A grinding fluid recycling device and its recycling method

Abstract

The present invention discloses a grinding fluid recovery and recycling device and a recovery and recycling method thereof. The recovery and recycling device includes a liquid collection module and a process module. The liquid collection module is used for recovering the grinding fluid on the grinding pad. The liquid collection module is provided with a liquid collection bucket. The first water outlet end of the liquid collection bucket is communicated with the second water inlet end of the liquid collection bucket through a circulation pipe. A first circulation pump and a filtration component are sequentially arranged on the circulation pipe along the flow path of the liquid therein. The process module is used for removing excessive deionized water in the recovered grinding fluid. The process module is communicated with the second water outlet end of the liquid collection bucket through a first delivery pipe. The first water outlet end of the process module is communicated with a liquid supply pipe for delivering the grinding fluid to the grinding pad. The present invention can effectively prevent the abrasives in the grinding fluid recovered into the liquid collection bucket from precipitating and aggregating into large particles, realizing the function of effectively and sustainably recovering and recycling the grinding fluid without affecting the grinding effect, and reducing the grinding cost.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical mechanical polishing, and particularly relates to a polishing liquid recovery and recycling device and a recovery and recycling method thereof. Background Art

[0002] In the production process of ultra-large scale integrated circuit chips, the importance of the planarization process has gradually emerged. As the only core technology that can perform global planarization of silicon wafers so far, chemical mechanical planarization (CMP) technology plays a crucial role in the field of chip manufacturing.

[0003] The main process of CMP can be generally summarized as follows: the polishing liquid generates physical and chemical effects with the wafer on the polishing pad, oxidizes the thin layer on the surface of the wafer, the oxidized surface becomes significantly softer, and then the abrasive in the polishing liquid peels it off from the surface and takes it away, thereby achieving planarization of the wafer surface. In the process of CMP, the main cost is the polishing liquid, accounting for about 60% of the total cost of CMP. Therefore, it is necessary to recycle the polishing liquid.

[0004] The recovery and recycling method of most existing polishing liquid recovery devices is as follows: the polishing liquid remaining after reacting with the wafer on the polishing pad, polishing waste, polishing pad debris, and deionized water are all poured into a temporary storage bucket for the polishing liquid to be recycled. Then, this kind of polishing liquid will be driven by a conveying device and passed through one or several of a coarse filter and a fine filter, and then transported to the polishing pad to react with the wafer. However, in the process of recycling the polishing liquid by the existing polishing liquid recovery device, the abrasive in the polishing liquid placed in the temporary storage bucket is easy to precipitate and agglomerate into large particles, and the precipitated and agglomerated large particles of abrasive will be continuously filtered out during the recovery and recycling process, so that the amount of abrasive in the polishing liquid gradually decreases as the number of filtrations increases, resulting in the need to discard the polishing liquid after recycling the polishing liquid a certain number of times, causing a large amount of waste. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the polishing liquid recovery device in the prior art needs to discard the polishing liquid after recycling the polishing liquid a certain number of times, resulting in a large amount of waste, so as to provide a polishing liquid recovery and recycling device and a recovery and recycling method thereof.

[0006] According to a polishing liquid recovery and recycling device provided by the first aspect of the present invention, it includes:

[0007] A liquid collection module for recovering the polishing liquid on the polishing pad. The liquid collection module is provided with a liquid collection bucket. The first water outlet end of the liquid collection bucket is connected to the second water inlet end of the liquid collection bucket through a circulation pipe. A first circulation pump and a filtering component are sequentially arranged on the circulation pipe along the flow path of the liquid therein;

[0008] A process module is used to remove excessive deionized water from the recycled abrasive slurry. The process module is connected to the second water outlet end of the liquid collecting bucket through a first delivery pipe, and a liquid supply pipe for delivering the abrasive slurry to the polishing pad is connected to the first water outlet end of the process module.

[0009] A kind of abrasive slurry recycling and circulating device according to the present invention has at least the following technical effects: 1. By connecting a circulation pipe between the first water outlet end and the second water inlet end of the liquid collecting bucket, when the liquid level height of the abrasive slurry recovered in the liquid collecting bucket reaches the first set height but does not reach the second set height for delivering the recovered abrasive slurry to the process module, start the first circulation pump to drive the abrasive slurry recovered in the liquid collecting bucket to circulate; ensure that during the process of recovering and placing the abrasive slurry in the liquid collecting bucket, it can effectively avoid the abrasives in the abrasive slurry recovered in the liquid collecting bucket from precipitating and agglomerating into large particles and being filtered by the filtering component, ensure the content of the abrasives in the abrasive slurry, and realize the function of effectively and sustainably recycling and using the abrasive slurry without affecting the polishing effect, reducing the polishing cost. 2. By providing a filtering component on the circulation pipe, large particle impurities in the abrasive slurry can be removed while driving the abrasive slurry recovered in the liquid collecting bucket to circulate, without the need to additionally configure a pipeline for removing impurities, making the device more miniaturized. 3. By connecting a process module between the second water outlet end of the liquid collecting bucket and the liquid supply pipe, during the process of the recovered abrasive slurry flowing through the process module, the excessive deionized water contained therein can be effectively removed, so that the concentration of the recovered abrasive slurry is restored to the concentration range required for normal polishing, and thus the abrasive slurry can be effectively and sustainably recycled and used without affecting the polishing effect, reducing the polishing cost.

[0010] Preferably, a first lower liquid level sensor is arranged at the lower inner side of the liquid collecting bucket, the first lower liquid level sensor is electrically connected to a controller, and the controller is electrically connected to the first circulation pump; and / or, a first electromagnetic valve for controlling its on-off is arranged on the first delivery pipe, and the first electromagnetic valve is electrically connected to the controller; a first upper liquid level sensor is arranged at the upper inner side of the liquid collecting bucket, and the first upper liquid level sensor is electrically connected to the controller.

[0011] Preferably, the process module includes a process bucket arranged between the first delivery pipe and the liquid supply pipe; the second water outlet end of the process bucket is connected to an ultrafiltration membrane filtration component through a second delivery pipe, and an ultrafiltration pump is arranged on the second delivery pipe; the ultrafiltration membrane filtration component is used to remove excessive deionized water from the recycled abrasive slurry, and the reflux end of the ultrafiltration membrane filtration component is connected to the process bucket.

[0012] Preferably, a self - circulation component for driving the circulating flow of the abrasive slurry is provided on the process barrel; a partition plate is arranged along the height direction inside the process barrel, and the partition plate divides the interior of the process barrel into a chamber A and a chamber B; the chamber A is communicated with the first delivery pipe, and the chamber B is communicated with the liquid supply pipe; the self - circulation component includes a stirring component arranged in the chamber A and a circulating delivery pipe communicating with the interior of the chamber B, and a second circulation pump is arranged on the circulating delivery pipe.

[0013] Preferably, a liquid supplement module communicated with the water inlet end of the process module through a third delivery pipe is further included, and the liquid supplement module is used for adjusting the concentration and pH value of the recycled abrasive slurry.

[0014] Preferably, the liquid supplement module includes a pH adjustment barrel for storing acid - base additives and an abrasive slurry supply barrel for storing new abrasive slurry. The pH adjustment barrel is communicated with the third delivery pipe through a fourth delivery pipe, and a second electromagnetic valve for controlling its on - off is arranged on the fourth delivery pipe; the abrasive slurry supply barrel is communicated with the third delivery pipe through a fifth delivery pipe, and a third electromagnetic valve for controlling its on - off is arranged on the fifth delivery pipe.

[0015] Preferably, a pH sensor for detecting the pH value of the recycled abrasive slurry and a first density sensor for detecting the concentration of the recycled abrasive slurry are arranged inside the process module. Both the pH sensor and the first density sensor are electrically connected to the same controller, and the controller is electrically connected to the second electromagnetic valve and the third electromagnetic valve.

[0016] A recycling and circulation method provided according to the second aspect of the present invention is applied to the abrasive slurry recycling and circulation device provided in the first aspect above. The recycling and circulation method includes the following steps:

[0017] Collect the abrasive slurry on the polishing pad back into the liquid collection barrel through the liquid return pipeline. When the liquid level of the recycled abrasive slurry in the liquid collection barrel reaches the first set height, start the first circulation pump to drive the recycled abrasive slurry to flow through the filter component along the circulation pipe in a circulating manner;

[0018] When the liquid level of the recycled abrasive slurry in the liquid collection barrel reaches the second set height, transport the recycled abrasive slurry through the first delivery pipe to the process module to remove excessive deionized water;

[0019] Transport the abrasive slurry after removing excessive deionized water back to the polishing pad through the liquid supply pipe.

[0020] A method for recycling and circulating abrasive slurry using the abrasive slurry recycling and circulation device according to the present invention has at least the following technical effects:

[0021] 1. A circulation pipe is connected between the first water outlet end and the second water inlet end of the liquid collection bucket. When the liquid level height of the abrasive slurry recovered into the liquid collection bucket reaches the first set height but does not reach the second set height for transporting the recovered abrasive slurry to the process module, the first circulation pump is started to drive the abrasive slurry recovered into the liquid collection bucket to circulate; ensuring that during the process of recovering and placing the abrasive slurry in the liquid collection bucket but before transporting it to the process module, it is possible to effectively prevent the abrasives in the abrasive slurry recovered into the liquid collection bucket from precipitating and agglomerating into large particles and being filtered by the filter assembly, ensuring the content of abrasives in the abrasive slurry, and realizing the function of effectively and sustainably recycling the abrasive slurry without affecting the grinding effect, reducing the grinding cost. 2. By providing a filter assembly on the circulation pipe, large particle impurities in the abrasive slurry can be removed while driving the abrasive slurry recovered in the liquid collection bucket to circulate, without the need to additionally configure a separate impurity removal pipeline, further simplifying the recovery and circulation process. 3. By connecting a process module between the second water outlet end of the liquid collection bucket and the supply pipe, during the process of the recovered abrasive slurry flowing through the process module, the excessive deionized water contained therein can be effectively removed, so that the concentration of the recovered abrasive slurry is restored to the concentration range required for normal grinding, thereby enabling the effective and sustainable recycling of the abrasive slurry without affecting the grinding effect, reducing the grinding cost.

[0022] Preferably, before the recovered abrasive slurry is transported back to the polishing pad through the supply pipe, the pH value and concentration of the recovered abrasive slurry are detected and compared with the set range; if the detected value is not within the set range, acid-base additives or fresh abrasive slurry are transported into the recovered abrasive slurry in the process module through the liquid supplement module for mixing until the detected values of the pH value and concentration of the recovered abrasive slurry are restored to the set range.

[0023] Preferably, the process module includes a process barrel, and a partition plate is arranged inside the process barrel to divide its interior into an A chamber and a B chamber. The A chamber is connected to the first delivery pipe, and the B chamber is connected to the supply pipe; the water outlet end of the A chamber is connected to an ultrafiltration membrane filter assembly through a second delivery pipe, an ultrafiltration pump is arranged on the second delivery pipe, the reflux end of the ultrafiltration membrane filter assembly is connected to a reflux pipe, and the water outlet end of the reflux pipe is respectively connected to the A chamber and the B chamber; a second density sensor for detecting the concentration of the abrasive slurry flowing through the interior of the reflux pipe is arranged inside the reflux pipe; during the process of removing the excessive deionized water in the abrasive slurry, the concentration of the abrasive slurry flowing through the interior of the reflux pipe is detected and compared with the set range. If the detected value is lower than the set range, the abrasive slurry that has been treated to remove the excessive deionized water is transported back to the A chamber; if the detected value reaches the set range, the abrasive slurry that has been treated to remove the excessive deionized water is transported to the B chamber.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 It is a schematic structural diagram of a grinding fluid recovery and circulation device according to an embodiment of the present invention;

[0027] Figure 2 It is a schematic structural diagram of a liquid collection module according to an embodiment of the present invention;

[0028] Figure 3 It is a schematic structural diagram of a process module according to an embodiment of the present invention;

[0029] Figure 4 It is a schematic structural diagram of a liquid replenishment module according to an embodiment of the present invention.

[0030] Description of the reference numerals:

[0031] 1 - Liquid collection module, 11 - Liquid collection barrel, 111 - First lower liquid level sensor, 12 - Circulation pipe, 13 - First circulation pump, 14 - First delivery pipe, 15 - First solenoid valve, 16 - First upper liquid level sensor, 171 - First coarse filter, 172 - Second fine filter, 18 - First drainage pipeline, 181 - Fourth solenoid valve, 182 - First upper limit liquid level sensor;

[0032] 2 - Grinding pad, 21 - Liquid return pipeline;

[0033] 3 - Process module, 31 - Liquid supply pipe, 311 - Third fine filter, 32 - Process barrel, 321 - Partition plate, 322 - A chamber, 323 - B chamber, 33 - Second delivery pipe, 34 - Ultrafiltration pump, 351 - Stirring assembly, 352 - Circulation delivery pipe, 353 - Second circulation pump, 354 - Second lower liquid level sensor, 355 - Third lower liquid level sensor, 356 - Second upper liquid level sensor, 357 - Third upper liquid level sensor, 361 - pH sensor, 362 - First density sensor, 37 - Second drainage pipeline, 371 - Fifth solenoid valve, 372 - Second upper limit liquid level sensor, 373 - Third upper limit liquid level sensor;

[0034] 4 - Ultrafiltration membrane filtration module, 41 - Return pipe, 42 - Second density sensor, 43 - Circulation pipeline, 44 - Sixth delivery pipe, 441 - Sixth solenoid valve, 45 - Seventh delivery pipe, 451 - Seventh solenoid valve;

[0035] 5 - Liquid supplement module, 51 - Third delivery pipe, 52 - pH - adjustment barrel, 53 - Abrasive liquid supply barrel, 54 - Fourth delivery pipe, 541 - Second solenoid valve, 55 - Fifth delivery pipe, 551 - Third solenoid valve. Detailed implementation manners

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is 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 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 of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0039] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] Embodiment 1

[0041] As Figures 1 to 3Shown is a polishing liquid recovery and recycling device provided by this embodiment, including a liquid collection module 1 and a process module 3. The liquid collection module 1 is used to recover the polishing liquid on the polishing pad 2. The liquid collection module 1 is provided with a liquid collection bucket 11. The first water outlet end of the liquid collection bucket 11 is connected to the second water inlet end of the liquid collection bucket 11 through a circulation pipe 12. Along the flow path of the liquid flowing through the inside of the circulation pipe 12, a first circulation pump 13 and a filtration component are sequentially arranged on the circulation pipe 12. The process module 3 is used to remove excessive deionized water in the recovered polishing liquid. The process module 3 is connected to the second water outlet end of the liquid collection bucket 11 through a first delivery pipe 14. A liquid supply pipe 31 for delivering the polishing liquid to the polishing pad 2 is connected to the first water outlet end of the process module 3.

[0042] Compared with the prior art, in the embodiment of the present invention, a circulation pipe 12 is connected between the first water outlet end and the second water inlet end of the liquid collection bucket 11. When the liquid level height of the polishing liquid recovered in the liquid collection bucket 11 reaches the first set height but does not reach the second set height for delivering the recovered polishing liquid to the process module 3, the first circulation pump 13 is started to drive the polishing liquid recovered in the liquid collection bucket 11 to circulate. It is ensured that during the process before the polishing liquid is recovered and placed in the liquid collection bucket 11 but not delivered to the process module 3, the abrasives in the polishing liquid recovered in the liquid collection bucket 11 can be effectively prevented from precipitating and agglomerating into large particles and being filtered by the filtration component, ensuring the content of abrasives in the polishing liquid, and realizing the function of effectively and sustainably recycling the polishing liquid without affecting the polishing effect, reducing the polishing cost. At the same time, by arranging a filtration component on the circulation pipe 12, large particle impurities in the polishing liquid can be removed while driving the polishing liquid recovered in the liquid collection bucket 11 to circulate, without the need to additionally configure an impurity removal pipeline, making the device more miniaturized. Also, by connecting a process module 3 between the second water outlet end of the liquid collection bucket 11 and the liquid supply pipe 31, during the process of the recovered polishing liquid flowing through the process module 3, the excessive deionized water contained in the polishing liquid can be effectively removed, enabling the recovered polishing liquid to be concentrated, so that the concentration of the recovered polishing liquid is restored to the concentration range required for normal polishing. Furthermore, the polishing liquid can be effectively and sustainably recycled without affecting the polishing effect. Compared with the existing recovery device that discards the whole polishing liquid after recycling it a certain number of times, the recovery and recycling device in the embodiment of the present invention can greatly reduce the polishing cost.

[0043] As Figure 2As shown in the figure, specifically, the filtering assembly includes a first coarse filter 171 and a second fine filter 172 arranged in sequence along the flow path of the liquid in the circulation pipe 12. The filtering precision of the first coarse filter 171 is preferably between 75 microns and 95 microns, which is convenient for initially filtering out large particle impurities in the recycled grinding liquid. The filtering precision of the second fine filter 172 is preferably between 10 microns and 25 microns, which is convenient for further filtering out large particle impurities in the recycled grinding liquid that have been initially filtered, more effectively removing large particle impurities in the recycled grinding liquid, and being able to more effectively avoid clogging of subsequent pipelines. It can be understood that, according to the actual grinding working conditions, in other embodiments, the filtering assembly may include three, four or five filters with different filtering precisions.

[0044] As Figure 2 shown, in some embodiments of the present invention, a first lower liquid level sensor 111 is arranged at the lower inner side of the liquid collecting bucket 11. The first lower liquid level sensor 111 is electrically connected to a controller, and the controller is electrically connected to the first circulation pump 13. Through the first lower liquid level sensor 111, the liquid level height of the grinding liquid recovered into the liquid collecting bucket 11 can be monitored in real time online, ensuring that when the liquid level height of the grinding liquid recovered into the liquid collecting bucket 11 reaches the first set height, the first lower liquid level sensor 111 accurately transmits a signal to the controller, and the controller controls the first circulation pump 13 to start and drive the grinding liquid recovered into the liquid collecting bucket 11 to circulate, effectively avoiding the abrasives in the grinding liquid recovered into the liquid collecting bucket 11 from precipitating and agglomerating into large particles and being filtered by the filtering assembly, and ensuring the content of abrasives in the grinding liquid. It should be noted that the controller uses a commonly used type of PLC controller on the existing market.

[0045] As Figure 1 and Figure 2 shown, specifically, two first solenoid valves 15 are arranged on the first delivery pipe 14. The first solenoid valves 15 are electrically connected to the controller. A first upper liquid level sensor 16 is arranged at the upper inner side of the liquid collecting bucket 11. The first upper liquid level sensor 16 is electrically connected to the controller. Through the first upper liquid level sensor 16, the liquid level height of the grinding liquid recovered into the liquid collecting bucket 11 can be monitored in real time online, ensuring that when the liquid level height of the grinding liquid recovered into the liquid collecting bucket 11 reaches the second set height, the first upper liquid level sensor 16 accurately transmits a signal to the controller, and the controller controls the first solenoid valves 15 to start and convey the grinding liquid recovered into the liquid collecting bucket 11 to the process module 3, ensuring the automatic and smooth progress of the recovery and circulation process. It can be understood that the number of the first solenoid valves 15 here is only a preference. In other embodiments, according to the length dimension of the first delivery pipe 14, the first solenoid valves 15 can be set to one, three or four or other numbers.

[0046] AsFigure 2 As shown, specifically, the liquid collecting bucket 11 is communicated with a first liquid discharging pipeline 18, and a fourth electromagnetic valve 181 electrically connected to the controller is arranged on the first liquid discharging pipeline 18; a first upper limit liquid level sensor 182 is arranged above the first upper liquid level sensor 16 on the inner side of the liquid collecting bucket 11, and the first upper limit liquid level sensor 182 is electrically connected to the controller. The first upper limit liquid level sensor 182 can be used to monitor in real time and online the liquid level height of the grinding liquid collected in the liquid collecting bucket 11, so as to ensure that when the liquid level height of the grinding liquid collected in the liquid collecting bucket 11 rises to the critical height for triggering the first upper limit liquid level sensor 182 due to over-collection or malfunction of the first upper liquid level sensor 16, the first upper limit liquid level sensor 182 accurately transmits a signal to the controller, and the controller controls the fourth electromagnetic valve 181 to open, so that the first liquid discharging pipeline 18 is communicated to timely discharge the grinding liquid exceeding the critical height, effectively avoiding the operation of the device in a non-safe state.

[0047] As Figure 2 shown, more specifically, two first upper limit liquid level sensors 182 are arranged, and the two first upper limit liquid level sensors 182 are arranged at intervals along the height direction of the liquid collecting bucket 11 at the upper end of the inner side of the liquid collecting bucket 11. The two first upper limit liquid level sensors 182 can play a role of mutual replacement. When one of the first upper limit liquid level sensors 182 is damaged, the other first upper limit liquid level sensor 182 can replace it to achieve the same function, further improving the reliability of the safety monitoring of the device. It should be understood that the height direction described in this embodiment refers to the up and down direction based on the Figure 2 viewpoint shown. [[ID=[]]

[0048] As Figure 3As shown, in some embodiments of the present invention, the process module 3 includes a process barrel 32 disposed between the first delivery pipe 14 and the liquid supply pipe 31; the ultrafiltration membrane filtration assembly 4 is provided with a water inlet end and a reflux end. The water inlet end of the ultrafiltration membrane filtration assembly 4 is connected to the second water outlet end of the process barrel 32 through a second delivery pipe 33. An ultrafiltration pump 34 is provided on the second delivery pipe 33. The reflux end of the ultrafiltration membrane filtration assembly 4 is communicated with the water inlet end of the process barrel 32. The second delivery pipe 33 constitutes a concentration loop. During the process of concentrating the recovered grinding fluid by removing excessive deionized water, the grinding fluid in the process barrel 32 is pumped through the second delivery pipe 33 by the ultrafiltration pump 34 to the ultrafiltration membrane filtration assembly 4. Under the action of pressure, the deionized water in the grinding fluid permeates through the ultrafiltration membrane of the ultrafiltration membrane filtration assembly 4, so that the grinding fluid is concentrated. The solution containing abrasive that does not permeate through the ultrafiltration membrane flows back to the process barrel 32 through the reflux end, thereby restoring the concentration of the recovered grinding fluid to the concentration range required for normal grinding, so that the grinding fluid can be effectively recycled sustainably without affecting the grinding effect, reducing the grinding cost.

[0049] Specifically, the ultrafiltration membrane filtration assembly 4 is further provided with a permeation end. A circulation pipeline 43 is connected to the permeation end of the ultrafiltration membrane filtration assembly 4. An osmosis barrel (not shown in the figure) and a backwashing pump (not shown in the figure) are sequentially provided on the circulation pipeline 43. During the process of concentrating the recovered grinding fluid by removing excessive deionized water, the solution permeating through the ultrafiltration membrane enters the osmosis barrel through the circulation pipeline 43; when it is necessary to backwash the ultrafiltration membrane in the ultrafiltration membrane filtration assembly 4 after a period of use, the backwashing pump is started to pump out the solution in the osmosis barrel to backwash the ultrafiltration membrane filtration assembly 4 to ensure the continuous and efficient operation of the filter membrane and improve the concentration treatment efficiency.

[0050] As Figure 3As shown, in some embodiments of the present invention, a self-circulation component for driving the circulating flow of the abrasive slurry is provided on the process barrel 32; a partition plate 321 is arranged along the height direction inside the process barrel 32, and the partition plate 321 divides the interior of the process barrel 32 into an A chamber 322 and a B chamber 323; the A chamber 322 is communicated with the first delivery pipe 14, and the B chamber 323 is communicated with the liquid supply pipe 31; the self-circulation component includes a stirring component 351 arranged in the A chamber 322 and a circulating delivery pipe 352 communicating with the interior of the B chamber 323, and a second circulation pump 353 is arranged on the circulating delivery pipe 352. By driving the abrasive slurry recovered into the A chamber 322 to stir and flow through the stirring component 351 and driving the abrasive slurry recovered into the B chamber 323 to circulate and flow by starting the second circulation pump 353, it is possible to effectively prevent the abrasives in the abrasive slurry recovered into the process barrel 32 from precipitating and aggregating into large particles, ensure the content of the abrasives in the abrasive slurry, and further ensure that the abrasive slurry can be effectively recycled sustainably without affecting the grinding effect, reducing the grinding cost. At the same time, by driving the abrasive slurry recovered into the B chamber 323 to circulate and flow, compared with stirring and flowing, it is more convenient to convey the abrasive slurry recovered into the B chamber 323 to the grinding pad 2 through the liquid supply pipe 31. It can be understood that according to the actual use needs, connecting a circulating delivery pipe 352 with a second circulation pump 353 to the A chamber 322 and arranging a stirring component 351 in the B chamber 323 can also achieve substantially the same effect as the above embodiments. It should be understood that the height direction described in this embodiment refers to the up and down direction based on Figure 3 the perspective shown.

[0051] As Figure 3 shown, specifically, a second lower liquid level sensor 354 is arranged at the lower inner side of the A chamber 322, the second lower liquid level sensor 354 is electrically connected to a controller, and the controller is electrically connected to the stirring component 351. Through the second lower liquid level sensor 354, the liquid level height of the abrasive slurry recovered into the A chamber 322 can be monitored in real time and online, ensuring that when the liquid level height of the abrasive slurry recovered into the A chamber 322 reaches the third set height in the A chamber 322, the second lower liquid level sensor 354 accurately transmits a signal to the controller, and the controller controls the stirring component 351 to start and drive the abrasive slurry recovered into the A chamber 322 to stir and flow, effectively preventing the abrasives in the abrasive slurry recovered into the A chamber 322 from precipitating and aggregating into large particles, ensuring the content of the abrasives in the abrasive slurry, and realizing the function of effectively recycling the abrasive slurry sustainably without affecting the grinding effect, reducing the grinding cost.

[0052] As Figure 3As shown, specifically, a second upper liquid level sensor 356 is provided at the upper inner side of the A chamber 322, and the second upper liquid level sensor 356 is electrically connected to the controller. Through the real-time monitoring of the second upper liquid level sensor 356, the liquid level height of the abrasive liquid recovered into the A chamber 322 can be monitored in real time online, ensuring that when the liquid level height of the abrasive liquid recovered into the A chamber 322 reaches the fourth set height in the A chamber 322, the second upper liquid level sensor 356 accurately transmits a signal to the controller, ensuring that when a set amount of abrasive liquid is filled in the A chamber 322, the abrasive liquid recovered into the A chamber 322 is conveyed to the next process, ensuring the automatic and smooth progress of the recovery and circulation process.

[0053] As Figure 3 shown, specifically, a third lower liquid level sensor 355 is provided at the lower inner side of the B chamber 323, the third lower liquid level sensor 355 is electrically connected to the controller, and the controller is electrically connected to the second circulation pump 353. Through the third lower liquid level sensor 355, the liquid level height of the abrasive liquid recovered into the B chamber 323 can be monitored in real time online, ensuring that when the liquid level height of the abrasive liquid recovered into the B chamber 323 reaches the fifth set height in the B chamber 323, the third lower liquid level sensor 355 accurately transmits a signal to the controller, and the controller controls the second circulation pump 353 to start and drive the abrasive liquid recovered into the B chamber 323 to circulate along the circulation delivery pipe 352, effectively avoiding the abrasives in the abrasive liquid recovered into the B chamber 323 from precipitating and aggregating into large particles, ensuring the content of the abrasives in the abrasive liquid, and realizing the function of effectively recycling the abrasive liquid sustainably without affecting the grinding effect, reducing the grinding cost.

[0054] As Figure 3 shown, specifically, a third upper liquid level sensor 357 is provided at the upper inner side of the B chamber 323, and the third upper liquid level sensor 357 is electrically connected to the controller. Through the third upper liquid level sensor 357, the liquid level height of the abrasive liquid recovered into the B chamber 323 can be monitored in real time online, ensuring that when the liquid level height of the abrasive liquid recovered into the B chamber 323 reaches the sixth set height, the third upper liquid level sensor 357 accurately transmits a signal to the controller, and the controller controls the liquid supply pipe 31 to be connected to convey the abrasive liquid recovered into the B chamber 323 to the grinding pad 2, ensuring the automatic and smooth progress of the recovery and circulation process.

[0055] As Figure 3As shown, specifically, the B chamber 323 is connected to a second liquid discharge pipeline 37, and a fifth solenoid valve 371 electrically connected to the controller is provided on the second liquid discharge pipeline 37; a second upper liquid level sensor 372 is provided above the third upper liquid level sensor 357 on the inner side of the B chamber 323, and the second upper liquid level sensor 372 is electrically connected to the controller. The second upper liquid level sensor 372 can be used to monitor in real time and online the liquid level height of the abrasive liquid recovered into the B chamber 323, ensuring that when the liquid level height of the abrasive liquid recovered into the B chamber 323 rises to the critical height triggering the second upper liquid level sensor 372 due to over-collection or malfunction of the third upper liquid level sensor 357, the second upper liquid level sensor 372 accurately transmits a signal to the controller, and the controller controls the fifth solenoid valve 371 to open, so that the second liquid discharge pipeline 37 is connected to timely discharge the abrasive liquid exceeding the critical height, effectively avoiding the operation of this device in a non-safe state.

[0056] As Figure 3 shown, more specifically, two second upper liquid level sensors 372 are provided, and the two second upper liquid level sensors 372 are arranged at intervals along the height direction of the liquid collection barrel 11 at the upper end inside the B chamber 323. The two second upper liquid level sensors 372 can play a role of mutual replacement. When one of the second upper liquid level sensors 372 is damaged, the other second upper liquid level sensor 372 can replace it to achieve the same function, further improving the reliability of the safety monitoring of this device.

[0057] As Figure 3 shown, specifically, in order to ensure that when the liquid level of the abrasive liquid recovered into the A chamber 322 exceeds the critical height, it can also be timely discharged through the second liquid discharge pipeline 37, the projection of the partition plate 321 in the horizontal direction falls within the range of the inner wall of the process barrel 32. It should be understood that the horizontal direction described in this embodiment refers to the front-back direction based on Figure 3 the perspective shown.

[0058] Specifically, in order to further improve the reliability of the safety monitoring of this device, two third upper liquid level sensors 373 are provided at intervals above the second upper liquid level sensor 356 on the inner side of the A chamber 322, and the two third upper liquid level sensors 373 are electrically connected to the controller. It can be understood that the third upper liquid level sensor 373 and the second upper liquid level sensor 372 are of the same model of liquid level sensor.

[0059] Considering that in the recycled abrasive liquid in the process barrel 32, under the cyclic flow of the self-circulation assembly, there may still be a very small amount of abrasives that precipitate and agglomerate into large particles; in order to ensure the subsequent grinding effect, as Figure 1 and Figure 3As shown, in some embodiments of the present invention, a number of third fine filtration filters 311 are provided on the liquid supply pipe 31. The filtration accuracy of the third fine filtration filter 311 is preferably three to seven microns, facilitating the removal of large particle impurities in the abrasive liquid before it is recycled back to the polishing pad 2 to ensure the polishing effect. It should be noted that the "number of" mentioned in this embodiment refers to one or two or more.

[0060] As Figure 1 As shown, in some embodiments of the present invention, the device further includes a liquid supplement module 5 connected to the water inlet end of the process module 3 through a third delivery pipe 51. When it is detected that the pH value and concentration of the recycled abrasive liquid after concentration treatment by removing excessive deionized water are not within the set range, the pH value and concentration of the recycled abrasive liquid can be adjusted to the set range by adding acid-base additives and fresh abrasive liquid into the process module 3 through the liquid supplement module 5, ensuring the particle concentration of abrasives and the like in the abrasive liquid, and further ensuring the effective sustainable recycling of the abrasive liquid without affecting the polishing effect, thereby reducing the polishing cost. It can be understood that the fresh abrasive liquid mentioned in this embodiment refers to the abrasive liquid that has not been used for polishing, and the concentration of the fresh abrasive liquid is higher than the set concentration range in the recycling process.

[0061] As Figure 4 Specifically, as shown, the liquid supplement module 5 includes a pH adjustment barrel 52 for storing acid-base additives and an abrasive liquid supply barrel 53 for storing fresh abrasive liquid. The pH adjustment barrel 52 is connected to the third delivery pipe 51 through a fourth delivery pipe 54, and a second solenoid valve 541 for controlling the on-off of the fourth delivery pipe 54 is provided on the fourth delivery pipe 54; the abrasive liquid supply barrel 53 is connected to the third delivery pipe 51 through a fifth delivery pipe 55, and a third solenoid valve 551 for controlling the on-off of the fifth delivery pipe 55 is provided on the fifth delivery pipe 55. The pH adjustment barrel 52 and the abrasive liquid supply barrel 53 are respectively connected to the process module 3 through the fourth delivery pipe 54 and the fifth delivery pipe 55, so that when it is detected that the pH value or concentration of the recycled abrasive liquid after concentration treatment by removing excessive deionized water is not within the set range, the acid-base additives can be added into the process module 3 through the connection of the fourth delivery pipe 54 to react with the concentrated abrasive liquid to adjust the pH value of the recycled abrasive liquid back to the set range; or the fresh abrasive liquid can be added into the process module 3 through the connection of the fifth delivery pipe 55 to mix with the concentrated abrasive liquid to adjust the concentration of the recycled abrasive liquid back to the set range. It can be understood that the liquid outlet end of the abrasive liquid supply barrel 53 is also connected to the polishing pad 2 through a pipeline to supply abrasive liquid to the polishing pad 2 during the initial use.

[0062] As Figure 3As shown, specifically, a pH sensor 361 for detecting the pH value of the recycled abrasive slurry and a first density sensor 362 for detecting the concentration of the recycled abrasive slurry are disposed in the B chamber 323. The pH sensor 361 and the first density sensor 362 are both electrically connected to the same controller, and the controller is electrically connected to the second solenoid valve 541 and the third solenoid valve 551. Through the real-time detection of the pH sensor 361, the pH value of the abrasive slurry recovered into the B chamber 323 can be monitored online, ensuring that when the pH value of the abrasive slurry in the B chamber 323 is not within the set pH value range, the controller controls the second solenoid valve 541 to open, so that the fourth delivery pipe 54 communicates to add acid-base additives into the B chamber 323 to mix and react with the concentrated abrasive slurry to adjust the pH value of the recycled abrasive slurry back to the set range. At the same time, through the real-time monitoring of the first density sensor 362, the concentration of the abrasive slurry recovered into the B chamber 323 can be monitored online in real time, ensuring that when the concentration of the abrasive slurry recovered into the B chamber 323 is lower than the concentration set range detected by the first density sensor 362, the controller controls the third solenoid valve 551 to open, so that the fifth delivery pipe 55 communicates to add new abrasive slurry into the B chamber 323 to mix with the concentrated abrasive slurry to adjust the concentration of the recycled abrasive slurry back to the set range. Realize the real-time online monitoring and adjustment of the concentration and pH value of the recycled abrasive slurry.

[0063] As Figure 3As shown, more specifically, the water outlet end of the A chamber 322 is communicated with the second delivery pipe 33, and the B chamber 323 is respectively communicated with the third delivery pipe 51 and the replenishment module 5; the return end of the ultrafiltration membrane filtration assembly 4 is communicated with a return pipe 41, and the water outlet end of the return pipe 41 is respectively communicated with the A chamber 322 and the B chamber 323. A second density sensor 42 for detecting the concentration of the abrasive liquid flowing through the inside of the return pipe 41 is arranged in the return pipe 41, and the second density sensor 42 is electrically connected to the controller. During the process of concentrating the abrasive liquid recovered in the A chamber 322 by removing excessive deionized water, the second density sensor 42 detects the concentration of the concentrated abrasive liquid flowing through the inside of the return pipe 41 and compares it with a set range. If the detected value is lower than the set range, the abrasive liquid that has been concentrated by removing excessive deionized water is transported back into the A chamber 322 for continuous circulating concentration treatment; if the detected value reaches the set range, the abrasive liquid that has been treated by removing excessive deionized water is transported into the B chamber 323 to ensure that the concentration of the recovered abrasive liquid transported into the B chamber 323 reaches the concentration set range detected by the second density sensor 42, thereby ensuring the particle concentration of abrasives and the like in the recycled abrasive liquid, realizing the function of effectively and sustainably recycling the abrasive liquid without affecting the grinding effect, and reducing the grinding cost. At the same time, by connecting the B chamber 323 to the replenishment module 5, when it is detected that the concentration of the abrasive liquid concentrated and recovered in the B chamber 323 is not within the concentration set range (this concentration set range is the concentration set range detected by the first density sensor 362, and the lower limit value of this concentration set range is higher than the lower limit value of the concentration set range detected by the second density sensor 42), new abrasive liquid can be added into the B chamber 323 through the replenishment module 5 to adjust the concentration of the recovered abrasive liquid to within the set range, so that the particle concentration of abrasives and the like in the abrasive liquid circulated and transported back to the grinding pad 2 is higher than the concentration set range detected by the second density sensor 42, ensuring that the concentration of the abrasive liquid recovered after being used for grinding again will fall within the set range detected by the second density sensor 42 after being concentrated by the ultrafiltration membrane filtration assembly 4. Through the mutual cooperation of the first density sensor 362 and the second density sensor 42, the accuracy of the control range of the abrasive liquid concentration can be greatly improved, avoiding the situation that the concentration of the recovered abrasive liquid always fails to reach the concentration set range detected by the second density sensor 42 after being concentrated by the ultrafiltration membrane filtration assembly 4, resulting in the inability to transport the recovered abrasive liquid into the B chamber 323, thereby affecting the normal progress of the recycling process.

[0064] Specifically, the water outlet end of the reflux pipe 41 is communicated with the A chamber 322 and the B chamber 323 through a sixth delivery pipe 44 and a seventh delivery pipe 45 respectively. A sixth electromagnetic valve 441 is provided on the sixth delivery pipe 44, and a seventh electromagnetic valve 451 is provided on the seventh delivery pipe 45. Both the sixth electromagnetic valve 441 and the seventh electromagnetic valve 451 are electrically connected to the same controller. It can be understood that the controllers described in this embodiment are all the same controller.

[0065] Embodiment 2

[0066] As Figures 1 to 4 shown is a method for recycling and circulating the grinding fluid by using the grinding fluid recovery and circulation device described in Embodiment 1 provided in this embodiment. The recycling and circulation method includes the following steps:

[0067] Collect the grinding fluid on the grinding pad 2 back into the liquid collection bucket 11 through the liquid return pipeline 21. When the liquid level of the grinding fluid recycled in the liquid collection bucket 11 reaches the first set height, start the first circulation pump 13 to drive the recycled grinding fluid to flow through the filter assembly along the circulation pipe 12 in a circulating manner;

[0068] When the liquid level of the grinding fluid recycled in the liquid collection bucket 11 reaches the second set height, transport the recycled grinding fluid to the process module 3 through the first delivery pipe 14 to remove excessive deionized water;

[0069] Transport the grinding fluid that has had excessive deionized water removed back to the grinding pad 2 through the supply pipe 31.

[0070] The recycling method of the embodiment of the present invention uses a circulation pipe 12 with a first circulation pump 13 to connect the first water outlet end and the second water inlet end of the liquid collection barrel 11. When the liquid level height of the abrasive slurry recovered in the liquid collection barrel 11 reaches the first set height but does not reach the second set height for transporting the recovered abrasive slurry to the process module 3, the first circulation pump 13 is started to drive the abrasive slurry recovered in the liquid collection barrel 11 to circulate along the circulation pipe 12; it is ensured that during the process of recovering and placing the abrasive slurry in the liquid collection barrel 11 but not transporting it to the process module 3, the abrasives in the abrasive slurry recovered in the liquid collection barrel 11 can be effectively prevented from precipitating and agglomerating into large particles and being filtered by the filter assembly, ensuring the content of abrasives in the abrasive slurry, and realizing the function of effectively and sustainably recycling the abrasive slurry without affecting the grinding effect. Compared with the method of discarding the whole abrasive slurry after a certain number of cycles in the prior art, the recycling method of the embodiment of the present invention can work continuously and has a higher recycling efficiency, and can effectively reduce the grinding cost. At the same time, by arranging a filter assembly on the circulation pipe 12, large particle impurities in the abrasive slurry can be removed while driving the abrasive slurry recovered in the liquid collection barrel 11 to circulate, without the need to additionally configure a pipeline for removing impurities, further simplifying the recycling process. A process module 3 is also connected between the second water outlet end of the liquid collection barrel 11 and the supply pipe 31. During the process of the recovered abrasive slurry flowing through the process module 3, the excessive deionized water contained in the abrasive slurry can be effectively removed, so that the recovered abrasive slurry is concentrated, and the concentration of the recovered abrasive slurry is restored to the concentration range required for normal grinding. Furthermore, the abrasive slurry can be effectively and sustainably recycled without affecting the grinding effect. Compared with the existing method of discarding the whole abrasive slurry after a certain number of cycles, the recycling method of the embodiment of the present invention can greatly reduce the grinding cost.

[0071] In some embodiments of the present invention, before the recovered abrasive slurry is transported back to the polishing pad 2 through the supply pipe 31, the pH value and concentration of the recovered abrasive slurry are detected and compared with the set range; if the detected value is not within the set range, an acid-base additive or fresh abrasive slurry is transported into the recovered abrasive slurry in the process module 3 through the liquid supplement module 5 for mixing until the detected values of the pH value and concentration of the recovered abrasive slurry are restored to the set range; ensuring the particle concentration of abrasives and the like in the abrasive slurry and the pH value of the abrasive slurry, realizing the function of effectively and sustainably recycling the abrasive slurry without affecting the grinding effect, and reducing the grinding cost. It can be understood that the fresh abrasive slurry described in this embodiment refers to the abrasive slurry that has not been used for grinding, and the concentration of the fresh abrasive slurry is higher than the set concentration range in the liquid supplement module 5.

[0072] In some embodiments of the present invention, the process module 3 includes a process barrel 32. Inside the process barrel 32, a partition plate 321 is arranged along its height direction to divide the interior of the process barrel 32 into an A chamber 322 and a B chamber 323. The A chamber 322 is communicated with the first delivery pipe 14, and the B chamber 323 is communicated with the liquid supply pipe 31. The water outlet end of the A chamber 322 is communicated with an ultrafiltration membrane filtration assembly 4 through a second delivery pipe 33. An ultrafiltration pump 34 is arranged on the second delivery pipe 33. The reflux end of the ultrafiltration membrane filtration assembly 4 is communicated with a reflux pipe 41. The water outlet end of the reflux pipe 41 is respectively communicated with the A chamber 322 and the B chamber 323. A second density sensor 42 for detecting the concentration of the abrasive liquid flowing through the interior of the reflux pipe 41 is arranged in the reflux pipe 41. During the process of concentrating the abrasive liquid recovered into the A chamber 322 by removing excessive deionized water, the second density sensor 42 detects the concentration of the concentrated abrasive liquid flowing through the interior of the reflux pipe 41 and compares it with a set range. If the detected value is lower than the set range, the abrasive liquid that has been concentrated by removing excessive deionized water is transported back into the A chamber 322 for continuous circulation and concentration treatment. If the detected value reaches the set range, the abrasive liquid that has been treated by removing excessive deionized water is transported into the B chamber 323 to ensure that the concentration of the recovered abrasive liquid transported into the B chamber 323 reaches the set range detected by the second density sensor 42, further ensuring the particle concentration of abrasives and the like in the recycled abrasive liquid, and realizing the function of effectively and sustainably recycling the abrasive liquid without affecting the grinding effect, effectively reducing the grinding cost. It should be understood that the height direction described in this embodiment refers to the up-and-down direction based on the Figure 3 viewpoint shown.

[0073] In some embodiments of the present invention, the B chamber 323 communicates with the liquid replenishment module 5. Inside the B chamber 323, a pH sensor 361 for detecting the pH value of the recycled abrasive slurry and a first density sensor 362 for detecting the concentration of the recycled abrasive slurry are provided. Both the pH sensor 361 and the first density sensor 362 are electrically connected to the same controller, and the controller is electrically connected to the liquid replenishment module 5. Before the recycled abrasive slurry is transported back to the polishing pad 2 through the supply pipe 31, the pH sensor 361 can be used to achieve online monitoring of the pH value of the abrasive slurry recovered into the B chamber 323, ensuring that when the detected pH value of the abrasive slurry in the B chamber 323 is not within the set pH value range, the controller controls the liquid replenishment module 5 to add acid-base additives into the B chamber 323 for mixing reaction with the concentrated abrasive slurry to adjust the pH value of the recycled abrasive slurry back to the set range. At the same time, the first density sensor 362 can be used to achieve real-time online monitoring of the concentration of the abrasive slurry recovered into the B chamber 323, ensuring that when the detected concentration of the abrasive slurry recovered into the B chamber 323 is lower than the corresponding concentration set range detected by the first density sensor 362, the controller controls the liquid replenishment module 5 to add new abrasive slurry into the B chamber 323 for mixing with the concentrated abrasive slurry to adjust the concentration of the recycled abrasive slurry back to the set range; realizing real-time online monitoring measurement and supplementary adjustment of the concentration and pH value of the recycled abrasive slurry, ensuring that the abrasive slurry recycled and transported back to the polishing pad 2 during the polishing process will ensure the consistency of wafer polishing, thereby realizing the function of effectively recycling and reusing the abrasive slurry sustainably without affecting the polishing effect, and effectively reducing the polishing cost.

[0074] Specifically, the liquid replenishment module 5 includes a pH adjustment barrel 52 for storing acid-base additives and a grinding fluid supply barrel 53 for storing newly ground fluid. The pH adjustment barrel 52 is communicated with the third delivery pipe 51 through a fourth delivery pipe 54, and a second electromagnetic valve 541 for controlling the on-off of the fourth delivery pipe 54 is arranged on the fourth delivery pipe 54; the grinding fluid supply barrel 53 is communicated with the third delivery pipe 51 through a fifth delivery pipe 55, and a third electromagnetic valve 551 for controlling the on-off of the fifth delivery pipe 55 is arranged on the fifth delivery pipe 55. Before the recycled grinding fluid is delivered back to the polishing pad 2 through the supply pipe 31, the pH sensor 361 can be used to monitor the pH value of the grinding fluid recovered into the B chamber 323 online, ensuring that when the pH value of the grinding fluid in the B chamber 323 is not within the set pH range, the controller controls the second electromagnetic valve 541 to open, so that the fourth delivery pipe 54 is communicated to add acid-base additives into the B chamber 323 to mix and react with the concentrated grinding fluid to adjust the pH value of the recycled grinding fluid to return to the set range. At the same time, through the real-time monitoring of the first density sensor 362, the concentration of the grinding fluid recovered into the B chamber 323 can be monitored online in real time, ensuring that when the concentration of the grinding fluid recovered into the B chamber 323 is lower than the concentration set range corresponding to the detection of the first density sensor 362, the controller controls the third electromagnetic valve 551 to open, so that the fifth delivery pipe 55 is communicated to add newly ground fluid into the B chamber 323 to mix with the concentrated grinding fluid to adjust the concentration of the recycled grinding fluid to return to the set range; realizing the real-time online monitoring measurement and supplementary adjustment of the concentration and pH value of the recycled grinding fluid, ensuring that the grinding fluid recycled and circulated back to the polishing pad 2 will ensure the consistency of wafer grinding during the grinding process, so as to realize the function of effectively recycling and reusing the grinding fluid sustainably without affecting the grinding effect, and effectively reducing the grinding cost.

[0075] In some embodiments of the present invention, a first density sensor 362 for detecting the concentration of the grinding fluid in the B chamber 323 is arranged in the B chamber 323. Before the grinding fluid is recycled, the newly ground fluid in the liquid replenishment module 5 is added into the B chamber 323, and the first density sensor 362 detects the concentration of the newly ground fluid and sets the concentration set range corresponding to the detection of the first density sensor 362 based on the detected concentration value; thus, different concentration set ranges corresponding to the detection of the first density sensor 362 can be switched according to the different concentrations of the grinding fluid required for actual grinding, and the applicable range is wider.

[0076] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A polishing liquid recycling device, characterized in that, Including: A liquid collection module (1) for recovering the grinding liquid on the grinding pad (2). The liquid collection module (1) is provided with a liquid collection bucket (11). The first water outlet end of the liquid collection bucket (11) is connected to the second water inlet end of the liquid collection bucket (11) through a circulation pipe (12). Along the flow path of the liquid therein, a first circulation pump (13) and a filtration component are sequentially arranged on the circulation pipe (12). A process module (3) for removing excessive deionized water in the recovered grinding liquid. The process module (3) is connected to the second water outlet end of the liquid collection bucket (11) through a first delivery pipe (14). The first water outlet end of the process module (3) is connected to a liquid supply pipe (31) for delivering the grinding liquid to the grinding pad (2). A first lower liquid level sensor (111) is arranged at the lower inner side of the liquid collection bucket (11). The first lower liquid level sensor (111) is electrically connected to a controller, and the controller is electrically connected to the first circulation pump (13). A first electromagnetic valve (15) for controlling its on-off is arranged on the first delivery pipe (14), and the first electromagnetic valve (15) is electrically connected to the controller. A first upper liquid level sensor (16) is arranged at the upper inner side of the liquid collection bucket (11), and the first upper liquid level sensor (16) is electrically connected to the controller. The process module (3) includes a process bucket (32) arranged between the first delivery pipe (14) and the liquid supply pipe (31). The second water outlet end of the process bucket (32) is connected to an ultrafiltration membrane filtration component (4) through a second delivery pipe (33). An ultrafiltration pump (34) is arranged on the second delivery pipe (33). The ultrafiltration membrane filtration component (4) is used to remove excessive deionized water in the recovered grinding liquid, and the reflux end of the ultrafiltration membrane filtration component (4) is connected to the process bucket (32). A self-circulation component for driving the grinding liquid to circulate is arranged on the process bucket (32). A partition plate (321) is arranged in the process bucket (32) along its height direction. The partition plate (321) divides the interior of the process bucket (32) into an A chamber (322) and a B chamber (323). The A chamber (322) is connected to the first delivery pipe (14), and the B chamber (323) is connected to the liquid supply pipe (31). The self-circulation component includes a stirring component (351) arranged in the A chamber (322) and a circulation delivery pipe (352) communicating with the interior of the B chamber (323). A second circulation pump (353) is arranged on the circulation delivery pipe (352). It further includes a liquid supplement module (5) connected to the water inlet end of the process module (3) through a third delivery pipe (51). The liquid supplement module (5) is used to adjust the concentration and pH value of the recovered grinding liquid.

2. The abrasive liquid recovery and recycling device according to claim 1, wherein The replenishing liquid module (5) includes a pH adjustment barrel (52) for storing acid-base additives and a grinding liquid supply barrel (53) for storing newly ground liquid. The pH adjustment barrel (52) is communicated with the third delivery pipe (51) through a fourth delivery pipe (54), and a second solenoid valve (541) for controlling its on-off is arranged on the fourth delivery pipe (54); the grinding liquid supply barrel (53) is communicated with the third delivery pipe (51) through a fifth delivery pipe (55), and a third solenoid valve (551) for controlling its on-off is arranged on the fifth delivery pipe (55).

3. The abrasive liquid recovery and recycling device according to claim 2, characterized in that, A pH sensor (361) for detecting the pH value of the recycled grinding liquid and a first density sensor (362) for detecting the concentration of the recycled grinding liquid are arranged in the process module (3). The pH sensor (361) and the first density sensor (362) are both electrically connected to the same controller, and the controller is electrically connected to the second solenoid valve (541) and the third solenoid valve (551).

4. A recycling method, characterized in that, Applied to the grinding liquid recycling and circulating device according to any one of claims 1 to 3, the recycling and circulating method includes the following steps: Collect the grinding liquid on the grinding pad (2) back into the liquid collecting barrel (11) through the liquid return pipeline (21). When the liquid level of the recycled grinding liquid in the liquid collecting barrel (11) reaches a first set height, start the first circulation pump (13) to drive the recycled grinding liquid to flow through the filter assembly along the circulation pipe (12) in a circulating manner; When the liquid level of the recycled grinding liquid in the liquid collecting barrel (11) reaches a second set height, convey the recycled grinding liquid to the process module (3) through the first delivery pipe (14) to remove excessive deionized water; Convey the grinding liquid after removing excessive deionized water back to the grinding pad (2) through the liquid supply pipe (31).

5. A recycling method according to claim 4, characterized in that, Before conveying the recycled grinding liquid back to the grinding pad (2) through the liquid supply pipe (31), detect the pH value and concentration of the recycled grinding liquid and compare them with the set range; if the detected value is not within the set range, convey acid-base additives or newly ground liquid into the recycled grinding liquid in the process module (3) through the replenishing liquid module (5) for mixing until the detected values of the pH value and concentration of the recycled grinding liquid are restored to within the set range.

6. A recycling method according to claim 4, wherein The process module (3) includes a process barrel (32). A partition plate (321) is arranged inside the process barrel (32) to divide its interior into an A chamber (322) and a B chamber (323). The A chamber (322) is communicated with the first delivery pipe (14), and the B chamber (323) is communicated with the liquid supply pipe (31). The water outlet end of the A chamber (322) is communicated with an ultrafiltration membrane filtration assembly (4) through a second delivery pipe (33). An ultrafiltration pump (34) is arranged on the second delivery pipe (33). The reflux end of the ultrafiltration membrane filtration assembly (4) is communicated with a reflux pipe (41). The water outlet end of the reflux pipe (41) is respectively communicated with the A chamber (322) and the B chamber (323). A second density sensor (42) for detecting the concentration of the abrasive slurry flowing through the interior of the reflux pipe (41) is arranged inside the reflux pipe (41). During the process of removing excessive deionized water from the abrasive slurry, the concentration of the abrasive slurry flowing through the interior of the reflux pipe (41) is detected and compared with a set range. If the detected value is lower than the set range, the abrasive slurry that has been treated to remove excessive deionized water is transported back into the A chamber (322). If the detected value reaches the set range, the abrasive slurry that has been treated to remove excessive deionized water is transported into the B chamber (323).

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