fluid heat exchange area, and, in conjunction with the periodic intake and exhaust process of the piezoelectric pump, enhances the chip's heat dissipation effect.

[0043] In one embodiment, such as Figure 6 As shown, the smooth-edge trapezoidal wave includes a rising segment, a positive flat-top segment, a falling segment, and a negative flat-top segment within one cycle; the smooth-edge trapezoidal wave is used to reduce the instantaneous impact of the piezoelectric actuator 2, so as to improve the stability of the suction and discharge process of the circular pump chamber 3.

[0044] Understandably, a trapezoidal wave with smooth edges is used as the driving waveform of the piezoelectric actuator 2. Within one cycle, the smooth trapezoidal wave includes a rising segment, a positive flat-top segment, a falling segment, and a negative flat-top segment. Compared to a sinusoidal driving waveform, it has a faster displacement response; compared to an ideal square wave driving waveform, it has a smoother edge transition. This balances driving response speed and displacement change stability, reduces the instantaneous impact of the piezoelectric actuator 2, improves the stability of the suction and discharge processes in the circular pump chamber 3, and avoids fluid fluctuations within the pump chamber caused by abrupt edge changes. Figure 6 As shown, the sinusoidal drive waveform has a smooth transition but reaches the peak displacement relatively slowly. The ideal square wave drive waveform has a fast response speed but obvious edge abrupt changes. The trapezoidal wave with smooth edges is the preferred drive waveform, which has smooth transition edges and relatively fast displacement response, thereby improving the overall performance of the micro planar piezoelectric pump.

[0045] In one embodiment, such as Figure 3 As shown, the first inlet 4 and the second inlet 5 are arranged in a mirror-symmetric manner with respect to the central axis of the circular pump chamber 3, and the axis of the outlet 6 is perpendicular to the line connecting the first inlet 4 and the second inlet 5, so as to balance the pressure distribution in the circular pump chamber 3.

[0046] Understandably, by arranging the first inlet 4 and the second inlet 5 in a mirror-symmetric manner with respect to the central axis of the circular pump cavity 3, and with the axis of the outlet 6 perpendicular to the line connecting the first inlet 4 and the second inlet 5, the fluid enters the circular pump cavity 3 symmetrically from both sides and flows out in a direction perpendicular to the line connecting the inlets, thereby balancing the pressure distribution within the circular pump cavity 3, avoiding eddies and dead zones caused by unilateral flow, and improving the uniformity of the flow field and the stability of fluid transport within the pump cavity.

[0047] In one specific embodiment, the operation process of the Tesla valve for chip heat dissipation and the piezoelectric pump with venturi-assisted rectification is as follows:

[0048] The Tesla valve and venturi-assisted piezoelectric pump used for chip heat dissipation are positioned above the chip body 13, which is mounted on a circuit board. During operation, the heat generated by the chip body 13 is first transferred to the copper lower cover plate 12. The piezoelectric actuator 2, under the influence of a driving electrical signal, generates periodic vibrations, causing the gas inside the pump body 1 to continuously draw in and expel, forming a continuous directional airflow. As this airflow passes through the copper lower cover plate 12, it effectively removes the heat transferred from the chip body 13 to the copper lower cover plate 12, thereby reducing the temperature of the chip surface and its surrounding area.

[0049] When a trapezoidal wave drive signal with smooth edges is applied to the piezoelectric actuator 2, the piezoelectric actuator 2 vibrates periodically and causes a slight deformation in the corresponding area of ​​the upper cover plate 11, causing the volume of the circular pump chamber 3 to change periodically. This drives the fluid to enter through the first inlet 4 and the second inlet 5, be rectified by the first Tesla valve 7 and the second Tesla valve 8, and then flow into the manifold 91. After passing through the Venturi structure 10, the fluid is discharged from the outlet 6. Specifically, when the volume of the circular pump chamber 3 increases, a negative pressure is generated inside the circular pump chamber 3. Fluid is simultaneously drawn in through the first inlet 4 and the second inlet 5, and flows forward into the manifold 91 through the first Tesla valve 7 and the second Tesla valve 8 (the asymmetry of the structure of the first-stage Tesla valve unit 81 and the second-stage Tesla valve unit 82 provides a low flow resistance path for the fluid during forward flow). Then, it enters the circular pump chamber 3 through the Venturi structure 10. At this time, the fluid passes through the diffuser section 1003, the throat 1002, and the contraction section 1001 in sequence. First, when the fluid flows from the diffuser section 1003 to the throat 1002, the fluid velocity gradually increases due to the gradual decrease in the cross-sectional area of ​​the flow channel, and reaches a higher velocity at the throat 1002, thereby enhancing the suction capacity of the circular pump chamber 3. Subsequently, when the fluid flows from the throat 1002 to the contraction section 1001, the fluid velocity gradually decreases due to the gradual increase in the cross-sectional area of ​​the flow channel, and the pressure is restored to a certain extent, so that the fluid can enter the circular pump chamber 3 more smoothly, reducing local eddies and energy loss during the suction process.

[0050] When the volume of the circular pump chamber 3 decreases, positive pressure is generated inside the circular pump chamber 3. The fluid inside the circular pump chamber 3 flows to the confluence port 91 through the Venturi structure 10. The fluid passes through the contraction section 1001, the throat 1002, and the diffuser section 1003 in sequence. First, when the fluid flows from the contraction section 1001 to the throat 1002, the fluid velocity gradually increases due to the gradual decrease in the cross-sectional area of ​​the flow channel, and reaches a higher velocity at the throat 1002, thereby increasing the speed at which the fluid is discharged from the circular pump chamber 3 to the confluence port 91. Subsequently, when the fluid flows from the throat 1002 to the diffuser section 1003, the fluid velocity gradually decreases due to the gradual increase in the cross-sectional area of ​​the flow channel, and part of the dynamic pressure is converted into static pressure, thereby allowing the fluid to diffuse and stabilize before entering the confluence port 91, reducing local energy loss and velocity pulsation during the discharge process. At this point, due to the asymmetrical structure of the first-stage Tesla valve unit 81 and the second-stage Tesla valve unit 82 connected in series, the asymmetrical flow channel structure will generate a difference in flow resistance in the forward and reverse directions. When flowing in the reverse direction, vortices are generated through the flow channel bifurcation to form high flow resistance, thereby achieving rectification and suppressing backflow without mechanical valve plates. This avoids the wear, fatigue, or jamming problems that may occur with mechanical valve plates during long-term operation. At the same time, the rectification effect is exponentially enhanced by the two-stage series arrangement, ensuring that backflow can still be effectively suppressed under the high-frequency operation conditions of the piezoelectric pump.

[0051] Furthermore, the trapezoidal wave with smooth edges includes a rising segment, a positive flat-top segment, a falling segment, and a negative flat-top segment within one cycle. Compared to the sinusoidal drive waveform, it has a faster displacement response, and compared to the ideal square wave drive waveform, it has a smoother edge transition. This balances the drive response speed and the stability of displacement change, reduces the instantaneous impact of the piezoelectric actuator 2, improves the stability of the suction and discharge process of the circular pump chamber 3, and avoids fluid fluctuations in the pump chamber caused by abrupt edge changes.

[0052] Furthermore, understandably, such as Figure 7 As shown, the outlet 6 of the piezoelectric pump body 1 is connected to the heat dissipation channel, which is set corresponding to the heat exchange area of ​​the chip body 13, which is attached to the chip substrate. A flow divider is provided at the outlet 6 of the piezoelectric pump. The flow divider is symmetrically arranged and located in the transition area where the airflow from the outlet 6 of the piezoelectric pump enters the heat dissipation channel. Multiple turbulence columns are arranged within the heat exchange area corresponding to the chip substrate. The working principle is as follows: During operation, the airflow output by the piezoelectric pump enters the heat dissipation channel from the outlet 6, first passing through the flow divider. The flow divider guides and distributes the airflow from the outlet 6, dividing it into upper, middle, and lower airflows, which then spread and flow along different areas of the chip substrate. This allows the airflow to comprehensively cover the heat exchange area corresponding to the chip, preventing the airflow from concentrating only in a localized area. Subsequently, the airflow continues to flow through the turbulence columns in the heat dissipation channel. The turbulence columns can disturb the fluid, break the thermal boundary layer formed by the medium near the chip substrate surface, enhance the convective heat transfer capability between the airflow and the chip substrate, and enable the heat transferred from the chip to the chip substrate to be quickly removed, thereby improving the heat dissipation efficiency of the chip and improving the uniformity of the temperature distribution on the chip surface.

[0053] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A piezoelectric pump for chip heat dissipation, characterized by a Tesla valve and a Venturi rectifier working together, wherein... The pump includes a pump body (1), a piezoelectric actuator (2) disposed on the upper cover plate (11) of the pump body (1), and a circular pump cavity (3) built into the lower cover plate (12) of the pump body (1); the circular pump cavity (3) is arranged opposite to the piezoelectric actuator (2); a first inlet (4) and a second inlet (5) are symmetrically arranged on opposite sides of the pump body (1), and an outlet (6) is provided on the other end of the pump body (1) on the perpendicular bisector of the line connecting the first inlet (4) and the second inlet (5); A fluid processing unit is provided between the circular pump chamber (3), the first inlet (4), the second inlet (5) and the outlet (6); The fluid processing unit includes a first Tesla valve (7) connected to the first inlet (4), a second Tesla valve (8) connected to the second inlet (5), a manifold (9) connecting the first Tesla valve (7) and the second Tesla valve (8), and a Venturi structure (10) connecting the manifold (9) and the circular pump chamber (3); the manifold (9) is connected to the outlet (6), and the front end of the Venturi structure (10), the rear end of the first Tesla valve (7), and the rear end of the second Tesla valve (8) are all connected to the manifold (91), which is the starting end of the manifold (9) and located between the Venturi structure (10) and the manifold (9); The piezoelectric actuator (2) is used to vibrate under the action of the driving electrical signal, so that the volume of the circular pump chamber (3) changes periodically, thereby driving the fluid to enter from the first inlet (4) and the second inlet (5), and after being rectified by the first Tesla valve (7) and the second Tesla valve (8), it flows into the confluence port (91), and then is discharged from the outlet (6) after passing through the Venturi structure (10); the driving waveform of the driving electrical signal is a trapezoidal wave with smooth edges.

2. The piezoelectric pump with Tesla valve and Venturi rectifier for chip heat dissipation according to claim 1, characterized in that, The first Tesla valve (7) and the second Tesla valve (8) have the same structure and are arranged in a mirror image. Both include a first-stage Tesla valve unit (81) and a second-stage Tesla valve unit (82) connected in series along the fluid flow direction. The first-stage Tesla valve unit (81) and the second-stage Tesla valve unit (82) are configured to provide a low flow resistance path when the fluid flows in the forward direction, and generate vortices through flow channel bifurcation when the fluid flows in the reverse direction to form a high flow resistance, thereby achieving rectification and suppressing backflow.

3. The piezoelectric pump with Tesla valve and Venturi rectifier for chip heat dissipation according to claim 2, characterized in that, The direction from the circular pump chamber (3) to the manifold (91) is defined as the pumping direction. The Venturi structure (10) includes a contraction section (1001), a throat (1002), and a diffuser section (1003) connected sequentially from the pumping direction. The cross-sectional area of ​​the channel of the contraction section (1001) gradually decreases from the pumping direction. The throat (1002) is the position of the smallest cross-section of the Venturi structure (10). The cross-sectional area of ​​the channel of the diffuser section (1003) gradually increases from the pumping direction. The fluid accelerates when passing through the contraction section (1001), reaches the highest flow velocity at the throat (1002), and then diffuses and stabilizes through the diffuser section (1003) before being discharged through the manifold (91).

4. The piezoelectric pump with Tesla valve and Venturi rectifier for chip heat dissipation according to claim 3, characterized in that, The piezoelectric actuator (2) is a multilayer composite structure, including a piezoelectric ceramic sheet (21), an upper copper sheet (22), a polyimide film (23), a lower copper sheet (24), and an aluminum alloy metal reflective layer (25) connected sequentially along the thickness direction; the piezoelectric ceramic sheet (21) is used to generate electrical effect deformation under the action of the driving electrical signal, and the upper copper sheet (22) and the lower copper sheet (24) are used for conductive connection.

5. The piezoelectric pump with Tesla valve and Venturi rectifier for chip heat dissipation according to claim 4, characterized in that, The upper cover plate (11) and the lower cover plate (12) are connected to form the pump body (1). The lower cover plate (12) is made of copper material and is used to directly contact and adhere to the heating surface of the chip to absorb the heat generated by the chip.

6. The piezoelectric pump with Tesla valve and Venturi rectifier for chip heat dissipation according to claim 5, characterized in that, The smooth-edge trapezoidal wave includes a rising segment, a positive flat-top segment, a falling segment, and a negative flat-top segment within one cycle; the smooth-edge trapezoidal wave is used to reduce the instantaneous impact of the piezoelectric actuator (2) to improve the stability of the suction and discharge process of the circular pump chamber (3).

7. The piezoelectric pump with Tesla valve and Venturi rectifier for chip heat dissipation according to claim 6, characterized in that, The first inlet (4) and the second inlet (5) are arranged in a mirror symmetric manner with respect to the central axis of the circular pump chamber (3), and the axis of the outlet (6) is perpendicular to the line connecting the first inlet (4) and the second inlet (5) to balance the pressure distribution in the circular pump chamber (3).

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