JP5248455B2 - Mask cleaning device - Google Patents

Description

  The present invention relates to a mask cleaning apparatus for cleaning a mask plate used in manufacturing an organic EL display by a combination of dry cleaning and wet cleaning.

  Unlike a liquid crystal display or the like, an organic EL display has advantages such as not requiring a backlight. In manufacturing an organic EL display, a microdot pattern of electroluminescent elements of each color of RGB is formed on the surface of a glass substrate. The electroluminescent elements are made of an organic material. Formation of a dot pattern of an organic material is performed by vacuum deposition. For this purpose, a mask plate is used. The mask plate is composed of a thin metal plate having a mask pattern in which minute through holes are formed at a predetermined pitch interval. The mask plate is fixed in a state where tension is applied to the frame body to constitute a mask member.

  Vacuum deposition is performed with the mask member mounted on the glass substrate and positioned at a predetermined position in the vacuum chamber. When this vacuum deposition is performed, the organic material also naturally adheres to the mask member. As the number of times of deposition increases, the amount of organic material attached to the mask member increases, and the organic material adhering to the mask pattern clogs the mask pattern. It is necessary to maintain the accuracy of the mask pattern by cleaning.

  Patent Document 1 describes that an organic material adhered and deposited on a mask member is removed by irradiating a laser beam. According to Patent Document 1, a pulse laser is applied to a mask member, and an organic material is peeled from the mask plate by a shock wave induced in the mask member. As a result, the organic material is in a floating state, but the floating material is configured to be sucked into the dust collector. Further, in order to completely remove the organic material remaining on the mask member after the dry cleaning by the laser light irradiation, wet cleaning is performed using water, alcohol, HFE (hydrofluoroether) or the like, The last drying is also disclosed in Patent Document 1.

JP 2009-117231 A

  When dry cleaning is performed by irradiating the mask member with laser light for cleaning, the organic material removed by this mask cleaning can be recovered and reused. Since the organic material constituting the electroluminescent element is expensive, it is desirable to reuse it in order to reduce the running cost of the organic EL manufacturing apparatus. Since laser light is scanned over the entire surface of the mask member at the time of dry cleaning, if the organic EL display becomes large, the mask member also becomes large. Therefore, it takes a long time to scan the laser light. On the other hand, when dipping is performed for wet cleaning of the mask member, the size of the mask member does not particularly affect the cleaning time. In addition, when performing shower cleaning or drying after cleaning, the mask member dimensions do not depend on the processing time as much as dry cleaning by laser light irradiation, but almost like mask cleaning like wet cleaning by dipping. It is not that it is not affected by the size of the.

  From the above, when the cleaning process of the mask member is configured to perform dry cleaning by laser light irradiation, then wet cleaning, and finally dry the mask member, the wet cleaning is particularly called dipping and showering. In addition, when it is performed in a plurality of stages, there is a problem that the cleaning of the mask member cannot be performed quickly and efficiently simply by arranging the stages.

  The present invention has been made in view of the above points, and an object of the present invention is to smoothly operate the cleaning process when the mask member is cleaned by combining dry cleaning and wet cleaning. It is possible to clean the mask member efficiently.

  In order to achieve the above-described object, the present invention is a mask cleaning apparatus for cleaning an organic EL mask member that removes an organic material adhering during pattern formation of a mask member used for organic EL pattern formation. A load stage for the mask member to be cleaned, a dry cleaning stage for separating and collecting the organic material adhering to the mask member by scanning the mask member with a laser beam, and a plurality of cleaning steps A wet cleaning stage comprising a stage and contacting a mask member from which an organic material has been removed in a dry cleaning stage; a drying stage for drying the mask member cleaned in the wet cleaning stage; and the load stage. Dedicated for loading the mask member into the dry cleaning stage. And supplying the mask member from the dry cleaning stage to an arbitrary wet cleaning stage constituting the wet cleaning stage, and supplying from an arbitrary wet cleaning stage to an arbitrary wet cleaning stage, The present invention is characterized by comprising an asynchronous mask transfer means for transferring from the final wet cleaning stage to the drying stage.

  Most of the organic material can be removed from the mask member by dry cleaning performed by irradiation with laser light. Specifically, the organic material can be peeled off from the mask member by dry cleaning, and the organic material thus peeled can be collected by suction. The organic material recovered in this way can be re-purified and reused. By increasing the recovery efficiency of the organic material adhering to the mask member, the recovery amount of the organic material is increased, and the load during the subsequent wet cleaning can be reduced. Here, in the case of dry cleaning, the cleaning time is roughly specified by the size of the mask member and the laser beam irradiation apparatus.

  The mask plate is made of metal, and generally a nickel alloy having a small thermal expansion coefficient is used. Therefore, when performing wet cleaning, a cleaning fluid that minimizes damage to the nickel alloy is used. Further, wet cleaning is performed by a complex cleaning method depending on whether different cleaning liquids are used, dipping, shower cleaning, ultrasonic vibration, or the like. Furthermore, the mask member is dried after the wet cleaning, and the transfer timing of the mask member from one stage to the other stage becomes fluid depending on various factors depending on how much heating is performed at the time of drying. . When the mask member size is large, dry cleaning by laser light irradiation is required for the longest time, and wet cleaning and drying can be performed in a shorter time.

  From the above, two types of mask member conveying means are provided. One transport means is a synchronous mask transport means for transferring a mask member at a constant timing, and the other transport means is an asynchronous mask transport means that operates at an arbitrary timing. The synchronous mask transfer means is used as a dedicated device for carrying the mask member from the load stage to the dry cleaning stage. On the other hand, the asynchronous mask transfer means is for taking out a mask member from an arbitrary stage and transferring it to an arbitrary stage.

  Here, the wet cleaning is typically dipping cleaning or shower cleaning, but other wet cleaning may be used. As the cleaning liquid, pure water, a cleaning liquid such as LC21, an alcohol-based cleaning liquid such as IPA (isopropyl alcohol), or a fluorine-based cleaning liquid such as HFE (hydrofluoroether) can be used. Also, the cleaning liquid can be subjected to ultrasonic vibration. Dipping cleaning and shower cleaning can be performed in one or more stages. Usually, the shower cleaning is a rinsing process in which the previous cleaning solution is washed away. Accordingly, a cleaning stage is provided every time the cleaning liquid is different and each cleaning method is different, and the cleaning stages are arranged in the mask member transport direction by the asynchronous mask transport means. When the cleaning is completed, the mask member is taken out from the stage and sent to the subsequent cleaning stage and from the final cleaning stage to the drying stage. If the cleaning liquid adheres to the mask member for a long time or high heat acts, the mask plate will be damaged. Therefore, it is necessary to avoid as much as possible the delay of the extraction timing after the processing at each stage of the mask member is completed. By providing the asynchronous mask transfer means, the mask member that has been processed can be transferred to the next processing step quickly and reliably with a smooth operation.

  By smoothly operating the cleaning process of the mask member, it is possible to minimize damage to the mask plate and to clean the mask member quickly and efficiently.

It is a front view of a mask member. It is composition explanatory drawing of the mechanism which performs dry cleaning with respect to a mask member. It is a block diagram showing the overall configuration of the mask cleaning device.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows a mask member. In the figure, reference numeral 1 denotes a mask plate, and the mask plate 1 is composed of a thin metal plate provided with a large number of minute through holes 2. The mask plate 1 is attached to the frame 3 with a predetermined tension, and a mask member 4 is configured. In manufacturing the organic EL display, each of the three micro-holes 2 is shifted in position, and the mask member 4 is sequentially positioned on a single glass substrate so as to face each other, and vacuum deposition is performed. Is done.

  When the vacuum deposition is repeated, the deposited organic material adheres to the mask member 4. Since the adhesion of the organic material is mainly the surface facing the evaporation source, mask cleaning for removing the organic material deposited on the mask member 4 is performed. Here, since the organic material may wrap around the back side, the mask cleaning is preferably performed on both sides.

  As a mask cleaning method, in the present invention, as shown in FIG. 2, laser dry cleaning performed by irradiating laser light is performed. In this method, a mask member 4 to which an organic material is adhered is held in a vertical state, a pulse laser is irradiated from a laser oscillator 5, and the pulse laser is applied to the mask member 4 through an objective lens 6 and a galvanometer mirror 7 in sequence. The organic material is peeled off from the mask plate 1 by irradiating the surface of the mask plate 1 of the mask member 4 with this laser light by the objective lens 6. Then, the organic material is peeled over the entire surface of the mask plate 1 by scanning the laser spot with the galvanometer mirror 7.

  A blower unit 8 is provided at an upper position of the mask member 4, and a suction unit 9 is provided at a lower position of the mask member 4. The organic material peeled off from the mask plate 1 by the laser light irradiation is conveyed to a downflow air flow composed of the air blowing unit 8 and the suction unit 9 and collected by the suction unit 9. This prevents the peeled organic material from reattaching to the mask plate 1 and allows the recovered organic material to be reused.

  Mask cleaning using laser light is performed as described above, but this alone does not clean the entire mask member 4. Therefore, the entire mask member 4 is cleaned by performing wet cleaning using a cleaning liquid after dry cleaning with laser light and then drying. The mask cleaning apparatus for this is configured as shown in FIG.

  In the figure, 10 is a load stage, 11 is a dry cleaning stage using laser light, 12 is a first wet cleaning stage performed by immersing the mask member 4 in a cleaning solution, and 13 is shower cleaning the mask member 4. A second wet cleaning stage is performed, 14 is a drying stage performed by supplying hot air to the mask member 4, and 15 is an unloading stage.

  A predetermined number of mask members 4 to be cleaned are stocked on the load stage 10, and the mask members 4 are taken out one by one from the load stage 10 and carried into the dry cleaning stage 11. The dry cleaning stage 11 is provided with the laser beam irradiation means shown in FIG.

  In the first wet cleaning stage 12, the mask member 4 that has been dry-cleaned and from which most of the organic material has been removed is immersed in the cleaning liquid, and cleaning between the frame body 3 and the mask plate 1 and the frame body 3 is performed by dipping. The organic material is eluted. As the cleaning liquid used in the first wet cleaning stage 12, pure water, a cleaning liquid such as LC21, an alcohol-based cleaning liquid such as IPA, a fluorine-based cleaning liquid such as HFE, or the like is used. Therefore, when a plurality of cleaning liquids are used in combination, the cleaning by the first wet cleaning stage 12 can be performed through two or more stages. In this case, a sub-stage composed of a plurality of dipping tanks filled with different cleaning liquids is provided.

  The second wet cleaning stage 13 performs shower cleaning, and this shower cleaning uses pure water and sprays the pure water on the mask member 4 in an ultrasonically vibrated state as necessary. To be configured. Here, the second wet cleaning stage 13 functions as a rinsing process for washing away the cleaning liquid after cleaning in the first wet cleaning stage 12 performed using the cleaning liquid.

  Furthermore, the mask member 4 wet-cleaned as described above is carried into the drying stage 14 and sprayed with hot air to remove droplets adhering to the mask member 4. Then, the mask member 4 dried in this way is sent to the unload stage 15, and when a predetermined number of mask members 4 are stocked on the unload stage 15, they are conveyed out of the system.

  Here, the dry cleaning stage 11, the first wet cleaning stage 12, the second wet cleaning stage 13 and the drying stage 14 are processing stages for processing the mask member 4. Each of the chambers 11C to 14C is fixedly held on each stage. The chambers 11C to 14C are provided with loading / unloading ports 11a to 14a for inserting and removing the mask member 4 at the upper position. On the other hand, for the load stage 10 and the unload stage 15, the storage boxes 10B and 15B provided with the loading / unloading ports 10a and 15a at the top are constituted by the carts 10T and 15T, and the carts 10T and 15T are self-propelled. Alternatively, the storage boxes 10B and 15B are introduced into and discharged from the load stages 10 and 15 by manual operation.

  Then, from the load stage 10, the mask members 4 are taken out one by one and sequentially supplied to the dry cleaning stage 11, the first wet cleaning stage 12, the second wet cleaning stage 13 and the drying stage 14, respectively. In order to carry and transfer between the stages 10 to 15 of the mask member 4, mask carrying means 20C and 20A are provided. The mask transfer means 20C is for transferring / transferring the mask member 4 from the load stage 10 to the dry cleaning stage 11, and the mask transfer means 20A is a stage from the dry cleaning stage 11 to the unload stage 15. The mask member 4 is conveyed between them.

  The mask conveying means 20C and the mask conveying means 20A have the same configuration. That is, as is apparent from FIG. 3, reference numeral 21 denotes a horizontal guide member. The horizontal guide member 21 is provided with an X-axis guide 21X, and an X-axis moving body 22 is engaged with the X-axis guide 21X. Thus, the X-axis moving body 22 can be moved in the X-axis direction, that is, the direction in which the stages 10 to 15 are arranged, by a driving means (not shown). The X-axis moving body 22 is elongated in the vertical direction, and a Z-axis guide 22Z in the vertical direction is formed. A Z-axis moving body 23 is mounted on the Z-axis guide 22Z, and the Z-axis moving body 23 can be moved in the Z-axis direction, that is, in the vertical direction by a driving unit (not shown). Further, an arm 24 is attached to the Z-axis moving body 23, and this arm 24 protrudes toward each stage 10-15. Further, the arm 24 is provided with two hands 25, 25, which have a predetermined length, and clamp the frame body 3 of the mask member 4 to their lower ends. A clamping member is provided.

  Each time the cleaning process at the dry cleaning stage 11 is completed, the mask transfer means 20C takes out the mask member 4 to be newly cleaned from the load stage 10 and enters the chamber 11C from the loading / unloading port 11a of the dry cleaning stage 11. It is for carrying in and is a synchronous mask transfer means.

  On the other hand, the mask conveying means 20A moves the mask member 4 between the dry cleaning stage 11, the first wet cleaning stage 12, the second wet cleaning stage 13, the drying stage 14 and the unload stage 15 which are processing stages. It is for delivery, and the mask member 4 is transferred and transferred between arbitrary stages, and is an asynchronous mask transfer means.

  The mask cleaning apparatus of the present invention is configured as described above. First, a predetermined number of mask members 4 are stocked on the load stage 10, and one mask member 4 stocked in this way is taken out by the mask carrying means 20 </ b> C and carried into the dry cleaning stage 11. That is, the X-axis moving body 22 is moved along the X-axis guide 21X of the horizontal guide member 21 of the mask transfer means 20C to a position facing the loading / unloading port 10a formed in the storage box 10B of the load stage 10, and The Z-axis moving body 23 is lowered along the Z-axis guide 22Z provided on the axis moving body 22. As a result, the hand 25 provided on the arm 24 is lowered and inserted into the storage box 10B. Therefore, one mask member 4 is taken out by a clamp member provided on the hand 25.

  Thereafter, the Z-axis moving body 23 is raised, the X-axis moving body 22 is moved to the upper position of the dry cleaning stage 11, and then the Z-axis moving body 23 is lowered again from the loading / unloading port 11a. The Z-axis moving body 23 is raised so as to be supplied to the chamber 11C and hold the mask member 4 in the chamber 11C. As a result, laser light is emitted from the laser oscillator 5 toward the mask plate 1 in the mask member 4, and the laser light is scanned along the mask plate 1 by the galvanometer mirror 7, whereby the organic material is removed from the mask plate 1. The organic material separated by the downflow air flow from the blower 8 toward the suction unit 9 is collected in the suction unit 9.

  When the cleaning at the dry cleaning stage 11 is completed, the mask transporting unit 20A is driven instead of the mask transporting unit 20C, and the mask member 4 after the dry cleaning is taken out and sent to the first wet cleaning stage 12. When the mask member 4 is taken out from the dry cleaning stage 11, a new mask member 4 is supplied from the load stage 10 to the dry cleaning stage 11 by the mask transport unit 20 </ b> C. The mask member 4 transferred to the first wet cleaning stage 12 is cleaned with the cleaning liquid in the dipping tank constituting the chamber 12C in the first wet cleaning stage 12. As a result, the organic material slightly remaining after the dry cleaning of the mask plate 1 and the organic material at the boundary between the frame 3 and the mask plate 1 and the frame 3 are removed.

  Next, the mask member 4 is transported and transferred from the first wet cleaning stage 12 to the second wet cleaning stage 13, and shower cleaning and rinsing are performed in the second wet cleaning stage 13. At this time, the mask member 4 is also transported by the mask transport means 20A. Further, when the processing in the second wet cleaning stage 13 is completed, the mask member 4 is supplied to the drying stage 14 and is dried with hot air in the drying stage 14. Then, the mask member 4 subjected to the drying process is transferred to the unload stage 15. Similarly, the transfer of the mask member 4 from the second wet cleaning stage 13 to the drying stage 14 and the transfer of the mask member 4 from the drying stage 14 to the unload stage 15 are similarly performed by the mask conveying means 20A. .

  Here, since most of the organic material adhering to the mask member 4 is removed in the dry cleaning stage 11, the load during the cleaning in the first wet cleaning stage 12 is reduced, and the inside of the chamber 12C is reduced. Contamination of the cleaning liquid is suppressed. Accordingly, the processing time in the first wet cleaning stage 12 and the processing time in the subsequent second wet cleaning stage 13 can be shortened, and damage to the mask member 4 can be suppressed to a minimum. In addition, since the mask transport unit 20A that can freely move between the stages 11 to 15 is driven independently of the mask transport unit 20C that transfers the mask member 4 from the load stage 10 to the dry cleaning stage 11, accurate timing is achieved. Thus, the mask conveying means 20A can be driven.

  By the way, in the processing stage comprising the dry cleaning stage 11, the first wet cleaning stage 12, the second wet cleaning stage 13 and the drying stage 14, the dry cleaning stage 11 scans the entire surface of the mask plate 1 with laser light. Because it has to be, it takes a long time. In particular, in the case of the large mask plate 1, the area of the laser beam irradiation scan is increased accordingly, so that a longer time is required. On the other hand, since most of the organic material is removed from the mask member 4 in the dry cleaning stage 11, the processing after the first wet cleaning stage 12 does not require a long processing time unlike the dry cleaning stage 11. . In particular, even when the size of the mask plate 1 is large, the processing time is not significantly different from that of a small mask plate.

  The transfer of the mask member 4 from the load stage 10 to the dry cleaning stage 11 is performed at regular intervals. This transfer is performed by the synchronous mask transfer means 20C, and the mask transfer means 20C transfers the mask member 4 periodically every predetermined time. The mask transfer means 20A is for moving the mask member 4 in the order of the dry cleaning stage 11, the first wet cleaning stage 12, the second wet cleaning stage 13, the drying stage 14, and the unload stage 15. The transfer timing is different for each. The mask member 4 is transferred and transferred between the five stages 11 to 15 by the mask transfer means 20A. Therefore, the mask transfer means 20A becomes an asynchronous transfer means.

  Here, in the first wet cleaning stage 12, the processing time varies depending on the concentration and temperature of the cleaning liquid. In the second wet cleaning stage 12, the processing time varies depending on the supply amount and supply pressure of shower cleaning, the temperature, and the like. Further, in the drying stage 14, the processing time varies depending on the temperature and the air volume. Therefore, it is desirable to set these process elements appropriately so that the damage to the mask member 4 is minimized and the processing time is shortened as much as possible.

  In any case, these processing stages require different processing times, and these processing stages are transported and transferred by the mask transport means 20A. Thus, by providing the two mask transfer means 20C and 20A, the mask member 4 can be transferred and transferred to the stages 10 to 15 quickly and easily. That is, the mask member 4 is transported / transferred first, and the mask member 4 is transported / transferred at a fixed timing, and the mask transporting means 20C is used. The mask member 4 can be transferred smoothly by transferring and transferring between the stages which are different in transfer timing and different transfer timings using another mask transfer means 20A.

  As described above, the mask cleaning performed by combining different cleaning methods of the dry cleaning and the wet cleaning and the drying of the mask member 4 after the wet cleaning can be performed quickly and efficiently, and the mask member 4 can be smoothly and without delay. Can be transported to each stage.

DESCRIPTION OF SYMBOLS 1 Mask board 2 Micro through-hole 3 Frame 4 Mask member 10 Load stage 11 Dry cleaning stage 12 First wet cleaning stage 13 Second wet cleaning stage 14 Drying stage 15 Unload stage 20C Synchronous mask conveyance means 20A Asynchronous type Mask transfer means

Claims (3)

A mask cleaning apparatus that cleans an organic EL mask member that removes an organic material adhering to a mask member used for pattern formation of an organic EL.
A load stage of the mask member to be cleaned;
A dry cleaning stage for separating and collecting the organic material adhering to the mask member by scanning the mask member with a laser beam;
A wet cleaning stage comprising a plurality of cleaning stages, the wet cleaning stage being performed by bringing the mask member from which the organic material has been removed in the dry cleaning stage into contact with the liquid;
A drying stage for drying the mask member cleaned in the wet cleaning stage;
A load-only synchronous mask transport means for transporting the mask member from the load stage to the dry cleaning stage;
The mask member is supplied from the dry cleaning stage to an arbitrary wet cleaning stage constituting the wet cleaning stage, is supplied from an arbitrary wet cleaning stage to an arbitrary wet cleaning stage, and further from the final wet cleaning stage. A mask cleaning apparatus comprising: an asynchronous mask transfer means for transfer to the drying stage. 2. The wet cleaning stage includes one or more first wet cleaning stages that perform cleaning by dipping and one or more second wet cleaning stages that perform shower cleaning. Mask cleaning device. 3. The mask cleaning apparatus according to claim 1, wherein an unload stage for storing a predetermined number of cleaned mask members is provided at a subsequent stage of the drying stage.

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