Etching liquid purification device and purification method

Abstract

The invention discloses an etching liquid purification device and method, and relates to the technical field of etching liquid purification, the purification device comprises a stirring tank, a circulating device, a filtering device and a plurality of feeding pipelines, the plurality of feeding pipelines are communicated with a stirring tank pipeline, the plurality of feeding pipelines are arranged, and the materials are added according to the mass according to the formula requirement, so that the raw materials are fully mixed; when raw materials enter the stirring tank, the raw materials are automatically stirred, the outer circulation loop is opened through the circulation device, liquid in the stirring tank is pumped out and conveyed through the circulation pipe, mass transfer and primary heat exchange are promoted in the circulation process, and particulate matter in the liquid is removed by integrating the filtering device on the outer circulation loop. Such as soluble particles and poorly soluble particles.

Description

Technical Field

[0001] The present invention relates to the technical field of etching solution purification, and specifically to an etching solution purification device and a purification method. Background Art

[0002] Etching solution is a commonly used chemical reagent in the production process of PCB boards. It is generally divided into alkaline etching solution and acidic etching solution, and it completes engraving by eroding materials.

[0003] Currently, in the production process of existing etching solutions, it is necessary to first add raw materials in two states, solid and liquid, and then perform liquid mixing, carry out internal circulation mixing on the raw material liquid, generally filter and purify after mixing, and fill after purification is completed. In order to ensure production efficiency, an external circulation process can be adopted for mixing and purification integration. However, in the initial stage, the main process is mixing, and the added solid particles accumulate in the filter layer, affecting the efficiency of the initial external circulation.

[0004] In addition, since the solid small particles include soluble solids and insoluble impurities, they are easily deposited at the bottom of the filter layer. The conventional filtration mode is single, the fluid flow pattern is stable, and the force application direction on the solid particles is relatively fixed, thus affecting the stripping efficiency of the solid particles on the surface of the filter layer. Summary of the Invention

[0005] The purpose of the present invention is to provide an etching solution purification device and a purification method to solve the problems raised in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions: The purification device includes a stirring tank, a circulation device, a filtration device, and a plurality of feed pipelines. There are several feed pipelines, and the several feed pipelines are connected to the stirring tank through pipelines. There is a discharge port at the lower end of the stirring tank, and a feed port at the upper end of the stirring tank. The circulation device is connected to the discharge port of the stirring tank through a pipeline, and the liquid delivery end of the circulation device is connected to the feed port at the upper end of the stirring tank through a pipeline. The circulation device is located on the external circulation loop of the stirring tank, and the filtration device is located on the external circulation loop.

[0007] By setting several feed pipelines and adding according to the mass requirements of the formula, when the raw materials enter the stirring tank, automatic stirring is carried out, and the external circulation loop is opened through the circulation device. The liquid in the stirring tank is pumped out and transported through the circulation pipe. The circulation process itself also promotes mass transfer and preliminary heat exchange. By integrating the filtration device on the external circulation loop, particulate matters in the liquid, such as soluble particles and insoluble particles, are removed.

[0008] Further, the circulation device includes a circulation pump and a circulation pipe. One end of the circulation pump is connected to the discharge port of the stirring tank, and the other end is connected to the filtration device through a pipeline; The circulation pipe is a three-way pipe. An inlet, a circulation port, and an outlet are successively arranged on the circulation pipe. One end of the inlet is connected to the filtering device, and the other end of the inlet is respectively connected to the circulation port and the outlet. A stop valve is provided on the outlet, and the end of the circulation port is connected to the feed port of the stirring tank through a pipeline.

[0009] The circulation pump, as the main power source for liquid external circulation, is used to pump the liquid in the stirring tank into the filtering device through a pipeline for automatic filtration. After the filtration is completed, it enters the circulation pipe through the inlet. Among the three ports of the circulation pipe, one is for feeding, and the other two are for discharging liquid. When the solution does not meet the standard, the stop valve is closed at this time, and the solution is introduced into the stirring tank through the circulation port for continuous stirring; when the solution meets the standard, the stop valve is opened, and the solution is exported from the outlet for automatic filling.

[0010] Furthermore, the filtering device includes a housing, a folding plate, and a cabinet body. A receiving cavity is provided on the cabinet body, the housing is placed in the receiving cavity, a filtering cavity is provided on the housing, a liquid inlet is provided at the lower end of the filtering cavity, the circulation pump is connected to the liquid inlet through a pipeline, a liquid outlet is provided on one side of the filtering cavity, a filtering layer is provided in the filtering cavity, and the filtering layer divides the filtering cavity into a impurity filtering cavity and a purification cavity. The liquid inlet is connected to the impurity filtering cavity through a pipeline, and the liquid outlet is connected to the purification cavity through a pipeline.

[0011] The cabinet body adopts a door structure for easy opening for maintenance. The housing is installed by setting the receiving cavity. The housing provides a filtering space through the filtering cavity, and the filtering cavity is divided into cavities by setting the filtering layer, including an impurity filtering cavity facing the liquid inlet direction and a purification cavity that has been filtered. The liquid is pumped into the impurity filtering cavity by the circulation pump, the solid particles are filtered by the filtering layer and intercepted in the impurity filtering cavity, and the filtered liquid is discharged through the liquid outlet and enters the subsequent circulation.

[0012] Furthermore, the filtering device further includes a rotary motor. A driving cavity is provided on the housing, the rotary motor is placed in the driving cavity, the output end of the rotary motor is fixedly connected to the folding plate. The folding plate includes a bottom plate and a sub-rotating plate. The output end of the rotary motor is fixedly connected to the bottom plate, one end of the bottom plate far from the rotation center is rotatably connected to the sub-rotating plate, a wedge block is provided at the lower end of the sub-rotating plate, and sealing plates are respectively provided on both sides of the sub-rotating plate; Impurity filtering state: The bottom plate and the folding plate are in the same horizontal plane, the sealing plate contacts the side of the bottom plate, and the liquid inlet faces the bottom plate; Impurity removal state: The bottom plate and the folding plate are in a vertical state, one side of the wedge block abuts against the bottom plate, and the liquid inlet faces the sub-rotating plate.

[0013] The rotary motor is installed through the drive cavity. The rotary motor is used to output torque to drive the folding plate to rotate for form switching. The entire filtration process is divided into two states. The first state is the impurity filtration state when the bottom plate and the folding plate are in the same horizontal plane. The liquid is pumped into the impurity filtration cavity. Under the action of the pressure difference, the liquid penetrates towards the filtration layer to complete filtration and enters the purification cavity. As the filtration progresses, solid small particles continuously accumulate on the surface of the filtration layer, affecting the filtration rate. The bottom plate is driven to rotate by the rotary motor, causing the sub-rotating plate to rotate accordingly until the bottom plate and the folding plate are in a vertical state. At this time, one side of the wedge block remains in contact with the bottom plate, entering the impurity removal state. The sealing plates on both sides, the bottom plate, and the sub-rotating plate form a relatively sealed impurity removal space. At this time, liquid is pumped into the impurity removal space, making the incoming liquid flow disorderly, and automatically flushing the bottom of the filtration layer through local turbulent flow to avoid local blockage affecting the filtration efficiency.

[0014] Furthermore, the folding plate further includes an opening plate. An opening groove is provided on the bottom plate. One end of the opening groove is provided in a through manner, and an opening spring is provided in the other end of the opening groove. The opening plate is slidably connected to the opening groove. One end of the opening plate is fixedly connected to the opening spring. The opening spring is located at one end of the opening groove close to the sub-rotating plate. An impact liquid inclined surface is provided on the opening plate.

[0015] The opening groove is set in sections, including a bearing cavity for installing the opening spring and a through groove for guiding the flow. During impurity filtration, since the opening spring is in a horizontal state, under the elastic force, the opening plate retracts into the bearing cavity, enabling the liquid to continuously enter the impurity filtration cavity for continuous filtration. When entering the impurity removal state, the bottom plate gradually becomes vertical, and the opening plate moves under the action of gravity and blocks the through groove to form a relatively sealed impurity removal space. By setting the impact liquid inclined surface, when the liquid hits the inclined surface, it will push the opening plate towards the opening spring, facilitating the improvement of the automatic reset efficiency for continuous filtration.

[0016] Furthermore, the filtration device further includes an impurity removal component and a heating wire. The heating wire is placed inside the liquid inlet. The heating wire and the rotary motor are connected to the same signal source. The impurity removal component includes an extension plate and an extension spring. An extension groove is provided on the sub-rotating plate. Both ends of the extension spring are fixedly connected to the wall surface of the extension groove and one side of the extension plate respectively. The extension plate is slidably connected to the extension groove. The side of the extension plate away from the extension spring abuts against the filtration layer.

[0017] By setting up the heating wire, which is not electrified under normal conditions and is controlled by the same signal source as the rotary motor. When it is detected that the pressure in the impurity filtering chamber increases, that is, when the solid impurities locally block the filter layer, the mode is switched by the output torque of the rotary motor. At the same time, local heating is carried out through the heating wire to increase the solubility, so that the soluble solid small particles dissolve, assisting local flushing and improving the removal efficiency of impurities on the surface of the filter layer. The extension spring is installed through the extension groove. Under the action of the extension spring, the extension plate is pushed to abut against the filter layer. During the upward movement of the extension plate, the surface of the filter layer is preliminarily cleaned. After the preliminary cleaning is completed, the local turbulent flow flushing and local temperature increase are adopted to improve the removal efficiency of impurities on the surface of the filter layer.

[0018] As an optimization, the filtering device further includes a baffle tube. There are two shells. One end of the baffle tube is connected to the liquid outlet pipeline of the rear shell, and the other end is connected to the liquid inlet pipeline of the rear shell. By setting two shells and adopting the method of gradually decreasing the particle size, layer-by-layer filtration is carried out. By setting the baffle tube, the liquid outlet of the front section is connected, and the preliminarily filtered liquid is sent to the liquid inlet of the rear section for re-filtration to improve the filtration effect.

[0019] As an optimization, the circulating device further includes a booster pump. The end liquid outlet is connected to the inlet pipeline through the booster pump. By setting the booster pump, the filtered liquid is pumped into the mixing tank for circulation, and the circulation efficiency is improved by increasing the pressure difference.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The filtering process is divided into two states. The first state is the impurity filtering state when the bottom plate and the folding plate are on the same horizontal plane. The liquid is pumped into the impurity filtering chamber. Under the action of the pressure difference, the liquid penetrates towards the filter layer, completes filtration, and enters the purification chamber. As the filtration progresses, the solid small particles continuously accumulate on the surface of the filter layer, affecting the filtration rate. The bottom plate is driven to rotate by the rotary motor, so that the sub-rotating plate rotates accordingly until the bottom plate and the folding plate are in a vertical state. At this time, one side of the wedge block remains in contact with the bottom plate, and the impurity removal state is entered. The sealing plates on both sides, the bottom plate and the sub-rotating plate form a relatively sealed impurity removal space. At this time, liquid is pumped into the impurity removal space, so that the entering liquid flows disorderly, and the bottom of the filter layer is automatically flushed by local turbulent flow to avoid local blockage affecting the filtration efficiency. The mode is switched by the output torque of the rotary motor. At the same time, local heating is carried out through the heating wire to increase the solubility, so that the soluble solid small particles dissolve, assisting local flushing and improving the removal efficiency of impurities on the surface of the filter layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the overall structural schematic diagram of the present invention; Figure 2 is the structural schematic diagram of the filtering device of the present invention; Figure 3Schematic diagram of the housing structure of the present invention; Figure 4 Schematic diagram of the folding plate structure of the present invention; Figure 5 Schematic diagram of the impurity removal state of the present invention; Figure 6 Schematic diagram of the opening plate structure of the present invention; Figure 7 Schematic diagram of the power transmission for state switching of the present invention; Figure 8 is Figure 4 Partial enlarged view A of the view.

[0022] In the figure: 1, stirring tank; 2, circulation device; 21, circulation pump; 22, circulation pipe; 221, inlet; 222, circulation port; 223, outlet; 23, stop valve; 24, booster pump; 3, filtering device; 31, housing; 311, filtering chamber; 312, liquid inlet; 313, liquid outlet; 314, drive chamber; 32, folding plate; 321, bottom plate; 3211, opening slot; 322, dividing rotating plate; 3221, extension slot; 323, opening plate; 3231, liquid impact slope; 324, opening spring; 325, sealing plate; 326, wedge block; 33, impurity removal component; 331, extension plate; 332, extension spring; 34, rotary motor; 35, baffle pipe; 36, heating wire; 37, cabinet; 38, filter layer; 4, feed pipeline. Specific embodiments

[0023] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0024] Embodiment: As Figures 1-8 shown, the present invention provides a technical solution for an etching solution purification device and a purification method.

[0025] The purification device includes a stirring tank 1, a circulation device 2, a filtering device 3 and a feed pipeline 4. There are several feed pipelines 4, and several feed pipelines 4 are in pipeline communication with the stirring tank 1. The lower end of the stirring tank 1 is provided with a discharge port, the upper end of the stirring tank 1 is provided with a feed port. The circulation device 2 is in pipeline communication with the discharge port of the stirring tank 1, the liquid delivery end of the circulation device 2 is in pipeline communication with the feed port at the upper end of the stirring tank 1. The circulation device 2 is located on the outer circulation loop of the stirring tank 1, and the filtering device 3 is located on the outer circulation loop.

[0026] By setting up a number of feed pipelines 4, the raw materials are added according to the mass as required by the formula. When the raw materials enter the mixing tank 1, they are automatically stirred, and the external circulation loop is opened through the circulation device 2 to extract the liquid in the mixing tank 1 and transport it through the circulation pipe. The circulation process itself also promotes mass transfer and preliminary heat exchange. By integrating the filtering device 3 on the external circulation loop, particulate matter in the liquid, such as soluble particles and insoluble particles, is removed.

[0027] Furthermore, the circulation device 2 includes a circulation pump 21 and a circulation pipe 22, one end of the circulation pump 21 is connected to the discharge port of the stirring tank 1, and the other end is connected to the pipeline of the filtering device 3; The circulation pipe 22 is a three-way pipe, and an inlet 221, a circulation port 222 and an outlet 223 are sequentially arranged on the circulation pipe 22. One end of the inlet 221 is connected to the filtering device 3, and the other end of the inlet 221 is respectively connected to the circulation port 222 and the outlet 223. A stop valve 23 is arranged on the outlet 223, and the end of the circulation port 222 is connected to the feed port pipeline of the stirring tank 1.

[0028] The circulation pump 21 serves as the main power source for the external circulation of the liquid, and is used to pump the liquid in the stirring tank 1 to the filtering device 3 through a pipeline for automatic filtration. After the filtration is completed, the liquid enters the circulation pipe 22 through the inlet 221. The circulation pipe 22 has three ports, one of which is used for feeding and the other two are used for discharging the liquid. When the solution has not yet reached the standard, the stop valve 23 is closed, and the solution is introduced into the stirring tank 1 through the circulation port 222 for continued stirring; when the solution reaches the standard, the stop valve 23 is opened, and the solution is led out from the outlet 223 for automatic filling.

[0029] Furthermore, the filtering device 3 includes a shell 31, a folding plate 32, and a cabinet 37. The cabinet 37 is provided with a accommodating cavity, the shell 31 is placed in the accommodating cavity, the shell 31 is provided with a filter cavity 311, the lower end of the filter cavity 311 is provided with a liquid inlet 312, the circulating pump 21 is connected to the liquid inlet 312 by a pipeline, a liquid outlet 313 is provided on one side of the filter cavity 311, a filter layer 38 is provided in the filter cavity 311, the filter layer 38 divides the filter cavity 311 into a filter cavity and a purification cavity, the liquid inlet 312 is connected to the filter cavity pipeline, and the liquid outlet 313 is connected to the purification cavity pipeline.

[0030] The cabinet 37 adopts a door structure, which is convenient for opening for maintenance. The shell 31 is installed by setting a receiving chamber. The shell 31 provides a filtering space through the filter chamber 311, and the filter chamber 311 is divided into chambers by setting a filter layer 38, including a filter chamber facing the liquid inlet direction and a purification chamber where filtering has been completed. The liquid is pumped into the filter chamber by the circulation pump 21, and the solid particles are filtered by the filter layer 38 and intercepted in the filter chamber. The filtered liquid is discharged through the liquid outlet 313 and enters the subsequent circulation.

[0031] Further, the filtering device 3 further includes a rotary motor 34. A driving cavity 314 is provided on the housing 31. The rotary motor 34 is placed in the driving cavity 314. The output end of the rotary motor 34 is fixedly connected to the folding plate 32. The folding plate 32 includes a bottom plate 321 and a split rotating plate 322. The output end of the rotary motor 34 is fixedly connected to the bottom plate 321. One end of the bottom plate 321 away from the rotation center is rotatably connected to the split rotating plate 322. A wedge block 326 is provided at the lower end of the split rotating plate 322. Sealing plates 325 are respectively provided on both sides of the split rotating plate 322; Impurity filtering state: The bottom plate 321 and the folding plate 32 are in the same horizontal plane. The sealing plate 325 contacts the side of the bottom plate 321. The liquid inlet 312 faces the bottom plate 321; Impurity removal state: The bottom plate 321 and the folding plate 32 are in a vertical state. One side of the wedge block 326 abuts against the bottom plate 321. The liquid inlet 312 faces the split rotating plate 322.

[0032] The rotary motor 34 is installed through the driving cavity 314. The rotary motor 34 is used to output torque to drive the folding plate 32 to rotate for state switching. The whole filtering process is divided into two states. The first state is the impurity filtering state when the bottom plate 321 and the folding plate 32 are in the same horizontal plane. The liquid is pumped into the impurity filtering cavity. Under the action of the pressure difference, the liquid penetrates towards the filter layer 38 to complete the filtering and enters the purification cavity; As the filtering progresses, solid small particles continuously accumulate on the surface of the filter layer, affecting the filtering rate. The rotary motor 34 drives the bottom plate 321 to rotate, causing the split rotating plate 322 to rotate accordingly until the bottom plate 321 and the folding plate 32 are in a vertical state. At this time, one side of the wedge block 326 remains in contact with the bottom plate 321, entering the impurity removal state. The sealing plates 325, the bottom plate 321 and the split rotating plate 322 on both sides form a relatively sealed impurity removal space. At this time, liquid is pumped into the impurity removal space, making the incoming liquid flow disorderly, and automatically flushing the bottom of the filter layer 38 through local turbulent flow to avoid local blockage affecting the filtering efficiency.

[0033] Further, the folding plate 32 further includes an opening plate 323. An opening groove 3211 is provided on the bottom plate 321. One end of the opening groove 3211 is provided with a through hole. An opening spring 324 is provided at the other end of the opening groove 3211. The opening plate 323 is slidably connected to the opening groove 3211. One end of the opening plate 323 is fixedly connected to the opening spring 324. The opening spring 324 is located at one end of the opening groove 3211 close to the split rotating plate 322. A liquid flushing inclined surface 3231 is provided on the opening plate 323.

[0034] The opening slot 3211 is set in sections, including a bearing cavity for installing the opening spring 324 and a through slot for guiding the flow. When filtering impurities, since the opening spring 324 is in a horizontal state, under the elastic force, the opening plate 323 retracts into the bearing cavity, allowing the liquid to continuously enter the filtering cavity for continuous filtration. When entering the impurity removal state, the bottom plate 321 gradually tends to be vertical, and the opening plate 323 moves under the action of gravity and blocks the through slot, forming a relatively sealed impurity removal space. By setting the flushing inclined surface 3231, when the liquid hits the inclined surface, it will push the opening plate 323 towards the opening spring 324, facilitating the improvement of the automatic reset efficiency for continuous filtration.

[0035] Furthermore, the filtering device 3 further includes an impurity removal component 33 and a heating wire 36. The heating wire 36 is placed inside the liquid inlet 312, and the heating wire 36 and the rotary motor 34 are connected to the same signal source. The impurity removal component 33 includes an extension plate 331 and an extension spring 332. An extension slot 3221 is provided on the split rotating plate 322. The two ends of the extension spring 332 are respectively fastened to the wall surface of the extension slot 3221 and one side of the extension plate 331. The extension plate 331 is slidably connected to the extension slot 3221, and the side of the extension plate 331 away from the extension spring 332 abuts against the filter layer 38.

[0036] By setting the heating wire 36, it is not energized under normal conditions and is controlled by the same signal source as the rotary motor 34. When it is detected that the pressure in the filtering cavity increases, that is, when the solid impurities locally block the filter layer 38, the mode is switched by the output torque of the rotary motor 34, and at the same time, local heating is carried out through the heating wire 36 to increase the solubility, so that the soluble solid small particles dissolve, assisting local flushing and improving the efficiency of removing impurities on the surface of the filter layer 38. By installing the extension spring 332 through the extension slot 3221, under the action of the extension spring 332, the extension plate 331 is pushed to abut against the filter layer 38. During the upward movement of the extension plate 331, the surface of the filter layer 38 is preliminarily cleaned. After the preliminary cleaning is completed, the method of local turbulent flow flushing and local temperature increase is adopted to improve the efficiency of removing impurities on the surface of the filter layer 38.

[0037] As an optimization, the filtering device 3 further includes a baffle tube 35. There are two housing 31. One end of the baffle tube 35 is connected to the liquid outlet 313 of the rear housing 31 through a pipeline, and the other end is connected to the liquid inlet 312 of the rear housing 31 through a pipeline. By setting two housing 31 and adopting the method of gradually decreasing the particle size for layer-by-layer filtration, by setting the baffle tube 35, the liquid outlet 313 of the front section is connected, and the preliminarily filtered liquid is sent to the liquid inlet 312 of the rear section for re-filtration to improve the filtration effect.

[0038] As an optimization, the circulation device 2 further includes a booster pump 24, and the end liquid outlet 313 is connected to the inlet 221 through a pipeline of the booster pump 24. By setting the booster pump 24 to assist in pumping the filtered liquid into the stirring tank 1 for circulation, the circulation efficiency is improved by increasing the pressure difference.

[0039] The purification method includes the following steps: S1. Inject raw materials into the stirring tank 1 through multiple feed pipelines 4 and conduct preliminary stirring.

[0040] S2. Guide the etching solution in the stirring tank 1 into the housing 31 through the circulation pump 21.

[0041] S3. Filter through the filter layer 38.

[0042] S4. Dissolve the soluble solids through heating and local shear flow.

[0043] S5. When the detected liquid index meets the standard, open the stop valve 23 to automatically fill the liquid.

[0044] The working principle of the present invention: The filtration process is divided into two states. The first state is the impurity filtration state when the bottom plate 321 and the folding plate 32 are at the same horizontal plane. The liquid is pumped into the impurity filtration chamber. Under the action of the pressure difference, the liquid penetrates towards the filter layer 38 to complete filtration and enters the purification chamber. As the filtration progresses, solid small particles continuously accumulate on the surface of the filter layer, affecting the filtration rate. The bottom plate 321 is driven to rotate by the rotary motor 34, causing the split rotating plate 322 to rotate accordingly until the bottom plate 321 and the folding plate 32 are in a vertical state. At this time, one side of the wedge block 326 remains in contact with the bottom plate 321, entering the impurity removal state. The sealing plates 325, the bottom plate 321, and the split rotating plate 322 on both sides form a relatively sealed impurity removal space. At this time, liquid is pumped into the impurity removal space, making the entering liquid flow disorderly, and automatically flushing the bottom of the filter layer 38 through local turbulent flow to avoid local blockage affecting the filtration efficiency. The mode is switched by the torque output of the rotary motor 34, and at the same time, local heating is performed through the heating wire 36 to increase the solubility, so that the soluble solid small particles are dissolved, assisting the local flushing and improving the impurity removal efficiency on the surface of the filter layer 38.

[0045] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An etching solution purification device, characterized in that: The purification device includes a stirring tank (1), a circulation device (2), a filtering device (3), and a feed pipeline (4). There are several feed pipelines (4), and the several feed pipelines (4) are connected to the stirring tank (1) through pipelines. The lower end of the stirring tank (1) is provided with a discharge port, and the upper end of the stirring tank (1) is provided with a feed port. The circulation device (2) is connected to the discharge port of the stirring tank (1) through a pipeline, and the liquid delivery end of the circulation device (2) is connected to the feed port at the upper end of the stirring tank (1) through a pipeline. The circulation device (2) is located on the outer circulation loop of the stirring tank (1), and the filtering device (3) is located on the outer circulation loop.

2. The etching solution purification device according to claim 1, wherein: The circulation device (2) includes a circulation pump (21) and a circulation pipe (22). One end of the circulation pump (21) is connected to the discharge port of the stirring tank (1), and the other end is connected to the filtering device (3) through a pipeline; The circulation pipe (22) is a three-way pipe. An inlet (221), a circulation port (222), and an outlet (223) are successively arranged on the circulation pipe (22). One end of the inlet (221) is connected to the filtering device (3), and the other end of the inlet (221) is respectively connected to the circulation port (222) and the outlet (223). A stop valve (23) is arranged on the outlet (223), and the end of the circulation port (222) is connected to the feed port of the stirring tank (1) through a pipeline.

3. The etching solution purification device according to claim 2, characterized in that: The filtering device (3) includes a housing (31), a folding plate (32), and a cabinet body (37). A receiving cavity is arranged on the cabinet body (37), and the housing (31) is placed in the receiving cavity. A filtering cavity (311) is arranged on the housing (31). A liquid inlet (312) is arranged at the lower end of the filtering cavity (311). The circulation pump (21) is connected to the liquid inlet (312) through a pipeline. A liquid outlet (313) is arranged on one side of the filtering cavity (311). A filtering layer (38) is arranged in the filtering cavity (311). The filtering layer (38) divides the filtering cavity (311) into a impurity filtering cavity and a purification cavity. The liquid inlet (312) is connected to the impurity filtering cavity through a pipeline, and the liquid outlet (313) is connected to the purification cavity through a pipeline.

4. An etching solution purification device according to claim 3, characterized in that: The filtering device (3) further includes a rotary motor (34). A driving cavity (314) is arranged on the housing (31). The rotary motor (34) is placed in the driving cavity (314). The output end of the rotary motor (34) is fixedly connected to the folding plate (32). The folding plate (32) includes a bottom plate (321) and a split rotating plate (322). The output end of the rotary motor (34) is fixedly connected to the bottom plate (321). One end of the bottom plate (321) far from the rotation center is rotatably connected to the split rotating plate (322). A wedge block (326) is arranged at the lower end of the split rotating plate (322), and sealing plates (325) are respectively arranged on both sides of the split rotating plate (322); Impurity filtering state: The bottom plate (321) and the folding plate (32) are in the same horizontal plane. The sealing plate (325) is in contact with the side of the bottom plate (321). The liquid inlet (312) faces the bottom plate (321); Impurity removal state: The bottom plate (321) and the folding plate (32) are in a vertical state. One side of the wedge block (326) abuts against the bottom plate (321), and the liquid inlet (312) faces the sub-rotating plate (322).

5. An etching solution purification device according to claim 4, characterized in that: The folding plate (32) further includes an opening plate (323). An opening groove (3211) is provided on the bottom plate (321). One end of the opening groove (3211) is provided with a through hole, and an opening spring (324) is arranged at the other end of the opening groove (3211). The opening plate (323) is slidably connected to the opening groove (3211). One end of the opening plate (323) is fixedly connected to the opening spring (324). The opening spring (324) is located at one end of the opening groove (3211) close to the sub-rotating plate (322). A liquid flushing inclined surface (3231) is provided on the opening plate (323).

6. The etching solution purification device according to claim 5, characterized in that: The filtering device (3) further includes an impurity removal assembly (33) and a heating wire (36). The heating wire (36) is placed in the liquid inlet (312). The heating wire (36) and the rotary motor (34) are connected to the same signal source. The impurity removal assembly (33) includes an extension plate (331) and an extension spring (332). An extension groove (3221) is provided on the sub-rotating plate (322). Both ends of the extension spring (332) are fixedly connected to the wall surface of the extension groove (3221) and one side of the extension plate (331). The extension plate (331) is slidably connected to the extension groove (3221). The side of the extension plate (331) away from the extension spring (332) abuts against the filter layer (38).

7. An etching solution purification device according to claim 6, characterized in that: The filtering device (3) further includes a baffle tube (35). There are two housings (31). One end of the baffle tube (35) is in pipeline communication with the liquid outlet (313) of the rear-stage housing (31), and the other end is in pipeline communication with the liquid inlet (312) of the rear-stage housing (31).

8. An etching solution purification device according to claim 7, characterized in that: The circulation device (2) further includes a booster pump (24). The liquid outlet (313) at the end is in pipeline communication with the inlet (221) through the booster pump (24).

9. The purification method of an etching solution purification device according to claim 8, characterized in that: The purification method includes the following steps: S1. Feeding; S2. External circulation; S3. Filtration; S4. Local forced dissolution; S5. Filling.

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