Piezoelectric driving high-frequency direct-writing dotting valve, system and method

Abstract

The invention discloses a piezoelectric driving high-frequency direct-writing dotting valve, system and method, and belongs to the technical field of high-frequency direct-writing dotting. The piezoelectric driving high-frequency direct-writing dotting valve comprises a valve body, a piezoelectric assembly in the valve body, an elastic piece, a displacement transmission assembly connected with the elastic piece, and a needle valve below the valve body. A transmission rod is arranged below the displacement transmission assembly, the bottom of the transmission rod is connected with the needle valve, a flow channel is formed in the needle valve, and the transmission rod is not in direct contact with feed liquid. The piezoelectric driving transmission rod drives the needle valve to do high-frequency reciprocating motion in the Z-axis direction, high-efficiency dotting is achieved, and the efficiency is remarkably higher than that of an existing direct writing scheme; besides, the needle valve is connected with an external feeding device, high-precision dotting of micro-scale liquid drops is achieved by means of the external feeding device, the requirements for high precision and high efficiency of micro-scale dotting are met, and wide application prospects are achieved in the actual production process.

Description

Technical Field

[0001] This invention belongs to the field of high-frequency direct-write dotting technology, and particularly relates to a piezoelectric-driven high-frequency direct-write dotting valve, system and method. Background Technology

[0002] In modern manufacturing, especially in fields with extremely high precision requirements such as electronics manufacturing, microelectromechanical systems (MEMS), and biomedicine, dotting is a crucial basic operation with increasingly stringent demands for both "droplet volume accuracy" and "dotting efficiency." For example, in electronics manufacturing, mini / micro LED chip packaging requires precise dotting of nanoliters or even picoliters of solder paste onto micron-level pads. This necessitates avoiding excessive solder that could cause short circuits between adjacent pads while ensuring efficient mass production. In biomedicine, drug microarray fabrication requires the precise dosing of picoliter-level drug-loaded solutions onto the substrate to ensure consistent drug dosage for accurate efficacy testing. In MEMS sensor manufacturing, picoliter-level dotting of functional materials can construct finer sensitive structures, improving sensor performance.

[0003] Currently, dotting technology mainly relies on two solutions: piezoelectric valves and direct-write printing. However, it is difficult to achieve both "droplet volume accuracy" and "dotting efficiency".

[0004] Among them, piezoelectric valves are widely used in medium-to-low precision, nano-scale dotting scenarios (such as conventional PCB solder paste dotting) due to their advantages of fast response speed (jet frequency can reach thousands of hertz). Piezoelectric valves operate based on the inverse piezoelectric effect, using the deformation of piezoelectric materials to propel fluid out of a nozzle. For example, patent CN 222901574 U discloses a piezoelectric valve structure including a valve body with a piezoelectric ceramic and a displacement transmission assembly; a flow channel seat with a liquid flow channel inside and an outlet hole at the end of the liquid flow channel; the flow channel seat also includes a striker assembly comprising a striker element and a striker guide sleeve slidably connected to each other, wherein the striker element is coaxially aligned with the outlet hole, the striker guide sleeve is fixedly connected to the flow channel seat, and a plug ring is provided between the striker guide sleeve and the liquid flow channel; a first end of the striker element is connected to the displacement transmission assembly, and a second end of the striker element passes sequentially through the striker guide sleeve and the plug ring and extends into the liquid flow channel; the piezoelectric ceramic drives the striker element to move axially via the displacement transmission assembly, thereby pushing the liquid in the liquid flow channel to the outlet hole.

[0005] However, limited by their working principle and structural design, the minimum droplet volume is generally limited to 0.5 nanoliters, making it difficult to break through to the picoliter level. On the one hand, the deformation accuracy of piezoelectric materials is limited by the piezoelectric coefficient of the material itself and the resolution of the driving voltage, making it impossible to generate the small pressure needed to propel picoliters of fluid. On the other hand, the nozzle diameter of piezoelectric valves is usually between 10 and 100 micrometers. The interaction between the surface tension and viscosity of the fluid in the flow channel makes it difficult for droplets smaller than 0.5 nanoliters to form a stable jet, easily resulting in "satellite droplets" (small stray droplets accompanying the main droplet) or "broken droplets" (droplets not completely detached from the nozzle). In addition, the landing accuracy problem of piezoelectric valves further restricts their application: changes in ambient temperature cause fluctuations in the piezoelectric coefficient, resulting in a deformation deviation of 5%-10% under the same voltage, which in turn changes the fluid jet force and direction. Small processing defects inside the nozzle (such as inner wall roughness > 0.5 micrometers) or fluid residues can interfere with the fluid flow trajectory, resulting in a landing error generally greater than ±10 micrometers. In applications such as Mini / Micro LEDs and high-precision biochips, where piezoelectric valves are required to achieve droplet-to-micron level precision, piezoelectric valves are no longer sufficient.

[0006] Furthermore, direct-write printing technology uses a precision screw or piston to extrude material from a micro-nozzle (with a minimum diameter of 1-5 micrometers). By directly controlling the fluid through extrusion, it can easily overcome the lower limit of picoliter droplet volume (minimum droplet volume can reach 10-100 picoliters), and the placement accuracy can be controlled within ±3 micrometers, perfectly adapting to microscale dotting scenarios. For example, in the biomedical field, direct-write printing can achieve precise co-deposition of single cells and picoliter bio-adhesive to construct organoid models; in MiniLED chip repair, direct-write dotting with picoliter solder paste can precisely repair the lack of solder on tiny pads.

[0007] However, the extremely low dotting efficiency of direct-write printing has become a core bottleneck restricting its large-scale application. To ensure stable extrusion and precise landing of picoliter droplets, the direct-write printhead needs to adopt a "point-by-point start-stop" movement mode. After completing the dotting of each point, the printhead must first decelerate and stop to complete the material extrusion, and then accelerate to move to the next dotting position. During this process, the acceleration, deceleration, and direction change of the printhead limit its movement speed, typically with a dotting frequency of 3-8Hz, far lower than the 500-1000Hz of piezoelectric valve printheads. According to actual production data, the effective dotting efficiency of direct-write printing is only tens to two hundred dots per minute, while the effective dotting efficiency of piezoelectric valves can reach tens of thousands per minute. The low efficiency of direct-write printing makes it difficult to adapt to large-scale mass production scenarios.

[0008] As fields such as electronics manufacturing, biomedicine, and MEMS move towards "microscale and high integration," the demand for dotting technology has clearly shifted towards "picoliter droplet volume + micron-level landing accuracy + dotting efficiency approaching that of piezoelectric valves." However, current technologies, while piezoelectric valves are highly efficient, cannot meet the requirements for microscale droplets, while direct-write printing, although capable of achieving microscale droplets, suffers from extremely low efficiency. For example, in the mass production of Mini / Micro LEDs, if direct-write printing is used for picoliter solder paste dotting, the daily capacity of a single production line is only 1 / 100th that of the piezoelectric valve solution; in high-throughput testing of biochips, the low efficiency of direct-write printing extends the single test cycle to several hours, failing to meet the needs of rapid R&D.

[0009] In summary, existing dotting technologies cannot simultaneously meet the comprehensive requirements of "pixel-level droplet volume, micron-level landing accuracy, and high-efficiency dotting," severely hindering technological upgrades and industrial development in the field of microscale manufacturing. Therefore, there is an urgent need to provide a piezoelectrically driven high-frequency direct-write dotting valve, system, and method that combines high precision and high efficiency. Summary of the Invention

[0010] The main objective of this invention is to provide a piezoelectrically driven high-frequency direct-write dotting valve, system, and method to solve the problem that existing microscale dotting technology cannot simultaneously achieve high precision and high efficiency.

[0011] In a first aspect, the present invention provides a piezoelectrically driven high-frequency direct-write dotting valve, comprising a valve body, a piezoelectric component, an elastic element, and a displacement transmission component connected to the elastic element inside the valve body, and a needle valve below the valve body; a transmission rod is provided below the displacement transmission component, the bottom of the transmission rod is connected to the needle valve, the needle valve has a flow channel inside, and the transmission rod does not directly contact the liquid. The displacement transmission component is used to amplify the driving amplitude of the piezoelectric component, thereby ensuring that the up-and-down movement amplitude of the needle valve driven by the transmission rod meets preset requirements.

[0012] Furthermore, the needle valve includes a needle valve body and a discharge section and a feed port fixed on the needle valve body, and the needle valve is fixedly connected to the bottom of the transmission rod.

[0013] Furthermore, the discharge section includes a needle connector and a discharge needle that are connected to each other, and the discharge section is connected to the needle valve body by threads.

[0014] Furthermore, a temperature control component is provided on the side of the needle valve to ensure that the temperature of the needle valve is controlled within a certain range; a needle valve blocking part is provided below the needle valve to ensure the stability of the lower stop point of the needle tip movement.

[0015] Furthermore, the needle valve, the temperature control component, and the needle valve blocking part form a cavity structure, and the needle valve body is disposed within the cavity structure.

[0016] Furthermore, a protrusion is provided at the bottom of one end of the displacement transmission assembly, and the protrusion is in direct contact with the upper part of the transmission rod.

[0017] Furthermore, the transmission rod is provided with an upper guide portion and a lower guide portion on both sides inside and below the valve body, respectively, to restrict the vertical movement of the transmission rod along the Z-axis and prevent tilting during movement.

[0018] Furthermore, the bottom end of the transmission rod is lower than the bottom end of the lower guide portion, which provides movement space for the transmission rod to drive the needle valve.

[0019] Furthermore, the discharge section is piezoelectrically driven to achieve vertical up-and-down movement along the Z-axis, with a maximum movement frequency of 1000Hz.

[0020] Secondly, the present invention provides a piezoelectric-driven high-frequency direct-write dotting system, the system comprising the aforementioned piezoelectric-driven high-frequency direct-write dotting valve, as well as a feeding device, a motion platform and a motion controller. The feed port of the piezoelectric-driven high-frequency direct-write dotting valve is connected to the feeding device through a feed pipe. The motion platform is disposed below the piezoelectric-driven high-frequency direct-write dotting valve, and the motion controller is used to control the movement of the motion platform.

[0021] Furthermore, the feeding device includes interconnected feeding conduit, storage syringe, discharge conduit, and flow control block. The feeding device can adjust the discharge speed of the liquid by adjusting the pressure. The feed pipe and the needle valve body are preferably connected by a pagoda head to ensure the sealing of the connection and facilitate disassembly and maintenance.

[0022] Thirdly, the present invention provides a dotting method based on the above-mentioned piezoelectric-driven high-frequency direct-write dotting system, the method comprising:

[0023] The product is adsorbed onto the motion platform, the piezoelectric component is used to set the dotting frequency of the piezoelectric-driven high-frequency direct-write dotting valve, the motion controller is used to set the motion speed of the motion platform, and the feeding device is used to set the feeding pressure.

[0024] Start the piezoelectric assembly and motion controller and turn on the feeding device, so that the needle valve moves vertically in the Z-axis direction and the motion platform moves horizontally in the X-axis direction under the drive of the transmission rod, thereby completing the piezoelectric-driven high-frequency direct-write dotting valve to mark dots on the product.

[0025] Furthermore, as the motion platform moves along the set direction, the needle valve performs high-frequency lifting and downward movement in the Z-axis direction to complete contact-type dotting on the product along a preset path. The motion platform's speed is 10–100 mm / s, the dotting frequency is 250–500 Hz, the distance between the needle tip and the substrate is <100 μm when the needle valve reaches its lower stop point during printing, and the set pressure range of the feeding device is 20–30 PSI. By controlling the dotting frequency of the needle valve through the piezoelectric component and the motion controller controlling the motion platform, complex path dotting operations can be completed on the product surface, achieving both high frequency and high precision dotting.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) This invention drives the needle valve to perform high-frequency reciprocating motion along the Z-axis by a piezoelectric drive transmission rod, achieving high-efficiency dotting. The motion frequency can reach up to 1000Hz, which is significantly more efficient than the existing direct writing scheme and directly supports high-speed continuous patterning precision manufacturing.

[0028] (2) By connecting the needle valve to an external feeding device, the present invention independently controls the discharge speed by relying on the pressure regulation of the external feeding device, ensuring that the volume of the droplet in a single dotting is below microliters (such as nanoliters / pixel), and simultaneously achieving high-precision dotting of micro-scale droplets.

[0029] (3) The present invention also includes a temperature control component, which is used to ensure that the temperature of the needle valve is controlled within a certain range, maintain the stability of the liquid viscosity, and avoid the distortion of the deposition morphology caused by the change of the rheological properties of the temperature-sensitive material; a needle valve blocking part is provided below the needle valve, which can fix the lower stop position, eliminate mechanical return error, and avoid piezoelectric stroke fluctuation, which would cause the needle tip to make hard contact with the substrate and cause damage.

[0030] (4) The present invention adopts contact dotting, without droplet flight process, which completely avoids the landing point deviation caused by environmental disturbances such as air flow and electric field interference during droplet flight process, further enhancing the stability and reliability of dotting process, improving dotting accuracy, and is suitable for high-precision scenarios such as high-precision patterned deposition, micro-circuit printing and biochip fabrication. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the piezoelectrically driven high-frequency direct-write dot valve;

[0032] Figure 2 This is a schematic diagram of the lower structure of the valve body of the piezoelectrically driven high-frequency direct-write dot valve.

[0033] Figure 3 This is a schematic diagram of the needle valve.

[0034] Figure 4 This is a schematic diagram of the structure of the piezoelectric-driven high-frequency direct-write dot-mapping system;

[0035] Figure 5 A schematic diagram of the process of marking points on the motion platform;

[0036] Figure 6 This is a photograph of the dotted object in Example 3;

[0037] Figure 7 This is a photograph of the dotted object in Example 4;

[0038] Explanation of reference numerals in the attached drawings: Valve body-1, piezoelectric component-2, elastic element-3, displacement transmission component-4, needle valve-5, transmission rod-6, flow channel-7, needle valve body-8, protrusion-9, upper guide-10, lower guide-11, temperature control component-12, needle valve blocking part-13, needle head connector-14, discharge needle head-15, feeding device-16, motion platform-17, cavity structure-18. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0041] 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 connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] As described in the background section of this invention, current dotting technologies mainly rely on two solutions: piezoelectric valves and direct-write printing. However, both methods struggle to achieve a balance between droplet volume accuracy and dotting efficiency. While piezoelectric valves offer faster dotting speeds, their minimum droplet volume is generally limited to 0.5 nanoliters due to their working principle and structural design, making it difficult to achieve the picoliter level, thus requiring further accuracy improvement. Direct-write printing ensures stable extrusion and precise placement of picoliter droplets, but its dotting efficiency is lower. After completing each dotting point, the printhead must decelerate, stop, extrude the material, and then accelerate to the next dotting position, making it unsuitable for large-scale mass production. Therefore, existing dotting technologies cannot simultaneously meet the comprehensive requirements of picoliter droplet volume, micron-level dotting accuracy, and high-efficiency dotting, severely hindering technological upgrades and industrial development in the microscale manufacturing field. Therefore, this invention aims to provide a piezoelectric-driven high-frequency direct-write dotting valve, system, and method that simultaneously achieves high precision and high efficiency.

[0043] Example 1

[0044] This embodiment provides a piezoelectrically driven high-frequency direct-write dot valve, such as Figure 1 As shown, the piezoelectric-driven high-frequency direct-write dot valve includes: a valve body 1, a piezoelectric component 2, an elastic element 3, and a displacement transmission component 4 connected to the elastic element 3 inside the valve body 1, and a needle valve 5 below the valve body 1. A transmission rod 6 is located below the displacement transmission component 4, and the bottom of the transmission rod 6 is connected to the needle valve 5. The needle valve 5 has a flow channel 7 inside, and the transmission rod 6 does not directly contact the liquid.

[0045] Specifically, the bottom of one end of the displacement transmission component 4 is provided with a protrusion 9, which directly contacts the upper part of the transmission rod 6. The piezoelectric component 2 drives the transmission rod 6 to reciprocate vertically up and down in a high-frequency motion along the Z-axis through the protrusion 9 of the displacement transmission component 4. When the piezoelectric component 2 is de-energized, the displacement transmission component 4 and the transmission rod 6 are reset through the elastic element 6. The displacement transmission component 4 acts similarly to a lever, amplifying the driving amplitude of the piezoelectric component 2, thereby ensuring that the up and down movement amplitude of the needle valve 5 driven by the transmission rod 6 meets the preset requirements. In actual operation, a maximum Z-axis movement amplitude of 400μm can be achieved. The piezoelectric component 2 and the discharge part of the needle valve 5 cooperate to achieve high-frequency and high-precision dotting of the piezoelectrically driven high-frequency direct-write dotting valve.

[0046] Specifically, the transmission rod 6 has an upper guide portion 10 and a lower guide portion 11 on its two sides, respectively, inside and below the valve body 1, to restrict the vertical movement of the transmission rod 6 along the Z-axis and prevent tilting during movement. The bottom end of the transmission rod 6 is lower than the bottom end of the lower guide portion 11, providing movement space for the transmission rod 6 to drive the needle valve 5. The transmission rod 6 and the needle valve 5 can be connected by welding to achieve a tight, integrated connection.

[0047] like Figure 2 As shown, a temperature control component 12 is provided on the side of the needle valve 5. The temperature control component is used to ensure that the temperature of the needle valve is controlled within a certain range. A needle valve blocking part 13 is also provided below the needle valve 5. The needle valve blocking part can ensure the stability of the lower stop point of the needle tip movement, but it is only used to block the needle valve body during the movement of the needle valve. The discharge port of the discharge needle 15 is always below the needle valve blocking part 13, which is used to make high-frequency dots above the product. The needle valve 5, the temperature control component 12 and the needle valve blocking part 13 form a cavity structure 18. The needle valve body 8 is set in the cavity structure. There is no liquid in the cavity structure 18, so the transmission rod 6 will not be in direct contact with the liquid.

[0048] like Figure 3 As shown, the needle valve 5 includes a needle valve body 8 and a discharge section and a feed port fixed on the needle valve body 8. The space between the discharge section and the feed port forms a flow channel 7. The discharge section includes a needle connector 14 and a discharge needle 15 connected to each other. The needle connector 14 is connected to the needle valve body 8 by threads, and the discharge needle 15 can be connected to the needle connector 14 by applying adhesive. The needle valve 5 is driven by a piezoelectric component 2 to achieve vertical up-and-down movement along the Z-axis, with a maximum movement frequency of 1000Hz. In addition, the feed port is located on the side of the needle valve body 8 and can be connected to an external feeding device 16, and the discharge is controlled by the external feeding device 16. The inner diameter of the discharge needle 15 is 5-100μm, which helps to achieve high-precision dotting.

[0049] Example 2

[0050] This embodiment provides a piezoelectric-driven high-frequency direct-write dot-mapping system, such as... Figure 4As shown, the piezoelectric-driven high-frequency direct-write dotting system includes: the piezoelectric-driven high-frequency direct-write dotting valve described in Example 1, as well as a feeding device 16, a motion platform 17, and a motion controller. The feed port of the piezoelectric-driven high-frequency direct-write dotting valve is connected to the feeding device 16 via a feed pipe; the motion platform 17 is located below the piezoelectric-driven high-frequency direct-write dotting valve and is used to support and position the product to be processed; the motion controller is used to control the movement of the motion platform 17; the feed pipe and the needle valve body 8 are preferably connected via a pagoda-shaped connector to ensure a tight connection and facilitate disassembly and maintenance.

[0051] Specifically, the feeding device can precisely control the discharge speed of the liquid material by adjusting the pressure according to different material viscosities and dispensing process requirements. The feeding device 16 includes a feeding conduit, a storage syringe, a discharge conduit, and a flow control block that are interconnected. The inlet end of the feeding conduit is connected to the discharge port. The top of the storage syringe is equipped with a flow control mechanism, and the top of the storage syringe is connected to the flow control connector via an adapter air pipe. The flow control connector is connected to the flow control mechanism. The discharge end of the feeding conduit is connected to the bottom of the storage syringe, and the inlet end of the discharge conduit is connected to the bottom of the storage syringe. The discharge end of the discharge conduit is connected to the inlet on the side of the needle valve body 8 via an inlet pipe, which is used to control the discharge of the discharge needle 15. The flow control mechanism is located at the top of the storage syringe and is a pneumatic controller.

[0052] Example 3

[0053] This embodiment provides a dotting method based on the above-described piezoelectric-driven high-frequency direct-write dotting system, which specifically includes the following steps:

[0054] (1) The product to be marked is adsorbed onto the motion platform 17. The position, angle, surface flatness and other data of the substrate are measured and collected with high precision by the vision and distance measurement components, so as to provide a data basis for subsequent marking path planning and parameter setting.

[0055] (2) Based on the obtained test data and the required dot position and spacing, the dot frequency of the piezoelectric drive high-frequency direct writing dot valve is set using the piezoelectric component 2, the motion speed of the motion platform 17 is set using the motion controller, and the feeding pressure is set using the feeding device 16. In this embodiment, the platform motion speed is set to 50 mm / s, the dot frequency is set to 250 Hz, the distance between the needle tip and the substrate is 20 μm when the needle valve is at the bottom stop during printing, the setting pressure of the feeding device is 30 PSI, and the inner diameter of the needle tip is 15 μm, so as to ensure the consistency of the dot pattern and the accuracy of the position.

[0056] (3) Start the piezoelectric component 2 and motion controller and turn on the feeding device 16 so that the needle valve 5 moves vertically in the Z-axis direction and the motion platform 17 moves horizontally in the X-axis direction under the drive of the transmission rod 6, thereby completing the piezoelectric-driven high-frequency direct writing dotting valve to mark the product above the motion platform 17.

[0057] like Figure 5 As shown, when the motion platform 17 moves along the set motion direction, the needle valve 5 performs high-frequency lifting and downward movement in the Z-axis direction to complete contact dotting on the product along a preset path. Through the coordinated control of the motion platform 17 by the motion controller and the needle valve 5 by the piezoelectric component 2, complex path dotting operations can be completed on the product surface, taking into account both high frequency and high precision of dotting.

[0058] like Figure 6 The image shown is a physical picture of the completed dotting process in this embodiment. It can be seen that the prepared microlens array is neatly arranged and evenly distributed. The shape of each dot is regular and the outline is clear. The dot diameter is uniform and controlled within the range of 46 to 49 μm. This indicates that the dotting method described in this invention has high precision and process stability and is suitable for high-quality manufacturing of high-precision microstructures such as microlens arrays.

[0059] Example 4

[0060] This embodiment also provides a dotting method, with steps similar to those in Embodiment 3, the only difference being that the dotting frequency in this embodiment is 500Hz.

[0061] Figure 7 This is a photograph of the actual object after dotting in this embodiment. As can be seen from the figure, this embodiment also obtains a microlens array with regular shape, clear outline, and good dot diameter uniformity.

[0062] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A piezoelectrically driven high-frequency direct-write dot valve, characterized in that, It includes a valve body (1), a piezoelectric component (2), an elastic element (3) inside the valve body (1) and a displacement transmission component (4) connected to the elastic element (3), and a needle valve (5) below the valve body (1); a transmission rod (6) is provided below the displacement transmission component (4), the bottom of the transmission rod (6) is connected to the needle valve (5), a flow channel (7) is provided inside the needle valve (5), and the transmission rod (6) does not directly contact the liquid.

2. The piezoelectrically driven high-frequency direct-write dot valve according to claim 1, characterized in that, The needle valve (5) includes a needle valve body (8) and a discharge section and a feed port fixed on the needle valve body (8).

3. The piezoelectrically driven high-frequency direct-write dot valve according to claim 2, characterized in that, The discharge section includes a needle connector (14) and a discharge needle (15) connected to each other, and the discharge section is connected to the needle valve body (8) by threads.

4. The piezoelectrically driven high-frequency direct-write dot valve according to claim 2, characterized in that, A temperature control component (12) is provided on the side of the needle valve (5), and a needle valve blocking part (13) is provided below the needle valve (5).

5. The piezoelectrically driven high-frequency direct-write dot valve according to claim 4, characterized in that, The needle valve (5), the temperature control component (12) and the needle valve blocking part (13) constitute a cavity structure (18), and the needle valve body (8) is disposed in the cavity structure.

6. The piezoelectrically driven high-frequency direct-write dot valve according to claim 1, characterized in that, The bottom of one end of the displacement transmission assembly (4) is provided with a protrusion (9), which is in direct contact with the upper part of the transmission rod (6).

7. The piezoelectrically driven high-frequency direct-write dot valve according to claim 1, characterized in that, The transmission rod (6) has an upper guide (10) and a lower guide (11) on both sides inside and below the valve body (1).

8. The piezoelectrically driven high-frequency direct-write dot valve according to claim 7, characterized in that, The bottom end of the transmission rod (6) is lower than the bottom end of the lower guide (11) to provide movement space for the transmission rod (6) to drive the needle valve (5) to move.

9. A piezoelectric-driven high-frequency direct-write dot-mapping system, characterized in that, The invention includes the piezoelectrically driven high-frequency direct-write dotting valve according to any one of claims 1-8, as well as a feeding device (16), a motion platform (17), and a motion controller. The feed port of the piezoelectrically driven high-frequency direct-write dotting valve is connected to the feeding device (16) through a feed pipe. The motion platform (17) is located below the piezoelectrically driven high-frequency direct-write dotting valve. The motion controller is used to control the movement of the motion platform (17).

10. A dotting method based on the piezoelectric-driven high-frequency direct-write dotting system of claim 9, characterized in that, The method includes: The product is adsorbed onto the motion platform (17), the piezoelectric component (2) is used to set the dotting frequency of the piezoelectric drive high-frequency direct writing dotting valve, the motion controller is used to set the motion speed of the motion platform (17), and the feeding device (16) is used to set the feeding pressure. Start the piezoelectric assembly (2) and motion controller and turn on the feeding device (16) so that the needle valve (5) moves vertically in the Z-axis direction and the motion platform (17) moves horizontally in the X-axis direction under the drive of the transmission rod (6), thereby completing the piezoelectric-driven high-frequency direct-write dotting valve to mark dots above the product.

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