JP2014077935A - Regeneration method and regeneration apparatus for resist stripping solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that, in a residue concentration step of further concentrating a separated residual solution from a high boiling point separation step, a resist component or the like is obtained as a resist-containing residual solution while a solvent and water can be extracted as a vaporized separated substance, however, as the resist component is a solid organic substance at normal temperature, there is a probability of solidification and sticking of the resist component near an inlet/outlet of a residue concentrator when temperature decreases.SOLUTION: A regeneration method for regenerating a used resist stripping solution includes: a low boiling point separation step of separating a low boiling point substance such as water; a high boiling point separation step of extracting a solvent or the like, and a resist-containing residual solution containing a resist component as separated substances; a residue concentration step of further concentrating the resist-containing residual solution in a residue concentrator to separate the solvent or the like, and returning the solvent or the like to the high boiling point separation step; a purification step of vaporizing and separating residual water as a waste solution B from the separated substance in the high boiling point separation step, and extracting a separated residual solution as a regenerated stripping solution; and a cleaning step of introducing the separated residual solution in the low boiling point separation step to flow down in the residue concentrator.

Description

  The present invention relates to a method of regenerating a resist stripping solution that separates and recycles a solvent component from a used resist stripping solution, and in particular, in a residue concentrator and piping for concentrating a resist-containing residual solution from a high boiling point separator. The present invention relates to a method and an apparatus for regenerating a resist stripping solution that makes it difficult to produce a fixed matter.

  In the manufacture of semiconductors, liquid crystal displays, and organic and inorganic EL displays, photolithography techniques are frequently used. Here, a material thin film is formed on a substrate, and a pattern is formed thereon with a resist. Then, an etching process is performed along the resist pattern to form a material thin film in a desired pattern. Then, the last remaining resist is peeled off.

  The resist is a resin material having photosensitivity. For example, a novolak resin or the like is preferably used. Therefore, in order to remove the resist, a release agent in which a solvent serves as a base is used. For example, an aqueous stripping solution composed of a plurality of solvent components and water, such as a mixture of monoethanolamine and dimethyl sulfoxide, a so-called thinner which is a mixture of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, and the like is used.

  These solvents are used in large quantities and are never cheap. From the viewpoint of recycling, separation and recycling is the most effective method for each solvent component, but it is a practical method for cost separation and purification until individual solvents can be reused. It has not reached. In general, a used resist stripping solution is often used as a combustion aid, but it sometimes has moisture and is used in large quantities, so that it is costly to decompose by combustion.

  Therefore, the used resist stripping solution is collected, vaporized and separated, and reused. Patent Document 1 discloses a method for regenerating such a solvent. In the regeneration method of Patent Document 1, the resin component is first removed from the used resist stripping solution, and then the low boiling point impurities are removed by evaporation. Then, the residual liquid is distilled, and the solvent component is evaporated and recovered as a condensate.

  Patent Document 1 discloses a method of using a resin removal apparatus that aggregates resist and other components, which are final residues after vaporizing and separating water and solvent, in a method of regenerating such a used resist stripping solution. Has been. This resin removing apparatus includes a sealed cylindrical main body having an inner wall surface as an evaporable surface that can be heated, and a rotating body having brushes radially disposed on an outer peripheral surface disposed in the cylindrical main body. The point that the used solvent is supplied during this period, the low boiling point substance and the solvent are evaporated, and only the resin component is allowed to flow down is described.

Japanese Patent No. 3409090

  In the residue concentration step of further concentrating the separation residue in the high boiling point separation step, the residue is a resist component after use (hereinafter simply referred to as “resist component”) or an inorganic solid material such as a metal-based wiring material (for example, aluminum). The solvent and water can be taken out as a vaporized product. However, this resist component is an organic substance. In general, these resist components are solid at room temperature and dissolve in a solvent. However, if the temperature drops near the outlet of the residue concentrator, it may solidify and become stuck.

  Once fixed, it is not easy to peel even at temperatures above the boiling point. When solid matter is generated in the residue concentrator and the solid matter grows, the heat transfer rate in the residue concentrator decreases, the effective volume decreases, and a predetermined treatment rate cannot be secured. There is a problem that the pipes are blocked when the fixed matter increases due to fixation.

  The present invention has been conceived in view of the above problems, and the resist component heated to a high temperature in the residue concentrator is caused to flow down from the inner wall of the residue concentrator, and the temperature decreases near the outlet of the residue concentrator to solidify. Concentrate the residue by supplying a resist-containing residual liquid containing a resist component and a solvent, and a low-boiling point component containing water to the residue concentrator during a specified time period (when the residue concentrator starts and stops) so that it does not stick. By washing the resist component that has been solidified and stuck near the outlet of the vessel, the resist component is prevented from sticking to the residue concentrator.

More specifically, the method for regenerating the resist stripper of the present invention is as follows.
Used for resist stripping, from at least a solvent, a low boiling point component containing water, and a used resist stripper containing a resist component,
A low boiling point separation step in which a part of the low boiling point component containing water is separated and vaporized and separated as waste liquid A;
The high-boiling point is obtained by vaporizing and separating the separation residual liquid in the low-boiling-point separation step, taking out the remainder of the low-boiling component containing water and the solvent as a separation liquid, and using the resist-containing residual liquid containing the resist component as the separation residual liquid. A separation process;
Further concentrating the resist-containing residual liquid in a residue concentrator, separating the low-boiling component containing the solvent and the water, and returning the residue to the high-boiling separation step,
The purification step of evaporating and separating the remaining water as waste liquid B from the separation liquid of the high boiling point separation process, and taking out the separation residual liquid as a resist stripping regenerating liquid
The residue concentrator has a washing step of uniformly flowing down the separation residual liquid of the low boiling point separation step.

In addition, the resist stripper regenerator of the present invention comprises:
Used for resist stripping, from at least a solvent, a low boiling point component containing water, and a used resist stripper containing a resist component,
A low boiling point separator that separates and removes a part of the low boiling point component containing water and vaporizes and separates it as waste liquid A;
The low-boiling separator separation residual liquid is vaporized and separated, the remaining low-boiling component containing water and the solvent are taken out as separation liquid, and the resist-containing residual liquid containing the resist component is used as the separation residual liquid. A separator,
Further concentrating the resist-containing residual liquid, separating the low-boiling component containing the solvent and the water and returning it to the high-boiling separator;
A purifier that separates the remainder of the low-boiling component containing water from the separation liquid of the high-boiling separator as a waste liquid B, and removes the separation residual liquid as a resist stripping regenerating liquid;
The residue concentrator has a cleaning means for uniformly flowing down the separation residual liquid of the low boiling point separator.

  In the resist stripper regenerator according to the present invention, there is provided cleaning means for uniformly flowing the separation residual liquid of the low boiling point separator into the residue concentrator. Since the separation residual liquid of the low boiling point separator can serve as a solvent for the resist component, even if the resist component starts to be fixed on the inner wall of the residue concentrator, it can be washed away before it is completely fixed. For this reason, it is difficult for sticking matter to be generated in the residue concentrator, sticking when the temperature is lowered at the time of stoppage, and special cleaning and cleaning are not required even when the apparatus is stopped.

It is a figure which shows the structure of the reproduction | regeneration apparatus of the resist stripping solution which concerns on this invention. It is a figure which shows the detailed structure of a separation apparatus. It is a figure which shows the detailed structure of a residue concentrator. A mode that the resist component has adhered is shown. It is a figure which shows a mode that the washing | cleaning means is operated with the residue concentrator.

  Hereinafter, a method and apparatus for regenerating a resist stripping solution according to the present invention will be described with reference to the drawings. In addition, the following description demonstrates one Embodiment of this invention, is not limited to the following description, It can change in the range which does not deviate from the meaning of this invention.

  First, FIG. 1 shows an outline of a regenerator 1 for resist stripping solution of the present invention. The regenerator 1 of the present invention includes a pipe LX for transferring a used resist stripping solution from a collection tank 50 in which a used resist stripping solution is stored, a resist concentrate and a resist stripping regeneration solution from the used resist stripping solution, A separation device 10 for discharging waste liquid A and waste liquid B, which is mainly water, is included. Further, the separation device 10 is provided with a low boiling point separator 12 for separating the waste liquid A (water) and a residue concentrator 15 for producing a resist concentrate. Details of the separation device 10 will be described later with reference to FIG.

  In photolithography used for manufacturing semiconductors and the like, circuits and insulating patterns are formed by etching. At this time, a resist pattern is formed in a portion that is left without being etched. Then, after the etching is completed, this resist is removed. A resist stripping solution is used in this resist removing step. The resist itself is a photosensitive resin, and it is basically an organic solvent that removes the resist. Here, the description will be continued assuming that the resist stripping solution is a mixed solution of a solvent and water. An additive may be used to enhance the corrosion protection effect of the metal wiring. In addition, a small amount of the stripping solution composition may be appropriately added to pure water depending on the concentration and pH of the alkaline solvent constituting the resist stripping solution and the metal wiring material formed by photolithography.

  As the solvent, a plurality of solvents may be contained. Preferably used are mixtures of amine compounds and glycol ethers. More specifically, the amine compound is monoethanolamine (MEA), and diethylene glycol monobutyl ether (BDG) is preferably used as the glycol ether.

  The resist stripping solution is used in a resist stripping process (not shown), and is used in the recovery tank 50 as a used resist stripping solution together with the stripped resist. FIG. 1 is described from its collection tank 50. The used resist stripping solution stored in the collection tank 50 is sent to the separation device 10 via the pipe LX by the pump 52.

From the separation device 10, a resist concentrated liquid in which substances such as aluminum and SiO ₂ used in resist and metal wiring patterns are concentrated, a resist stripping regenerating liquid that is a mixed liquid of main solvent components, and water as waste liquid A. As a main low-boiling component and waste liquid B, a modified solvent and water having a lower boiling point than the main solvent component are separated and discharged.

  Throughout the present specification, the “modified solvent” refers to a solvent having a lower boiling point than the main solvent component, and may include a part of the main solvent component. In vapor separation, substances with boiling points around the separation temperature are included in the separation side and the residue side. Therefore, if an attempt is made to increase the recovery rate of the main solvent, water will be mixed into the main solvent side, and a solvent component will be mixed into the water side if the purity of the main solvent to be recovered is increased. That is, how much main solvent is contained in the “modified solvent” is determined by the operating conditions of the apparatus.

<Description of separation device>
Here, with reference to FIG. 2, the detail of the separation apparatus 10 is demonstrated. The separation device 10 includes a low boiling point separator 12, a high boiling point separator 14, a residue concentrator 15, and a purifier 16. The inlet 10i of the separation device 10 and the low boiling point separator 12 are communicated with each other through a pipe L0. The low boiling point separator 12 and the high boiling point separator 14 are communicated with each other through a pipe L1. The separation residual liquid of the low boiling point separator 12 is transferred to the high boiling point separator 14 through the pipe L1. Further, the vapor separated liquid from the low boiling point separator 12 is taken out through the pipe L2. This vapor-like separation liquid is waste liquid A. Waste liquid A is most of the water in the resist stripping solution.

  The high boiling point separator 14 is communicated with the residue concentrator 15, the pipe L3, and the pipe L4. The resist-containing residual liquid that is the separation residual liquid of the high boiling point separator 14 is transferred to the residue concentrator 15 through the pipe L3. Further, the vapor-like separation liquid from the residue concentrator 15 is sent again to the high boiling point separator 14 through the pipe L4. The vapor-like separation liquid from the high boiling point separator 14 is transferred to the purifier 16 through the pipe L5.

  In the middle of the pipe L1 for transferring the separation residual liquid of the low boiling point separator 12, a flow path changing means V20 is disposed. The configuration of the flow path changing unit V20 is not particularly limited, such as a combination of a three-way valve and an automatic valve. The branch side of the flow path changing unit V20 communicates with a pipe L3 that transfers the separation residual liquid (resist-containing residual liquid) of the high boiling point separator 14 to the residue concentrator 15.

  Therefore, by connecting the flow path changing means V20 to the branch side, the branch side of the flow path changing means V21 is opened, and the separation residual liquid of the low boiling point separator 12 can be directly transferred to the residue concentrator 15. The flow path changing means V20 is controlled to be opened and closed by a control device (not shown).

  Further, a flow path changing means V22 is provided in the pipe L8 which is a discharge pipe of the residue concentrator 15. From the flow path changing means V22, the discharged liquid can be returned to the recovery tank 50 via the pipe L22.

  The separation residual liquid is taken out from the purifier 16 through the pipe L6. The separation residual liquid at this time is a mixed liquid of a plurality of main solvents in the resist stripping liquid, and this is a resist stripping regenerating liquid. Further, the vapor-like separation liquid of the purifier 16 is transferred to the reflux tank 17 through the pipe L7. The waste liquid B is taken out from the reflux tank 17 through the pipe L11. This waste liquid B is a modified solvent and moisture having a lower boiling point than the main solvent component of the stripping solution. The remainder of the reflux tank 17 is returned to the vicinity of the top of the purifier 16 again through the pipe L10. A vacuum pump VP is disposed in the pipe L7.

The operation of the separation apparatus 10 configured as described above will be described. A used resist stripping solution is introduced into the separation device 10. The used resist stripping solution is a mixed state of the resist stripping solution, the stripped resist component, and a film-forming substance (inorganic solid material) having a pattern formed such as aluminum or SiO ₂ . In other words, water, a solvent, a mixed solution of a resist component and an inorganic solid material are introduced into the separation device 10 through the pipe LX.

  A low boiling point separator 12 is installed in the first stage of the separation apparatus 10. The low boiling point separator 12 has a cylindrical shape made of stainless steel, and is surrounded by a heat insulating material such as glass wool. In addition, a heater (reboiler) (not shown) is attached, and the used stripping solution from the recovery tank 50 heated to 40 to 60 ° C. in advance with a heat exchanger is heated via the heater to have a low boiling point. It is introduced into the separator 12. The inside of the low boiling point separator 12 is at normal pressure, preferably heated to 115 to 140 ° C. at the bottom and 85 to 115 ° C. at the top, more preferably 120 to 135 ° C. at the bottom. It is good to heat at 90-110 degreeC.

  Here, water in the used resist stripping solution is mainly vaporized and roughly separated. Since the vapor pressure of the constituent liquid components is reduced by reducing the pressure in the high-boiling separator 14 at the next stage, a large amount of water having a low boiling point is completely vaporized, and occupies most of the volume of the high-boiling separator 14. This is because the separation efficiency of a material having a higher boiling point is lowered. Therefore, the waste liquid A which is a vapor-like separation liquid from the low boiling point separator 12 is almost moisture. The vaporized and separated water is taken out as a waste liquid A through the pipe L2.

  The separation residual liquid at the bottom of the low boiling point separator 12 is heated from about 120 ° C. to 150 ° C. by a heater (reboiler) (not shown) and transferred to the high boiling point separator 14 via the pipe L1. The pipe L1 is covered with a heat insulating material such as glass wool. The separation residual liquid in the pipe L1 is kept at a temperature of approximately 115 ° C. to 140 ° C. The heat insulating material that keeps the temperature of the pipe L1 is called the pipe heat retaining means HL1. The separation residual liquid may absorb carbon dioxide in the air when it becomes a used resist stripping liquid. When this carbon dioxide gas reacts with a solvent (for example, monoethanolamine), a carbonate is formed.

  Since this carbonate easily absorbs carbonic acid at a predetermined temperature or less and is difficult to separate, it is separated together with the solvent in the subsequent high boiling point separation step. If the solvent mixed with the carbonate is used again as a resist stripping solution, the function of the stripping property is impaired, stripping failure occurs, and causes a substrate failure such as residue residue. Keeping the pipe L1 from 120 ° C. to 150 ° C. during the transfer of the separation residual liquid of the low boiling point separator 12 prevents the reaction between the solvent and carbon dioxide gas or the resist component in the used resist stripping solution. This is for preventing precipitation.

  The high boiling point separator 14 is a stainless steel tube like the low boiling point separator 12 and has a heater (reboiler). The surroundings are heated with an electric heater, steam from a boiler, heated oil, or the like and covered with a heat insulating material such as glass wool. The inside of the high boiling point separator 14 is depressurized to about 1.9 to 2.1 kPa (14 to 16 Torr), and the temperature is adjusted to 90 to 110 ° C. at the top and 95 to 110 ° C. at the bottom. Under this environment, the solvent is vaporized and separated. Of course, the remaining water and carbon dioxide are also vaporized and separated simultaneously.

  These vapor-like separation liquids are transferred to the purifier 16 by the pipe L5. As with the pipe L1, the pipe L5 is covered with a heat insulating material and kept at a temperature of about 90 ° C. to 110 ° C. It is the pipe heat retaining means HL5 that keeps the pipe L5 warm. The arrangement of the pipe heat retaining means HL5 is to prevent the reaction between the solvent and the carbon dioxide gas. Also, the pressure inside the pipe L5 is reduced by a vacuum pump VP which is a pressure reducing means in the system that is taken out from the pipe L7 between the purifier 16 and the reflux tank 17. Further, the pressure reduction by the vacuum pump VP is performed in the high boiling point separator 14, and the vapor-like separated liquid inside is transferred to the purifier 16.

  The separation residual liquid remaining in the high boiling point separator 14 is a high boiling point solvent component, a resist component, and an inorganic solid. This separation residual liquid is a resist-containing residual liquid. The resist-containing residual liquid is transferred to the residue concentrator 15 via the pipe L3. The residue concentrator 15 vaporizes and separates the resist-containing residual liquid sent from the pipe L3 under a reduced pressure at a temperature of 125 ° C. or lower again, and transfers the vaporized and separated liquid to the high boiling point separator 14 through the pipe L4. Let In addition, it is water and a solvent which are transferred to the high boiling point separator 14 here. Further, the vapor-like separation liquid of the residue concentrator 15 becomes a resist concentrated liquid.

  Therefore, most of the resist concentrate obtained from the residue concentrator 15 via the pipe L8 is a resist component and an inorganic solid. The residue concentrator 15 is also provided with a pipe L9 through which the separation residual liquid of the low boiling point separator 12 can be directly introduced from the pipe L1. The separation residual liquid from the pipe L9 is used when the residue concentrator 15 is washed as will be described later.

  The vapor-like separation liquid from the high boiling point separator 14 is transferred to the purifier 16. The purifier 16 also has a cylindrical shape made of stainless steel, and adopts a system having a heater (reboiler) in the same manner as the low boiling point separator 12 and the high boiling point separator 14. The surrounding area is covered with a heat insulating material such as glass wool. The vapor-like separation liquid from the high boiling point separator 14 is discharged to the middle of the purifier 16. The temperature inside the purifier 16 is adjusted at 80 to 90 ° C. at the reboiler, 65 to 90 ° C. at the middle stage, and 25 to 32 ° C. at the top of the column.

  Further, the pressure is reduced to about 1.9 to 2.1 kPa (14 to 16 Torr) by the vacuum pump VP. Here, the solvent is liquefied and recovered as a residual liquid through the pipe L6. Although not shown, the pipe L6 exchanges heat with the pipe LX, and collects the separation residual liquid at a more stable temperature. This separation residual liquid is a resist stripping reproduction liquid. That is, the resist stripping / regenerating solution is a mixture of a plurality of solvents.

  On the other hand, moisture and carbon dioxide are transferred to the reflux tank 17 through the pipe L7 as a vapor-like separation liquid. The pipe L7 is also kept at a temperature of about 20 to 25 ° C. by covering the periphery with a heat insulating material like the pipe L5 and the pipe L1. The pipe heat retaining means disposed in the pipe L7 is referred to as a pipe heat retaining means HL7. From the reflux tank 17, water and carbonate are taken out as waste liquid B through the pipe L11, and a part thereof is returned to the purifier 16 again.

  FIG. 3 shows an enlarged view around the residue concentrator 15 of FIG. The residue concentrator 15 is a thin film falling-type concentrator, and a heating means 34 for heating the inner wall surface 35 is provided outside the cylindrical main body. An axis that supports the brush 36 is disposed at the center of the main body. The shaft center is connected to the drive shaft of the motor 30 at the upper part of the main body. The tip of the brush 36 is in contact with the inner wall surface 35 inside the main body. That is, the brush 36 rotates while sliding on the surface of the inner wall surface 35 inside the main body.

  A circular plate that rotates in synchronization with the brush 36 is provided above the brush 36 and directly below the liquid inlet 32. This is because the liquid introduced from the liquid inlet 32 is caused to flow down uniformly on the inner wall surface 35. The liquid flowing down the heated inner wall surface 35 is collected at the receiving portion bottom 37 and communicated with the pipe L8 serving as a discharge pipe.

  The separation residual liquid (resist-containing residual liquid) from the high boiling point separator 14 is transferred to the liquid inlet 32 of the residue concentrator 15 by the pipe L3. In FIG. 3, the valves that are stopped by the flow path changing means V20, V21, and V22 are represented by black triangles. Most of the separation residual liquid is a resist component and an inorganic solid, but some amount of substances such as moisture and solvent to be vaporized and separated by the high boiling point separator 14 still remains.

  The separation residual liquid (resist-containing residual liquid) from the high boiling point separator 14 introduced from the liquid introduction port 32 flows down on the upper rotating circular plate and is in close contact with the heating means 34 of the residue concentrator 15. The wall surface 35 flows down thinly and uniformly. The separated separation liquid (resist-containing residual liquid) that has flowed down is uniformly thinned by the brush 36 while being heated, and most of the vaporized substances (water and solvent) are vaporized and separated. The separated product separated by vaporization is returned to the high boiling point separator 14 by the pipe L4. The separation residual liquid remaining without being evaporated is discharged to the pipe L8 as a resist concentrate.

  The heating means 34 of the residue concentrator 15 has a jacket structure for heating a metal inner surface. The metal inner surface is heated by introducing steam into the jacket portion so that the vaporization vapor temperature can be controlled at 95 to 125 ° C, more preferably 100 to 120 ° C. However, there is a portion where the temperature partially decreases inside the residue concentrator 15. For example, the upper end and the lower end of the heating means 34, particularly the receiving portion bottom portion 37 near the mouth of the pipe L8 to be discharged. In such a place, the resist component may be fixed as a fixed object 38. The resist component is an organic substance that is solid at room temperature and dissolves in a solvent. However, it often has a high boiling point substance, and is most difficult to vaporize during the composition of the resist stripping solution.

  If the fixed matter 38 is generated in the residue concentrator 15, the effective area in the residue concentrator 15 may be reduced or the rotation of the brush 36 may be hindered.

  Therefore, in the separation device 10 of the regenerator 1 according to the present invention, the flow path changing means V20, V21 and the pipe L9 for directly introducing the separation residual liquid of the low boiling point separator 12 into the residue concentrator 15 as a cleaning liquid are provided. Is provided. That is, the flow path changing means V20 and V21 and the pipe L9 constitute a cleaning means. Separation apparatus 10 has a separation residual liquid in low boiling point separator 12 via flow path changing means V20 disposed in the middle of pipe L1, pipe L9 communicating therewith, and flow path changing means V21 provided in pipe L3. Can be supplied. The separation residual liquid of the low boiling point separator 12 is a solvent-rich solution obtained by partially separating water from the used resist stripping solution.

  The supply of the solvent-rich solution as the cleaning liquid is mainly performed when the separation apparatus 10 itself is stopped, more specifically, before the operation of the residue concentrator 15 is stopped. This is because, if the residue concentrator 15 is not washed before the temperature is lowered, the fixed matter 38 is generated. Referring to FIG. 4, when the cleaning means is operated, the flow path changing means V20 and V21 are set on the branch side, and the solvent-rich solution from the low boiling point separator 12 is introduced from the pipe L9 through the pipe L3. Liquid is fed to the mouth 32.

  In FIG. 4, the water stop direction is represented by a black triangle in the flow path changing means V <b> 20, V <b> 21, V <b> 22 as in FIG. 3. While rotating the brush 36, the cleaning liquid is allowed to flow down the inner wall surface 35 of the residue concentrator 15 to prevent the addition of additives and the like, and the fixed matter 38 (see FIG. 3) is washed away. The receiving portion bottom 37 is also washed away with a solvent-rich solution before the resist component is fixed at low temperature.

  At this time, the temperature of the heating means 34 is lowered to at least the temperature of the component having the highest boiling point in the cleaning liquid (solvent component of the solvent-rich solution). The temperature is lowered by adjusting the heating means 34. For example, when the heating means 34 is performed by supplying a heating medium such as steam or heating oil, the inflow of these is stopped. This is because the cleaning liquid (solvent component in the solvent-rich solution) does not evaporate.

  A flow path changing means V22 is disposed in the pipe L8 which is a discharge pipe of the residue concentrator 15. When a solvent-rich solution (cleaning liquid) is supplied from the liquid inlet 32 when the residue concentrator 15 is started and stopped, the pipe L22 that communicates with the recovery tank 50 and the residue concentrator 15 communicate with each other. The flow path is selected as follows. Therefore, the washed-out fixed matter 38 is returned to the recovery tank 50 through the pipe L22. This is because the solvent-rich solution used for cleaning contains a large amount of solvent that can be reused. The step of supplying the used resist stripping solution into the residue concentrator 15 in this way may be called a cleaning step of the residue concentrator 15.

  The high boiling point separator 14 is continuously operated for a predetermined time, and the separation residual liquid (resist-containing residual liquid) is discharged to the residue concentrator 15. When the operation of the high boiling point separator 14 is stopped and the discharge of the separation residual liquid (resist-containing residual liquid) from the pipe L3 is stopped, the cleaning means is operated to supply the cleaning liquid (solvent rich solution) to the residue concentrator 15. However, the cleaning process is performed by continuing the operation for a predetermined time. That is, the cleaning process is performed at least before the operation of the residue concentrator 15 is completed. In addition, you may comprise so that continuous operation of these predetermined time may be switched with a timer.

  Further, this washing step may be performed before the operation of the residue concentrator 15 is started. Even if the cleaning process is performed before the end of the operation, some sticking matter remains and the driving part may stick. In such a case, if the residue concentrator 15 is rapidly started up, the drive part may be damaged. Since the washing step is a separation residual liquid of approximately 120 ° C. to 150 ° C. from the low boiling point separator 12, the residual concentrator 15 can be smoothly started by advancing the starting procedure while flowing the liquid to the inner wall surface 35. .

  As described above, the regenerator 1 according to the present invention cleans the inside of the residue concentrator 15 with the separation residual liquid (solvent rich solution) of the low boiling point separator 12, so that a fixed matter is generated in the residue concentrator 15. There is nothing. Therefore, at the time of restarting after stopping, it is possible to start up smoothly without performing special cleaning / cleaning for preventing operational troubles due to the solid matter.

  The apparatus and method for regenerating a resist stripping solution of the present invention can be suitably used for recycling a resist stripping solution in a manufacturing plant such as an electronic device having a step of forming a wiring pattern using photolithography. it can.

DESCRIPTION OF SYMBOLS 1 Regenerator 10 Separator 10i Inlet 12 Low boiling separator 14 High boiling separator 15 Residue concentrator 16 Purifier 17 Reflux tank 30 Motor 32 Liquid inlet 34 Heating means 35 Inner wall surface 36 Brush 37 Receiving part bottom part 38 Fixed substance 50 Collection tank 52 Pump HL1, HL5, HL7 Piping heat insulation means LX, L0, L1, L2, L3, L4, L5, L6, L7, L8, L9 Piping L10, L11, L22 Piping V20, V21, V22 Flow path changing means VP Vacuum pump

Claims (12)

Used for resist stripping, from at least a solvent, a low boiling point component containing water, and a used resist stripper containing a resist component,
A low boiling point separation step in which a part of the low boiling point component containing water is separated and vaporized and separated as waste liquid A;
The high-boiling point is obtained by vaporizing and separating the separation residual liquid in the low-boiling-point separation step, taking out the remainder of the low-boiling component containing water and the solvent as a separation liquid, and using the resist-containing residual liquid containing the resist component as the separation residual liquid. A separation process;
Further concentrating the resist-containing residual liquid in a residue concentrator, separating the low-boiling component containing the solvent and the water, and returning the residue to the high-boiling separation step,
The purification step of evaporating and separating the remaining water as waste liquid B from the separation liquid of the high boiling point separation process, and taking out the separation residual liquid as a resist stripping regenerating liquid
A method for regenerating a resist stripping solution, comprising: a cleaning step of uniformly flowing down the separation residual solution of the low boiling point separation step in the residue concentrator.   2. The method for regenerating a resist stripping solution according to claim 1, wherein in the cleaning step, the temperature in the residue concentrator is set to a temperature at least equal to or lower than the boiling point of the solvent of the separation residual solution in the low boiling point separation step. .   The separation residual liquid of the low boiling point separation step is transferred while being kept warm when transferred from the low boiling point separation step to the high boiling point separation step. A method for regenerating a resist stripping solution described in 1.   The separation liquid of the high boiling point separation step is transferred while being decompressed and kept warm when being transferred from the high boiling point separation step to the purification step. A method for regenerating a resist stripping solution according to claim 1.   The method for regenerating a resist stripping solution according to any one of claims 1 to 4, wherein the cleaning step is performed before the residue concentration step is stopped.   The method for regenerating a resist stripping solution according to any one of claims 1 to 5, wherein the cleaning step is performed before the start of the residue concentration step. Used for resist stripping, from at least a solvent, a low boiling point component containing water, and a used resist stripper containing a resist component,
A low boiling point separator that separates and removes a part of the low boiling point component containing water and vaporizes and separates it as waste liquid A;
The low-boiling separator separation residual liquid is vaporized and separated, the remaining low-boiling component containing water and the solvent are taken out as separation liquid, and the resist-containing residual liquid containing the resist component is used as the separation residual liquid. A separator,
Further concentrating the resist-containing residual liquid, separating the low-boiling component containing the solvent and the water and returning it to the high-boiling separator;
A purifier that separates the remainder of the low-boiling component containing water from the separation liquid of the high-boiling separator as a waste liquid B, and removes the separation residual liquid as a resist stripping regenerating liquid;
An apparatus for regenerating a resist stripping solution, comprising cleaning means for uniformly flowing down the separation residual liquid of the low boiling point separator in the residue concentrator.   8. The heating apparatus according to claim 7, further comprising a heating unit configured to set the temperature in the residue concentrator to a temperature at least equal to or lower than the boiling point of the solvent of the separation residual liquid of the low boiling point separator when the cleaning unit is operated. Of the resist stripping solution.   The pipe heat retaining means for keeping the pipe warm is provided in a pipe for transferring the separation residual liquid of the low boiling separator from the low boiling separator to the high boiling separator. The apparatus for regenerating a resist stripping solution according to any one of claims 7 and 8.   The piping for transferring the separation liquid of the high boiling separator from the high boiling separator to the purifier is provided with a decompression means for decompressing the inside of the piping and a piping heat retaining means for keeping the piping warm. An apparatus for regenerating a resist stripping solution according to any one of claims 7 to 9.   11. The apparatus for regenerating a resist stripping solution according to claim 7, wherein the cleaning unit operates before the residue concentrator is stopped.   12. The resist stripper regenerating apparatus according to claim 7, wherein the cleaning unit operates before the residue concentrator is activated.