A filter for removing impurities from an etching solution

Abstract

The present invention relates to the technical field of impurity removal from etching solutions, and particularly provides a filter for removing impurities from etching solutions, comprising: a cylinder body, on the side wall of which there is a communication pipeline for communicating the inside and the outside; at least one liquid collecting pipe arranged in the cylinder body and connected to the communication pipeline; at least one filter screen sleeved on the outer periphery of at least one liquid collecting pipe and arranged in one-to-one correspondence with at least one liquid collecting pipe; wherein, a plurality of porous pipes are arranged between each liquid collecting pipe and the corresponding filter screen, the plurality of porous pipes are spirally wound around the liquid collecting pipe, and each porous pipe is connected to the liquid collecting pipe; the communication pipeline is connected with a liquid outlet and a backflush port on the outer side of the cylinder body. In the solution of the present invention, by arranging the spirally wound porous pipes, the filter screen and the filter cake accumulated on the filter screen form corresponding spiral shapes. Through backflushing, the filter screen expands from the spiral shape into a cylindrical shape, so that the caked filter cake on the filter screen breaks and falls off, improving the slag removal effect and ensuring the subsequent filtering effect and filtering efficiency of the filter screen.

Description

Technical Field

[0001] The present invention relates to the technical field of etching solution impurity removal, and particularly to a filter for removing impurities from an etching solution. Background Art

[0002] An etching solution is a chemical solution widely used in various fields such as the semiconductor industry, metal processing, optical engineering, and art production. Among them, the etching solution plays an important role especially in the manufacturing process of semiconductor devices. For example, in the manufacturing process of the chip of an RFID tag, the etching solution is used to remove the oxide layer on the silicon wafer to achieve fine processing of the circuit pattern.

[0003] After the etching solution finishes processing a semiconductor device (such as the chip of an RFID tag), the generated etching waste liquid often contains a large amount of solid impurities. In order to recycle the etching solution for a second time, a filter screen is usually used to filter the etching solution. During the filtration process of the etching solution, impurities will continuously accumulate on the filter screen to form a filter cake. After the filter cake reaches a certain degree, it will affect the filtration effect and filtration efficiency of the filtration equipment. Therefore, it is necessary to remove the filter cake.

[0004] In existing filtration equipment, the filter element is usually set in a gear shape, so that the filter screen attached to the filter element forms a wavy shape in the circumferential direction. After the filter cake is generated, a back-blowing technique is used to expand the gear-shaped filter screen into a circular shape to remove the filter cake. However, since the deformation amount of the filter screen at the wave crest is very small or even may not exist, it will cause the filter cake at the wave crest to be difficult to fall off, and large block-shaped long-columnar filter cakes still remain on the wave crest. Obviously, the slag removal effect of the existing filtration equipment is poor, seriously affecting the subsequent filtration effect and filtration efficiency. Summary of the Invention

[0005] An object of the present invention is to improve the slag removal effect of the filter for removing impurities from an etching solution.

[0006] Specifically, the present invention provides a filter for removing impurities from an etching solution, including: a cylinder body, on the side wall of which there is a communication pipeline for communicating inside and outside; at least one liquid collecting pipe arranged in the cylinder body and connected to the communication pipeline; at least one filter screen sleeved on the outer periphery of at least one liquid collecting pipe and arranged in one-to-one correspondence with at least one liquid collecting pipe; wherein, a plurality of porous pipes are arranged between each liquid collecting pipe and the corresponding filter screen, the plurality of porous pipes are spirally wound around the liquid collecting pipe, and each porous pipe is connected to the liquid collecting pipe; the communication pipeline is connected with a liquid outlet and a backflush port on the outside of the cylinder body.

[0007] Furthermore, the porous pipe has elasticity and can expand and contract along the axial direction of the liquid collecting pipe; the liquid collecting pipe includes a fixed pipe and a movable pipe; one end of the fixed pipe is connected to the communication pipeline, and the other end is sleeved on the movable pipe; the movable pipe expands and contracts relative to the fixed pipe.

[0008] Further, the filter for removing impurities from the etching solution further includes: a negative pressure device connected to the liquid outlet; a backwashing device connected to the backwashing port; and the backwashing device is configured to backwash the liquid collecting pipe after the negative pressure device stops working.

[0009] Further, the filter for removing impurities from the etching solution further includes: a liquid discharging device provided on the outer periphery of the cylinder body and connected to the liquid discharging port provided at the bottom of the cylinder body; the liquid discharging device is configured to discharge the remaining etching solution in the cylinder body through the liquid discharging port before the backwashing device starts to work.

[0010] Further, a limiting block is formed on the inner wall surface of the fixed pipe to limit the maximum retraction distance of the moving pipe.

[0011] Further, a sensing device is also provided on the limiting block to monitor the position of the moving pipe.

[0012] Further, the liquid outlet and the backwashing port are arranged in parallel.

[0013] Further, a sealed cavity is formed at one end of the liquid collecting pipe away from the connecting pipeline, and the ends of multiple porous pipes communicate with the sealed cavity.

[0014] Further, the filter for removing impurities from the etching solution further includes: a spraying device provided at the top of the cylinder body.

[0015] Further, a slag discharging port is provided at the bottom of the cylinder body, and an inverted conical inclined surface is formed around the slag discharging port.

[0016] The beneficial effects of the present invention are:

[0017] For the filter for removing impurities from the etching solution of the present invention, by arranging a spirally wound porous pipe between the liquid collecting pipe and the filter screen, during the process of discharging the etching solution, the filter screen is pushed by the etching solution and adheres to the porous pipe to form a spiral-shaped mesh surface. The filter cake accumulated on the filter screen also forms a corresponding spiral shape. The spiral-shaped filter cake is easier to break and peel off both axially and circumferentially, thereby reducing the difficulty of cleaning the filter screen. Through backwashing, the filter screen expands from a spiral shape into a cylindrical shape, so that the caked filter cake on the filter screen breaks and falls off, thereby completing the cleaning of the filter screen. The cleaning effect is good, the operation is simple and convenient, and the subsequent filtering effect and filtering efficiency of the filter screen are ensured.

[0018] Furthermore, for the filter for removing impurities from the etching solution of the present invention, the porous tube is set as an elastic member, and the liquid collecting tube is set as a telescopic member, so that the filter screen can deform accordingly with the telescopic movement of the porous tube and the liquid collecting tube. When the porous tube and the liquid collecting tube retract, the filter screen can be embedded into the gap between the porous tubes. The greater the retraction amount of the porous tube and the liquid collecting tube, the greater the embedding amount of the filter screen in the gap between the porous tubes. Under the action of the backwashing force, the filter screen expands radially, and the porous tube and the liquid collecting tube elongate axially and drive the filter screen to stretch. The greater the embedding amount of the filter screen in the gap of the porous tube, the greater the expansion amount in the radial direction after backwashing, and the greater the thrust force generated, and the better the slag cleaning effect. The inertia generated by the movement of the porous tube and the liquid collecting tube makes the filter residue easier to fall off from the filter screen. At the same time, the tremor generated by pulling the filter screen when the porous tube and the liquid collecting tube elongate to the limit distance further improves the slag cleaning effect and efficiency of the filter screen. The effective removal of the filter cake greatly improves the filtering effect and efficiency of the filter for removing impurities from the etching solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Some specific embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings in an exemplary but not restrictive manner. The same reference numerals in the drawings denote the same or similar components or parts.

[0020] Figure 1 is a schematic structural diagram of a filter for removing impurities from an etching solution according to an embodiment of the present invention.

[0021] Figure 2 is an exploded schematic diagram of a filter for removing impurities from an etching solution according to an embodiment of the present invention.

[0022] Figure 3 is a schematic structural diagram of a filter for removing impurities from an etching solution from another angle according to an embodiment of the present invention.

[0023] Figure 4 is along Figure 3 The schematic cross-sectional view taken along the cutting line A-A in

[0024] Figure 5 is Figure 4 The schematic enlarged view of the area B in

[0025] Figure 6 is Figure 4 The schematic enlarged view of the area C in

[0026] Wherein: 100, cylinder body; 110, connecting pipeline; 111, liquid outlet; 112, backwashing port; 120, negative pressure device; 130, backwashing device; 140, control valve; 150, liquid discharging device; 160, liquid discharging port; 170, spraying device; 171, spraying nozzle; 172, cleaning port; 180, slag discharging port; 181, inclined surface; 182, baffle; 190, liquid inlet; 200, liquid collecting pipe; 210, fixed pipe; 211, limiting block; 212, sensing device; 220, movable pipe; 230, sealed cavity; 240, adapter; 300, filter screen; 400, porous pipe; 500, base. Detailed implementation manners

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In this article, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features, that is, including one or more of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. When a certain feature "includes or contains" a certain or certain features it covers, unless otherwise specifically described, this indicates that other features are not excluded and other features may be further included.

[0029] Unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation" and the like should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. Those of ordinary skill in the art should be able to understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0030] It should be understood that the orientation or positional relationship indicated by terms such as "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial direction", "radial direction", "circumferential direction" and the like is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0031] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply indicates that the horizontal height of the first feature is less than that of the second feature.

[0032] The following will refer to Figures 1 to 6 to describe a filter for removing impurities from an etching solution provided by the present invention.

[0033] Figure 1 is a schematic structural view of a filter for removing impurities from an etching solution according to an embodiment of the present invention. Figure 2 is an exploded schematic view of a filter for removing impurities from an etching solution according to an embodiment of the present invention. Figure 3 is a schematic structural view of a filter for removing impurities from an etching solution from another angle according to an embodiment of the present invention. Figure 4 is along Figure 3 the schematic cross-sectional view taken along the cutting line A-A in Figure 5 is Figure 4 the schematic enlarged view of area B in Figure 6 is Figure 4 the schematic enlarged view of area C in

[0034] The filter for removing impurities from an etching solution generally may include: a cylinder body 100, at least one liquid collecting pipe 200, at least one filter screen 300, and a plurality of porous pipes 400.

[0035] A communicating pipeline 110 communicating inside and outside is provided on the side wall of the cylinder body 100. At least one liquid collecting pipe 200 is arranged in the cylinder body 100 and is connected to the communicating pipeline 110. At least one filter screen 300 is sleeved on the outer periphery of at least one liquid collecting pipe 200 and is arranged in one-to-one correspondence with at least one liquid collecting pipe 200. Among them, a plurality of porous pipes 400 are arranged between each liquid collecting pipe 200 and the corresponding filter screen 300. The plurality of porous pipes 400 are spirally wound around the liquid collecting pipe 200, and each porous pipe 400 is connected to the liquid collecting pipe 200. The communicating pipeline 110 is connected with a liquid outlet 111 and a backwashing port 112 on the outside of the cylinder body 100.

[0036] In the solution of this embodiment, by arranging a porous tube 400 spirally wound between the liquid collecting tube 200 and the filter screen 300, during the process of discharging the etching solution, the filter screen 300 is pushed by the etching solution and adheres to the porous tube 400 to form a spiral mesh surface. The filter cake accumulated on the filter screen 300 also forms a corresponding spiral shape. Using backwashing to clean the filter screen 300 not only has a good slag cleaning effect, but also is simple and convenient to operate, ensuring the subsequent filtering effect and filtering efficiency of the filter screen 300.

[0037] Generally, the filter screen 300 can be made of a filter cloth without elasticity or with less elasticity, such as polyester filter cloth, nylon filter cloth, etc. After being backwashed, the filter screen 300 expands from a spiral shape into a cylindrical shape, driving the caked filter cake on it to deform, break, and fall off. During the backwashing process, the trough area of the filter cake bulges radially outward under the action of the backwashing force. During the process of the trough area of the filter cake bulging outward, internal thrusts that are located on the tangent plane and perpendicular to the spiral line and interact with each other are generated inside the filter cake in the trough area. The extrusion force perpendicular to the spiral line is decomposed into an axial thrust and a circumferential thrust. Under the combined action of the forces in the three dimensions of radial, axial, and circumferential directions, the filter cake is not only more likely to break, but also the filter residue formed after breaking is smaller in size and easier to peel off, thereby reducing the slag cleaning difficulty of the filter screen 300.

[0038] Both ends of the cylinder 100 are sealed, and the etching solution to be filtered is stored inside the cylinder 100. During the working process of the filter for etching solution impurity removal, the etching solution inside the cylinder 100 first passes through the filter screen 300, then enters the porous tube 400 through the holes on the porous tube 400, and then enters the liquid collecting tube 200 connected to the porous tube 400, and finally flows to the liquid outlet 111 through the connecting pipeline 110 and is discharged from the liquid outlet 111.

[0039] In some embodiments, multiple liquid collecting tubes 200 can be arranged inside the cylinder 100, and the multiple liquid collecting tubes 200 are evenly distributed inside the cylinder 100 to improve the filtering effect and filtering efficiency.

[0040] The number of porous tubes 400 wound around each liquid collecting tube 200 can be set according to requirements. In some embodiments, the larger the size ratio of the liquid collecting tube 200 to the porous tube 400, the more the number of porous tubes 400 is set to ensure that the efficiency of the porous tube 400 supplying the filtering liquid can meet the output efficiency of the liquid collecting tube 200. In the solution of this embodiment, the number of porous tubes 400 is preferably set to 6.

[0041] Such as Figure 2 、 5As shown in FIGS. 6, in some embodiments, the ends of the plurality of porous tubes 400 are surrounded together to just form a circle. The central area of the circle formed by the plurality of porous tubes 400 can be used to place the liquid collecting tube 200. The plurality of porous tubes 400 jointly support the filter screen 300, which not only has a good supporting effect, but also ensures the effective filtering area of the filter screen 300.

[0042] Generally, a liquid inlet 190 can also be provided at the top of the cylinder body 100 for conveying the etching solution to be filtered into the cylinder body 100. The filter for etching solution impurity removal generally can include a base 500. The base 500 is arranged at the bottom of the cylinder body 100 for supporting and fixing the cylinder body 100.

[0043] The porous tube 400 has elasticity and can expand and contract along the axial direction of the liquid collecting tube 200. The liquid collecting tube 200 includes a fixed tube 210 and a movable tube 220; one end of the fixed tube 210 is connected to the connecting pipeline 110, and the other end is sleeved on the movable tube 220; the movable tube 220 expands and contracts relative to the fixed tube 210.

[0044] In the solution of this embodiment, the porous tube 400 is set as an elastic member, and the liquid collecting tube 200 is set as a telescopic member, so that the filter screen 300 can stretch or retract into the gap between the porous tubes 400 along with the expansion and contraction of the porous tube 400 and the liquid collecting tube 200. The greater the retraction amount of the porous tube 400 and the liquid collecting tube 200, the greater the embedding amount of the filter screen 300 in the gap between the porous tubes 400. Under the action of the backwashing force, the filter screen 300 expands radially, and the porous tube 400 and the liquid collecting tube 200 elongate axially and drive the filter screen 300 to stretch. The greater the embedding amount of the filter screen 300 in the gap between the porous tubes 400, the greater the expansion amount in the radial direction after backwashing, and the greater the thrust force generated, and the better the slag cleaning effect. The inertia generated by the movement of the porous tube 400 and the liquid collecting tube 200 makes the filter residue easier to fall off from the filter screen 300. At the same time, the tremor generated by the porous tube 400 and the liquid collecting tube 200 pulling the filter screen 300 after elongating to the limit distance further improves the slag cleaning effect and slag cleaning efficiency of the filter screen 300. The effective removal of the filter cake greatly improves the filtering effect and filtering efficiency of the filter for etching solution impurity removal.

[0045] The porous tube 400 is preferably made of a metal material.

[0046] The fixed tube 210 is fixed relative to the connecting pipeline 110, and the connection between the fixed tube 210 and the connecting pipeline 110 has good sealing performance. In some embodiments, the fixed tube 210 can be fixedly installed on the connecting pipeline 110 by welding. In other embodiments, the fixed tube 210 can be detachably installed on the connecting pipeline 110 by threaded connection.

[0047] In some embodiments, when the porous tube 400 is wound around the liquid collecting tube 200 without retracting, the length of the filter screen 300 in the axial direction can be greater than or equal to the length of the porous tube 400 in the axial direction. This enables the filter screen 300 to be more embedded in the gaps between the porous tubes 400 when the porous tube 400 retracts. The larger the ratio of the length of the filter screen 300 to the length of the porous tube 400 in the axial direction, the more fabric of the filter screen 300 can be embedded in the gaps between the porous tubes 400 (i.e., the larger the contact area between the filter screen 300 and the porous tube 400), the greater the deformation of the filter screen 300 after backwashing and expansion, and the more conducive it is to peeling off the filter cake.

[0048] The filter for removing impurities from the etching solution generally may further include a negative pressure device 120 and a backwashing device 130.

[0049] The negative pressure device 120 is connected to the liquid outlet 111. The backwashing device 130 is connected to the backwashing port 112. And the backwashing device 130 is configured to backwash the liquid collecting tube 200 after the negative pressure device 120 stops working.

[0050] In the solution of this embodiment, by providing the negative pressure device 120 at the liquid outlet 111 and using the negative pressure device 120 to extract the filtered liquid, the flow of the filtered liquid becomes smoother, thereby improving the filtration efficiency. As the filter residue on the filter screen 300 continuously accumulates and cakes, the liquid permeability effect of the filter screen 300 becomes worse and worse. Under the action of negative pressure, the porous tube 400 and the liquid collecting tube 200 retract axially, and the filter screen 300 shrinks accordingly and clings more tightly to the porous tube 400. After the negative pressure device 120 stops working, the backwashing device 130 is used to backwash the liquid collecting tube 200, so that the porous tube 400 and the liquid collecting tube 200 change from the retracted state to the extended state. The inertia and tremor generated by the movement of the porous tube 400 and the liquid collecting tube 200 are greater, and the deformation of the filter screen 300 is also greater, further improving the slag removal effect.

[0051] In some preferred embodiments, the backwashing device 130 is configured to backwash the liquid collecting tube 200 at the moment when the negative pressure device 120 stops working. The liquid collecting tube 200 and the porous tube 400 change from the maximum retracted state to the maximum extended state instantaneously, driving the largest telescopic change amount of the filter screen 300, and the generated inertia and tremor are also the largest, thereby further improving the slag cleaning effect and slag cleaning efficiency of the filter screen 300. The backwashing device 130 injects gas into the communication pipeline 110, so that the inside of the liquid collecting tube 200 changes from the negative pressure state to the positive pressure state, thereby pushing the moving tube 200 to extend and driving the porous tube 400 to elongate to achieve backwashing.

[0052] In some embodiments, a plurality of control valves 140 may be provided on the communication pipeline 110 to respectively control the gas-liquid flow of a plurality of pipelines in the communication pipeline 110. In some embodiments, the communication pipeline 110 may be integrally formed with the cylinder 100 to improve the structural stability.

[0053] In some embodiments, the filter for removing impurities from the etching solution may further be provided with a pressurizing device to further improve the filtration efficiency by pressurizing the etching solution in the cylinder 100. The backwashing device 130 may be configured to backwash the liquid collecting pipe 200 at the moment when the pressurizing device and the negative pressure device 120 stop working simultaneously.

[0054] In some other embodiments, the filter for removing impurities from the etching solution may be provided with only a pressurizing device (i.e., without the negative pressure device 120). By pressurizing the etching solution in the cylinder 100, the etching solution is pressed to flow through the liquid collecting pipe 200 and then discharged from the cylinder 100 through the connecting pipeline. Under the pressure of the pressurizing device, the etching solution flows through the filter screen 300 to the liquid collecting pipe 200, driving the filter screen 300 to closely adhere to the porous pipe 400. After the filter residue on the filter screen 300 caking affects the liquid permeability effect of the filter screen 300, the liquid collecting pipe 200 and the porous pipe 400 contract under the pressure of the pressurizing device. The backwashing device 130 may be configured to backwash the liquid collecting pipe 200 at the moment when the pressurizing device stops working.

[0055] In some preferred embodiments, the elastic coefficient of the porous pipe 400 is configured to be small, so that when the filter screen 300 is blocked, the porous pipe 400 can retract smoothly in time under the hydraulic action of the etching solution or the negative pressure action of the negative pressure device 120.

[0056] The impurities in the etching solution will settle freely. Therefore, in the area of the filter screen 300 closer to the bottom, more impurities will accumulate.

[0057] In the solution of this embodiment, the backwashing device 130 is used to elongate the liquid collecting pipe 200 and the porous pipe 400, driving the filter screen 300 to move. The displacement amount of the area of the filter screen 300 closer to the bottom end is larger, and the generated inertia and tremor force are also larger. The cleaning strength of the filter screen 300 is adapted to the distribution of the impurities accumulated on the filter screen 300, further improving the slag cleaning effect of the filter screen 300.

[0058] Generally, the filter for removing impurities from the etching solution may further include a liquid discharging device 150.

[0059] The liquid discharging device 150 is provided on the outer periphery of the cylinder 100 and is connected to a liquid discharging port 160 provided at the bottom of the cylinder 100. The liquid discharging device 150 is configured to discharge the remaining etching solution in the cylinder 100 through the liquid discharging port 160 before the backwashing device 130 starts to work.

[0060] In the solution of this embodiment, the liquid discharge port 160 is arranged at the bottom of the cylinder body 100, and the pressure generated by the height difference is used to accelerate the discharge of the etching solution from the liquid discharge port 160, thereby improving the discharge efficiency of the etching solution. The liquid discharge device 150 is configured to discharge the remaining etching solution to be filtered in the cylinder body 100 before the backwashing device 130 starts backwashing, thereby avoiding the influence of the hydraulic pressure of the etching solution on the backwashing and ensuring the backwashing effect of the backwashing device 130.

[0061] In addition, after the filter screen 300 is cleaned, the etching solution discharged by the liquid discharge device 150 can be re-injected into the cylinder body 100 for filtration to avoid waste of the etching solution and improve the effective utilization rate of the etching solution.

[0062] In some embodiments, the liquid discharge device 150 can be configured as a liquid extraction pump, and the liquid extraction pump is used to extract the etching solution, further improving the liquid discharge efficiency. A liquid extraction pipe connected to the liquid discharge port 160 can be arranged in the cylinder body 100 to improve the discharge effect of the etching solution at the bottom of the cylinder body 100.

[0063] A limiting block 211 is formed on the inner wall surface of the fixed pipe 210 to limit the maximum moving distance of the moving pipe 220.

[0064] In the solution of this embodiment, by setting the limiting block 211, after the moving pipe 220 retracts to a certain distance, it abuts against the limiting block 211, thereby avoiding excessive retraction of the moving pipe 220.

[0065] In some preferred embodiments, the maximum retraction distance of the moving pipe 220 can be determined according to the degree of hardening of the filter residue on the filter screen 300. When the accumulation of the filter cake on the filter screen 300 seriously affects the filtration efficiency, the retraction distance of the moving pipe 220 can be set to the maximum retraction distance of the moving pipe 220 at this time.

[0066] In some embodiments, the limiting block 211 can be configured as an annular protrusion on the inner wall surface of the fixed pipe 210, so that the abutting force between the limiting block 211 and the moving pipe 220 is more evenly distributed, the abutting effect is better, and local excessive wear can also be avoided.

[0067] A sensing device 212 is also arranged on the limiting block 211 to monitor the position of the moving pipe 220.

[0068] The position of the moving pipe 220 reflects the degree of accumulation of the filter cake on the filter screen 300. The greater the retraction distance of the moving pipe 220, the more serious the accumulation of the filter cake.

[0069] In the solution of this embodiment, by providing a sensing device 212 to monitor the position of the moving pipe 220, the degree of accumulation of the filter cake on the filter screen 300 can be understood in real time, so as to determine the best timing for backwashing. The starting timing of the backwashing device 130 is determined according to the position of the moving pipe 220, which improves the intelligence level of the equipment, ensures the subsequent filtration effect, and avoids wasting time due to excessive cleaning, thereby improving the overall filtration efficiency.

[0070] After the moving pipe 220 retracts to abut against the limit block 211, it indicates that the filter cake has become very seriously caked at this time and must be cleaned. In some embodiments, only one liquid collecting pipe 200 is provided in the cylinder body 100. When it is detected that the moving pipe 220 moves to abut against the limit block 211, that is, the filtration effect and filtration efficiency of the liquid collecting pipe 200 can no longer meet the normal requirements, the filter cake is cleaned to ensure the subsequent filtration effect and filtration efficiency.

[0071] In other embodiments, a plurality of liquid collecting pipes 200 are provided in the cylinder body 100, and a sensing device 212 is provided on each liquid collecting pipe 200. When it is detected that most of the moving pipes 220 move to abut against the limit block 211, that is, the filtration effect and filtration efficiency of the filter for etching solution impurity removal can no longer meet the normal requirements, the filter cake is cleaned to ensure the subsequent filtration effect and filtration efficiency.

[0072] The liquid outlet 111 and the backwashing port 112 are arranged in parallel.

[0073] In the solution of this embodiment, the liquid outlet 111 and the backwashing port 112 are arranged in parallel, so that the liquid outlet and the backwashing do not interfere with each other, improving the structural rationality of the equipment and ensuring the normal operation of the liquid outlet and the backwashing.

[0074] In some preferred embodiments, the cylinder body 100 is arranged vertically along its axis, and the liquid collecting pipe 200 is also arranged vertically along its axis. The top end of the liquid collecting pipe 200 is connected to the communication pipeline 110, and the bottom end is communicated with the bottom end of the porous pipe 400 wound thereon, so that the liquid collecting pipe 200 can extract the filtered liquid from the bottom end, thereby ensuring that no matter how the liquid level line of the etching solution in the cylinder body 100 changes, the liquid collecting pipe 200 can extract the etching solution for filtration to the greatest extent, thereby ensuring the output efficiency of the filtered liquid of the filter for etching solution impurity removal.

[0075] A sealed cavity 230 is formed at one end of the liquid collecting pipe 200 away from the communication pipeline 110, and the ends of a plurality of porous pipes 400 are communicated with the sealed cavity 230.

[0076] In the solution of this embodiment, by providing a sealed cavity 230, the liquid collection pipe 200 extracts liquid from within the cavity, which not only makes the extraction of the etching liquid smoother, ensuring that the liquid collection pipe 200 is filled with liquid, but also enables the extraction of the filtered liquid output by other porous pipes 400 when the filter screen 300 on some of the porous pipes 400 becomes blocked, thus guaranteeing the extraction effect of the etching liquid.

[0077] In some embodiments, one end of the filter screen 300 close to the sealed cavity 230 can be fixedly connected to the wall surface of the sealed cavity 230. When the sealed cavity 230 moves downward under the backwashing effect, it can drive the filter screen 300 to expand, and after the filter screen 300 is fully expanded, a certain tremor force is applied to the filter screen 300, thereby improving the cleaning effect of the filter screen 300.

[0078] In some embodiments, the sealed cavity 230 as a whole can be cylindrical. A connector 240 can be provided between the liquid collection pipe 200 and the communication pipeline 110 to connect the liquid collection pipe 200 and the communication pipeline 110. Sealing rings can be provided between the connector 240, the liquid collection pipe 200, and the communication pipeline 110 to improve the sealing effect. The shape of the connector 240 can be adapted to the shape of the sealed cavity 230 (cylindrical), and one end of the filter screen 300 and the porous pipe 400 close to the communication pipeline 110 can both be fixedly connected to the connector 240 to improve the structural stability.

[0079] The filter for removing impurities from the etching liquid generally can also include a spraying device 170.

[0080] The spraying device 170 is provided at the top of the cylinder 100.

[0081] In the solution of this embodiment, by providing the spraying device 170, the filter residue on the filter screen 300 is washed with the sprayed water flow, thereby improving the cleaning effect of the filter screen 300 and increasing the discharge efficiency of the filter residue.

[0082] In some preferred embodiments, the spraying device 170 can include a plurality of spray nozzles 171, and the plurality of spray nozzles 171 are evenly distributed to further improve the cleaning effect. A cleaning port 172 is provided at the top of the cylinder 100 for injecting cleaning liquid into the spraying device 170. The cleaning liquid can be clean water.

[0083] A slag discharge port 180 is provided at the bottom of the cylinder 100, and an inverted conical inclined surface 181 is formed around the slag discharge port 180.

[0084] In the solution of this embodiment, by providing the slag discharge port 180 at the bottom of the cylinder 100 and providing the inverted conical inclined surface 181 around the slag discharge port 180, the filter residue converges along the inclined surface 181 to the slag discharge port 180 under the action of gravity, thereby increasing the discharge efficiency of the filter residue.

[0085] A baffle 182 that can be opened and closed is provided at the slag discharge port 180 for opening or shielding the slag discharge port 180.

[0086] The specific working process of the filter for removing impurities from the etching solution provided by the present invention will be described in combination with the above embodiments:

[0087] The etching solution enters the interior of the cylinder body 100 through the liquid inlet 190, is filtered through the filter screen 300, then enters the closed cavity 230 through the porous pipe 400, then enters the liquid collecting pipe 200, then flows into the connecting pipeline 110, and finally is discharged from the liquid outlet 111.

[0088] During the filtering process of the etching solution, impurities in the etching solution continuously accumulate on the filter screen 300 to form a filter cake. As the accumulation degree of the filter cake increases, the liquid permeability of the filter screen 300 becomes worse. Under the action of the hydraulic pressure and the negative pressure device 120, a negative pressure is formed in the liquid collecting pipe 200, causing the moving pipe 220 to retract, and driving the porous pipe 400 and the filter screen 300 to retract.

[0089] After it is detected by the sensing device 212 that most of the moving pipes 220 move to abut against the limit block 211, the injection of the etching solution into the cylinder body 100 is stopped, and the working state of the negative pressure device 120 is maintained. Then the liquid discharging device 150 is started to discharge the remaining etching solution in the cylinder body 100. After the remaining etching solution in the cylinder body 100 is discharged, the negative pressure device 120 is closed, and at the moment when the negative pressure device 120 stops working, the backwashing device 130 is started to inject gas into the liquid collecting pipe 200 for backwashing. Under the backwashing action, the moving pipe 220 extends, and drives the porous pipe 400 and the filter screen 300 to extend and vibrate, so that the filter cake accumulated on the filter screen 300 is broken and falls off. The spraying device 170 is started to spray and clean the filter screen 300 to wash away the filter residue. The filter residue is discharged from the slag discharge port 180 at the bottom of the cylinder body 100.

[0090] After the cleaning work of the filter screen 300 is completed and the filter residue is cleaned and discharged, the etching solution is re-injected for filtering.

[0091] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0092] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the appended claims.

Claims

1. A filter for removing impurities from an etching solution, characterized in that, Comprising: A cylinder body, on the side wall of which there is a communication pipeline for communicating the inside and the outside; At least one liquid collecting pipe, arranged in the cylinder body and connected to the communication pipeline; At least one filter screen, sleeved on the outer periphery of at least one of the liquid collecting pipes and arranged in one-to-one correspondence with at least one of the liquid collecting pipes; wherein, A plurality of porous pipes are arranged between each of the liquid collecting pipes and the corresponding filter screen, the plurality of porous pipes are spirally wound around the liquid collecting pipe, and each of the porous pipes is connected to the liquid collecting pipe; The porous pipe has elasticity and can expand and contract along the axial direction of the liquid collecting pipe; The liquid collecting pipe includes a fixed pipe and a movable pipe; one end of the fixed pipe is connected to the communication pipeline, and the other end is sleeved on the movable pipe; the movable pipe expands and contracts relative to the fixed pipe; when the porous pipe is wound around the liquid collecting pipe and does not retract, the length of the filter screen in the axial direction is greater than or equal to the length of the porous pipe in the axial direction; a limiting block is formed on the inner wall surface of the fixed pipe to limit the maximum retraction distance of the movable pipe, and a sensing device is also arranged on the limiting block to monitor the position of the movable pipe; the communication pipeline is connected with a liquid outlet and a backwashing port on the outer side of the cylinder body; a negative pressure device, connected to the liquid outlet; A backwashing device, connected to the backwashing port; and the backwashing device is configured to backwash the liquid collecting pipe after the negative pressure device stops working.

2. The filter for removing impurities from the etching solution according to claim 1, characterized in that, Further comprising: A liquid discharging device, arranged on the outer periphery of the cylinder body and connected to a liquid discharging port arranged at the bottom of the cylinder body; The liquid discharging device is configured to discharge the remaining etching solution in the cylinder body through the liquid discharging port before the backwashing device starts working.

3. The filter for removing impurities from etching solution according to claim 1, wherein The liquid outlet and the backwashing port are arranged in parallel.

4. The filter for removing impurities from etching solution according to claim 1, wherein One end of the liquid collecting pipe far away from the communication pipeline forms a sealed cavity, and the ends of the plurality of porous pipes are communicated with the sealed cavity.

5. The filter for removing impurities from the etching solution according to claim 1, wherein, Further comprising: A spraying device, arranged on the top of the cylinder body.

6. The filter for removing impurities from etching solution according to claim 1, wherein A slag discharging port is arranged at the bottom of the cylinder body, and an inclined surface in an inverted conical shape is formed around the slag discharging port.

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