JP2015020100A - Cleaning fluid of resist peeling liquid filtration filter, cleaning device and cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reuse again as a filtration filter by removing resist from a filter having filtrated resist peeling liquid obtained by removing positive type resist from a substrate.SOLUTION: A resist peeling liquid filtration filter after use is immersed into a cleaning fluid of the resist peeling liquid filtration filter containing ammonia as much as 2.5-12.5 mass% with respect to the whole amount of the cleaning fluid and hydrogen peroxide as much as 8.8-17.5 mass% with respect to the whole amount of the cleaning fluid. Hereby, attached resist can be removed, and further the resist peeling liquid filtration filter can be reused.

Description

  The present invention relates to a resist stripper filtration filter cleaning liquid, a cleaning apparatus, and a cleaning method for cleaning a resist stripper filter for filtering a resist stripper used for manufacturing liquid crystal and organic EL display devices and semiconductors. .

  In the resist stripping cleaning process in TFT (Thin Film Transistor) manufacturing processes such as liquid crystal and organic EL (Electro-Luminescence), resist deposits in the stripping solution and various foreign substances are reattached to the substrate, resulting in a product yield. In order to prevent deterioration, a peeling device is provided with a filter for filtering the peeling solution and the cleaning solution.

  In recent years, the size of the substrate has increased with the 8th to 10th generations, and the resolution has increased with full HD to 4K2K, and the risk of defects due to foreign matter adhering to the TFT pattern has increased dramatically. Yes.

  Therefore, measures such as increasing the filtration accuracy of the filter or increasing the filtration flow rate are taken. However, as a result, clogging of the filter occurs frequently, and in the case where there are many, there may be a case where the filter needs to be replaced in a cycle of several days.

  For example, in the 8th generation and later large substrate peeling and cleaning devices, usually 3 or more filters are installed per unit, and filter replacement, filter replacement labor and equipment operation due to frequent filter replacement Decreasing the rate is a major issue for factory operation. Therefore, regeneration of a clogged filter can be considered.

  Several proposals have heretofore been made from the viewpoint of regenerating the filter used in the etching process. For example, in an etching process of an insulating film such as silicon nitride (SiNx) in an LSI (Large Scale Integration) circuit or a TFT manufacturing process, a hardly soluble scale is deposited in the etchant, and the etchant filter is blocked. Therefore, an apparatus capable of exchanging and regenerating the filter without stopping the etching apparatus has been proposed.

  In Patent Document 1, two filters for filtering a fluorine-based etching solution used in the etching process are prepared. When one of the filters is clogged, the filter is switched to the other filter, and the clogged filter is washed with a cleaning solution. Techniques for cleaning and reusing are disclosed.

  The cleaning liquid used here is 1 to 20% by weight of a first chelating agent selected from alkylene polyamine polyacetic acid or an ammonium salt or alkali metal salt thereof, and a carboxylic acid or an ammonium salt thereof optionally having a hydroxyl group. Or 1 to 20% by weight of a second chelating agent selected from alkali metal salts and different from the first chelating agent, an alkali agent sufficient to make the pH of the cleaning liquid 9 to 11 and water, The total amount of the chelating agent and the second chelating agent is 5 to 30% by weight.

  Further, there is Patent Document 2 from the viewpoint of regeneration of a filter that filters the processing liquid at the time of etching. Patent Document 2 discloses that particles accumulated in a filter for filtering a processing solution for etching are dissolved and removed with a chemical solution. In this case, the material to be etched is a silicon nitride film, the etching treatment liquid is phosphoric acid, and the chemical liquid uses hydrofluoric acid.

  On the other hand, a photolithography technique is used for etching, and there is a disclosed technique for cleaning a filter for filtering a resist stripping solution used at that time. According to Patent Document 3, first, the substrate on which the resist remains is washed with a persulfuric acid solution in which ozone and / or hydrogen peroxide is added to a sulfuric acid solution. Next, the resist and the like are separated from the persulfuric acid solution containing the washed resist and the like by a filter.

  This filter is provided with two systems. When one of the filters is clogged, the filter is switched to the other and the filtration is continued. The filter that has been clogged first removes the persulfuric acid solution with compressed air. Then, ultrapure water is supplied to the filter, and the resist clogged in the filter is removed.

JP 2005-251936 A Japanese Patent Laid-Open No. 06-310487 JP 2007-266477 A

  Patent documents 1 and 2 mainly relate to regeneration of a filter obtained by filtering an etching solution obtained by etching silicon nitride. Therefore, even if knowledge is obtained regarding a filter cleaning apparatus in which two systems of filters are prepared and regenerated while switching, it cannot be said that it is disclosed in terms of regeneration of the filter after filtering the photoresist.

  On the other hand, Patent Document 3 is an invention relating to regeneration of a filter obtained by filtering a solution containing a photoresist used in an etching process. However, it is said that a persulfuric acid solution is used for substrate cleaning, and the resist hardly dissolves in this solution. Further, after removing the persulfuric acid solution with compressed air, the resist residue is removed from the filter with ultrapure water.

  However, usually, the resist remaining on the substrate when etching is completed is dissolved and removed with a resist stripping solution. When the resist stripping solution is filtered, a sticky resist solution remains as a filtration residue on the filter. This filtration residue adheres to the fibers constituting the filter. Therefore, it cannot be removed with ultrapure water as disclosed in Patent Document 3.

  Therefore, it can be concluded that Patent Document 3 does not disclose any knowledge about regeneration of a filter obtained by filtering a resist stripping solution obtained by removing a resist from a substrate.

  The present invention has been conceived in view of the above problems, and a cleaning liquid for removing a resist that has been removed by washing a filter (resist peeling liquid filtration filter) obtained by filtering a resist peeling liquid from which a resist has been removed from a substrate, and a resist An apparatus and a cleaning method for cleaning a stripping solution filtration filter are provided.

More specifically, the resist remover filtration filter cleaning liquid according to the present invention is:
It contains ammonia and hydrogen peroxide.

Further, the ammonia is contained in an amount of 2.5 to 12.5% by mass with respect to the total amount of the cleaning liquid,
The hydrogen peroxide is contained in an amount of 8.8 to 17.5% by mass with respect to the total amount of the cleaning liquid.

Moreover, the resist stripping solution filtration filter cleaning device according to the present invention is:
A washing tank;
Cleaning liquid supply means for supplying a cleaning liquid into the cleaning tank;
A filter cartridge connection disposed in the cleaning tank;
A first pipe coupled to the filter cartridge connection part;
A water outlet is connected to the first pipe, and the water inlet is connected to a pump connected to a second pipe communicating with the inside of the cleaning tank;
A cooling means for cooling the cleaning liquid in the cleaning tank;
It has exhaust means provided in the washing tank.

Moreover, the resist stripping solution filtration filter cleaning method according to the present invention includes:
An association process for associating the filter cartridge to be cleaned with the cleaning liquid;
A cooling step for cooling the cleaning liquid;
A separation step for separating the cleaning liquid and the filter cartridge to be cleaned;
It has a rinse process which wash | cleans the said to-be-cleaned filter cartridge with a rinse liquid.

  The cleaning solution for the resist stripping solution filtering filter according to the present invention can dissolve and remove the resist attached to the filter that filters the resist stripping solution that strips the developed positive resist from the substrate. Therefore, the used resist stripping solution filtration filter can be regenerated and used instead of being discarded.

  In addition, the cleaning liquid according to the present invention can remove even the resist adhering to the back of the bowl-shaped element only by immersing the used resist stripping solution filtration filter.

  In addition, the cleaning device for the resist stripping solution filtration filter according to the present invention includes a cooling unit, a defoaming unit, and an exhaust unit against the heat and bubbles generated when the post-use filter is cleaned with the cleaning solution according to the present invention. Since it has, it can wash | clean safely.

  Moreover, by having a stirring means, washing | cleaning can be completed more rapidly than the case where it is just immersed and left.

It is a figure which shows the structure of the resist peeling liquid filtration filter washing | cleaning apparatus which concerns on this invention. It is a figure which shows the state which installed the filter after use in the filter cartridge connection part in a washing tank, and has introduce | transduced the washing | cleaning liquid. It is a figure which shows the state by which the filter after use is completely immersed and wash | cleaned in the washing | cleaning liquid. It is a figure which shows the state which the washing | cleaning by a washing | cleaning liquid is complete | finished and the washing | cleaning liquid is discharged | emitted from the washing tank. It is a figure which shows the state which introduce | transduces a pure water into a washing tank and is performing the rinse process. It is a figure which shows the structure of the resist stripping solution filtration filter washing | cleaning apparatus which concerns on Embodiment 2. FIG. It is a figure which shows the association process in which the filter after use was immersed in the washing | cleaning liquid. It is a figure which shows the state in which the rinse process is performed by the 1st rinse tank after the washing | cleaning by a washing | cleaning liquid. It is a figure which shows the state in which the rinse process is performed by the 2nd rinse tank. (A) It is a figure which shows the structure of the evaluation jig | tool for investigating water permeability, and (b) the example of a measurement result.

  Hereinafter, the cleaning liquid, the cleaning apparatus, and the cleaning method of the resist stripping solution filtration filter according to the present invention will be described. The following description shows an embodiment of the photoresist stripping solution according to the present invention, and the following embodiments and examples may be modified without departing from the gist of the present invention.

(Embodiment 1)
FIG. 1 shows a cleaning apparatus for a resist stripping solution filtration filter according to the present invention (hereinafter simply referred to as “cleaning apparatus”). The cleaning apparatus 1 includes a cleaning tank 10, a filter cartridge connection unit 12, a pump 14, a cleaning liquid supply unit 16, a foam discharge unit 20, and an exhaust unit 22. Moreover, you may have the controller 30. FIG. FIG. 1 shows a case where there are three filter cartridge connecting portions 12.

  The cleaning tank 10 has a used resist stripping solution filtration filter (hereinafter also simply referred to as “after-use filter”) disposed therein, and a tank for removing the resist adhering to the post-use filter 9 (see FIG. 2) with the cleaning liquid. It is. The cleaning tank 10 is provided with a drain 10e and a bubble discharging means 20. The drain 10 e is a drainage path for discharging the solution in the cleaning tank 10. A drain valve 10ev is provided. The drain valve 10ev is preferably configured to be opened and closed by an external instruction CV10v.

  The foam discharging means 20 is a discharge port provided on the upper side surface of the cleaning tank 10. As will be described later, the cleaning liquid used in the cleaning tank 10 is a mixed solution of hydrogen peroxide and ammonia. When the filter is cleaned after use with this cleaning solution, it generates heat and foams. Therefore, the bubbles are discharged from the washing tank 10 by the bubble discharging means 20. The bubble discharging means 20 may be a through hole formed on the upper side surface of the cleaning tank 10.

  When the bubble discharging means 20 is configured by a through hole, the liquid level of the cleaning liquid rises up to the through hole, and the bubbles can be discharged while overflowing the cleaning liquid. Therefore, it is preferable to provide the through hole at a position above the liquid level where the post-use filter disposed in the cleaning tank 10 is completely immersed in the cleaning liquid.

  Further, the bubble discharging means 20 may be configured to suck and remove bubbles from the upper part of the cleaning tank 10. Moreover, the upper surface of the cleaning tank 10 may be opened, and an overflow tank (not shown) may be provided around the cleaning tank 10 to overflow the cleaning liquid from the upper end of the cleaning tank 10 and discharge the bubbles.

  The cleaning tank 10 is also provided with an exhaust means 22. Since the cleaning liquid contains hydrogen peroxide, a large amount of oxygen is released when the resist is dissolved. Therefore, attention is necessary for ignition. The upper end of the cleaning tank 10 may be opened, but it is desirable that the suction fan is rotated above the cleaning tank 10 to forcibly discharge it.

  The cleaning tank 10 is preferably provided with a temperature sensor 28. When the cleaning liquid dissolves the resist adhering to the filter after use, reaction heat is generated and the temperature of the cleaning liquid rises. Therefore, the cooling means 24 mentioned later is operated. Therefore, the measurement of the temperature of the cleaning liquid by the temperature sensor 28 can obtain information on the presence or absence of the operation of the cooling means 24 and the effect of the operation. Note that the temperature sensor 28 is preferably configured to transmit the measured temperature to the outside (a controller 30 described later) by a signal St.

  The cleaning tank 10 is preferably provided with a liquid level sensor 27. This is because the detection of the liquid level in the cleaning tank 10 can control the input / output of the cleaning liquid and the input / output of pure water.

  In the cleaning tank 10, a filter cartridge connection part 12 for setting a filter after use is provided. The filter cartridge connection part 12 is a cleaning liquid spout fitted into the connection port of the resist stripping liquid filtration filter. It is formed according to the connection port of the post-use filter to be cleaned. A plurality of filter cartridge connection portions 12 may be arranged in the cleaning tank 10.

  A first pipe 11 a is connected to the filter cartridge connection portion 12. The first pipe 11 a is connected to the water outlet 14 o of the pump 14 outside the cleaning tank 10. The handling of the first piping 11a is not particularly limited. A liquid-tight through hole may be provided on the side surface of the cleaning tank 10, and may extend outside the cleaning tank 10 from the liquid-tight through hole. The liquid supplied through the first pipe 11a is ejected from the filter cartridge connection part 12.

  A pressure sensor (indicated as “PI” in FIG. 1) 26 is provided between the first pipe 11 a and the pump 14. The type of the pressure sensor 26 is not particularly limited. The pressure sensor 26 preferably has a function of transmitting the currently measured pressure value to the outside as a signal Sp.

  A second pipe 11 b is connected to the water inlet 14 i of the pump 14. The other opening of the second pipe 11 b is disposed at the bottom of the cleaning tank 10. This is because the cleaning liquid can be pumped even when the level of the cleaning liquid in the cleaning tank 10 is low. It is desirable that the pump 14 is configured so that the operation can be started / stopped or the supply amount can be adjusted by an instruction Cp from the outside.

  The cleaning apparatus 1 preferably has a cleaning liquid cooling means 24. In the figure, “HEX” is indicated. This is because the cleaning liquid containing hydrogen peroxide foams exothermically. The cooling means 24 can be provided in the 1st piping 11a or the 2nd piping 11b. The form of the cooling means 24 is not particularly limited. In FIG. 1, the structure which provided the cooling means 24 in the 2nd piping 11b was shown. The cooling means 24 in FIG. 1 represents a heat exchanger. When the cooling water is supplied to the supply port 24i, heat exchange is performed with the second pipe 11b, and the cooling water that has received the heat is discharged from the discharge port 24o.

  The cooling unit 24 may have, for example, a structure in which a cooling pipe is disposed around the side surface of the cleaning tank 10 or a structure in which a cooling pipe is directly disposed inside the cleaning tank 10. Further, the cooling means 24 may be capable of adjusting the cooling efficiency by an instruction Ctm from the outside.

  The cleaning liquid supply means 16 supplies the cleaning liquid to the cleaning tank 10 from the outside of the cleaning tank 10. A supply pipe 16a for supplying cleaning liquid and an open / close valve 16b can be used. A cleaning liquid tank (not shown) is disposed upstream of the supply pipe 16a. The open / close valve 16b is preferably configured to be opened and closed by an external instruction CV16b.

  The pure water supply means 17 supplies pure water to the cleaning tank 10 from the outside of the cleaning tank 10. The pure water supply means 17 can be composed of a supply pipe 17a for supplying pure water and an open / close valve 17b. A pure water tank (not shown) is disposed upstream of the supply pipe 17a. Note that the opening / closing valve 17b is preferably configured to be opened and closed by an instruction CV17b from the outside.

  The washing tank 10 may be provided with shower means 18. The shower means 18 spreads the cleaning liquid on the liquid level of the cleaning tank 10 or on the resist stripping solution filtration filter disposed in the cleaning tank 10. In particular, the shower means 18 is effective in removing bubbles generated on the liquid surface of the cleaning liquid in the cleaning tank 10.

  The shower means 18 can be constituted by a supply pipe 18a, an opening / closing valve 18b, and a water spout 18c. The supply pipe 18 a can also be used as the supply pipe 16 a of the cleaning liquid supply means 16. This is because the same cleaning solution is allowed to flow. Further, the opening / closing valve 18b is preferably configured to be opened and closed by an instruction CV18b from the outside.

  Moreover, the controller 30 which controls the whole operation | movement may be provided. The controller 30 is connected to the pump 14, the cooling means 24, the pressure sensor 26, the liquid level sensor 27, the temperature sensor 28, the open / close valves 16b, 17b, 18b, and the drain valve 10ev. Then, the controller 30 transmits the signals of the instruction signals Cp, Ctm, CV16b, CV17b, CV18b, CV10v to the pump 14, the cooling means 24, the open / close valves 16b, 17b, 18b, and the drain valve 10ev, and the operation To control.

  In addition, signals Sp, SL, and St are received from the pressure sensor 26, the liquid level sensor 27, and the temperature sensor 28.

  Operation | movement of the washing | cleaning apparatus 1 which has the above structure is demonstrated. First, the cleaning tank 10 is in a state where there is no cleaning liquid. That is, after the previous cleaning, the solution in the cleaning tank 10 is discharged through the drain 10e. The open / close valve 17b of the pure water supply means 17, the open / close valve 16b of the cleaning liquid supply means 16, the open / close valve 18b of the shower means 18, and the drain valve 10ev of the drain 10e are closed.

  In such a state, the post-use filter 9 that is an object to be cleaned is attached to the filter cartridge connecting portion 12 (see FIG. 2). Thereafter, the operator may issue an instruction to the controller 30 or may perform each operation with his / her own hand. The following description will be made assuming that the controller 30 performs processing.

  The controller 30 transmits an instruction CV16b to the opening / closing valve 16b and opens the opening / closing valve 16b. When the opening / closing valve 16b is opened, the cleaning liquid flows through the supply pipe 16a and is injected into the cleaning tank 10. Here, the post-use filter 9 associates with the cleaning liquid (association step). The cleaning liquid is a mixed solution of hydrogen peroxide and ammonia as shown in the examples described later. In FIG. 2, the closed on-off valves 17b, 18b, and 10ev are filled with black.

  When the cleaning liquid reaches a higher liquid level than the opening of the second pipe 11b disposed at the lower part of the cleaning tank 10, the controller 30 transmits an instruction Cp to the pump 14 to operate the pump 14. The controller 30 can know the liquid level of the cleaning liquid from the signal SL from the liquid level sensor 27.

  When the pump 14 is activated, the cleaning liquid in the cleaning tank 10 is sucked into the second pipe 11b and sucked into the water inlet 14i of the pump 14. The cleaning liquid is supplied from the water outlet 14o of the pump 14 to the filter cartridge connecting portion 12 in the cleaning tank 10 through the first pipe 11a. Then, the cleaning liquid is ejected from the inside of the filter 9 after use. At this time, the resist adhering to the filter 9 after use is dissolved in the cleaning liquid. This may be referred to as a step of stirring the cleaning liquid (stirring step).

  When the cleaning solution dissolves the resist, an exothermic reaction occurs and the temperature rises. The controller 30 monitors the temperature of the cleaning liquid based on the signal St from the temperature sensor 28. When the temperature reaches a predetermined temperature or higher, a cooling instruction Ctm is transmitted to the cooling means 24. The cooling means 24 cools the cleaning liquid circulating in the pump 14, the first pipe 11a, and the second pipe 11b to a predetermined temperature (cooling step).

  The temperature of the cleaning liquid increases due to an exothermic reaction. In order to dissolve the resist adhering to the filter 9 after use, it is better that the temperature of the cleaning liquid is high to some extent. However, if it becomes too high, the material of the filter 9 after use becomes unbearable. The cleaning liquid is preferably about 50 ° C. to 70 ° C.

  When the liquid level of the cleaning tank 10 increases and reaches the level of the bubble discharging means 20, the cleaning liquid overflows (see FIG. 3). Further, foaming occurs when the temperature of the cleaning liquid increases. Therefore, when the liquid level of the cleaning liquid reaches the level of the bubble discharging means 20, the controller 30 sends an instruction CV 18b to the opening / closing valve 18b to activate the shower means 18 (defoaming step). The shower unit 18 sprays the cleaning liquid from above the liquid surface of the cleaning liquid and defoams it. Further, when the cleaning liquid overflows from the bubble discharging means 20, bubbles are also removed (bubble discharging step). The defoaming step may be operated before the liquid level reaches the level of the bubble discharging means 20.

  The controller 30 monitors the signal Sp from the pressure sensor 26 after operating the pump 14. Then, the circulation of the cleaning liquid is continued until the pressure of the pressure sensor 26 (feeding pressure of the cleaning liquid) becomes a predetermined pressure or less. While the resist is adhered, the pressure of the cleaning liquid is high. However, when the resist is dissolved and removed from the filter 9 after use, the pressure of the cleaning liquid is lowered.

  The controller 30 stops the shower unit 18, the pump 14, and the cooling unit 24 when the cleaning liquid supply pressure becomes a predetermined value or less. Then, the instruction CV10v is sent and the drain valve 10ev is opened. Thus, the cleaning liquid in the cleaning tank 10 is discharged (see FIG. 4). This can be said to be a separation process between the cleaning solution and the resist stripping solution filtration filter.

  When the cleaning liquid is discharged from the cleaning tank 10, the controller 30 closes the drain valve 10ev, transmits an instruction CV17b, and opens the open / close valve 17b. When the opening / closing valve 17b is opened, pure water is introduced into the cleaning tank 10 through the supply pipe 17a (see FIG. 5).

  When the surface of the pure water is above the opening in the cleaning tank 10 of the second pipe 11b, the controller 30 starts the pump 14. The pure water in the washing tank 10 is ejected from the inside of the filter 9 after use from the pump 14 to the outside. With this operation, the post-use filter 9 is rinsed (rinse washed) (rinsing step). In the rinsing step, the pump 14 is operated for a predetermined time determined in advance, and pure water is passed through the filter 9 after use. Further, in the rinsing process, it is not necessary to check the pressure supplied from the pump 14. This is because the flow resistance is low because the resist is already dissolved.

  When the passage of pure water for a predetermined time is completed, the controller 30 stops the pump 14, opens the drain valve 10ev, and discharges pure water. In addition, you may perform a rinse process in multiple times. By the above operation, the resist adhering to the post-use filter 9 is dissolved, and the post-use filter 9 can be reused. The resist stripping solution filtration filter after cleaning is referred to as a post-cleaning filter.

  In addition, when performing the rinse process in multiple times, when the water level of the washing tank 10 reaches the level of the bubble discharging means 20, the supply of pure water is stopped and the liquid is passed for a predetermined time. Thereafter, the pure water in the washing tank 10 is discharged, and the rinsing process is repeated a plurality of times. When the rinsing process is performed once, it may be performed while overflowing pure water. Of course, even when the rinsing process is performed a plurality of times, the pure water may overflow in each process.

(Embodiment 2)
In FIG. 6, the structure of the resist stripping solution filtration filter washing | cleaning apparatus 2 which concerns on this Embodiment is shown. In the case of Embodiment 1, since cleaning and rinsing with a cleaning liquid are performed in one cleaning tank 10, cleaning of the filter 9 after the next use cannot be started unless cleaning and rinsing are completed. In the present embodiment, a tank for cleaning with a cleaning liquid and a tank for rinsing are prepared separately.

  The resist stripping solution filtration filter cleaning device 2 according to the present embodiment includes a cleaning tank 40 and rinse tanks 42 and 44. Thus, by separately having the cleaning tank 40 and the rinsing tanks 42 and 44, the post-use filter 9 can be washed in a flowing manner and made recyclable. In this embodiment, the case where there are two rinsing tanks will be described. However, the number of rinsing tanks may be one, or may be three or more.

  The post-use filter 9 is placed in the cleaning tub 8 and moves between the cleaning tank 40 and the rinsing tanks 42 and 44. In other words, in the first embodiment, the type of liquid that passes through the post-use filter 9 is changed, but in this embodiment, the post-use filter 9 itself moves. The cleaning bowl 8 is moved by the moving device 50. As the moving device 50, for example, a crane including a rail 51, a winding pulley 52, and a chuck 53 can be suitably used.

  The cleaning tank 40 includes a drain 40e, a drain valve 40ev, a foam discharge unit 20, a shower unit 18, a cleaning liquid supply unit 16, a pump 14, a second pipe 11b, an exhaust unit 22, a cooling unit 24, a pressure sensor 26, and a temperature sensor. 28 is provided. However, the filter cartridge connection part 12 is not provided. Therefore, the first pipe 11 a communicates only with the cleaning tank 40 and does not communicate with the filter cartridge connection portion 12.

  The rinse tanks 42 and 44 are a first rinse tank 42 and a second rinse tank 44. Since the first rinse tank 42 and the second rinse tank 44 have the same configuration, the first rinse tank 42 will be described. The first rinse tank 42 includes a drain 42e and a drain valve 42ev. Further, pure water supply means 41 is provided. The pure water supply means 41 includes a supply pipe 41a and an opening / closing valve 41v. The opening / closing valve 41v is preferably configured to be opened / closed by an external instruction CV41v.

  Further, the first rinsing tank 42 may have an overflow means 42 ov and an aeration means 43. The overflow means 42ov is a waste water means for replacing pure water for rinsing. It may be a through hole formed in the upper side surface of the first rinse tank 42.

  The aeration means 43 includes an air diffusion pipe 43a, an air pipe 43b, and an open / close valve 43v. The air diffuser 43a is disposed so as to be under the washing basket 8 containing the filter 9 after use. The air pipe 43b extends from a compressed air source (not shown). An open / close valve 43v is provided in the middle of the air pipe 43b. That is, when the opening / closing valve 43v is opened, the compressed air is released from the diffuser tube 43a. The opening / closing valve 43v is preferably configured to be opened and closed by an instruction CV43v from the outside.

  The second rinsing tank 44 may be composed of the same components as the first rinsing tank 42. Therefore, it has the drain 44e, the drain valve 44ev, the pure water supply means 47, the overflow means 44ov, and the aeration means 45.

  Further, the resist stripping solution filtration filter cleaning device 2 is provided with a moving device 50 for transferring the cleaning basket 8 from the cleaning tank 40 to the first rinse tank 42 and from the first rinse tank 42 to the second rinse tank 44. The moving device 50 can place the cleaning basket 8 into the cleaning tank 40 from the initial placement location.

  Further, a transfer pallet (not shown) from the cleaning tank 40 to the first rinse tank 42, from the first rinse tank 42 to the second rinse tank 44, and from the second rinse tank 44 to the next process or the next process. Can be placed on top. Note that the hoisting pulley 52 of the moving device 50 and the raising / lowering and gripping / opening of the chuck 53 may be controlled by an instruction Cm from the outside.

  Further, the resist stripping solution filtration filter cleaning device 2 may have a controller 32. The controller 32 manages the movement of the washing tub 8 to each tank, the residence time for each tank, and the amount of solution supplied to each tank.

  Operation | movement of the resist stripping solution filtration filter washing | cleaning apparatus 2 which has the above structure is demonstrated. Referring to FIG. 7, the inside of cleaning tank 40 may be filled with a cleaning liquid. This is because the post-use filter 9 is put in the cleaning basket 8 and immersed in the cleaning tank 40.

  The controller 32 transmits an instruction Cm (see FIG. 6) to the moving device 50, causes the cleaning device 8 to be acquired from the first placement location, and is immersed in the cleaning tank 40 (association step). Needless to say, a post-use filter 9 to be cleaned is placed in the cleaning bowl 8.

  The controller 32 operates the pump 14 to circulate the cleaning liquid in the cleaning tank 40 (stirring step). When the post-use filter 9 in the cleaning bowl 8 associates with the cleaning liquid, the resist to which the cleaning liquid has adhered is dissolved. In addition, as shown also in the Example mentioned later, the washing | cleaning liquid which concerns on this invention can remove the adhering resist only by immersing the filter 9 after use. Therefore, the stirring step is not necessarily required.

  When the filter 9 is immersed in the cleaning liquid after use, heat generation and foaming occur. Therefore, the controller 32 detects the temperature of the temperature sensor 28 in the cleaning tank 40, and when the temperature becomes higher than a predetermined temperature, the controller 32 operates the cooling means 24 to cool the cleaning liquid (cooling process).

  Moreover, since it foams, the shower means 18 may be operated and the foam in the washing tank 40 may be defoamed (defoaming process). The exhaust means 22 is preferably always operated. In the present embodiment, the cleaning with the cleaning liquid is continued for a predetermined time determined in advance.

  Therefore, when the cleaning for a predetermined time is completed, the controller 32 transmits an instruction Cm (see FIG. 6) to the moving device 50, and transfers the cleaning basket 8 from the cleaning tank 40 to the first rinse tank 42 (see FIG. 8). ). In the first rinsing tank 42, the aeration means 43 is activated when the cleaning tub 8 is immersed in water (rinsing step). Specifically, the controller 32 transmits an instruction CV43v (see FIG. 6) to the open / close valve 43v, and sends air to the air diffuser 43a. By the operation of the aeration means 43, an impact is given to the cleaning basket 8 with air (aeration process).

  Due to the impact of the air, the post-use filter 9 vibrates in the cleaning basket 8 and the removal of the cleaning liquid is promoted. This first rinsing step is also performed for a predetermined time. During this time, a predetermined amount of pure water may be supplied from the pure water supply means 41 to the first rinsing tank 42 and the pure water may be discharged from the overflow means 42ov. This is to replace a certain amount of pure water.

  When the controller 32 performs the first rinsing process for a predetermined time, the controller 32 transmits an instruction Cm (see FIG. 6) to the moving device 50, and transfers the cleaning basket 8 to the second rinsing tank 44 (see FIG. 9). Even in the second rinse tank 44, the aeration means 45 is operated, and rinsing is performed while applying a shock to the filter 9 after use with compressed air. The second rinsing step is also performed for a predetermined time. Alternatively, a predetermined amount of pure water may be supplied to the second rinse tank 44 by the pure water supply means 47 so as to overflow from the overflow means 44ov, and the pure water in the second rinse tank 44 may be replaced.

  When the rinsing process in the second rinsing tank 44 is completed, the controller 32 transmits an instruction Cm to the moving device 50 and moves it to a predetermined position for drying the resist stripping solution filtration filter in the cleaning tub 8. The resist stripping solution filtration filter after cleaning is referred to as a post-cleaning filter.

  When a plurality of rinse tanks are prepared as in the present embodiment, the amount of pure water supplied to each rinse tank may not be the same. Specifically, in the case of the present embodiment, the pure water supply amount to the first rinse tank 42 and the pure water supply amount to the second rinse tank 44 may not be the same. For example, the amount of pure water supplied to the first rinse tank 42 may be less than the amount of pure water supplied to the second rinse tank 44.

  By having a plurality of rinsing tanks, the effect of removing the cleaning liquid is ensured even if the rinsing pure water in the first rinsing tank 42 is somewhat mixed with the cleaning liquid. On the other hand, if the amount of pure water supplied to the first rinse tank 42 can be reduced, the cost can be reduced.

  Moreover, although FIG. 7 to FIG. 9 have been described so that one washing basket 8 sequentially moves in each tank, the next washing bowl 8 may be placed in the tank after the washing bowl 8 has moved. For example, FIG. 6 shows a state in which the cleaning basket 8 is immersed in three tanks.

  As described above, the resist stripping solution filtration filter cleaning device 2 according to the present embodiment dissolves and removes the resist from the resist stripping solution filtration filter to which the resist is attached, and can be used again.

  Examples of the cleaning solution for the resist stripping solution filtration filter will be described below. The resist remover filtration filter is made of polypropylene and has a diameter of several μm to several tens of μm. The resist is a positive resist. Positive resists are frequently used for FPD and organic EL etching. A novolac resin is used as the resin component, and a photosensitive substance such as diazonaphthoquinone (DNQ) is used as the dissolution inhibitor.

  The resist stripping solution filtration filter is formed by bundling polypropylene (PP) fibers having a diameter of several μm to several tens of μm into a bowl-shaped element. The filtration accuracy (the size of foreign matter that can be filtered off) is 10 μm. The outer shape is 130 mm in diameter and 250 mm in length. It is put in a PP filter cartridge with a 30 × 50 mm square grid formed on the side. One end of the filter cartridge is provided with a flanged opening (diameter 50 mm) for pipe connection.

  In order to evaluate the cleaning effect of the resist stripping solution filtering filter, it is common to pass the liquid through the filter cartridge and measure the static pressure difference before and after the filter cartridge at a predetermined flow rate. However, the filter cartridge itself processes a large flow rate of 200 L / min, and the apparatus becomes large in order to evaluate the actual scale filter cartridge itself in the cleaning evaluation experiment. In addition, when the apparatus is increased in size, the amount of chemical solution and energy consumed is large, and it cannot be said that it is practical in terms of cost, labor, safety, and environmental load. Therefore, an evaluation jig for evaluating the water permeability of the filtration filter is required.

  FIG. 10A shows a configuration of an evaluation jig 60 for evaluating the water permeability of the filtration filter. The evaluation jig 60 includes a pure water supply source 67, a filter holder 62, a primary side pipe 66a, a secondary side pipe 66b, a manual valve 63, a flow meter 64, and a Bourdon tube pressure gauge 65.

  The filtration filter to be measured was obtained by disassembling the filter cartridge, taking out the filter material portion (element), cutting it into a circular shape with a diameter of 47 mm, and forming a filter piece 61 for experiments. The filter piece 61 was set on an In-Line Filter Holder, 47 mm (referred to as a filter holder 62) manufactured by Merck Millipore Corporation. The primary side 62 a of the filter holder 62 communicated with the pure water supply source 67. Further, the secondary side 62b of the filter holder 62 was in an open state. The pure water supply source 67 is supplied with pure water at a pressure higher by 0.3 MPa than the atmospheric pressure. In addition, all the following pressure displays show atmospheric pressure as a reference | standard (0 Mpa).

  A manual valve 63 for adjusting the flow rate, a flow meter 64 for measuring the flow rate, and a Bourdon tube pressure gauge 65 for measuring the pressure are installed on the pipe 66a on the primary side 62a of the filter holder 62. Note that the discharge port 66bx of the pipe 66b on the secondary side 62b of the filter holder 62 is arranged to be above the filter holder 62 in the gravity direction so that the secondary side pipe 66b is filled with pure water. ing. As the primary side pipe 66a, a normal PVC pipe or SUS pipe for water supply was used, and as the secondary side pipe 66b, a soft PVC hose was used.

  The evaluation was performed according to the following procedure. A filter piece 61 made from the filter element to be evaluated was held between the filter holder 62 of the evaluation jig 60. The filter piece 61 is held liquid-tight between the primary side pipe 66a and the secondary side pipe 66b. The manual valve 63 is opened and pure water is allowed to flow. Then, the flow rate Q is read from the flow meter 64 and the pressure ΔP is read from the Bourdon tube pressure meter 65. The inspection of the filter piece 61 by the evaluation jig 60 is referred to as “water passage inspection”.

  FIG. 10B illustrates a graph in which the relationship between the flow rate Q and the pressure ΔP is plotted as a result of the water flow inspection. The horizontal axis is the flow rate Q, and the vertical axis is the pressure ΔP. If the ΔP-Q relationship of the new filter is represented by a line 72, the relationship of ΔP-Q of the post-use filter is as shown by the line 70. Therefore, if the ΔP-Q relationship of the post-cleaning filter approximates the line 72, it can be said that the filter can be recycled.

  More specifically, a new resist stripping filter (hereinafter referred to as a “new filter”) has a pressure of 0.005 MPa to flow 600 ml of pure water per minute. On the other hand, in the post-use filter when the resist stripping solution is filtered and replaced, a pressure of 0.058 MPa is required to flow 500 ml of pure water per minute. That is, the resist stripping solution filtration filter after use has a single digit feeding pressure higher than that of a new one.

  The effect of the cleaning liquid according to the present invention was confirmed in the following manner. The filter after use was immersed for a predetermined time in the cleaning liquid according to the present invention (6 levels) and the cleaning liquid of the comparative example (10 levels), and the color change of the elements was visually confirmed. In addition, water permeability was checked with pure water after washing. For some of the filters after washing, the filter cartridge was disassembled, the bowl-shaped element was taken out, and visual observation, electron microscope observation, and IR absorbance analysis were performed.

  Table 1 shows the compositions of cleaning liquids of Examples and Comparative Examples (hereinafter also referred to as “sample cleaning liquids”). It also describes the determination of the washability of the post-use filter for each composition. In the determination, a case where it can be determined that it can be used practically is indicated by “◯” (circle), and cleaning is possible, but a case where it can be determined that practical use is difficult is indicated by “Δ” (triangle). The case where is not possible is represented by “x” (X). In addition, that it can be used practically means the case where the resist adhering to the filter after use can be removed in a few hours.

  Referring to Table 1, the examples were prepared from aqueous ammonia and aqueous hydrogen peroxide. A cleaning liquid having a predetermined composition ratio was prepared by mixing an appropriate amount of 25% by mass of ammonia water, 35% by mass of hydrogen peroxide water and pure water. For example, in the cleaning liquid of Example 1, the composition ratio was 2.5 mass% ammonia and 17.5 mass% hydrogen peroxide.

On the other hand, a comparative example is as follows.
The cleaning liquid of Comparative Example 1 is a hydrogen peroxide solution having a concentration of 8.8% by mass.
The cleaning liquid of Comparative Example 2 is a hydrogen peroxide solution having a concentration of 17.5% by mass.
The cleaning liquid of Comparative Example 3 is a hydrogen peroxide solution having a concentration of 35.0% by mass.
The cleaning liquid of Comparative Example 4 is a mixed liquid in which sulfuric acid is 5.0% by mass and hydrogen peroxide is 17.5% by mass.
The cleaning liquid of Comparative Example 5 is 68.0% by mass sulfuric acid.
The cleaning liquid of Comparative Example 6 is 96.0% by mass sulfuric acid.
The cleaning liquid of Comparative Example 7 is 99.8% by mass of acetone.
The cleaning liquid of Comparative Example 8 is 2.5% by mass of tetramethylammonium hydroxide (TMAH).
The cleaning liquid of Comparative Example 9 is 25% by mass of TMAH.
The cleaning liquid of Comparative Example 10 is monoethanolamine (MEA).

  A container containing 4 L of each sample cleaning solution was prepared, and the filter was immersed in the sample cleaning solution after use.

  In the sample cleaning solutions of Examples 1 to 6, after immersion for 3 hours, rinsing with pure water and visual inspection, the filter after cleaning became white in all cases. After washing these filters, the filters were disassembled and the saddle-like elements were observed in detail, but no portion remained brown. Even by observation with an electron microscope, no foreign matter remained between the fibers.

  Also, a water flow test was conducted, but the water flow pressure was the same as that of a new filter. Further, when IR absorbance was examined, no characteristic peak of novolak resin or a photosensitizer-derived substance (indenecarboxylic acid) after exposure was observed. In addition, when about 40 minutes passed after being immersed, it foamed violently and the temperature of the cleaning liquid also rose to 60 ° C.

  Comparative Examples 1 to 3 are hydrogen peroxide solutions having different concentrations. The filter after use immersed in these sample cleaning solutions did not lose the brown color in 3 hours. Therefore, it was continuously immersed for 10 days. After immersion for 10 days, the filter was rinsed with pure water to obtain the washed filters of Comparative Examples 1 to 3. As a result of visual observation, although a light brown color remained, it was considerably lighter brown than the filter after use. As for the degree of thinness, Comparative Example 3 having a high hydrogen peroxide content ratio was the thinnest, and Comparative Example 1 having a low hydrogen peroxide content ratio was darker than Comparative Example 3.

  When the filter was disassembled after washing and observed with an electron microscope, in the case of Comparative Example 1, it was confirmed that deposits remained between the fibers. In Comparative Example 3, the presence of deposits was slightly confirmed. When the water flow test was performed, the pressure was reduced to about one third as a result of comparison with the post-use filter. However, as in the example, the feed pressure did not decrease to the extent of a new filter.

  Comparative Example 4 is a mixed solution of sulfuric acid and hydrogen peroxide. The filter after use immersed in the sample cleaning solution of Comparative Example 4 did not change the color of the brown element when immersed for 3 hours as in Comparative Examples 1 to 3. Therefore, as in Comparative Examples 1 to 3, it was allowed to stand for 10 days. After immersion for 10 days, rinsing was performed to obtain a filter after washing. The washed filter of Comparative Example 4 had a lighter element color than the used filter. The color intensity was determined to be the same as in Comparative Example 2.

  Comparative Examples 5 and 6 are concentrated sulfuric acid. The post-use filter elements immersed in the sample cleaning solutions of Comparative Examples 5 and 6 did not change color in 3 hours. Therefore, it was immersed for 10 days. However, the color of the filter element after use for 10 days was almost unchanged. Considering the result of Comparative Example 4, it was considered that sulfuric acid hardly contributed to the regeneration of the filter after use.

  Comparative Example 7 is a single acetone. As in Comparative Examples 1 to 6, there was no change in the color of the filter element after use after immersion for 3 hours. Therefore, it was immersed for 10 days. However, there was no change in the color of the elements.

  Comparative Examples 8 and 9 are TMAH. TMAH is a chemical used at the time of development of etching, and is used when removing the exposed resist. However, even when immersed in TMAH for 10 days, there was no change in the color of the filter element after use. After immersion for 10 days, rinsing was performed and a water flow test was performed.

  Comparative Example 10 is monoethanolamine (MEA). The element color did not change after the MEA was also immersed for 10 days.

  As described above, it has been found that a cleaning solution containing ammonia and hydrogen peroxide is effective for removing deposits from the resist stripping solution filter and regenerating it like a new one. As shown in Comparative Examples 1 to 3, it is considered that hydrogen peroxide solution has a certain effect, but if it takes 10 days to remove the deposit, the resist stripping solution filtration filter should be replaced. Sometimes it is not in time for the cycle. Therefore, hydrogen peroxide solution alone is not effective.

  The cleaning solution for the resist stripping filter according to the present invention removes even the deepest part of the element folded in a bowl and stored in the filter cartridge by simply immersing the filter for several hours after use. Can do.

  The cleaning solution, cleaning device, and cleaning method for the resist stripping filter of the present invention can be suitably used for regeneration of a filter that filters the resist stripping solution when a positive resist is used. This can be suitably used for general production of FPD such as a liquid crystal display, a plasma display, and an organic EL.

DESCRIPTION OF SYMBOLS 1, 2 Resist stripping solution filtration filter washing | cleaning apparatus 8 Washing bowl 9 After use filter 10 Washing tank 10e Drain 10ev Drain valve 11a First piping 11b Second piping 12 Filter cartridge connection part 14 Pump 14i Water inlet 14o Water outlet 16 Cleaning liquid Supply means 16a Supply pipe 16b Open / close valve 17 Pure water supply means 17a Supply pipe 17b Open / close valve 18 Shower means 18a Supply pipe 18b Open / close valve 18c Sprinkling port 20 Foam discharge means 22 Exhaust means 24 Cooling means 24i (Cooling water) supply port 24o (Cooling water) outlet 26 Pressure sensor 27 Liquid level sensor 28 Temperature sensor 30, 32 Controller 40 Washing tank 40e Drain 40ev Drain valve 41 Pure water supply means 41a Supply pipe 41v Open / close valve 42 First rinse tank 42e Drain 42ev Drain Valve 42ov Overflow means 43 Aeration means 43a Aeration pipe 43b Air pipe 43v Open / close valve 44 Second rinse tank 44e Drain 44ev Drain valve 44ov Overflow means 45 Aeration means 47 Pure water supply means 50 Moving device 51 Rail 52 Winding pulley 53 Chuck

Claims (13)

An association process for associating the filter cartridge to be cleaned with the cleaning liquid;
A cooling step for cooling the cleaning liquid;
A separation step for separating the cleaning liquid and the filter cartridge to be cleaned;
A resist stripping liquid filtration filter cleaning method comprising a rinsing step of cleaning the filter cartridge to be cleaned with a rinsing liquid.   The resist stripping solution filtration filter cleaning method according to claim 1, further comprising a stirring step of stirring the cleaning solution after the association step.   Furthermore, it has the defoaming process of defoaming the foaming foam, The resist stripping solution filtration filter washing | cleaning method described in the claim of any one of Claim 1 or 2 characterized by the above-mentioned. In the rinsing step,
The resist stripping solution filtration filter cleaning method according to any one of claims 1 to 3, further comprising an aeration step of exposing the filter cartridge to be cleaned to aeration in the rinse liquid. The step of associating the filter cartridge to be cleaned with the cleaning liquid,
Allowing the cleaning liquid to pass through the filter cartridge to be cleaned;
The resist stripping solution filtration filter cleaning method according to any one of claims 1 to 4, wherein the cleaning solution is continued until a feeding pressure of the cleaning solution becomes a predetermined pressure or less.   6. The method of cleaning a resist stripping solution filter according to claim 1, wherein the cleaning liquid contains ammonia and hydrogen peroxide.   A cleaning solution for a resist stripping solution filtration filter, comprising ammonia and hydrogen peroxide. The ammonia is contained in an amount of 2.5 to 12.5% by mass with respect to the total amount of the cleaning liquid,
The cleaning solution for a resist stripping solution filtration filter according to claim 7, wherein the hydrogen peroxide is contained in an amount of 8.8 to 17.5 mass% with respect to the total amount of the cleaning solution. A washing tank;
Cleaning liquid supply means for supplying a cleaning liquid into the cleaning tank;
A filter cartridge connection disposed in the cleaning tank;
A first pipe coupled to the filter cartridge connection part;
A water outlet is connected to the first pipe, and the water inlet is connected to a pump connected to a second pipe communicating with the inside of the cleaning tank;
A cooling means for cooling the cleaning liquid in the cleaning tank;
An apparatus for cleaning a resist stripping solution filtration filter, comprising exhaust means provided in the cleaning tank.   The resist stripping solution filtration filter cleaning device according to claim 9, wherein a pressure sensor is provided in the first pipe. A washing tank;
Cleaning liquid supply means for supplying a cleaning liquid into the cleaning tank;
A first pipe communicating with the inside of the cleaning tank;
A water outlet is connected to the first pipe, and the water inlet is connected to a pump connected to a second pipe communicating with the inside of the cleaning tank;
A cooling means for cooling the cleaning liquid in the cleaning tank;
An apparatus for cleaning a resist stripping solution filtration filter, comprising exhaust means provided in the cleaning tank. Shower means for spraying a cleaning liquid from the upper part of the cleaning tank;
The resist stripping solution filtering filter cleaning device according to any one of claims 9 to 11, further comprising foam overflow discharge means provided in the cleaning tank.   The resist cleaning solution filtration filter cleaning device according to any one of claims 9 to 12, wherein the cleaning solution contains ammonia and hydrogen peroxide.