A pump control assembly for a supply pump and a liquid supply system

Abstract

The utility model discloses a kind of pump control assembly and liquid supply system for supply pump, the pump control assembly includes gas flow channel, first open-close valve, second open-close valve and pressure sensor, the gas flow channel includes air inlet flow channel, air outlet flow channel, gas flow channel, the air inlet flow channel is used to communicate with positive pressure gas source, the air outlet flow channel is used to communicate with negative pressure gas source, the gas flow channel is used to communicate with the air cavity of supply pump, the first open-close valve and the second open-close valve are all with valve flow channel, throttle hole is located the junction of first open-close valve and / or second open-close valve and gas flow channel communication;The flow area of throttle hole is less than the flow area of gas flow channel and valve flow channel, throttle hole has increased local gas pressure loss effect to avoid high pressure direct action on pressure sensor, so that the pressure detection of gas flow channel and air cavity inside is more accurate.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, and in particular to a pump control component and liquid supply system for supplying pumps. Background Technology

[0002] In the chemical solution application process of semiconductor manufacturing equipment, in order to coat the semiconductor wafer with a predetermined amount of photoresist solution each time, a chemical solution supply system as described in patent number JP4265820B2 has been proposed. This system includes a chemical solution supply pump that draws the chemical solution contained in a chemical solution tank and coats the drawn-in solution onto the semiconductor wafer in a predetermined amount each time. Specifically, the chemical solution supply pump has a diaphragm separating a pump chamber for filling the chemical solution from a working chamber for the flow of working gas. The outer edge of the diaphragm is sealed. One side of the diaphragm forms the pump chamber, which is a liquid chamber, and the opposite side forms the working chamber, which is a gas chamber. During liquid discharge, working gas is introduced into the gas chamber to apply positive pressure to the diaphragm to compress the pump chamber volume. During liquid suction, a vacuum is drawn into the gas chamber to generate negative pressure and expand the pump chamber volume. The switching between positive pressure filling and negative pressure suction of the gas chamber is achieved by using a positive pressure gas source and a negative pressure gas source in conjunction with the control of two solenoid valves.

[0003] Therefore, the components that input or extract gas into or out of the gas chamber of the photoresist supply pump, as well as the solenoid valve, become the pump control components. The stability of the photoresist discharge rate and the repeatability of the coating process in the supply pump mainly rely on the pressure stability in the working chamber, which serves as the gas chamber. This places high demands on the pressure control of the pump control components. Generally speaking, during the photoresist coating process on wafers, it is necessary to control a stable flow rate and the coating amount within ±0.01ml. Therefore, a more precise pneumatic photoresist diaphragm pump is required.

[0004] The pressure sensor for detecting the air pressure in the working chamber of the existing liquid supply pump is located outside the air chamber, within the pump control assembly. It detects the pressure of the working gas before it enters the air chamber to provide feedback on the air pressure in the air chamber. For positive pressure filling of the air chamber, the pressure sensor is located downstream of the solenoid valve, that is, on the side of the solenoid valve closer to the air chamber. Taking the solenoid valve as a reference, the space between the solenoid valve and the air chamber, plus the air chamber itself, is called the rear end. The pressure sensor is used to detect the air pressure at the rear end to control the opening and closing of the solenoid valve. The space between the solenoid valve and the driving air source, including the driving air source, is called the front end.

[0005] However, due to the above structural configuration, the air chamber pressure in the prior art has a series of problems. First, the high pressure of the driving air source acts directly on the pressure sensor through the solenoid valve. Often, the actual pressure in the air chamber has not yet reached the set value, but the pressure sensor may have already detected that the pressure has reached the set value. In addition, the gas pressure output by the air source itself also has a certain fluctuation, which leads to unstable control of the air chamber pressure.

[0006] Therefore, the pump control components need to be optimized to address the problem of unstable pressure control within the gas chamber in the existing drug supply pump's pump control components. Utility Model Content

[0007] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a pump control component and liquid supply system for a supply pump, which solves the problem of unstable pressure control in the air chamber by the pump control component of existing liquid supply pumps.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A pump control assembly for a supply pump having a liquid chamber and a gas chamber, the pump control assembly being connected to the gas chamber of the supply pump to control the inflow or outflow of working gas into the gas chamber, thereby causing the liquid chamber to drain or draw liquid.

[0010] The pump control assembly includes a gas flow channel, a first on / off valve, a second on / off valve, and a pressure sensor. The gas flow channel includes an inlet flow channel, an outlet flow channel, and a runoff flow channel. The inlet flow channel is used to connect with a positive pressure gas source, the outlet flow channel is used to connect with a negative pressure gas source, and the runoff flow channel is used to connect with the gas chamber supplying the pump. Both the first on / off valve and the second on / off valve have valve flow channels.

[0011] The first on / off valve can connect the inlet air passage and the outlet air passage, the second on / off valve can connect the outlet air passage and the outlet air passage, and the pressure sensor is connected to the outlet air passage.

[0012] It also includes a throttling orifice corresponding to the first on-off valve and / or the second on-off valve, the throttling orifice being located at the connection between the first on-off valve and / or the second on-off valve and the gas flow channel, the flow area of ​​the throttling orifice being smaller than the flow area of ​​the gas flow channel and the valve flow channel;

[0013] It also includes a control module for controlling the opening and closing of the first and second on / off valves.

[0014] The pump control component of the supply pump of this utility model is provided with a throttling orifice at the connection between the first on / off valve and / or the second on / off valve and the gas flow channel. The flow area of ​​the throttling orifice is very small. Whether it is gas inlet or outlet, the flow area of ​​the throttling orifice is the smallest in terms of the gas flow path. The gas passing through the throttling orifice causes pressure loss and the flow velocity increases. Thus, the local pressure loss is increased, which plays the role of isolating the high pressure at the front end, avoiding the high pressure at the front end from directly acting on the pressure sensor, causing the gas pressure in the flow channel to rise or fall sharply, and also suppressing the fluctuation of the gas source pressure itself.

[0015] Specifically, during air intake, the intake passage is connected to the positive pressure air source. Gas enters through the intake passage under positive pressure, passes through the first on / off valve, enters the flow passage, and then flows into the air chamber of the supply pump. Since the positive pressure air source has a higher pressure, the flow passage is directly connected to the air chamber. The throttling orifice is positioned at the connection between the first on / off valve and the gas flow passage. If the throttling orifice is positioned between the intake passage and the first on / off valve, the gas needs to pass through the throttling orifice before entering the first on / off valve. The throttling orifice upstream of the first on / off valve is used to reduce the positive pressure air source pressure at the first on / off valve, thereby reducing the air source pressure wave. Alternatively, the throttling orifice can be positioned between the first on / off valve and the airflow channel. After flowing out of the first on / off valve, the gas first passes through the throttling orifice before entering the airflow channel. The throttling orifice downstream of the first on / off valve is used to reduce the positive pressure of the gas source at the first on / off valve, thereby reducing gas source pressure fluctuations. Both of these different ways of setting the throttling orifice ultimately achieve the effect of reducing the high pressure directly acting inside the airflow channel and suppressing the pressure fluctuations of the gas source. This makes the pressure detection of the pressure sensor inside the airflow channel and the air chamber more accurate, improving the accuracy and stability of the supply pump's dispensing of adhesive.

[0016] During gas discharge, the discharge channel is connected to the negative pressure gas source. Under the action of negative pressure, the gas in the discharge channel is first extracted, and then the gas in the flow channel and the gas chamber enters the discharge channel through the second opening and closing valve and is then extracted. Similarly, the negative pressure of the negative pressure gas source is relatively large, and the flow channel flows directly into the gas chamber. The throttle orifice is set at the connection between the second opening and closing valve and the gas flow channel. If the throttle orifice is set between the discharge channel and the second opening and closing valve, during gas extraction, the negative pressure acts on the throttle orifice first and then on the second opening and closing valve, avoiding the direct action of a large negative pressure on the second opening and closing valve and the pressure sensor, so that the second opening and closing valve opens stably, connecting the subsequent gas flow. The flow channel allows the gas in the airflow channel and air chamber to be stably drawn into the outlet airflow channel and then extracted; or, for example, the throttling orifice is set between the second on / off valve and the airflow channel to prevent negative pressure and high pressure from directly acting on the pressure sensor, so that the gas in the airflow channel and air chamber can stably enter the second on / off valve through the throttling orifice, and finally enter the outlet airflow channel and be extracted; the above two different settings of the throttling orifice ultimately reduce the negative pressure and high pressure inside the airflow channel from directly acting on the pressure sensor and suppress the pressure fluctuation of the negative pressure source, so that the pressure detection inside the airflow channel and air chamber is more accurate, and the accuracy and stability of the supply pump suction are improved.

[0017] Preferably, the throttling orifice further comprises a connecting section with the first on / off valve or the second on / off valve, and the flow area of ​​the throttling orifice is smaller than the flow area of ​​the connecting section.

[0018] With this configuration, the flow area of ​​the throttling orifice is smaller than the flow area of ​​the valve passages of the first and second on / off valves, and also smaller than the flow area of ​​the connecting section. The connecting section serves as a transition, with one end connected to the throttling orifice and the other end connected to the valve passage of the first or second on / off valve. When the throttling orifice is upstream of the first or second on / off valve, gas flows through the orifice to the valve passage. Due to the reduced flow area of ​​the throttling orifice, the gas velocity increases, and the larger flow area of ​​the connecting section acts as a flow buffer. The function of the throttling orifice is to prevent excessively high-velocity gas from directly impacting the first or second on / off valve. When the throttling orifice is located downstream of the first or second on / off valve, gas flows from the first or second on / off valve to the throttling orifice, causing some gas to be blocked in the valve flow channel. Setting a connecting section with a large flow area can buffer the gas. The connecting section can homogenize the flow field and attenuate the eddies and pressure pulsations generated when the gas flows through the throttling orifice, which helps to maintain the pressure balance upstream and downstream of the first or second on / off valve, thereby protecting the first or second on / off valve.

[0019] Preferably, the volume of the connecting section is T1, and the volume of the airflow passage is T2, satisfying that the value of T1:T2 is not greater than 0.1. The ratio of the volume of the connecting section to the volume of the airflow passage is set to control the distance between the throttling orifice and the first or second on / off valve within a certain range. That is, the throttling orifice is positioned adjacent to the on / off valve. If the distance is too great, gas may accumulate into high pressure within the connecting section, still interfering with the airflow passage and the gas chamber. If the distance is too small, the buffering effect of the connecting section is not significant, which is detrimental to protecting the first or second on / off valve.

[0020] Preferably, the flow area of ​​the throttling orifice is 0.05 mm. 2 -0.3mm 2 This configuration allows the throttling orifice to isolate high pressure and reduce pressure fluctuations, while avoiding the noise and vibration risks caused by an excessively small flow area of ​​the throttling orifice, thus ensuring the normal operation of the first and second on / off valves.

[0021] Preferably, the pump control assembly further includes a pump control housing and a mounting plate that is sealed to the pump control housing, wherein the inlet air passage and the outlet air passage are both formed inside the pump control housing, and the outlet air passage is at least partially formed between the pump control housing and the mounting plate;

[0022] The first and second on / off valves are mounted on the side of the mounting plate opposite to the pump control housing. There are two throttling orifices, both of which are located on the mounting plate along the thickness direction. One throttling orifice corresponds to the first on / off valve, and the other throttling orifice corresponds to the second on / off valve.

[0023] This configuration allows the pump control housing and mounting plate to jointly form the airflow path. On the one hand, it greatly reduces the difficulty of machining the chamber, making the machining method flexible and efficient, with a wide range of materials to adapt to different working conditions. It also simplifies assembly, reduces costs, and facilitates maintenance and repair. On the other hand, it eliminates external pipes and joints, significantly reducing the volume of the air path and making the entire pump assembly lighter and easier to carry and transport. The throttling orifice is located on the side of the mounting plate facing the pump control housing, directly connecting to the inlet, outlet, or outlet airflow path. The first and second on / off valves are installed on the side of the mounting plate away from the pump control housing, maintaining a suitable distance between the throttling orifice and the first or second on / off valve, protecting the first and second on / off valves while reducing pressure fluctuations.

[0024] Preferably, an air vent groove is formed on one of the pump control housing and the mounting plate, which is sealed to the other to form an air vent cavity, and the air vent cavity constitutes part of the air vent channel;

[0025] The mounting plate has a first through hole, a second through hole, a third through hole and a fourth through hole extending along the thickness direction of the mounting plate. The first through hole is connected to the air intake channel, the second through hole is connected to the air outlet groove, and the inlet of the first on / off valve is connected to the first through hole and the outlet is connected to the second through hole.

[0026] The third through hole is connected to the air passage groove, the fourth through hole is connected to the air outlet passage, the inlet of the second on / off valve is connected to the third through hole, and the outlet is connected to the fourth through hole.

[0027] One of the throttling orifices is located at one end of the second through hole near the air passage; the other throttling orifice is located at one end of the fourth through hole near the air outlet passage.

[0028] With this configuration, the function of the air vent is to stabilize the gas entering or leaving the air vent, buffer pressure fluctuations, reduce the impact on the air vent of the supply pump, and stabilize the deformation of the diaphragm. This ensures that the liquid intake and discharge of the supply pump are more controllable and stable. Compared with the original air vent pipeline, the air vent can force the airflow to diffuse and change its direction, thereby generating a turbulence effect, eliminating gas pressure fluctuations, suppressing pressure oscillations, achieving pressure equalization, and improving control stability. Especially for applications with high flow stability requirements, it can reduce flow fluctuations caused by pulsation. The air vent is formed by the air vent grooves on the opposite surfaces of the pump control housing and the mounting plate, and constitutes part of the air vent channel. The resulting air vent has a relatively flat chamber structure. The flat chamber not only helps gas diffusion and buffering, but also forms a reasonable volume-to-surface area ratio in a limited space, avoiding response delays caused by excessive volume or insufficient buffering caused by insufficient volume.

[0029] Both the first and second on / off valves have inlets and outlets. The first, second, third, and fourth through holes of the mounting plate are connected to the inlet air passage, the outlet air passage, and the flow passage, respectively. One of the throttling orifices is located at the end of the second through hole near the flow passage. In terms of gas flow, it is located downstream of the first on / off valve, which can increase pressure loss and suppress pressure fluctuations in the flow passage. The other throttling orifice is located at the end of the fourth through hole near the outlet air passage. In terms of negative pressure, the negative pressure acts on the throttling orifice first and then on the second on / off valve, avoiding large pressure fluctuations caused by large negative pressure acting directly on the second on / off valve.

[0030] Preferably, both the first and second on / off valves are solenoid valves; they have a fast response speed and can achieve precise flow regulation. The solenoid valves are connected to the control module, enabling remote automated control and improving the automation level of the supply pump.

[0031] This invention also provides a liquid supply system, which includes the pump control component described in any of the above claims, and a supply pump connected to the pump control component.

[0032] In summary, compared with the prior art, the present invention has at least the following beneficial effects: The pump control component and liquid supply system of the supply pump of the present invention are provided with a throttling orifice at the connection between the first and / or second on / off valve and the gas flow channel. The flow area of ​​the throttling orifice is very small. Whether it is gas inlet or outlet, the flow area of ​​the throttling orifice is the smallest in terms of the gas flow path. This increases the local pressure loss, plays the role of isolating high pressure, avoids the pressure in the gas chamber from rising or falling sharply, makes the pressure detection in the flow channel and inside the gas chamber more accurate, and improves the accuracy and stability of the supply pump in suction and discharge of glue. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the framework of the liquid supply system according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the pump control assembly according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the pump control housing according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the mounting plate according to an embodiment of the present utility model;

[0038] Figure 5 This is a cross-sectional schematic diagram of the pump control assembly at the second through hole according to an embodiment of the present invention;

[0039] Figure 6 This is a cross-sectional view of the pump control assembly at the fourth through hole according to an embodiment of the present invention;

[0040] Figure 7 This is a cross-sectional schematic diagram of the pump control assembly at the first through hole according to an embodiment of the present invention;

[0041] Figure 8 This is a cross-sectional view of the pump control assembly at the third through hole according to an embodiment of the present invention;

[0042] Figure 9 This is a cross-sectional schematic diagram of the pump control assembly at the pressure sensor according to an embodiment of the present invention;

[0043] Figure 10 The red line represents the pressure monitoring curve of the pressure sensor on the airflow channel, while the blue line represents the pressure detection curve of the pump control component and control method based on the embodiments of this utility model.

[0044] Explanation of reference numerals in the attached figures

[0045] 1. Supply pump; 11. Gas chamber; 12. Liquid chamber; 13. Diaphragm;

[0046] 2. Pump control assembly; 21. First on / off valve; 22. Second on / off valve; 23. Valve flow path; 24. Pressure sensor; 25. Throttling orifice; 26. Connecting section;

[0047] 3. Pump control housing; 31. Inlet air passage; 32. Outlet air passage;

[0048] 4. Mounting plate; 41. Airflow channel; 411. Airflow groove; 412. First airflow groove; 413. Second airflow groove; 42. First through hole; 43. Second through hole; 44. Third through hole; 45. Fourth through hole; 46. Inspection channel. Detailed Implementation

[0049] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0050] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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 this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 utility model based on the specific circumstances.

[0052] like Figure 1 As shown, the pump control component 2 of this embodiment is used in conjunction with the supply pump 1. Specifically, the supply pump 1 has a liquid chamber 12 and a gas chamber 11. The pump control component 2 is connected to the gas chamber 11 of the supply pump 1 to control the flow of working gas into or out of the gas chamber 11, so that the liquid chamber 12 discharges or draws in liquid. The working gas is an inert gas, such as nitrogen. The supply pump 1 can be a diaphragm pump. The liquid chamber 12 and the gas chamber 11 are separated by a diaphragm 13. The flow of gas into or out of the gas chamber 11 causes a change in the volume of the gas chamber 11, thereby controlling the deformation direction of the diaphragm 13 and causing a change in the volume of the liquid chamber 12, thus achieving the discharge or drawing in of the liquid. The diaphragm pump is an existing structure, and its working principle and specific structure will not be described in detail here.

[0053] Pump control assembly 2 includes a gas flow channel, a first on / off valve 21, a second on / off valve 22, and a pressure sensor 24. The gas flow channel includes an inlet flow channel 31, an outlet flow channel 32, and a discharge flow channel 41. The inlet flow channel 31 is used to connect to a positive pressure gas source, the outlet flow channel 32 is used to connect to a negative pressure gas source, and the discharge flow channel 41 is used to connect to the gas chamber 11 supplying pump 1. Both the first on / off valve 21 and the second on / off valve 22 have valve flow channels 23. The first on / off valve 21 can connect and disconnect the inlet flow channel 31 and the discharge flow channel 41, and the second on / off valve 22 can connect and disconnect the outlet flow channel 32 and the discharge flow channel 41. The pressure sensor... Device 24 is connected to the airflow channel 41. Pressure sensor 24 is used to detect the air pressure value in airflow channel 41. It also includes a control module that controls the opening and closing of the first opening and closing valve 21 and the second opening and closing valve 22. The control module is configured to control the opening and closing frequency of the first opening and closing valve 21 and the second opening and closing valve 22 based on the detection signal of pressure sensor 24. The reference numerals of the control module are not shown in the figure. The control module can be a separate controller or a module integrated into a chip or circuit board in the housing. It is not limited to the setting of the control module. The control module can adopt an existing control structure.

[0054] In such Figure 1In the illustrated embodiment, both the first on / off valve 21 and the second on / off valve 22 are provided with throttling orifices 25 at their connections to the gas flow channel. Specifically, the throttling orifices 25 are located downstream of both the first and second on / off valves 21 and 22. The flow area of ​​the throttling orifice 25 is smaller than that of the gas flow channel and the valve flow channel 23. Whether for inlet or outlet gas, the flow area of ​​the throttling orifice 25 is the smallest in terms of the gas flow path. This increases the local pressure loss, isolating the high pressure at the valve's front end and preventing a sharp rise or fall in pressure within the gas chamber 11. It should be noted that the upstream and downstream locations mentioned herein refer to the gas flow path, while the front and rear ends refer to the on / off valves.

[0055] Specifically, during air intake, the intake passage 31 is connected to the positive pressure air source. Gas enters through the intake passage 31 under positive pressure, passes through the first on / off valve 21, enters the flow passage 41, and then flows into the air chamber 11 of the supply pump 1. The positive pressure air source has a relatively high pressure and may experience some pressure fluctuations. The flow passage 41 is directly connected to the air chamber 11, causing the pressure inside the air chamber 11 to be subject to the high pressure of the air source and to experience pressure fluctuations itself. Therefore, the throttling orifice 25 is positioned at the connection between the first on / off valve 21 and the gas flow passage. If the throttling orifice 25 is positioned between the intake passage 31 and the first on / off valve 21, the gas needs to pass through the throttling orifice 25 before entering the first on / off valve 21, utilizing the throttling effect upstream of the first on / off valve 21. The orifice 25 is used to reduce the high pressure of the gas at the first on / off valve 21 and suppress the pressure fluctuation of the positive pressure. Alternatively, the orifice 25 can be set between the first on / off valve 21 and the flow channel 41. After flowing out of the first on / off valve 21, the gas first passes through the orifice 25 and then enters the flow channel 41. The orifice 25 downstream of the first on / off valve 21 is used to reduce the high pressure of the gas and suppress the pressure fluctuation of the positive pressure on the flow channel 41. Both of these methods can increase the local pressure loss to isolate the high pressure at the front end of the valve, and ultimately reduce the pressure fluctuation inside the flow channel 41 affected by the gas source pressure. This makes the pressure detection inside the flow channel 41 and the gas chamber 11 more accurate, and improves the accuracy and stability of the glue dispensing of the supply pump 1.

[0056] Specifically, during evacuation, the outlet air passage 32 is connected to the negative pressure air source. Under the action of negative pressure, the gas in the outlet air passage 32 is first extracted, and then the gas in the flow passage 41 and the gas chamber 11 enters the outlet air passage 32 through the second on / off valve 22 and is then extracted. Similarly, the negative pressure of the negative pressure air source is relatively large, and the flow passage 41 flows directly with the gas chamber 11. The throttling orifice 25 is set at the connection between the second on / off valve 22 and the gas flow passage. If the throttling orifice 25 is set between the outlet air passage 32 and the second on / off valve 22, during evacuation, the negative pressure acts on the throttling orifice 25 first and then on the second on / off valve 22, avoiding the large negative pressure directly acting on the second on / off valve 22 and causing a large impact, so that the second on / off valve 22 opens stably, connecting the subsequent flow passage 41, so that... The gas in the air passage 41 and the air chamber 11 is stably drawn to the outlet air passage 32 and then extracted. Alternatively, the throttle orifice 25 is set between the second on / off valve 22 and the air passage 41. The throttle orifice 25 can prevent large negative pressure from directly acting on the pressure sensor 24 and the air passage 41. This allows the gas in the air passage 41 and the air chamber 11 to stably pass through the throttle orifice 25 into the second on / off valve 22, and finally into the outlet air passage 32 and be extracted. Both of these situations can increase the local pressure loss to isolate the high pressure at the front end of the valve, and ultimately reduce the influence of the gas source pressure on the air passage 41. This makes the pressure detection in the air passage 41 and the air chamber 11 more accurate, and improves the accuracy and stability of the adhesive suction of the supply pump 1.

[0057] It should be noted that the connection point mentioned above is not limited to a specific location, but can refer to a region near the valve or a certain distance from the valve. The throttle orifice 25 can be set near the valve, as long as the throttle orifice 25 can isolate the front pressure, increase the gas pressure loss, and stabilize the pressure in the gas chamber 11.

[0058] In other embodiments, the throttle orifice 25 may be provided only for the first on / off valve 21, located upstream or downstream of the first on / off valve 21; or the throttle orifice 25 may be provided only for the second on / off valve 22, located upstream or downstream of the second on / off valve 22. Alternatively, the two throttling orifices 25 can be respectively set to correspond to the first on / off valve 21 and the second on / off valve 22. This means that a throttling orifice 25 is set to the side of the first on / off valve 21 and the second on / off valve 22, and the positions of the throttling orifices 25 can be configured in several ways, as follows: one is located upstream of the first on / off valve 21 and the other is located downstream of the second on / off valve 22; or, the two throttling orifices 25 are respectively set to correspond to the first on / off valve 21 and the second on / off valve 22, with one located downstream of the first on / off valve 21 and the other upstream of the second on / off valve 22; or, the two throttling orifices 25 are respectively set to correspond to the first on / off valve 21 and the second on / off valve 22, with one located upstream of the first on / off valve 21 and the other upstream of the second on / off valve 22; or, the two throttling orifices 25 are respectively set to correspond to the first on / off valve 21 and the second on / off valve 22, with one located downstream of the first on / off valve 21 and the other downstream of the second on / off valve 22. It should be noted that upstream and downstream refer to the direction of gas flow. During gas intake, the gas flows from the intake channel 31 to the gas chamber 11. The upstream end of the first on / off valve 21 is the end near the intake channel 31, and the downstream end is the end near the outlet channel 41. During gas exhaust, the gas flows from the gas chamber 11 to the outlet channel 32. The upstream end of the second on / off valve 22 is the end near the outlet channel 41, and the downstream end is the end near the outlet channel 32.

[0059] exist Figures 2 to 9 In the illustrated embodiment, both the first on / off valve 21 and the second on / off valve 22 have an inlet and an outlet. One throttling orifice 25 is correspondingly disposed between the outlet of the first on / off valve 21 and the airflow passage 41, and the other throttling orifice 25 is correspondingly disposed between the outlet of the second on / off valve 22 and the airflow passage 32. That is, the two throttling orifices 25 are respectively disposed for the first on / off valve 21 and the second on / off valve 22, with one located downstream of the first on / off valve 21 and the other located downstream of the second on / off valve 22.

[0060] The inlet of the first on / off valve 21 is connected to the intake air passage 31. Although the high pressure of the intake air passage 31 will act on the first on / off valve 21, causing it to directly act on the pressure sensor 24 when it is open, the throttle orifice 25 increases the pressure loss of the intake gas, isolating the high pressure of the gas directly acting on the pressure sensor 24. This makes the gas entering the flow passage 41 smoother and more stable, and the pressure sensor 24 can detect the pressure in the flow passage 41 more accurately. The inlet of the second on / off valve 22 is connected to the flow passage 41, and the outlet is connected to the outlet air passage 32 through the throttle orifice 25. The high pressure of the negative pressure gas source will not directly act on the second on / off valve 22 and the pressure sensor 24. The pressure at the inlet and outlet of the second on / off valve 22 is relatively balanced and will not affect the gas output in the flow passage 41. The throttle orifice 25 increases the pressure loss of the output gas, allowing the gas in the flow passage 41 to exit smoothly, and the pressure sensor 24 can detect the pressure in the flow passage 41 more accurately.

[0061] like Figure 5 and Figure 6 As shown, a connecting section 26 is provided between the throttling orifice 25 and the first on / off valve 21 or the second on / off valve 22. The flow area of ​​the throttling orifice 25 is smaller than the flow area of ​​the connecting section 26. The flow area of ​​the throttling orifice 25 is smaller than the flow area of ​​the valve passage 23 of the first on / off valve 21 and the second on / off valve 22. The connecting section 26 serves as a transition, with one end connected to the throttling orifice 25 and the other end connected to the valve passage 23 of the first on / off valve 21 or the second on / off valve 22. When the throttling orifice 25 is located upstream of the first on / off valve 21 or the second on / off valve 22, the gas flows through the throttling orifice 25 to the valve passage 23 of the first on / off valve 21 or the second on / off valve 22. Due to the reduced flow area of ​​the throttling orifice 25, the gas velocity increases. The connecting section 26, with its larger flow area, can slow the flow and prevent excessively high-velocity gas from directly impacting the first on / off valve 21 or the second on / off valve 22. A first on / off valve 21 or a second on / off valve 22; when the throttle orifice 25 is located downstream of the first on / off valve 21 or the second on / off valve 22, the gas flows from the first on / off valve 21 or the second on / off valve 22 to the throttle orifice 25. The flow area of ​​the throttle orifice 25 is smaller than the flow area of ​​the valve channel 23, causing some gas to be blocked in the valve channel 23. The connecting section 26 with a larger flow area can buffer the gas. The connecting section 26 can homogenize the flow field and attenuate the eddies and pressure pulsations generated when the gas flows through the throttle orifice 25, which is conducive to maintaining the pressure balance upstream and downstream of the first on / off valve 21 or the second on / off valve 22, thereby protecting the first on / off valve 21 or the second on / off valve 22.

[0062] The volume of the connecting section 26 is T1, and the volume of the air passage 41 is T2, satisfying that the ratio of T1:T2 is no greater than 0.1. The volume of the air passage 41 is relatively constant. By ensuring that the ratio of T1:T2 is less than or equal to 0.1, the volume of the connecting section 26 can be controlled, thereby controlling the distance between the throttle orifice 25 and the first on / off valve 21 or the second on / off valve 22 within a certain range. If the distance is too great, gas may accumulate in the connecting section 26, forming high pressure, which will still interfere with the air passage 41 and the gas chamber 11. If the distance is too small, the buffering effect of the connecting section 26 is not significant, which is detrimental to protecting the first on / off valve 21 or the second on / off valve 22. For example, the volume of the air passage 41 can be measured as the air passage 41 to calculate whether the volume ratio of the connecting section 26 and the air passage 41 is satisfied.

[0063] Preferably, the flow area of ​​the throttling orifice 25 is 0.05 mm. 2 -0.3mm 2 This configuration allows the orifice 25 to effectively isolate high pressure and reduce pressure fluctuations, while avoiding the noise and vibration risks caused by an excessively small flow area, thus ensuring the normal operation of the first on / off valve 21 and the second on / off valve 22. Furthermore, due to the small area of ​​the orifice 25, to prevent particles in the working gas from clogging it, filters can be installed upstream and downstream of the orifice 25 in the gas flow path to filter particles and ensure that the orifice 25 performs its pressure isolation and filtering functions.

[0064] like Figure 3 and Figure 4 As shown, the pump control assembly 2 also includes a pump control housing 3 and a mounting plate 4 that is sealed to the pump control housing 3. The inlet air passage 31 and the outlet air passage 32 are both formed inside the pump control housing 3. At least a portion of the outlet air passage 41 is formed between the pump control housing 3 and the mounting plate 4. The pump control housing is divided into the pump control housing 3 and the mounting plate 4, and the outlet air passage 41 is formed by the pump control housing 3 and the mounting plate 4 together. On the one hand, it can greatly reduce the processing difficulty of the chamber, the processing method is flexible and efficient, the material selection is wide to adapt to different working conditions, the assembly is simple, the cost is low, and it is easy to maintain and repair. On the other hand, it eliminates external pipes and joints, greatly reduces the volume of the air passage, and makes the whole liquid supply system of the pump 1 lighter and easier to carry and transport.

[0065] like Figure 4 As shown, there are two throttling orifices 25, both located along the thickness direction of the mounting plate 4 on the side of the mounting plate 4 facing the pump control housing 3, directly connecting to the inlet air passage 31, the outlet air passage 32, or the outlet air passage 41; as Figure 5 and Figure 6As shown, the first on / off valve 21 and the second on / off valve 22 are mounted on the side of the mounting plate 4 away from the pump control housing 3. One throttling orifice 25 corresponds to the first on / off valve 21, and the other throttling orifice 25 corresponds to the second on / off valve 22. The connecting section 26 is opened in the mounting plate 4 along the thickness direction of the mounting plate 4 corresponding to the throttling orifice 25, with one end exposed on the side of the mounting plate 4 away from the pump control housing 3. The thickness of the mounting plate 4 can maintain a suitable distance between the throttling orifice 25 and the first on / off valve 21 or the second on / off valve 22, protecting the first on / off valve 21 and the second on / off valve 22 while reducing pressure fluctuations.

[0066] In some embodiments, an air vent groove 411 is formed on one of the pump control housing 3 and the mounting plate 4, which seals with the other to form an air vent chamber, the air vent chamber constituting part of the air vent channel 41. For example... Figure 3 As shown, in this embodiment, the mounting plate 4 has an air venting groove 411 on the side facing the pump control housing 3. When the mounting plate 4 and the pump control housing 3 are sealed together, the air venting groove 411 and the corresponding area of ​​the side of the pump control housing 3 facing the mounting plate 4 respectively form an air venting cavity, which constitutes part of the air venting channel 41. The function of the air vent is to stabilize and diffuse the gas entering or exiting the air vent 11, buffer pressure fluctuations, reduce the impact on the air vent 11 of the supply pump 1, and stabilize the deformation of the diaphragm 13. This ensures that the liquid intake and discharge of the supply pump 1 are more controllable and stable. Compared with the original air vent pipeline, the air vent can force the airflow to diffuse and change its direction, thereby generating a turbulence effect, eliminating gas pressure fluctuations, suppressing pressure oscillations, achieving pressure equalization, and improving control stability. Especially for applications with high flow stability requirements, it can reduce flow fluctuations caused by pulsation. The air vent is formed by the air vent grooves on the opposite surfaces of the pump control housing 3 and the mounting plate 4, and constitutes part of the air vent channel 41. The air vent formed by this is a relatively flat chamber structure. The flat chamber not only facilitates gas diffusion and buffering, but also forms a reasonable volume-to-surface area ratio in a limited space, avoiding response delay caused by excessive volume or insufficient buffering caused by insufficient volume.

[0067] like Figures 4 to 8As shown, the mounting plate 4 has a first through hole 42, a second through hole 43, a third through hole 44, and a fourth through hole 45 extending along the thickness direction of the mounting plate 4. The first through hole 42 communicates with the air inlet channel 31, the second through hole 43 communicates with the air outlet channel 411, the inlet of the first on / off valve 21 is connected to the first through hole 42, and the outlet is connected to the second through hole 43; the third through hole 44 communicates with the air outlet channel 411, the fourth through hole 45 communicates with the air outlet channel 32, and the inlet of the second on / off valve 22 is connected to the third through hole 44, and the outlet is connected to the fourth through hole 45. By using the mounting plate 4 to set each through hole, the on / off valve and the corresponding flow channel can be connected without additional external connectors and pipelines, which can improve the three-dimensional space utilization of the pump control component 2 and make the pipeline layout more compact. One of the throttling orifices 25 is the portion of the second through-hole 43 near the air passage 411; the other throttling orifice 25 is the portion of the fourth through-hole 45 near the outlet air passage 32. It should be noted that in some embodiments, there is a case where the connecting section 26 is not provided, and the through-hole is equal to the throttling orifice 25.

[0068] In this embodiment, some gas flow channels are set on the pump control housing 3. Therefore, it is only necessary to increase the thickness of the pump control housing 3 to provide space for setting each channel and ensure structural strength. The mounting plate 4 is mainly used to install the first on / off valve 21 and the second on / off valve 22, set the air passage groove of the chamber, and the channel connecting the on / off valve and the corresponding flow channel. It does not require a large thickness, so that the overall thickness of the pump control assembly 2 is small and the structure is compact.

[0069] like Figure 2 As shown, in this embodiment, both the first on / off valve 21 and the second on / off valve 22 are solenoid valves; they have a fast response speed and can achieve precise flow regulation. The solenoid valves are connected to the control module via communication or electrical connection, enabling remote automated control and improving the automation level of the supply pump 1.

[0070] like Figure 4 As shown, the air vent 411 includes a first air vent 412 extending along the length of the mounting plate 4 and a second air vent 413 extending along the height of the mounting plate 4. Simultaneously, the air vent 411 needs to avoid the inlet air passage 31 and the outlet air passage 32. Therefore, the air vent 411 can be shaped like a "7", a "T", or a "U" shape, or other similar structures, to fully utilize the surface area of ​​the mounting plate 4, making the first and second on / off valves 21 and 22 more compactly installed, and reducing the overall size of the pump control assembly 2. Furthermore, the communication ports of the first and second on / off valves 21 and 22 with the air vent chamber are both located in the first air vent 412, and the detection flow channel 46 communicating with the second air vent 413 is at a certain distance, preventing pressure fluctuations during the opening and closing of the first and second on / off valves 21 and 22 from interfering with the detection accuracy of the pressure sensor 24.

[0071] like Figure 9 As shown, a pressure sensor 24 is also fixed on the side of the mounting plate 4 away from the pump control housing 3. The mounting plate 4 also has a detection channel 46 extending along the thickness direction of the mounting plate 4. The position of the detection channel 46 corresponds to the position of the pressure sensor 24 and is connected to the second air passage 413. Thus, the pressure sensor 24 is connected to the air passage chamber / air passage 411, and the air passage chamber is connected to the air chamber 11 supplying the pump 1. Therefore, the pressure sensor 24 can detect the pressure value of the air chamber 11 through the air passage chamber. At the same time, the pump control assembly 2 also includes a control valve 21 for the first opening and closing valve 2 and a control valve 2 for the second opening and closing valve 2. The control module for opening and closing (not shown) includes pressure sensor 24, first opening / closing valve 21, and second opening / closing valve 22, all of which are communicatively or electrically connected to the control module. The control module can control the opening and closing of the first opening / closing valve 21 and the second opening / closing valve 22 based on the pressure detection value detected by pressure sensor 24. In this embodiment, the control module is a chip on a circuit board, and pressure sensor 24 is an existing sensor integrated into the circuit. Of course, in other embodiments, it is not necessarily an integrated design. Different control modules and pressure sensors 24 can be selected for installation design according to the actual control requirements.

[0072] Furthermore, considering the inherent detection delay of the pressure sensor and the intermittent opening and closing of the solenoid valve for inflation or deflation, the pressure in the gas chamber is prone to overshoot and excessive fluctuation. The specific reasons for these defects are as follows: Due to the small volume of the gas at the downstream end and the detection delay of the pressure sensor, when the pressure sensor detects the gas pressure and reaches the set value, the actual pressure in the gas chamber of the liquid supply pump exceeds the required set pressure, resulting in overshoot and causing the pressure in the gas chamber to fail to meet the control requirements.

[0073] Because the pump control component controls the air passage opening and closing via a solenoid valve, the solenoid valve opens and closes intermittently during inflation and deflation. Each time the solenoid valve opens, the high pressure at its front end directly acts on the pressure sensor. Taking positive pressure inflation as an example, within one intermittent cycle, the initial high pressure acting on the pressure sensor causes the detected value to rise to a certain extent. When the high-pressure gas is delivered into the air chamber, the detected value of the pressure sensor will drop to a certain extent. In the next cycle, the detected value of the pressure sensor repeats the situation of the previous cycle, resulting in significant pressure fluctuations in the pressure value detected by the pressure sensor. For details, please refer to the appendix to the specification of this patent. Figure 10 The pressure detection curve of series 2 in the figure shows that the pressure in the air chamber is unstable, resulting in inaccurate detection.

[0074] Therefore, this utility model embodiment also discloses a control method for the supply pump 1. The control module controls the pump control component 2 based on the following control method to enable the supply pump 1 to draw in or discharge liquid, including the following steps:

[0075] The first on / off valve 21 or the second on / off valve 22 is opened, and the positive pressure gas source or the negative pressure gas source is connected to the gas flow channel, so that the gas enters the gas chamber 11 of the supply pump 1 through the first on / off valve 21 and the throttle orifice 25, or the gas in the gas chamber 11 of the supply pump 1 flows out and passes through the second on / off valve 22 and the throttle orifice 25.

[0076] Based on the pressure sensor 24 detecting the pressure value in the airflow passage 41, the first on / off valve 21 or the second on / off valve 22 is controlled to open and close at a set frequency and a set duty cycle, so that the deviation between the pressure detection value and the pressure preset value is reduced until the pressure detection value equals the pressure preset value.

[0077] Specifically, the diaphragm pump 1 has a draining step and a suction step, and the suction and draining steps of the photoresist are achieved by the negative pressure and positive pressure of the pump control component 2, respectively.

[0078] Liquid suction procedure: The negative pressure gas source is connected to the outlet gas channel 32. The control module controls the second on / off valve 22 to open. The gas in the outlet gas channel 32 is first drawn away by the negative pressure gas source. Due to the action of the throttling orifice 25, the high pressure of the negative pressure does not directly act on the second on / off valve 22. Then, the gas in the flow channel 41 and the gas chamber 11 enters the inlet of the second on / off valve 22 under the action of negative pressure, and then flows out of the outlet gas channel 32 through the connecting section 26 and the throttling orifice 25 from the outlet of the second on / off valve 22. There is no specific limitation on whether the gas first enters the second on / off valve 22 or the throttling orifice 25 when it is drawn away. It depends on the settings of the throttling orifice 25 and the second on / off valve 22. In this process, the second opening and closing valve 22 is opened and closed at a high frequency, specifically based on the pressure sensor 24 detecting the difference between the pressure detection value and the pressure preset value in the airflow channel 41. The second opening and closing valve 22 is controlled to open and close at a set frequency and a set duty cycle until the pressure detection value equals the negative pressure preset value. At this time, the second opening and closing valve 22 is completely closed and no longer executes the command to open and close at the set frequency and set duty cycle. At this time, the air in the air chamber 11 can be vented, and the liquid suction is completed so that the liquid chamber 12 is basically filled with liquid. Of course, the negative pressure preset value is set differently depending on the amount of liquid suction required, and the liquid chamber 12 may not be completely filled with liquid.

[0079] Drainage steps: The positive pressure gas source is connected to the inlet gas channel 31. The control module controls the first on / off valve 21 to open, and the working gas enters the inlet gas channel 31, then enters the inlet of the first on / off valve 21, and then flows out from the outlet of the first on / off valve 21. It then enters the flow channel 41 through the connecting section 26 and the throttle orifice 25, and flows into the gas chamber 11. Similarly, there is no specific limitation on whether the gas enters through the throttle orifice 25 or the first on / off valve 21 first. It depends on the relative positional relationship between the throttle orifice 25 and the first on / off valve 21. During this process, the first... The first on / off valve 21 is opened and closed at a high frequency. Specifically, it is based on the pressure sensor 24 detecting the difference between the pressure detection value and the pressure preset value in the airflow channel 41. The first on / off valve 21 is controlled to open and close at a set frequency and a set duty cycle until the pressure detection value equals the positive pressure preset value. When the liquid discharge is completed, the first on / off valve 21 closes. This can fill the gas chamber 11 with gas, so that the liquid chamber 12 is basically emptied of liquid. Of course, the positive pressure preset value is set differently depending on the amount of liquid discharge required, and a certain amount of liquid can also remain in the liquid chamber 12.

[0080] As can be seen from the above steps, the control method of this utility model combines the opening mode of the first opening and closing valve 21 and the second opening and closing valve 22 with the throttle orifice 25. The throttle orifice 25 avoids the high pressure of the positive or negative pressure air source from directly acting on the pressure sensor 24 connected to the airflow channel 41. If the throttle orifice 25 is not set, the positive or negative pressure will directly act on the pressure sensor 24. In fact, the gas has not been fully delivered to the air chamber 11, and the air pressure in the air chamber 11 has not reached the pressure preset value. However, the detection value of the pressure sensor 24 has reached the pressure preset value, which may cause the pressure in the working chamber to be lower than the pressure preset value, and also affect the dispensing or dispensing of the supply pump 1.

[0081] However, if only the throttle orifice 25 is set without controlling the opening and closing of the first and second opening and closing valves 21 and 22 according to the above control method, although the time for the pressure sensor 24 to reach the preset pressure value can be delayed after isolating part of the high pressure and increasing the gas flow rate, the pressure overshoot and large fluctuation amplitude of the gas chamber 11 may still occur due to the monitoring delay problem of the pressure sensor 24 itself and the small volume of the valve rear end. Therefore, the control method of this utility model controls the first opening and closing valve 21 or the second opening and closing valve 22 to open and close at a set frequency and a set duty cycle under different working states, which solves the problem of the monitoring delay of the pressure sensor 24 and the problem of excessive pressure fluctuation amplitude in the gas chamber 11, and makes full use of the filtering function of the throttle orifice 25. The filtering effect is shown in the figure. Figure 10 Compared to the pressure detection curve of Series 2 in the prior art, which has a larger pressure fluctuation amplitude, the pressure detection curve of the air chamber 11 that realizes the filtering function of the throttle orifice 25 in this patent has a smaller fluctuation amplitude.

[0082] It should also be noted that the control method of this embodiment enables the high-frequency opening and closing of the on / off valve during the diaphragm pump's liquid suction and discharge process, and performs closed-loop control based on the final pressure value detected by the pressure sensor 24. If the pressure in the air chamber 11 is lower than the preset negative pressure value during the liquid suction step, the second on / off valve 22 will be closed, while the first on / off valve 21 will be opened and closed at high frequency to pressurize the air chamber 11, eventually bringing the pressure in the air chamber 11 down to the preset negative pressure value. If the pressure in the air chamber 11 is higher than the preset positive pressure value during the liquid discharge step, the first on / off valve 21 will be closed, while the second on / off valve 22 will be opened and closed at high frequency to depressurize the air chamber 11, eventually bringing the pressure in the air chamber 11 down to the preset positive pressure value. Therefore, this control method, combined with the dynamic adjustment of the pressure in the air chamber 11 by the pressure sensor 24, achieves a stable control effect, enabling the photoresist flow rate of the supply pump 1 to be more stable and the amount of photoresist suction and discharge to be more precisely controllable during the photoresist suction and discharge process.

[0083] In this embodiment, the set frequency refers to the time it takes for the first on / off valve 21 or the second on / off valve 22 to complete a complete on / off cycle during the liquid aspiration or drainage process. The frequency can be represented by the cycle. The cycle time Xms includes at least the time x1 for a single opening, the continuous opening time Y, and the time x2 for a single closing. This is because the first on / off valve 21 and the second on / off valve 22 in this embodiment are solenoid valves, which are opened by electromagnetic force and closed by spring force. Therefore, opening and closing require a certain amount of time, and the times used by the two are different, that is, x1 and x2 are not the same. It is also necessary to consider the size of the cycle Xms as a fixed value. If the value of Xms is too small, the opening state of the valve in the previous cycle has not yet closed before the opening signal of the next cycle is executed, which causes the valve to always be in the open state and cannot achieve high-frequency opening and closing. If the value of Xms is too large, it will lead to a longer control cycle, an increased control delay, a decrease in control accuracy, and the valve will not be able to respond to the pressure change detected by the pressure sensor 24 in time. As a preferred option, X is no greater than 30, and the reasonable high-frequency control cycle also falls within the low-pass filtering range of the throttle orifice 25. For an on / off valve, x1 and x2 are also fixed parameters, while x1 and x2 of the first on / off valve 21 and the second on / off valve 22 may be different and need to be determined according to the specific on / off valve selected.

[0084] In this embodiment, setting the duty cycle refers to opening for Y ms within one opening / closing cycle X ms, where Y / X is the duty cycle. Y is set based on the pressure difference between the pressure detected by pressure sensor 24 and the preset pressure value, thereby dynamically adjusting the duty cycle of the opening / closing valve to achieve a stable control effect. For example, opening for 3 ms every 12 ms, where 12 ms is one cycle time from opening to closing of the opening / closing valve, and 3 ms is the continuous opening time of the opening / closing valve, thus achieving high-frequency opening and closing of the opening / closing valve. Specifically, it is proportional to the difference between the pressure detected by pressure sensor 24 in the gas flow channel and the preset pressure value; that is, the larger the difference, the larger Y is, and the smaller the difference, the smaller Y is. When the actual pressure value is far from the preset pressure value, the opening / closing valve needs to be open for more time to replenish or release gas. In addition, it should be noted that x1+x2+Y≤X and less than or equal to 30 ms; otherwise, the opening signal of the next cycle will be executed before the opening / closing valve in the previous cycle has closed, resulting in the opening / closing valve always being in the open state. The relationship between Y and the pressure difference e(t) between the detected pressure value and the preset pressure value in the gas flow channel can be obtained through a conversion formula, as follows: Where α < 1, the value of α is obtained by adjusting the given opening time of the opening and closing valves and the measured value of the pressure compensation rate under open-loop control. Specifically, the opening time of the first opening and closing valve 21 and the second opening and closing valve 22 is controlled to a given opening time, that is, a fixed opening time is given. Then, the rate of change of pressure difference is measured, and the final control effect is observed to adjust α. P K T K D These are traditional PID parameters, which need to be adjusted specifically. The PID algorithm is a mature existing technology, and related details will not be elaborated here. e(t) is the pressure difference between the pressure sensor's detected pressure value and the preset pressure value, which has an exponential relationship with the opening time Y of the valve.

[0085] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A pump control assembly for a supply pump, the supply pump (1) having a liquid chamber (12) and a gas chamber (11), the pump control assembly (2) being connected to the gas chamber (11) of the supply pump (1) to control the inflow or outflow of working gas into the gas chamber (11), causing the liquid chamber (12) to discharge or draw liquid; characterized in that, The pump control assembly (2) includes a gas flow channel, a first on / off valve (21), a second on / off valve (22), and a pressure sensor (24). The gas flow channel includes an inlet flow channel (31), an outlet flow channel (32), and a runoff flow channel (41). The inlet flow channel (31) is used to communicate with a positive pressure gas source, the outlet flow channel (32) is used to communicate with a negative pressure gas source, and the runoff flow channel (41) is used to communicate with the gas chamber (11) supplying the pump (1). Both the first on / off valve (21) and the second on / off valve (22) have valve flow channels (23). The first on / off valve (21) can connect the inlet air passage (31) and the outlet air passage (41) on / off, and the second on / off valve (22) can connect the outlet air passage (32) and the outlet air passage (41) on / off. The pressure sensor (24) is connected to the outlet air passage (41). It also includes a throttling orifice (25) corresponding to the first on-off valve (21) and / or the second on-off valve (22), the throttling orifice (25) being located at the connection between the first on-off valve (21) and / or the second on-off valve (22) and the gas flow channel, the flow area of ​​the throttling orifice (25) being smaller than the flow area of ​​the gas flow channel and the valve flow channel (23); It also includes a control module for controlling the opening and closing of the first on / off valve (21) and the second on / off valve (22).

2. The pump control assembly as claimed in claim 1, characterized in that, The throttling orifice (25) also has a connecting section (26) between it and the first on / off valve (21) or the second on / off valve (22), and the flow area of ​​the throttling orifice (25) is smaller than the flow area of ​​the connecting section (26).

3. The pump control assembly as described in claim 2, characterized in that, The volume of the connecting segment (26) is T1, and the volume of the airflow channel (41) is T2, satisfying that the value of T1:T2 is not greater than 0.

1.

4. The pump control assembly as claimed in claim 1, characterized in that, The flow area of ​​the throttling orifice (25) is 0.05 mm. 2 -0.3mm 2 .

5. The pump control assembly as described in any one of claims 1 to 4, characterized in that, The pump control assembly (2) further includes a pump control housing (3) and a mounting plate (4) that is sealed to the pump control housing (3). The inlet air passage (31) and the outlet air passage (32) are both formed inside the pump control housing (3). The outlet air passage (41) is at least partially formed between the pump control housing (3) and the mounting plate (4). The first on / off valve (21) and the second on / off valve (22) are installed on the side of the mounting plate (4) away from the pump control housing (3). The throttling orifice (25) is provided in two parts, both of which are provided on the mounting plate (4) along the thickness direction of the mounting plate (4). One throttling orifice (25) corresponds to the first on / off valve (21), and the other throttling orifice (25) corresponds to the second on / off valve (22).

6. The pump control assembly as claimed in claim 5, characterized in that, An air vent groove (411) is formed on one of the pump control housing (3) and the mounting plate (4), and an air vent cavity is formed by sealing and fitting with the other. The air vent cavity constitutes part of the air vent channel (41). The mounting plate (4) has a first through hole (42), a second through hole (43), a third through hole (44) and a fourth through hole (45) extending along the thickness direction of the mounting plate (4). The first through hole (42) is connected to the air intake channel (31), the second through hole (43) is connected to the air outlet groove (411), and the inlet of the first on / off valve (21) is connected to the first through hole (42) and the outlet is connected to the second through hole (43). The third through hole (44) is connected to the air passage groove (411), the fourth through hole (45) is connected to the air outlet passage (32), and the inlet of the second on / off valve (22) is connected to the third through hole (44) and the outlet is connected to the fourth through hole (45). One of the throttling orifices (25) is a portion of the second through hole (43) near the air passage (411); the other throttling orifice (25) is a portion of the fourth through hole (45) near the air outlet passage (32).

7. The pump control assembly as claimed in claim 1, characterized in that, Both the first on / off valve (21) and the second on / off valve (22) are solenoid valves.

8. A liquid supply system, characterized in that, It includes the pump control assembly as described in any one of claims 1 to 7, and the supply pump (1) connected to the pump control assembly (2).

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