CN214634616U - System for non-free resin in desorption photoresist stripping liquid - Google Patents

Abstract

The utility model provides a system of non-free state resin in desorption photoresist stripping liquid. The system comprises a filtering device, wherein the filtering device comprises at least one filter for filtering non-free resin in the waste stripping liquid to be treated, a first-stage filter element and a second-stage filter element are arranged in the filter from top to bottom, an electric heating unit is arranged in the second-stage filter element, and the electric heating unit is a resistance wire capable of being electrified and generating heat and is used for heating the waste stripping liquid flowing through the second-stage filter element to separate out the non-free resin in the waste stripping liquid on the second-stage filter element. The system can realize on-line continuous operation, has controllable process parameters, high device stability, low cost and easy operation, obviously reduces the impurity content in the stripped liquid, and is beneficial to the normal operation of the subsequent stripping liquid rectification regeneration purification process.

Description

System for non-free resin in desorption photoresist stripping liquid

Technical Field

The utility model relates to a photoresist stripper retrieves regeneration field, especially relates to a system that is arranged in the photoresist to peel off and retrieves non-free state resin in the photoresist stripper of a among the regenerated pretreatment process.

Background

In the manufacturing process of semiconductor integrated circuits, displays and the like, photoresist (photo-resist) is an essential substance in a photolithography process, which is one of processes generally used for manufacturing TFT control circuits in integrated circuits or flat panel display devices, for example. After the photolithography process is completed, the photoresist is removed from the device by a stripper at an elevated temperature. The stripper solution for removing the photoresist is a necessary chemical in the integrated circuit process. The stripping solution used in industry is mainly a mixture of organic amine and organic solvent, and contains a small amount of water and a small amount of additives. In the process of removing the photoresist, a large amount of stripping liquid is mainly used to fully dissolve and take away the residual photoresist, so that the waste stripping liquid contains photoresist components in a dissolved or non-free state, including phenolic resin fragments, photosensitive resin and the like in the photoresist. The remaining majority are recyclable components of value for reuse.

In order to recover valuable components in the stripping liquid, the valuable components are recovered through a recovery system, a waste stripping liquid recovery system or a solvent regeneration system utilizes the difference of the boiling points of chemicals in the stripping liquid to evaporate and fractionate the waste stripping liquid to realize refining regeneration, and the waste stripping liquid is adjusted, compounded and then reused in the photoresist stripping process. In a stripping solution recovery system, in order to ensure that an evaporation fractionation system can normally operate, an important step is to remove residual undissolved components of photoresist in a stripping solution so as to avoid the situation that the normal operation of the system is influenced by the thermal change of resin or the adhesion or hardening of the resin on an equipment pipeline due to sudden cooling under the condition that the temperature of the stripping solution containing the residual photoresist in the rectification process is changed violently from a tower bottom to a tower top. Because the resin is partially dissolved in the solvent and is in a non-free state and has the characteristic of heat sensitivity, the currently used solvent recovery method mostly adopts a rectification technology, waste stripping liquid containing photoresist fragments and resin needs to be heated during rectification, the heated resin can be separated out at high temperature and adhered to the pipe wall of a tower kettle heater, or adhered to the pipe wall of a cooler after the tower top cooler is suddenly cooled, the heat exchanger efficiency is influenced after long-term deposition due to the very low heat conductivity coefficient of the resin, and the adhered resin is very tightly combined with the pipe wall of the heat exchanger and is difficult to remove, so that the continuity of the operation of the device is influenced. If the resin removal is not complete, the effective solvent recovery of the spent stripper is reduced under the same purity standards for the recovered solvent. A part of the stripping solution containing a high concentration of resin must be discharged as waste liquid, which reduces the recovery efficiency and also increases the discharge of waste liquid.

Therefore, in the existing stripping solution or solvent recovery system, the photoresist resin in the stripping solution is separated or treated before rectification separation or after dehydration and fractionation, so as to avoid the problem of wall adhesion of a heat exchanger during rectification. Existing resin separation or treatment methods include: photochemical reaction, rotary scraper (knife) evaporation, nanofiltration membrane filtration, macroporous adsorption resin adsorption and the like.

These different methods have certain removal effects in engineering practice, but have disadvantages. Because the photoresist concentration in the stripping solution is too low, the photochemical reaction method can only change the partially dissolved photoresist, and the partially dissolved photoresist is dissolved in the solvent, and the residual resin component is not removed. The resin solid adhered to the inner wall is separated by a physical scraping method through the rotating scraper device, and the resin is tightly adhered to the inner wall of the container at high temperature, so that the inner wall of the device still needs to be manually cleaned after long-time operation, and the operation continuity is influenced. The nanofiltration membrane filtration and macroporous adsorption resin adsorption method can effectively remove macromolecules in the waste stripping liquid, but the filtration membrane and the adsorption resin have small holes, are easily blocked by dissolved resin, cannot be used continuously, are inconvenient to regenerate, have short effective use time and are uneconomical.

CN103721427A discloses a regeneration method and a regeneration device for a resist stripping solution. Wherein the regeneration method comprises the following steps: a low boiling point separation step of separating low boiling point substances such as water; a high boiling point separation step of taking out a resist-containing residual liquid, a solvent, and the like as a separated product; a residue concentrating step of further concentrating the resist-containing residue solution in a residue concentrator, separating the solvent and the like, and returning the solvent and the like to the high boiling point separating step; a purification step of separating the remaining part of the water as a waste liquid B by vaporization from the separated product of the high boiling point separation step and taking out the separation residue liquid as a stripping regeneration liquid; a washing step of allowing the separation residue liquid of the low boiling point separation step to flow down in the residue concentrator.

CN102951761A discloses a method for recovering a waste photoresist stripping solution, which comprises the steps of firstly adopting a proper amount of water to precipitate a linear phenolic resin which is the main component of a photoresist in two steps under an acidic condition to obtain the linear phenolic resin which can be used as the photoresist again; then activated carbon is used for adsorption decoloration and removal of metal ions; and finally, removing low-boiling-point substances such as water and the like through two-step reduced pressure distillation, and recovering to obtain pure photoresist stripping liquid.

CN1939567A discloses an apparatus for recovering a solvent from a waste liquid discharged from a resist stripping process, comprising: a resin component removing device for removing the resin component contained in the waste liquid; a first distillation column for removing low boiling impurities contained in the waste liquid; a second distillation column for removing high boiling point impurities contained in the waste liquid; and a solvent storage tank for replenishing industrial solvent to one or both of the first distillation column and the second distillation column.

However, in the current regeneration process for removing the resist stripping solution, the pretreatment process for removing dissolved resin or solid impurities still has the defects of low efficiency, incomplete impurity removal and the like. Therefore, it is an urgent need to solve the problem of finding a method and a device for removing impurities in photoresist stripper with low cost, controllable process parameters and high device stability.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problem, the utility model provides a system of non-separation state resin in desorption photoresist. The system can realize on-line continuous operation, has controllable process parameters, high device stability, low cost and easy operation, obviously reduces the impurity content in the stripped liquid, and is beneficial to the normal operation of the subsequent stripping liquid rectification regeneration purification process.

The utility model provides a system for removing non-free resin in waste photoresist stripping liquid, which comprises a filtering device, a waste stripping liquid feeding device, a waste stripping liquid input pipeline and a waste stripping liquid output pipeline;

the device comprises a filtering device and a control device, wherein the filtering device comprises at least one filter and is used for filtering non-free resin in waste stripping liquid to be treated, a first-stage filter element and a second-stage filter element are arranged in the filter from top to bottom, an electric heating unit is arranged in the second-stage filter element, and the electric heating unit is a resistance wire capable of being electrified and generating heat and is used for heating the waste stripping liquid flowing through the second-stage filter element so that the non-free resin in the waste stripping liquid is separated out on the second-stage filter element;

and the waste stripping liquid feeding device is communicated with the filtering device, the waste stripping liquid to be treated is supplied into the filtering device from the lower part of the filtering device through the waste stripping liquid input pipeline, and the waste stripping liquid filtered by the filter is supplied to the subsequent process from the upper part of the filtering device through the waste stripping liquid output pipeline. Preferably, the subsequent process is a rectifying tower purification process.

Furthermore, in the filter, the aperture of the primary filter element is folded and stacked by a filtering wire mesh with the aperture of 1000-1500 μm to form a filter element with the thickness of 19-20 cm, and the aperture of the secondary filter element is folded and stacked by a filtering wire mesh with the aperture of 400-600 μm to form a filter element with the thickness of 20-25 cm.

Further, filter equipment includes two at least parallelly connected settings the filter, useless stripping liquid input pipeline includes the input branch road of being connected with every filter correspondence, useless stripping liquid output pipeline includes the output branch road of being connected with every filter correspondence, each be equipped with the feed liquor valve on the input branch road respectively, each be equipped with out the liquid valve on the output branch road respectively.

Furthermore, the system also comprises an alkali liquor storage and regeneration device, an alkali liquor input pipeline, an alkali liquor circulating and recycling pipeline and a switching control device;

the alkali liquor storage and regeneration device is used for conveying alkali liquor into the filtering device, backwashing the filter to dissolve and remove blocking matters precipitated on the secondary filter element so as to ensure the continuous operation of the system, circulating the alkali liquor with impurities back to the alkali liquor storage and regeneration device through the alkali liquor circulation and reuse pipeline, filtering by the alkali liquor storage and regeneration device, retaining solid impurities in the alkali liquor storage and regeneration device, continuously returning the regenerated alkali liquor output from the alkali liquor storage and regeneration device to the filter, and continuously performing alkali liquor backwashing operation;

and the switching control device is used for controlling the operation of the filtering device and the alkali liquor storage and regeneration device so as to ensure the continuous operation of the system.

Furthermore, an alkali liquor regeneration unit and an alkali liquor storage unit are arranged in the alkali liquor storage regeneration device, the alkali liquor regeneration unit is a storage tank which is closed at the periphery and open at the upper part, a filter screen is arranged in the alkali liquor regeneration unit, the alkali liquor after backwashing is led into the lower part of the filter screen through a pipe orifice of the alkali liquor circulation and reuse pipeline, impurities filtered by the filter screen are discharged outwards from an impurity removal opening at the lower part of the alkali liquor regeneration unit, and the alkali liquor higher than the filter screen reversely overflows into the alkali liquor storage unit to form regenerated alkali liquor which is continuously used for alkali liquor backwashing operation.

Furthermore, backwashing inlet valves are respectively arranged on branches of the alkali liquor input pipeline which enter the filters, backwashing outlet valves are also arranged on branches of the alkali liquor circulation recycling pipeline which are connected with the filters, the automatic switching of the backwashing inlet valves and the backwashing outlet valves is controlled by the switching control device, and the filters in a blocking state are backwashed while the stripping liquor filtering operation is kept to be continuously carried out, so that the continuous non-stop operation of the system is ensured.

Further, the system further comprises:

the pure water input pipeline is arranged in front of the backwashing inlet valve and is communicated with the alkali liquor input pipeline to form a parallel pipeline, a pure water supply valve for controlling pure water supply is arranged on the pure water input pipeline, an alkali liquor supply valve for controlling alkali liquor supply is arranged on the alkali liquor input pipeline, and the pure water input pipeline and the alkali liquor input pipeline are switched by controlling respective valves through the switching control device;

and the wastewater discharge pipeline is arranged behind the backwashing outlet valve and is communicated with the alkali liquor circulation and reuse pipeline to form a parallel pipeline, a wastewater discharge valve for controlling wastewater discharge is arranged on the wastewater discharge pipeline, a backwash liquid return valve for controlling the circulation of the backwashed alkali liquor is arranged on the alkali liquor circulation and reuse pipeline, and the wastewater discharge pipeline and the alkali liquor circulation and reuse pipeline are switched by controlling respective valves through the switching control device.

Furthermore, the system also comprises an alkali liquor supplementing pipeline which is used for supplementing fresh alkali liquor to the alkali liquor storage and regeneration device; the system also comprises a lye discharge pipeline which is used for discharging part of lye out of the system.

Furthermore, the outside of the filter is also provided with a heat preservation unit, and pipelines connected with all the devices are also provided with the heat preservation unit.

The utility model also provides a method for utilize aforementioned system to implement the resin of non-free state in the desorption photoresist stripping liquid, the method includes, in the filter equipment arbitrary one the filter carries out following step:

s1: and a heating and filtering step of supplying the waste stripping liquid to be treated in the waste stripping liquid feeding device from the position below the filtering device to any one of the filters in the filtering device through the waste stripping liquid input pipeline, filtering large-particle impurities by the primary filter element in the filter, precipitating the non-free resin on the surface of the secondary filter element through heating of the secondary filter element, and leading out the filtered liquid from the waste stripping liquid output pipe to enter a subsequent step.

Preferably, the subsequent process is a rectifying tower purification process.

Further, in step S1, the non-free resin and other impurities are contained in an amount of 0.2 to 3 wt% in the initial feed of the spent stripping liquid, based on the mass of the initial stream of the spent stripping liquid, and the feed rate is 0.5 to 5m³And h, the heating temperature of the secondary filter element is 60-140 ℃.

Further, the method also comprises the following steps of closing a liquid inlet valve and a liquid outlet valve corresponding to the blocked filter through the switching control device when the filter is blocked, and then opening a backwashing inlet valve and a backwashing outlet valve corresponding to the blocked filter, wherein the following steps are carried out:

s2: an alkali liquor backwashing step of supplying the alkali liquor output from the alkali liquor storage and regeneration device from above the filter device to the blocked filter via the alkali liquor input pipeline, wherein the alkali liquor backflushes the blocked filter in a direction opposite to the direction of feeding the waste stripping liquid in step S1, and the alkali liquor backwashing process comprises physical cleaning and chemical reaction cleaning; and then, supplying the alkali liquor after the back washing from the lower part of the filtering device to the alkali liquor storage and regeneration device through the alkali liquor recycling pipeline for recycling and regeneration.

Further, in step S2, the feeding speed of the alkali liquor is 0.8-3m³The initial concentration is 1-12%, the temperature of the alkali liquor backwashing process is controlled at 20-45 ℃, and the cleaning chemical reaction principle is OH in the alkali liquor^-The ions react with aldehyde hydroxyl in the resin to dissolve the resin, or the polyester resin is hydrolyzed under the action of strong alkali to be cleaned; the alkali liquor contains 1-12% of KOH, NaOH or tetramethylammonium hydroxide (TMAH), 1-8% of ethanol and the balance of pure water.

Further, the method performs step S3 after step S2:

s3: a pure water backwashing step of supplying pure water in the pure water supply device, which backwashes the filter in a direction opposite to the direction in which the waste stripping liquid is fed in step S1, into the filter from above the filter device via the pure water feed line; and then discharging the waste water after the back washing out of the system from the position below the filtering device through the waste water discharge pipeline.

Further, any one of the filters in the filtering device sequentially performs the steps S1, S2 and S3, and the filters operate independently, and the same step or different steps can be performed at the same time, so that the continuous filtering and backwashing operation of the system is ensured.

Further, the content of non-free resin and other impurities in the spent stripper from which non-free resin is removed after steps S1, S3 and S3 is less than 0.1 wt% based on the mass of the initial stream of the spent stripper.

Further, the method also comprises a working procedure of alkali liquor supplement and alkali liquor discharge, when the system is operated, the partially regenerated alkali liquor is continuously discharged out of the system, and the discharge proportion is 1-5% of the circulation amount of the alkali liquor; when alkali liquor is discharged, alkali liquor is supplemented to the alkali liquor storage and regeneration device, and the concentration of the supplemented alkali liquor is 3-5 times of the concentration of the initial alkali liquor.

In the present invention, the waste stripping solution is mainly a mixture of organic amine and organic solvent, such as a solvent mixed with ethanolamine (MEA) and DMSO, or MEA and diethylene glycol monobutyl ether (BDG) in a predetermined ratio, and the like. The non-free resin in the waste stripping liquid comprises phenolic resin, polyester resin and the like, and the solid impurities in the waste stripping liquid are mainly photoresist photosensitive material fragments and resin fragments.

The utility model discloses in, the term "non-free state resin" means to dissolve resin particle or the micromolecule in useless stripping liquid, can't get rid of through conventional filtering means, and when carrying the useless stripping liquid of non-free state resin and carrying out follow-up rectification procedure, because the heat sensitivity of this kind of resin, can appear and the adhesion on the heat exchanger pipe wall during heating or cooling, long-term deposit influences heat exchanger efficiency, and then leads to stripping liquid rate of recovery to descend. The utility model discloses a heating element among the filter equipment makes non-free state resin condense, coke and appear on the filter screen of filter to effectively get rid of non-free state resin.

The utility model discloses following beneficial effect has:

1. the utility model discloses a filter among the filter equipment is equipped with two-stage filter core and electrical heating unit through inside, can peel off liquid to useless and carry out thermal treatment, makes the adhesion of changing on the filter core of resin, improves the desorption rate, and these operations in the pretreatment process have guaranteed that the follow-up refined regeneration process of useless peeling off liquid can not cause equipment high temperature surface adhesion coking.

2. The utility model discloses a filter equipment contains two at least filters, but each filter independent operation, and when the filter core in arbitrary filter blockked up or the heating unit breaks down, other filter replaceable work have guaranteed the continuous of filtering process and have gone on.

3. The system of the utility model is also provided with an alkali liquor storage regeneration device and a pure water filtering device, which carries out online backwashing on the filter and further ensures the continuous production of the system by dissolving and removing the blockage on the filter element.

4. The utility model discloses a system can realize the full automatic switch-over process of heating filtration process, alkali lye backwash process, pure water backwash process through setting up the control of switching control device to each valve.

5. The utility model discloses a need not to use moving parts such as scraper blade in the system, operation maintenance is simple.

6. The utility model discloses an do not introduce extra reagent in the stripping solution, reduce the pollution of reagent to stripping solution.

7. The system of the utility model can also remove the stripping liquid containing the solvent such as monoethanolamine MEA and the like due to MEA and CO₂The salt generated by the reaction avoids the pipeline blockage of subsequent process equipment.

Drawings

FIG. 1 is a flow chart of the process for removing non-free resin from a photoresist stripper according to the present invention;

fig. 2 is a schematic structural diagram of the filter 101/102/103 according to the present invention.

Reference numerals:

1-filtration device

101-first filter, 102-second filter, 103-third filter

1011-outer cover

1012-first-stage filter element

1013-two-stage filter element

1014-electric heating unit

1015-electric heating unit lead-out power supply wiring

2-alkali liquor storage and regeneration device

201-lye regeneration Unit

202-lye storage unit

2011-filtering net

2012 impurity removal port

3-switching control device

4-waste stripping liquid feeding device

5-pure water supply device

L1 waste stripping liquid input pipeline

L2-waste stripping liquid output pipeline

L3-alkali liquor input pipeline

L4-lye circulation and reuse pipeline

L5-pure water input pipeline

L6 waste water discharge pipeline

L7-lye supply pipeline

L8-alkali liquor discharge pipeline

A1-1-first intake valve; a1-2-a second liquid inlet valve, A1-3-a third liquid inlet valve; a2-1-first outlet valve; a2-2-second effluent valve; a2-3-third effluent valve;

b1-1-first backwash outlet valve; b1-2-second backwash outlet valve; b1-3-third backwash outlet valve; b2-1-first backwash inlet valve; b2-2-second backwash inlet valve; b2-3-third backwash inlet valve;

c1-lye feed valve; c2-pure water feeding valve, D1-backwash liquid reflux valve; d2 waste water discharge valve

Detailed Description

As shown in FIG. 1, the system for removing non-free resin from the waste photoresist stripper of the present invention has a waste stripper throughput of 3 ten thousand tons/year and an operation time of 8000 hours. The system is one part of a waste stripping liquid treatment system and is arranged on a discharge pipeline of a tower kettle of a primary rectifying tower in the waste stripping liquid treatment system. The feeding temperature of the waste stripping liquid of the system is 121 ℃.

The waste stripping liquid to be treated by the system is mainly a mixture of organic amine and a solvent, and comprises ethanolamine (MEA), diethylene glycol monobutyl ether (BDG), water and impurities (including waste photoresist). The weight ratio of the components is as follows: MEA: 16.2%, BDG: 63.5%, water: 19.6%, impurities: 0.7 percent. The impurities in the waste stripping liquid include phenolic resin, polyester resin, and photo-resist photo-sensitive material chips and resin chips.

The system comprises a filtering device 1, a waste stripping liquid feeding device 4, a waste stripping liquid input pipeline L1 and a waste stripping liquid output pipeline L2;

the filtering device 1 comprises at least one filter, which is used for filtering non-free resin in the waste stripping liquid to be treated, a first-stage filter element 1012 and a second-stage filter element 1013 are arranged in the filter from top to bottom, an electric heating unit 1014 is arranged in the second-stage filter element 1013, and the electric heating unit 1014 is a resistance wire which can be electrified and heated and is used for heating the waste stripping liquid flowing through the second-stage filter element 1013 so as to separate the non-free resin in the waste stripping liquid out on the second-stage filter element 1013;

the waste stripping liquid feeder 4 communicates with the filter device 1, and supplies the waste stripping liquid to be treated from below the filter device 1 to the filter device 1 through a waste stripping liquid inlet line L1, and supplies the waste stripping liquid filtered by the filter from above the filter device 1 to the subsequent process through a waste stripping liquid outlet line L2.

In a preferred embodiment, the subsequent step is a rectifying column purification step.

As shown in fig. 2, the housing 1011 of each filter is cylindrical and has a diameter of 160mm, wherein the primary filter element 1012 is folded and stacked by a filter screen having a pore size of 1000 μm to form a filter element having a thickness of 19cm, and the secondary filter element 1013 is folded and stacked by a filter screen having a pore size of 400 μm to form a filter element having a thickness of 20 cm; preferably, the wire mesh material of the filter element is 316L stainless steel.

In another preferred embodiment, the filtering device 1 comprises two filters 101 and 102 arranged in parallel, the input line L1 of spent stripper comprises an input branch connected to each filter, the output line L2 of spent stripper comprises an output branch connected to each filter, an inlet valve is arranged on each input branch, and an outlet valve is arranged on each output branch. As shown in fig. 1, corresponding to the first filter 101, connected thereto are a first liquid inlet valve a1-1 and a first liquid outlet valve a 2-1; corresponding to the second filter 102, a second liquid inlet valve A1-2 and a second liquid outlet valve A2-2 are connected with the second filter; optionally, a third filter 103 can be further included, and connected with a third liquid inlet valve A1-3 and a third liquid outlet valve A2-3. In a further preferred embodiment, during the use of the system, a corresponding number of parallel filters can be set based on the treatment capacity of the stripping liquid, a plurality of filters are simultaneously opened for simultaneous filtration, and the filters with clogging phenomena are simultaneously subjected to corresponding lye backwashing and/or pure water backwashing.

In a further preferred embodiment, as shown in fig. 1, when the first filter 101 is clogged, the second inlet valve a1-2 and the second outlet valve a2-2 connected to the second filter 102 are opened by the switching control device 3 to realize that the treatment of the stripping liquid is continued by the second filter 102, the first inlet valve a1-1 and the first outlet valve a2-1 connected to the first filter 101 are closed, the first backwash inlet valve B2-1 and the first backwash outlet valve B1-1 connected to the first filter are opened to allow the alkali liquid to enter and flow out from the upper part and the lower part of the first filter 101, so that the blockage substances deposited on the first filter element 1013 and the second filter element 1013 of the filter are dissolved and/or washed and fallen off, and then the alkali liquid is carried away by the alkali liquid, and the liquid flowing out from the first backwash outlet valve B1-1 enters the circulation and reuse pipeline L4, the alkali liquor is conveyed to the lower part of the filter screen 2011 in the alkali liquor regeneration unit 201, the liquid level at the lower part of the filter screen 2011 rises along with the increase of the inflow alkali liquor, and flows into the alkali liquor storage unit 202 after overflowing from the edge of the alkali liquor regeneration unit 201 after passing through the filter screen 2011 to continue the backwashing operation.

In a further preferred embodiment, as shown in fig. 1, the present system further comprises a pure water supply 5: used for washing the alkali liquor in the filtering device 1, the alkali liquor input pipeline L3 and the alkali liquor recycling pipeline L4; the pure water supply device 5 is connected with an alkali liquor input pipeline L3 through a pure water input pipeline L5, a pure water supply valve C2 is arranged on a pure water input pipeline L5, an alkali liquor supply valve C1 is arranged on an alkali liquor input pipeline L3, an alkali liquor supply valve C1 and a pure water supply valve C2 are electrically connected with the switching control device 3, when pure water cleaning operation is required, the switching controller 3 controls the alkali liquor supply valve C1 and the backwash liquid return valve D1 on the alkali liquor input pipeline L3 to be closed, controls the pure water supply valve C2 on the pure water input pipeline L3 and the wastewater discharge valve D2 on the wastewater discharge pipeline to be opened, pure water flows in from the upper part of the cleaned first filter 101 through a pipeline, residual alkali liquor and/or various impurities are removed, then the pure water flows out from the lower part through the first backwash outlet valve B1-1, and the discharged wastewater is discharged through the wastewater discharge pipeline L6.

Necessary, switching control device 3 can be based on the liquid of peeling off and handle, alkali lye backwash, pure water backwash's needs control the switching to corresponding valve to realize going on in succession of whole operation, and because the utility model discloses a mode of design makes the maintenance of filter easier, reduce cost, simultaneously, because a large amount of non-free state's resin is in the utility model discloses an impurity in a large number of deposits pipeline and reactor no longer exists in the material that can guarantee to get into follow-up rectification technology in the processing method is detached, improves follow-up production's security greatly, reduces the cost of equipment maintenance and maintenance in the follow-up technology.

The utility model discloses further provide a processing method that uses aforementioned system to carry out among the useless stripper of desorption photoresist non-free state resin, the method includes, in filter equipment 1 arbitrary one filter implement following step:

s1: a heating and filtering step of supplying the waste stripping liquid to be treated in the waste stripping liquid feeding device 4 from below the filtering device 1 to any one of the filters of the filtering device 1 via the waste stripping liquid inlet line L1, filtering large-particle impurities by the primary filter element 1012 in the filtering of the first filter 101, heating the secondary filter element 1013 to precipitate non-waste free resin on the surface of the secondary filter element 1013, and leading out the filtered liquid from the waste stripping liquid outlet line L2 to a subsequent step. Preferably, the subsequent process is a rectifying column purification process.

In a preferred embodiment, in step S1, the initial charge of spent stripper has a non-free resin and other impurities content of 0.7 wt.% based on the mass of the initial stream of spent stripper, and a feed rate of 3.9m³And h, the heating temperature of the secondary filter element is 125 ℃.

In a preferred embodiment, when the first filter 101 is clogged, the following step S2 is performed: the second liquid inlet valve A1-2 and the second liquid outlet valve A2-2 connected with the second filter 102 are opened through the switching control device 3 to realize the continuous treatment of the stripping liquid through the second filter 102, the first liquid inlet valve A1-1 and the first liquid outlet valve A2-1 connected with the first filter 101 are closed, then the first backwashing inlet valve B2-1 and the first backwashing outlet valve B1-1 connected with the first filter are opened to enable the alkali liquor to enter from the upper part and flow out from the lower part of the first filter 101, so that the blockage substances precipitated on the first filter element 1012 and the second filter element 1013 of the filter are taken away by the alkali liquor after being dissolved and/or washed and fallen off, and the fluid flowing out from the first backwashing outlet valve B1-1 enters the alkali liquor circulation and reuse pipeline L4 and is conveyed to the lower part of the filter screen 2011 in the alkali liquor regeneration unit 201, as the inflow of alkali liquor is increased, the liquid level at the lower part of the filter screen 2011 rises, and flows into the alkali liquor storage unit 202 after overflowing from the edge of the alkali liquor regeneration unit 201 after passing through the filter screen 2011 to continue the backwashing operation.

In another preferred embodiment, the feed rate of the lye is 4.2m³Initial concentration of 10% (all nonaqueous)The sum of solute concentration) and the temperature of the alkali liquor backwashing process is controlled at 25 ℃, and the cleaning chemical reaction principle is that OH-ions in the alkali liquor react with aldehyde hydroxyl in the resin to dissolve the resin, or polyester resin is hydrolyzed and cleaned under the action of strong alkali; the alkali liquor contains 7% of NaOH, 3% of ethanol and the balance of pure water;

in a further embodiment, after the backwashing operation is finished, the following step S3 is performed: the switching controller 3 controls an alkali liquor feeding valve C1 and a backwash liquid backflow valve D1 on an alkali liquor input pipeline L3 to be closed, controls a pure water feeding valve C2 on a pure water input pipeline L3 and a wastewater discharge valve D2 on a wastewater discharge pipeline to be opened, pure water flows in from the upper part of the cleaned first filter 101 through the pipeline, residual alkali liquor and/or various impurities are removed, then the pure water flows out from the lower part through a first backwash outlet valve B1-1, and discharged wastewater is discharged through a wastewater discharge pipeline L6.

In the system, the time of any filter for filtering is 2h, the alkali liquor backwashing time is 20-30min, the pure water backwashing time is 20-30min, and the rest time is waiting time.

In a further preferred embodiment, the method further comprises a lye supplementing and lye discharging process, when the system is operated, the part of regenerated lye is continuously discharged out of the system, the discharge proportion is 4.3 percent of the circulation amount of the lye, and the discharge amount of the lye is 180L/h; when alkali liquor is discharged, alkali liquor is supplemented to the alkali liquor storage and regeneration device, the amount of the supplemented alkali liquor is 190L/h, the concentration is 36% NaOH, the concentration is 3% ethanol, and the balance is water.

Finally, the content of non-free resin and other impurities in the spent stripper from which non-free resin has been removed after steps S1, S3 and S3 is less than 0.1% by weight, based on the mass of the initial stream of spent stripper.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any other way, and any modifications or equivalent changes made according to the technical spirit of the present invention are still within the scope of the present invention.

Claims (6)

1. A system for removing non-free resin in a photoresist stripping solution is characterized by comprising a filtering device (1), a waste stripping solution feeding device (4), a waste stripping solution input pipeline (L1) and a waste stripping solution output pipeline (L2);

the filtering device (1) comprises at least one filter, the filter is used for filtering non-free resin in waste stripping liquid to be treated, a primary filter element (1012) and a secondary filter element (1013) are arranged in the filter from top to bottom, an electric heating unit (1014) is arranged in the secondary filter element (1013), the electric heating unit (1014) is a resistance wire which can be electrified to generate heat, and is used for heating the waste stripping liquid flowing through the secondary filter element (1013), so that the non-free resin in the waste stripping liquid is precipitated on the secondary filter element (1013);

the waste stripping liquid feeding device (4) is communicated with the filtering device (1), the waste stripping liquid to be treated is fed into the filtering device (1) from the lower part of the filtering device (1) through the waste stripping liquid input pipeline (L1), and the waste stripping liquid filtered by the filter is fed into the subsequent process from the upper part of the filtering device (1) through the waste stripping liquid output pipeline (L2).

2. The system as claimed in claim 1, wherein in the filter, the primary filter element (1012) is folded by a filter screen with aperture of 1000-1500 μm and stacked to a thickness of 19-20 cm, and the secondary filter element (1013) is folded by a filter screen with aperture of 400-600 μm and stacked to a thickness of 20-25 cm.

3. The system according to claim 1 or 2, characterized in that said filtering device (1) comprises at least two said filters arranged in parallel, said input line (L1) of spent stripper comprising an input branch associated with each filter, said output line (L2) of spent stripper comprising an output branch associated with each filter, an inlet valve being provided in each of said input branches, and an outlet valve being provided in each of said output branches.

4. The system according to claim 1 or 2, characterized in that the system further comprises a lye storage regeneration device (2), a lye input line (L3), a lye circulation and reuse line (L4) and a switching control device (3);

the alkali liquor storage and regeneration device (2) is used for conveying alkali liquor into the filtering device (1), backwashing the filter to dissolve and remove the blockage precipitated on the secondary filter element (1013) so as to ensure the continuous operation of the system, circulating the alkali liquor with impurities back to the alkali liquor storage and regeneration device (2) through the alkali liquor circulation and reuse pipeline (L4), filtering by the alkali liquor storage and regeneration device (2), retaining solid impurities in the alkali liquor storage and regeneration device (2), continuously returning the regenerated alkali liquor output from the alkali liquor storage and regeneration device (2) to the filter, and continuously performing alkali liquor backwashing operation;

the switching control device (3) is used for controlling the operation of the filtering device (1) and the alkali liquor storage and regeneration device (2) so as to ensure the continuous operation of the system.

5. The system according to claim 4, characterized in that an alkali liquor regeneration unit (201) and an alkali liquor storage unit (202) are arranged in the alkali liquor storage regeneration device (2), the alkali liquor regeneration unit (201) is a storage tank with closed periphery and open top, a filter screen (2011) is arranged in the alkali liquor regeneration unit (201), the alkali liquor after backwashing is introduced to the lower part of the filter screen (2011) through a pipe opening of the alkali liquor circulation and reuse pipeline (L4), impurities filtered by the filter screen (2011) are discharged from an impurity removal opening (2012) below the alkali liquor regeneration unit (201), and the alkali liquor higher than the filter screen (2011) reversely overflows into the alkali liquor storage unit (202) to form the regenerated alkali liquor, and is continuously used for backwashing operation.

6. The system of claim 4, wherein a backwash inlet valve is arranged on a branch of the alkali liquor input pipeline (L3) which enters each filter, a backwash outlet valve is arranged on a branch of the alkali liquor recycling pipeline (L4) which is connected with each filter, the automatic switching of the backwash inlet valve and the backwash outlet valve is controlled by the switching control device (3), and the filter in a blocking state is backwashed while the stripping liquor filtering operation is kept to be continued, so that the continuous non-stop operation of the system is ensured.

Images