Filter for impurity removal of etching liquid

Abstract

The invention relates to the technical field of impurity removal of etching liquid, and particularly provides a filter for impurity removal of etching liquid, comprising: a cylinder, the side wall of which is provided with a communicating pipeline communicating the inside and the outside; the at least one liquid collecting pipe is arranged in the cylinder body and is connected with the communicating pipeline; the at least one filter screen is arranged on the periphery of the at least one liquid collecting pipe in a sleeving manner and is in one-to-one correspondence with the at least one liquid collecting pipe; wherein a plurality of perforated pipes are arranged between each liquid collecting pipe and the corresponding filter screen, the plurality of perforated pipes are spirally wound on the liquid collecting pipe, and each perforated pipe is connected with the liquid collecting pipe; and the communicating pipeline is connected with a liquid outlet and a backflushing port on the outer side of the barrel. According to the scheme provided by the invention, the filter screen and the filter cakes accumulated on the filter screen form a corresponding spiral form by arranging the spirally wound porous pipe. Through back flushing, the filter screen expands from a spiral form to a cylindrical form, so that hardened filter cakes on the filter screen are broken and fall off, the slag removal effect is improved, and the subsequent filtering effect and filtering efficiency of the filter screen are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of etching liquid impurity removal, in particular to a filter for etching liquid impurity removal. Background Art

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

[0003] After the etching liquid has finished processing semiconductor devices (such as the chip of the RFID tag), the generated etching waste liquid often contains a large amount of solid impurities. In order to recycle the etching liquid for secondary use, the etching liquid is usually filtered using a filter. During the filtering process of the etching liquid, impurities will continue to accumulate on the filter to form a filter cake. When the filter cake reaches a certain level, it will affect the filtering effect and filtering efficiency of the filtering equipment. Therefore, the filter cake needs to be removed.

[0004] In existing filtering equipment, the filter element is usually set in a gear shape, so that the filter screen attached to the filter element forms a wave shape in the circumferential direction. After the filter cake is produced, the back-blowing technology is used to expand the gear-shaped filter screen into a circle to remove the filter cake. However, since the deformation of the filter screen at the wave crest is very small or even non-existent, the filter cake at the wave crest is difficult to fall off, and large pieces of long columnar filter cake still remain on the wave crest. Obviously, the existing filtering equipment has a poor slag removal effect, which seriously affects the subsequent filtering effect and filtering efficiency. Summary of the invention

[0005] An object of the present invention is to improve the cleaning effect of a filter for removing impurities from etching liquid.

[0006] In particular, the present invention provides a filter for removing impurities from etching liquid, comprising: a cylinder, a connecting pipeline connecting the inside and the outside is arranged on the side wall of which; at least one liquid collecting pipe is arranged in the cylinder and connected to the connecting pipeline; at least one filter screen is sleeved on the outer circumference of the at least one liquid collecting pipe and is arranged one-to-one with the at least one liquid collecting pipe; wherein a plurality of porous tubes are arranged between each liquid collecting pipe and the corresponding filter screen, the plurality of porous tubes are spirally wound on the liquid collecting pipe, and each porous tube is connected to the liquid collecting pipe; the connecting pipeline is connected to a liquid outlet and a recoil port on the outside of the cylinder.

[0007] Furthermore, the porous tube is elastic and can be expanded and contracted along the axial direction of the liquid collecting tube; the liquid collecting tube includes a fixed tube and a movable tube; one end of the fixed tube is connected to the connecting pipe, and the other end is sleeved on the movable tube; the movable tube is expanded and contracted relative to the fixed tube.

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

[0009] Furthermore, the filter for removing impurities from the etching liquid also includes: a drainage device, which is arranged on the outer periphery of the cylinder and connected to a drainage port arranged at the bottom of the cylinder; the drainage device is configured to discharge the remaining etching liquid in the cylinder through the drainage port before the recoil device starts working.

[0010] Furthermore, a limit block is formed on the inner wall surface of the fixed tube to limit the maximum retraction distance of the movable tube.

[0011] Furthermore, a sensor device is provided on the limit block to monitor the position of the moving tube.

[0012] Furthermore, the liquid outlet and the backwash outlet are arranged in parallel.

[0013] Furthermore, a closed cavity is formed at one end of the liquid collecting pipe away from the connecting pipeline, and the ends of the plurality of porous tubes are connected to the closed cavity.

[0014] Furthermore, the filter for removing impurities from the etching liquid also includes: a spray device, which is arranged on the top of the cylinder.

[0015] Furthermore, a slag discharge port is provided at the bottom of the cylinder, and an inverted cone-shaped inclined surface is formed around the slag discharge port.

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

[0017] The filter for removing impurities from etching liquid of the present invention is provided with a spirally wound porous tube between the liquid collecting pipe and the filter screen, so that in the process of discharging the etching liquid, the filter screen is pushed by the etching liquid and adheres to the porous tube to form a spiral mesh surface. The filter cake accumulated on the filter screen also forms a corresponding spiral shape. The filter cake in the spiral shape is easier to break and peel off both in the axial direction and in the circumferential direction, thereby reducing the difficulty of cleaning the filter screen. Through backwashing, the filter screen expands from a spiral shape to 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. Not only is the cleaning effect good, but the operation is also simple and convenient, ensuring the subsequent filtering effect and filtering efficiency of the filter screen.

[0018] Furthermore, in the filter for removing impurities from etching liquid 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 be deformed accordingly with the expansion and contraction of the porous tube and the liquid collecting tube. The filter screen can be embedded in the gap between the porous tubes when the porous tube and the liquid collecting tube retract. 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 recoil force, the filter screen expands in the radial direction, and the porous tube and the liquid collecting tube extend axially and drive the filter screen to extend. 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 recoil, 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 it easier for the filter residue to fall off the filter screen. At the same time, the vibration generated by pulling the filter screen after the porous tube and the liquid collecting tube extend to the limit distance further improves the slag cleaning effect and slag cleaning efficiency of the filter screen. The effective removal of the filter cake greatly improves the filtering effect and efficiency of the filter used for removing impurities from the etching solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts.

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

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

[0022] Figure 3 1 is a schematic structural diagram from another angle of a filter for removing impurities from etching liquid according to an embodiment of the present invention.

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

[0024] Figure 5 yes Figure 4 Schematic enlargement of region B.

[0025] Figure 6 yes Figure 4 Schematic enlargement of area C in the middle.

[0026] Among them: 100, cylinder; 110, connecting pipeline; 111, liquid outlet; 112, recoil port; 120, negative pressure device; 130, recoil device; 140, control valve; 150, discharge device; 160, discharge port; 170, spray device; 171, spray nozzle; 172, cleaning port; 180, slag discharge port; 181, inclined surface; 182, baffle; 190, liquid inlet; 200, liquid collecting pipe; 210, fixed pipe; 211, limit block; 212, sensor device; 220, movable pipe; 230, closed cavity; 240, adapter; 300, filter screen; 400, porous pipe; 500, base. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is 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] The terms "first" and "second" herein are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features, that is, include one or more of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. When a feature "includes or contains" one or some of the features it covers, unless otherwise specifically described, this indicates that other features are not excluded and may further include other features.

[0029] Unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. A person skilled in the art should be able to understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0030] It should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a 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, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0032] Refer to the following Figures 1 to 6 The present invention will now describe a filter for removing impurities from etching liquid.

[0033] Figure 1 The figure is a schematic diagram of the structure of a filter for removing impurities from etching liquid according to an embodiment of the present invention. Figure 2 The figure is a schematic diagram of an exploded view of a filter for removing impurities from etching liquid according to an embodiment of the present invention. Figure 3 1 is a schematic structural diagram from another angle of a filter for removing impurities from etching liquid according to an embodiment of the present invention. Figure 4 is along Figure 3 A schematic cross-sectional view taken along the cutting line AA in FIG. Figure 5 yes Figure 4 Schematic enlargement of region B. Figure 6 yes Figure 4 Schematic enlargement of area C in the middle.

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

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

[0036] In the solution of this embodiment, a spirally wound porous tube 400 is arranged between the liquid collecting pipe 200 and the filter screen 300, so that in the process of discharging the etching liquid, the filter screen 300 is pushed by the etching liquid 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. The filter screen 300 is cleaned by backwashing, which not only has a good cleaning effect, but also is simple and convenient to operate, ensuring the subsequent filtering effect and filtering efficiency of the filter screen 300.

[0037] The filter screen 300 can generally use filter cloth that is not elastic or has low elasticity, such as polyester filter cloth, nylon filter cloth, etc. After the filter screen 300 is subjected to recoil, it expands from a spiral shape to a cylindrical shape, causing the filter cake compacted thereon to deform, break and fall off. During the recoil process, the trough area of ​​the filter cake bulges radially outward under the action of the recoil force. In the process of the trough area of ​​the filter cake bulging outward, a thrust force that interacts with each other and is located on the tangent plane and perpendicular to the spiral line is generated inside the filter cake in the trough area. The extrusion force perpendicular to the spiral line is decomposed into an axial thrust force and a circumferential thrust force. Under the combined action of forces in the radial, axial and circumferential dimensions, the filter cake is not only more likely to break, but also the filter residue formed after the break is smaller in size and easier to peel off, thereby reducing the difficulty of cleaning the filter screen 300.

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

[0039] In some embodiments, a plurality of liquid collecting pipes 200 may be disposed in the cylinder 100 , and the plurality of liquid collecting pipes 200 are evenly distributed in the cylinder 100 to improve filtering effect and filtering efficiency.

[0040] The number of porous tubes 400 wrapped around each liquid collecting pipe 200 can be set according to demand. In some embodiments, the larger the size ratio between the liquid collecting pipe 200 and the porous tube 400, the more porous tubes 400 are set, so as to ensure that the efficiency of the porous tubes 400 in supplying the filtrate can meet the output efficiency of the liquid collecting pipe 200. In the solution of this embodiment, the number of porous tubes 400 is preferably set to 6.

[0041] like Figure 2 , 5As shown in FIG. 6 , in some embodiments, the ends of the multiple porous tubes 400 are wrapped together to form a circle. The central area of ​​the circle formed by the multiple porous tubes 400 can be used to place the liquid collecting pipe 200. The multiple 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] The top of the cylinder 100 may also be generally provided with a liquid inlet 190 for conveying the etching liquid to be filtered into the cylinder 100. The filter for removing impurities from the etching liquid may generally include a base 500. The base 500 is provided at the bottom of the cylinder 100 for supporting and fixing the cylinder 100.

[0043] The porous tube 400 is elastic and can be expanded and contracted 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 pipe 110, and the other end is sleeved on the movable tube 220; the movable tube 220 is expandable relative to the fixed tube 210.

[0044] In the scheme of this embodiment, the porous tube 400 is set as an elastic member, and the liquid collecting pipe 200 is set as a telescopic member, so that the filter screen 300 can be extended or retracted into the gap between the porous tubes 400 as the porous tubes 400 and the liquid collecting pipe 200 are extended. The greater the retraction amount of the porous tube 400 and the liquid collecting pipe 200, the greater the embedding amount of the filter screen 300 in the gap between the porous tubes 400. Under the action of the recoil force, the filter screen 300 expands in the radial direction, and the porous tube 400 and the liquid collecting pipe 200 extend in the axial direction and drive the filter screen 300 to extend. The greater the embedding amount of the filter screen 300 in the gap of the porous tube 400, the greater the expansion amount in the radial direction after recoil, 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 pipe 200 makes it easier for the filter residue to fall off the filter screen 300. At the same time, the vibration caused by the porous tube 400 and the liquid collecting pipe 200 pulling the filter screen 300 after being extended 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 removing impurities from the etching liquid.

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

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

[0047] In some embodiments, when the porous tube 400 is wound around the liquid collecting tube 200 and does not retract, the length of the filter screen 300 in the axial direction may be greater than or equal to the length of the porous tube 400 in the axial direction. This allows the filter screen 300 to be more embedded in the gaps between the porous tubes 400 when the porous tubes 400 retract. 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 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 recoil expansion, and the more conducive to peeling the filter cake.

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

[0049] The negative pressure device 120 is connected to the liquid outlet 111. The backflushing device 130 is connected to the backflushing port 112. The backflushing device 130 is configured to backflush the liquid collecting pipe 200 after the negative pressure device 120 stops working.

[0050] The scheme of this embodiment is to set a negative pressure device 120 at the liquid outlet 111, and use the negative pressure device 120 to extract the filtrate, so that the circulation of the filtrate is smoother, thereby improving the filtration efficiency. As the filter residue on the filter screen 300 continues to accumulate and harden, the liquid permeability of the filter screen 300 becomes worse and worse. Under the action of negative pressure, the porous tube 400 and the liquid collecting pipe 200 shrink axially, and the filter screen 300 shrinks accordingly and becomes closer to the porous tube 400. After the negative pressure device 120 stops working, the recoil device 130 is used to recoil the liquid collecting pipe 200, so that the porous tube 400 and the liquid collecting pipe 200 are transformed from the retracted state to the extended state. The inertia and vibration generated by the movement of the porous tube 400 and the liquid collecting pipe 200 are greater, and the deformation of the filter screen 300 is also greater, which further improves the slag removal effect.

[0051] In some preferred embodiments, the recoil device 130 is configured to recoil the liquid collecting pipe 200 at the moment when the negative pressure device 120 stops working. The liquid collecting pipe 200 and the porous pipe 400 are instantly transformed from the maximum retracted state to the maximum extended state, driving the filter screen 300 to produce the largest expansion and contraction change, and the generated inertia and vibration are also the largest, thereby further improving the slag cleaning effect and slag cleaning efficiency of the filter screen 300. The recoil device 130 injects gas into the connecting pipeline 110 to transform the liquid collecting pipe 200 from a negative pressure state to a positive pressure state, thereby pushing the moving pipe 200 to extend and driving the porous pipe 400 to extend, thereby achieving recoil.

[0052] In some embodiments, a plurality of control valves 140 may be provided on the communication pipeline 110 to respectively control the gas and liquid flow of the 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 structural stability.

[0053] In some embodiments, the filter for removing impurities from the etching liquid may also be provided with a pressurizing device to further improve the filtering efficiency by pressurizing the etching liquid in the barrel 100. The backflushing device 130 may be configured to backflush the liquid collecting pipe 200 at the moment when the pressurizing device and the negative pressure device 120 stop working at the same time.

[0054] In other embodiments, the filter for removing impurities from the etching liquid may be provided with only a pressurizing device (i.e., no negative pressure device 120 is provided), and the etching liquid in the cylinder 100 is pressurized to force the etching liquid to flow to the connecting pipeline through the collecting pipe 200 and then be discharged from the cylinder 100. Under the pressure of the pressurizing device, the etching liquid flows to the collecting pipe 200 through the filter screen 300, driving the filter screen 300 to be close to the porous tube 400. After the filter residue on the filter screen 300 is compacted to affect the liquid permeability of the filter screen 300, the collecting pipe 200 and the porous tube 400 shrink under the pressure of the pressurizing device. The recoil device 130 can be configured to recoil the collecting pipe 200 at the moment when the pressurizing device stops working.

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

[0056] Impurities in the etching solution will settle freely, so the closer the area on the filter screen 300 is to the bottom, the more impurities will accumulate.

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

[0058] The filter for removing impurities from the etching liquid may generally further include a drain device 150 .

[0059] The drain device 150 is disposed on the outer periphery of the barrel 100 and connected to a drain port 160 disposed at the bottom of the barrel 100. The drain device 150 is configured to drain the remaining etching liquid in the barrel 100 through the drain port 160 before the recoil device 130 starts to work.

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

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

[0062] In some embodiments, the liquid discharge device 150 can be configured as a liquid pump, which extracts the etching liquid using the liquid pump, further improving the liquid discharge efficiency. A liquid extraction pipe connected to the liquid discharge port 160 can be provided in the cylinder 100 to improve the discharge effect of the etching liquid at the bottom of the cylinder 100.

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

[0064] In the solution of this embodiment, by providing the limit block 211 , the moving tube 220 is caused to abut against the limit block 211 after being retracted to a certain distance, thereby preventing the moving tube 220 from excessively retracting.

[0065] In some preferred embodiments, the maximum retraction distance of the moving tube 220 can be determined according to the degree of compaction of the filter residue on the filter screen 300. When the filter cake accumulation on the filter screen 300 seriously affects the filtering efficiency, the retraction distance of the moving tube 220 can be set to the maximum retraction distance of the moving tube 220.

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

[0067] A sensor device 212 is also provided on the limit block 211 to monitor the position of the moving tube 220 .

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

[0069] The solution of this embodiment monitors the position of the mobile tube 220 by setting the sensor device 212, so that the accumulation degree of the filter cake on the filter screen 300 can be understood in real time, so as to determine the best time for backwashing. The start time of the backwashing device 130 is determined according to the position of the mobile tube 220, which improves the intelligence of the equipment, ensures the subsequent filtering effect, avoids excessive cleaning and wastes time, and thus improves the overall filtering efficiency.

[0070] After the moving tube 220 retracts to abut against the stop block 211, it indicates that the filter cake is severely compacted and must be cleaned. In some embodiments, only one collecting pipe 200 is provided in the cylinder 100. When it is detected that the moving tube 220 moves to abut against the stop block 211, that is, the filtering effect and filtering efficiency of the collecting pipe 200 cannot meet normal requirements, the filter cake is cleaned to ensure the subsequent filtering effect and filtering efficiency.

[0071] In other embodiments, a plurality of liquid collecting pipes 200 are provided in the cylinder 100, and a sensor device 212 is provided on each liquid collecting pipe 200. When it is detected that most of the movable pipes 220 have moved to abut against the limit block 211, that is, the filtering effect and filtering efficiency of the filter for removing impurities from the etching liquid cannot meet normal requirements, the filter cake is cleaned to ensure the subsequent filtering effect and filtering efficiency.

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

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

[0074] In some preferred embodiments, the cylinder 100 is vertically arranged along its axis, and the liquid collecting pipe 200 is also vertically arranged along its axis. The top of the liquid collecting pipe 200 is connected to the connecting pipe 110, and the bottom is connected to the bottom of the porous pipe 400 wound thereon, so that the liquid collecting pipe 200 can extract the filtrate from the bottom, thereby ensuring that no matter how the liquid level line of the etching liquid in the cylinder 100 changes, the liquid collecting pipe 200 can extract the etching liquid to the maximum extent for filtration, thereby ensuring the output efficiency of the filtrate of the filter for removing impurities from the etching liquid.

[0075] A sealed cavity 230 is formed at one end of the liquid collecting pipe 200 away from the connecting pipe 110 , and ends of the plurality of porous pipes 400 are connected to the sealed cavity 230 .

[0076] The solution of this embodiment, by providing a closed cavity 230, allows the liquid collecting pipe 200 to extract liquid from the cavity, which not only makes the extraction of etching liquid smoother and ensures that the liquid collecting pipe 200 is full of liquid, but also when the filter screen 300 on an individual porous tube 400 is blocked, the filtered liquid output by other porous tubes 400 can be extracted, thereby ensuring the extraction effect of etching liquid.

[0077] In some embodiments, one end of the filter 300 close to the closed cavity 230 can be fixedly connected to the wall of the closed cavity 230. When the closed cavity 230 moves downward under the recoil effect, it can drive the filter 300 to stretch, and after the filter 300 is fully stretched, a certain vibration force is applied to the filter 300, thereby improving the cleaning effect of the filter 300.

[0078] In some embodiments, the enclosed cavity 230 may be cylindrical as a whole. An adapter 240 may be provided between the liquid collecting pipe 200 and the connecting pipe 110 to connect the liquid collecting pipe 200 and the connecting pipe 110. A sealing ring may be provided between the adapter 240 and the liquid collecting pipe 200 and the connecting pipe 110 to improve the sealing effect. The shape of the adapter 240 may be adapted to the shape of the enclosed cavity 230 (cylindrical), and the filter screen 300 and the end of the porous pipe 400 close to the connecting pipe 110 may be fixedly connected to the adapter 240 to improve the structural stability.

[0079] The filter for removing impurities from the etching solution may generally further include a spray device 170 .

[0080] The spray device 170 is disposed at the top of the cylinder 100 .

[0081] The solution of this embodiment is to provide a spray device 170 to use the spraying water flow to wash the filter residue on the filter screen 300, thereby improving the cleaning effect of the filter screen 300 and improving the discharge efficiency of the filter residue.

[0082] In some preferred embodiments, the spray device 170 may 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 spray device 170. The cleaning liquid may 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] The solution of this embodiment is to set a slag discharge port 180 at the bottom of the cylinder 100 and set an inverted cone-shaped inclined surface 181 around the slag discharge port 180, so that the filter residue is gathered to the slag discharge port 180 along the inclined surface 181 under the action of gravity, thereby improving the discharge efficiency of the filter residue.

[0085] An openable and closable baffle 182 is provided at the slag discharge port 180 for opening or covering the slag discharge port 180 .

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

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

[0088] During the filtration process of the etching liquid, impurities in the etching liquid are continuously accumulated on the filter screen 300 to form a filter cake. As the accumulation of the filter cake increases, the liquid permeability of the filter screen 300 deteriorates. 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 the sensing device 212 detects that most of the moving tubes 220 move to the point where they collide with the limit block 211, the injection of etching liquid into the cylinder 100 is stopped, and the negative pressure device 120 is kept in working condition. Then the liquid discharge device 150 is started to discharge the remaining etching liquid in the cylinder 100. After the remaining etching liquid in the cylinder 100 is discharged, the negative pressure device 120 is closed, and at the moment when the negative pressure device 120 stops working, the recoil device 130 is started to inject gas into the liquid collecting pipe 200 for recoil. Under the recoil effect, the moving tube 220 extends, and drives the porous tube 400 and the filter screen 300 to stretch and vibrate, so that the filter cake accumulated on the filter screen 300 breaks and falls off. Start the spray device 170 to spray and clean the filter screen 300 to wash away the filter residue. The filter residue is discharged from the residue discharge port 180 at the bottom of the cylinder 100.

[0090] After the cleaning 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 may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0092] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A filter for removing impurities from etching liquid, characterized in that: include: The cylinder has a side wall provided with a connecting pipe connecting the inside and the outside; At least one liquid collecting pipe, arranged in the cylinder and connected to the connecting pipeline; At least one filter screen is sleeved on the outer periphery of at least one of the liquid collecting pipes and is arranged one-to-one with at least one of the liquid collecting pipes; wherein, A plurality of porous tubes are arranged between each of the liquid collecting pipes and the corresponding filter screen, the plurality of porous tubes are spirally wound on the liquid collecting pipe, and each of the porous tubes is connected to the liquid collecting pipe; The communicating pipeline is connected with a liquid outlet and a backwash port on the outside of the cylinder.

2. The filter for removing impurities from etching solution according to claim 1, characterized in that: The porous tube is elastic and can be expanded and contracted along the axial direction of the liquid collecting tube; The liquid collecting pipe comprises a fixed pipe and a movable pipe; one end of the fixed pipe is connected to the connecting pipe, and the other end is sleeved on the movable pipe; the movable pipe is telescopic relative to the fixed pipe.

3. The filter for removing impurities from etching liquid according to claim 2, characterized in that: Also includes: A negative pressure device connected to the liquid outlet; A recoil device connected to the recoil port; and The backflushing device is configured to backflush the liquid collecting pipe after the negative pressure device stops working.

4. The filter for removing impurities from etching liquid according to claim 3, characterized in that: Also includes: A liquid discharge device, arranged on the outer periphery of the cylinder and connected to a liquid discharge port arranged at the bottom of the cylinder; The liquid discharge device is configured to discharge the etching liquid remaining in the cylinder through the liquid discharge port before the recoil device starts to work.

5. The filter for removing impurities from etching liquid according to claim 2, characterized in that: A limit block is formed on the inner wall surface of the fixed tube to limit the maximum retraction distance of the movable tube.

6. The filter for removing impurities from etching liquid according to claim 5, characterized in that: The limit block is also provided with a sensor device to monitor the position of the moving tube.

7. The filter for removing impurities from etching solution according to claim 1, characterized in that: The liquid outlet and the backwash port are arranged in parallel.

8. The filter for removing impurities from etching liquid according to claim 1, characterized in that: A closed cavity is formed at one end of the liquid collecting pipe away from the connecting pipeline, and ends of the plurality of porous tubes are connected to the closed cavity.

9. The filter for removing impurities from etching solution according to claim 1, characterized in that: Also includes: The spray device is arranged on the top of the cylinder.

10. The filter for removing impurities from etching liquid according to claim 1, characterized in that: The bottom of the cylinder is provided with a slag discharge port, and an inverted cone-shaped inclined surface is formed around the slag discharge port.

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