A multi-group piston continuous conveying photoresist conveying pump and a control method thereof

Abstract

The application discloses a photoresist conveying pump with multiple groups of pistons for continuous conveying and a control method thereof. The photoresist conveying pump comprises multiple diaphragm pumps and piston rod assemblies installed in the diaphragm pumps, and further comprises a mounting base and a single eccentric crank connecting rod mechanism for driving the multiple piston rod assemblies to rotate and reciprocate alternately. One side of the piston rod assembly is provided with a swing lever assembly. A lifting linkage structure is arranged between one end of the swing lever assembly and an input end of the piston rod assembly. The other end of the swing lever assembly is provided with a second straight slot and a transverse adjusting unit fixed to the mounting base. An intermediate lifting transmission shaft is arranged on the transverse adjusting unit. A second driving roller shaft is arranged at the upper end of the intermediate lifting transmission shaft. The second driving roller shaft is movably installed in a corresponding second straight slot. Through the variable force arm lever principle and the coaxial disc linkage configuration in the pure mechanical level, the on-line and high-precision multi-cavity displacement synchronous stepless fine adjustment is realized.

Description

Technical Field

[0001] This invention relates to the field of precision fluid transport machinery technology, and in particular to a photoresist delivery pump with multiple sets of pistons for continuous transport and its control method. Background Technology

[0002] In the core photolithography coating process for manufacturing semiconductor chip integrated circuits, thin-film transistor liquid crystal displays, and OLED panels, the quantitative delivery accuracy of photoresist directly determines the uniformity of the coating film thickness. Because photoresist is an expensive, high-viscosity fluid, it is highly sensitive to shear forces and is extremely prone to particle precipitation or drying crystal formation due to localized severe friction, water hammer impact, or residue in dead corners.

[0003] Currently, most conventional high-precision metering pumps employ a dual-piston reversing action. During the instantaneous switching of the pistons at the dead point of reciprocating reversal, inherent pulsations and pressure drops inevitably occur within the fluid pipeline, making it impossible to achieve truly continuous, pulsation-free delivery throughout the entire cycle. To meet the requirement of pulsation-free continuous delivery, the industry has begun to explore multi-cylinder parallel diaphragm pump configurations, utilizing the phase overlap of multiple chambers to eliminate reversing pulsations. However, existing multi-cylinder diaphragm pumps, operating under continuous rotation, find it extremely difficult to achieve online, dynamic, and high-precision fine-tuning of displacement. Traditional displacement adjustment methods either rely on the electronic control layer directly changing the motor speed or employ complex rigid linkage eccentricity adjustment mechanisms.

[0004] Therefore, how to design a system that can maintain the rigid and regular alternating continuous pumping of multiple pump assemblies, and can adjust the reciprocating stroke amplitude of multiple pistons online with high precision and high synchronization through a very simple single control source without stopping the machine, is a technical problem that urgently needs to be solved in the field of semiconductor precision liquid supply equipment.

[0005] Therefore, the existing field of precision fluid transport machinery technology needs further improvement. Summary of the Invention

[0006] The purpose of this invention is to provide a photoresist delivery pump with multiple sets of pistons for continuous delivery and its control method. The aim is to achieve online, high-precision multi-cavity displacement synchronous stepless fine adjustment through the variable lever principle of the purely mechanical level and the coaxial disk linkage configuration.

[0007] To achieve the above objectives, the present invention adopts the following solution: a photoresist delivery pump with multiple sets of pistons continuously delivering photoresist, comprising multiple diaphragm pumps, piston rod assemblies installed within the diaphragm pumps, a mounting base, and a single eccentric crank-connecting rod mechanism for driving the reciprocating motion of the piston rod assemblies, characterized in that: a swing lever assembly is provided on one side of the piston rod assembly, one end of the swing lever assembly is linked to the piston rod assembly, and the other end is provided with a second straight slot; a lateral adjustment unit and an intermediate lifting transmission shaft are provided on the mounting base; the upper end of the intermediate lifting transmission shaft is fitted into the second straight slot, and the lower end is connected to a lifting and holding control unit driven by the single eccentric crank-connecting rod mechanism for lifting and lowering; a synchronous adjustment unit for changing the position of the lateral adjustment unit is provided within the mounting base; the lateral adjustment unit drives the intermediate lifting transmission shaft to change its position within the second straight slot, thereby adjusting the reciprocating stroke of the piston rod assembly online.

[0008] Furthermore, the number of diaphragm pumps is three, and they are evenly distributed around the central circumference of the mounting base.

[0009] Furthermore, the swing lever assembly includes a mounting plate disposed within the mounting base, the mounting plate having a shaft hole for inserting the lever shaft, and the lever shaft having a first lever arm and a second lever arm facing opposite directions at both ends, with the second straight slot disposed on the second lever arm; The first lever arm is provided with a first straight groove extending along its length, and the input end of the piston rod assembly is provided with a first drive roller shaft movably installed in the first straight groove, thereby forming the lifting linkage structure.

[0010] Furthermore, the lateral adjustment unit includes a lateral rail disposed on the mounting plate and a lateral adjustment block slidably disposed on the lateral rail; the intermediate lifting transmission shaft includes a vertical bushing disposed on the lateral adjustment block and a vertical lifting shaft movably disposed within the vertical bushing, and the second drive roller shaft is located at the upper end of the vertical lifting shaft.

[0011] Furthermore, the lifting and holding control unit includes a vertical guide rail unit fixedly installed on the mounting plate, a lifting horizontal guide rail is movably arranged on the vertical guide rail unit, and a transverse guide block is provided at the lower end of the vertical lifting shaft and is movably locked on the lifting horizontal guide rail.

[0012] Furthermore, the synchronous adjustment unit includes an adjustment disc rotatably disposed in the middle of the mounting base. The lower end face of the adjustment disc has a plurality of eccentric hinge parts evenly distributed around its rotation center circumference. The transverse adjustment block is provided with a control hinge part. The control hinge part and the corresponding eccentric hinge part are hinged with a tensioning connecting rod. A worm gear transmission unit for controlling the rotation of the adjustment disc is provided on one side of the mounting base.

[0013] Furthermore, the diaphragm pump is provided with an inlet end and an outlet end, with multiple inlet ends connected to the same input pipeline and multiple outlet ends connected to the same output pipeline.

[0014] A method for controlling a photoresist delivery pump includes the following steps: Step 1, Dynamic Pumping: Start the single eccentric crank connecting rod mechanism to drive the lifting and holding control unit to perform a reciprocating lifting motion at a constant height; Step 2, Stroke Calculation: Obtain the target photoresist output amount, and calculate the target position of the intermediate lifting transmission shaft and the target displacement of the lateral adjustment unit based on the position transmission relationship of the swing lever assembly. Step 3, Online Adjustment: Under continuous pumping conditions, control the synchronous adjustment unit to drive the lateral adjustment unit to move the intermediate lifting transmission shaft to the target position; Step 4, Follow-up amplitude: The lifting and holding control unit transmits the reciprocating lifting action to the second straight slot through the intermediate lifting transmission shaft, changing the swing amplitude of the swing lever assembly, and thus changing the reciprocating extension and retraction stroke of the piston rod assembly.

[0015] In summary, the advantages of this invention over the prior art are: This invention addresses the shortcomings of existing precision fluid transport machinery technology. Through its structural design, it offers the following advantages: It breaks the limitations of traditional stop-and-adjustment methods, completely decoupling the "main shaft pumping power" and "displacement adjustment power" in terms of hardware structure. A single eccentric crank-connecting rod mechanism provides a constant-height reciprocating power source, while the displacement is purely controlled by the lateral adjustment unit changing the lever's force point. The pump can also be smoothly and steplessly fine-tuned online during continuous operation. Utilizing the nonlinear displacement transmission characteristics of the lever principle, when the intermediate lifting drive shaft moves to a fine adjustment zone far from the lever axis, even if the vertical lifting shaft experiences minor axial vibrations, the stroke jitter on the piston rod assembly approaches zero due to the small position transmission coefficient at that point. This establishes a high-resolution precision vibration filtering barrier at the physical level. Through the geometric constraints of the central coaxial adjustment disc and the three peripheral tensioning connecting rods, only a small angular rotation input to the worm gear transmission unit is needed to push or pull the lateral adjustment blocks of the three annular diaphragm pumps in and out completely equally and synchronously. This completely solves the problem of residual pressure pulsation caused by uneven adjustment of each flow channel in multi-cylinder pumps, ensuring extremely high repeatability throughout the entire cycle. Attached Figure Description

[0016] Figure 1 This is the front view of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 For the present invention Figure 2 Sectional view along line BB; Figure 4 For the present invention Figure 2 A sectional view along line CC.

[0017] Figure 5 For the present invention Figure 4 Sectional view along line EE; Figure 6 For the present invention Figure 5 A magnified view of a portion at point D; Figure 7 For the present invention Figure 1 A sectional view along line AA. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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 scope of protection of the present invention.

[0019] Please see Figures 1-7This invention provides a photoresist delivery pump with multiple sets of pistons for continuous delivery; the delivery pump includes a mounting base and three diaphragm pumps 1 arranged in parallel and evenly distributed around the center circumference of the mounting base. Each diaphragm pump 1 has a piston rod assembly 2 that is precisely and movably embedded inside to change the volume of the internal drug chamber.

[0020] A single eccentric crank-connecting rod mechanism 3 is integrated in the middle of the mounting base to provide the main rotational power and drive the piston rod assemblies 2 of the three diaphragm pumps to perform reciprocating linear reciprocating telescoping motion in turn with phase difference, thereby forming a completely complementary sinusoidal non-pulsating continuous flow at the fluid confluence output end.

[0021] On one side of each piston rod assembly 2, there is a set of swing lever assembly 4 for changing the displacement magnification. The swing lever assembly 4 includes a precision mounting plate 401 that is horizontally and rigidly fixed in the mounting base.

[0022] The mounting plate 401 has a high-precision shaft hole 402, and a lever shaft 403 is inserted and supported in the shaft hole 402 through a rolling bearing. The left and right ends of the lever shaft 403 extend horizontally and are rigidly connected to a first lever arm 404 and a second lever arm 405 facing completely opposite directions, thus forming a rigid double-arm lever that can deflect around a fixed center.

[0023] The first lever arm 404 is connected to the mechanical input end of the piston rod assembly 2 via a lifting linkage structure 5. Specifically, the lifting linkage structure 5 includes a first straight slot 501 precisely formed on the first lever arm 404 and extending straight along the length of the first lever arm 404. A first drive roller shaft 502 (preferably a high-hardness rolling bearing roller shaft) is vertically fixed to the axial input end of the piston rod assembly 2.

[0024] The first drive roller 502 is movably mounted in the corresponding first straight slot 501 with a micro-clear gap, thereby smoothly converting the arc-shaped deflection motion of the first lever arm 404 into the pure axial linear reciprocating motion of the piston rod assembly 2. Simultaneously, a second straight slot 6 is provided on the second lever arm 405 (i.e., the other end of the swing lever assembly 4). Below the second lever arm 405, a horizontally rigidly fixed transverse adjustment unit 7 is mounted on the mounting plate 401. The transverse adjustment unit 7 includes a transverse track 701 and a transverse adjustment block 702 slidably disposed on the transverse track 701. The transverse adjustment block 702 carries an intermediate lifting transmission shaft 8 capable of axial displacement. The intermediate lifting transmission shaft 8 includes a vertical bushing 801 fixed on the transverse adjustment block 702, and a vertical lifting shaft 802 movably sleeved inside the vertical bushing 801, capable of free vertical sliding up and down. A second drive roller 11 is rigidly and vertically mounted at the top of the vertical lifting shaft 802. This second drive roller 11 is movably embedded in the slide rail of the second straight groove 6 of the second lever arm 405. By horizontally driving the transverse adjustment block 702 to slide along the transverse track 701, the radial coordinates of the intermediate lifting transmission shaft 8 within the second straight groove 6 can be precisely changed.

[0025] Because the physical distance between the second drive roller shaft 11 and the lever shaft 403 changes dynamically, when the vertical lifting shaft 802 is pushed by the lower mechanism and given a constant lifting height, according to the lever transmission ratio principle, the absolute swing amplitude (angle of deflection) generated by the swing lever assembly 4 will change nonlinearly and significantly. This change in swing angle is proportionally amplified by the first straight slot 501, ultimately changing the axial reciprocating extension and retraction amplitude of the piston rod assembly 2, thus realizing a purely mechanical adjustment of the displacement reference.

[0026] To ensure that the intermediate lifting drive shaft 8 receives a stable and rigid vertical power input during operation when it is pushed to any horizontal physical coordinate position by the horizontal adjustment unit 7, a lifting and holding control unit 9 is arranged below the horizontal track 701.

[0027] The lifting and holding control unit 9 includes a vertical guide rail unit 901 vertically fixed on the mounting plate 401. A lifting horizontal guide rail 902 is mounted on the vertical guide rail unit 901 for vertical movement. The track surface of the lifting horizontal guide rail 902 is perfectly horizontally parallel to the transverse rail 701. A transverse guide block 903 is rigidly and vertically mounted at the bottom end of the aforementioned vertical lifting shaft 802. The transverse guide block 903 is movably engaged within the lifting horizontal guide rail 902 with a backlash-free sliding fit. Through this "double parallel slide rail" configuration, when the lifting horizontal guide rail 902 performs a constant vertical lifting and reciprocating motion under the drive of the single eccentric crank-connecting rod mechanism 3, regardless of where the intermediate lifting drive shaft 8 slides due to lateral adjustment, the transverse guide block 903 at its bottom can smoothly slide and follow within the lifting horizontal guide rail 902. Furthermore, the vertical displacement of the lifting horizontal guide rail 902 is transmitted without loss to the upper second drive roller shaft 11 through the horizontal guide block 903 and the vertical lifting shaft 802, ensuring perfect decoupling and follow-up maintenance of power transmission and dynamic adjustment.

[0028] In order to achieve absolutely equal and synchronized online dynamic discharge calibration of the three diaphragm pumps 1 evenly distributed in the ring, a synchronization adjustment unit 10 is configured in the inner center section of the mounting base.

[0029] The synchronous adjustment unit 10 includes an adjustment disk 101 coaxially positioned at the center of the mounting base. Three eccentric hinge portions 102 are symmetrically distributed around the lower outer edge of the adjustment disk 101's rotation center. Correspondingly, each of the three peripheral transverse adjustment blocks 702 has a protruding control hinge portion 103. A fixed-length tension / opening connecting rod 104 is hinged between each control hinge portion 103 and the eccentric hinge portion 102. A worm gear transmission unit 105, directly driven by a high-resolution stepper motor, is mounted on the outer wall of the mounting base. The output end of this transmission unit is rigidly connected to the central adjustment disk 101, used to control the adjustment disk 101 to perform extremely small angular rotations. Because the worm gear transmission unit has a natural "reverse mechanical self-locking" function, once the adjustment motor stops supplying power, the worm gear can firmly lock the adjustment disk 101, preventing the fluid reaction force during high-frequency pumping from causing physical drift in the adjustment angle.

[0030] When dynamic adjustment is required, the worm gear transmission unit 105 micro-drives the adjustment disc 101 to rotate. The rotation angle of the adjustment disc 101 is controlled by three tensioning connecting rods 104, which push and pull the three transverse adjustment blocks 702 along the transverse track 701 with absolutely consistent geometric stroke, thereby changing the position of the three intermediate lifting transmission shafts 8 and thus achieving absolute synchronous adjustment of the extension and retraction amplitude of the multi-chamber piston.

[0031] The single eccentric crank-connecting rod mechanism 3 at the main drive system level includes a single eccentric rotating component 301 coaxially mounted at the center of the mounting base and driven by the main servo motor. Below each lifting horizontal guide rail 902, a set of radial guide rails 302 extending along the geometric radial direction of the single eccentric rotating component 301 are arranged. A radial slider 303, performing a horizontal radial reciprocating linear motion, is movably mounted within each radial guide rail 302. A first hinge portion 304 is provided on the top surface of the radial slider 303, and a second hinge portion 305 is provided at the center of the bottom surface of the corresponding lifting horizontal guide rail 902. An inclined reversing link 306 is hinged between the first hinge portion 304 and the second hinge portion 305.

[0032] The reversing link 306 converts the horizontal radial displacement of the radial slider 303 into the axial vertical lifting motion of the lifting cross rail 902. The radial slider 303 also has a third hinge 307. A crank connecting rod 308 is hinged between the single eccentric rotating assembly 301 and the third hinge 307. When the single eccentric rotating assembly 301 rotates continuously at a constant speed, the three staggered crank connecting rods 308 rigidly drive the three peripheral radial sliders 303 to alternately perform a constant-amplitude horizontal reciprocating motion. After the reversing link 306 changes direction, the three lifting cross rails 902 produce equal-amplitude, alternating vertical reciprocating motions, thereby establishing the bottom-level conveying cycle of the entire machine.

[0033] The present invention also provides a control method for a photoresist delivery pump that continuously delivers photoresist using multiple sets of pistons, the specific implementation steps of which are as follows: Step 1, Continuous Dynamic Pumping Step: Start the main servo motor of the single eccentric crank-connecting rod mechanism 3 to keep the single eccentric rotating component 301 rotating at its rated constant speed. The single eccentric rotating component 301, through the linkage of three sets of crank-connecting rods 308 and reversing connecting rods 306, drives the lifting horizontal guide rails 902 of the three lifting and holding control units 9 to perform alternating vertical reciprocating lifting and lowering movements with a constant height and spatial phase angles staggered between them.

[0034] Step 2: Displacement Demand Perception and Target Calculation: The machine control terminal acquires the current semiconductor process target photoresist single-cycle discharge volume demand in real time. Based on the nonlinear position transfer coefficient equation of the swing lever component 4 embedded in the control algorithm, the required piston target stroke is input, and the target lever arm length (i.e., the absolute distance from the second drive roller shaft 11 to the lever shaft 403) is calculated precisely.

[0035] The lever arm distance is then converted into the absolute target lateral displacement of the lateral adjustment block 702 on the lateral track 701.

[0036] Step 3, Multi-pump Synchronous Online Adjustment: Under the dynamic state of continuous pumping and non-stop operation of the single eccentric crank-connecting rod mechanism 3, the control terminal inputs specific control pulses to the worm gear transmission unit 105, driving the central adjusting disk 101 to rotate by a specified angle. The adjusting disk 101, through three fixed-length tensioning and relaxing connecting rods 104, synchronously and equidistantly pushes and pulls the three peripheral lateral adjusting blocks 702 with completely identical geometric and mechanical constraints, until the lateral adjusting blocks 702 precisely reach the calculated absolute target lateral displacement position.

[0037] Step 4, Stroke Follow-up Direction Change Step: During the sliding of the lateral adjustment block 702, the lateral guide blocks 903 at the bottom of each intermediate lifting transmission shaft 8 maintain continuous lifting while simultaneously sliding horizontally in the track groove of the lifting horizontal guide rail 902. At this time, the lifting horizontal guide rail 902, through its repositioned vertical lifting shaft 802 and the second drive roller shaft 11 at the top, nonlinearly transmits the constant height lifting action to the corresponding second straight slot 6 according to the changed transmission coefficient. This changes the actual swing amplitude of the swing lever assembly 4. The change in swing amplitude, through the linkage between the first straight slot 501 and the first drive roller shaft 502, ultimately proportionally changes the axial reciprocating extension and retraction amplitude of the three piston rod assemblies 2. Thus, online precise calibration of photoresist continuous discharge without pulsation is completed without stopping the machine.

[0038] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A photoresist delivery pump with multiple sets of pistons for continuous delivery, comprising multiple diaphragm pumps (1), piston rod assemblies (2) installed within the diaphragm pumps (1), a mounting base, and a single eccentric crank-connecting rod mechanism (3) for driving the piston rod assembly (2) to reciprocate, characterized in that: A swing lever assembly (4) is provided on one side of the piston rod assembly (2). One end of the swing lever assembly (4) is linked with the piston rod assembly (2), and the other end is provided with a second straight groove (6). The mounting base is equipped with a horizontal adjustment unit (7) and a middle lifting transmission shaft (8). The upper end of the intermediate lifting transmission shaft (8) is fitted into the second straight slot (6), and the lower end is connected to a lifting and holding control unit (9) driven by the single eccentric crank connecting rod mechanism (3) for lifting and lowering. The mounting base is provided with a synchronous adjustment unit (10) for changing the position of the lateral adjustment unit (7). The lateral adjustment unit (7) drives the intermediate lifting transmission shaft (8) to change its position within the second straight slot (6) in order to adjust the reciprocating stroke of the piston rod assembly (2) online.

2. The photoresist delivery pump according to claim 1, characterized in that: The number of diaphragm pumps (1) is three, and they are evenly distributed around the central circumference of the mounting base.

3. The photoresist delivery pump according to claim 1 or 2, characterized in that: The swing lever assembly (4) includes a mounting plate (401) disposed in the mounting base. The mounting plate (401) is provided with a shaft hole (402) through which the lever shaft (403) passes. The lever shaft (403) is provided with a first lever arm (404) and a second lever arm (405) facing opposite directions at both ends. The second straight slot (6) is disposed on the second lever arm (405). The first lever arm (404) is provided with a first straight groove (501) extending along its length direction, and the input end of the piston rod assembly (2) is provided with a first drive roller (502) movably installed in the first straight groove (501), thereby forming the lifting linkage structure (5).

4. The photoresist delivery pump according to claim 3, characterized in that: The lateral adjustment unit (7) includes a lateral rail (701) disposed on the mounting plate (401) and a lateral adjustment block (702) slidably disposed on the lateral rail (701); the intermediate lifting transmission shaft (8) includes a vertical bushing (801) disposed on the lateral adjustment block (702) and a vertical lifting shaft (802) movably disposed within the vertical bushing (801), and the second drive roller shaft (11) is located at the upper end of the vertical lifting shaft (802).

5. The photoresist delivery pump according to claim 4, characterized in that: The lifting and holding control unit (9) includes a vertical guide rail unit (901) fixedly installed on the mounting plate (401), a lifting horizontal guide rail (902) is movably arranged on the vertical guide rail unit (901), and a horizontal guide block (903) is movably locked on the lifting horizontal guide rail (902) at the lower end of the vertical lifting shaft (802).

6. The photoresist delivery pump according to claim 5, characterized in that: The synchronous adjustment unit (10) includes an adjustment disc (101) rotatably disposed in the middle of the mounting base. Multiple eccentric hinge parts (102) are evenly distributed around the lower end surface of the adjustment disc (101) around its rotation center circumference. A control hinge part (103) is provided on the transverse adjustment block (702). A tensioning connecting rod (104) is hinged between the control hinge part (103) and the corresponding eccentric hinge part (102). A worm gear transmission unit (105) for controlling the rotation of the adjustment disc (101) is provided on one side of the mounting base.

7. The photoresist delivery pump according to claim 6, characterized in that: The diaphragm pump (1) is provided with an inlet end (200) and an outlet end (300), and multiple inlet ends (200) are connected to the same input pipeline, and multiple outlet ends (300) are connected to the same output pipeline.

8. A control method for a photoresist delivery pump as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1, Dynamic pumping: Start the single eccentric crank connecting rod mechanism (3) to drive the lifting and holding control unit (9) to perform a constant height reciprocating lifting action; Step 2, Stroke Calculation: Obtain the target photoresist output amount, and calculate the target position of the intermediate lifting transmission shaft (8) and the target displacement of the lateral adjustment unit (7) based on the position transmission relationship of the swing lever assembly (4); Step 3, Online Adjustment: Under continuous pumping conditions, control the synchronous adjustment unit (10) to drive the lateral adjustment unit (7) to move the intermediate lifting transmission shaft (8) to the target position; Step 4, follow-up amplitude: The lifting and holding control unit (9) transmits the reciprocating lifting action to the second straight slot (6) through the intermediate lifting transmission shaft (8), changes the swing amplitude of the swing lever assembly (4), and thus changes the reciprocating extension and retraction stroke of the piston rod assembly (2).

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