KR20220089669A - Nozzle cleaning apparatus and coating apparatus - Google Patents

Abstract

In order to efficiently clean the nozzle that discharges the dispersion-based coating liquid, the nozzle cleaning apparatus according to the present invention includes a lower end of a cleaning tank in which a storage area for storing a cleaning liquid for cleaning the lower end of the nozzle is formed, and a lower end of the nozzle in the cleaning liquid stored in the storage area. A cleaning tank having an opening allowing immersion of the liquid, a liquid tank installed below the cleaning tank in a state in which the lower end of the cleaning tank is immersed in the liquid while storing the liquid, and ultrasonic vibration in the liquid stored in the liquid tank to generate the liquid, the cleaning tank An ultrasonic vibrator for applying ultrasonic vibration to the lower end of the nozzle through the lower end and the cleaning liquid is provided. The lower end of the washing tank and the storage area are finished in a shape that tapers toward the ultrasonic vibrator when viewed from the first horizontal direction.

Description

Nozzle cleaning apparatus and applicator {NOZZLE CLEANING APPARATUS AND COATING APPARATUS}

The present invention relates to a nozzle cleaning apparatus for cleaning a nozzle that discharges a dispersion-based coating liquid in which a pigment, microcapsules, etc. are dispersed, and a coating apparatus equipped with the nozzle cleaning apparatus.

In order to manufacture liquid crystal display displays or optical filters, there have been proposed more coating devices than before in which a dispersion-based coating solution in which a dispersion-based material such as a pigment or microcapsule is dispersed is applied to an object to be coated, such as a substrate or substrate. has been For example, in Japanese Patent Application Laid-Open No. 2009-226287 (Patent Document 1), a dispersion-based coating liquid is discharged onto the surface of a base material such as a plastic sheet from a discharge port formed at the tip of a slot die corresponding to an example of the nozzle of the present invention. , a coating film of the dispersion-based coating liquid is formed on the substrate. Moreover, in Unexamined-Japanese-Patent No. 2018-149468 (patent document 2), the dispersion system coating liquid is discharged to a rectangular-shaped board|substrate from the discharge port of the slit nozzle corresponded to an example of the nozzle of this invention, and the dispersion system coating liquid is discharged on the board|substrate. of the coating film is formed.

In such a coating apparatus, a residue adheres to the vicinity of the discharge port of a nozzle (slot die, slit nozzle, etc.) by application|coating of a coating liquid. That is, the tip of the nozzle is contaminated with residual deposits. Therefore, it is necessary to wash|clean a nozzle appropriately using the nozzle washing|cleaning apparatus of patent document 2, for example. This nozzle cleaning apparatus is provided with a cleaning tank. The washing tank is opened upward, and stores the rinse liquid (washing liquid). This rinsing liquid is a solvent for the residual deposits adhering to the nozzle.

In the nozzle cleaning apparatus described above, the cleaning tank has a box shape with a bottom having a rectangular cross section, and is capable of storing a relatively large amount of rinsing liquid. For this reason, the rinse liquid required for nozzle cleaning also becomes large. For this reason, the problem that running cost increases, and the time required for replacement|exchange of a rinse liquid is long, and the efficiency of nozzle cleaning is lowered.

In particular, when a dispersed coating liquid is used, the dispersed material is often a solid insoluble in the cleaning liquid, and it is difficult to efficiently remove the dispersed material adhering to the vicinity of the nozzle discharge port only with the cleaning liquid. it is thought That is, a cooling water storage tank storing cooling water for cooling the ultrasonic vibrator is disposed below the cleaning tank in a state in which the lower surface of the cleaning tank is immersed in the cooling water stored in the cooling water storage tank. In addition, an ultrasonic vibrator is disposed on the inner bottom surface of the cooling water storage tank, and the ultrasonic vibration is propagated through the cooling water to the cleaning tank. This ultrasonic vibration is also imparted to the tip of the nozzle through the cleaning liquid, so that the dispersed material can be efficiently removed from the vicinity of the discharge port of the nozzle. However, bubbles generated in the cooling water during application of ultrasonic vibration may adhere to the outer bottom surface of the cleaning tank to lower the propagation efficiency of the ultrasonic vibration, which is one of the main reasons for the decrease in the efficiency of nozzle cleaning.

In addition, as described above, the dispersed material removed from the vicinity of the discharge port of the nozzle by the ultrasonic vibration spreads over the entire inner bottom of the cleaning tank and is deposited. Therefore, it is difficult to efficiently discharge the dispersed material from the cleaning tank with the rinsing liquid, thereby reducing the efficiency of nozzle cleaning.

This invention was made in view of the said subject, and an object of this invention is to provide the nozzle cleaning apparatus and coating apparatus which can wash|clean efficiently the nozzle which discharges a dispersion system coating liquid.

One aspect of the present invention is a nozzle cleaning apparatus for cleaning a nozzle that discharges a dispersion-based coating liquid from a first horizontally extending slit-shaped discharge port formed at the lower end of the nozzle, the storage area for storing the cleaning liquid for cleaning the lower end of the nozzle is provided. A cleaning tank having a lower end of the cleaning tank to be formed and an opening allowing the lower end of the nozzle to be immersed in the cleaning liquid stored in the storage area, and a liquid tank installed below the cleaning tank in a state in which the lower end of the cleaning tank is immersed in the liquid while storing the liquid; An ultrasonic vibrator is provided that generates ultrasonic vibrations in the liquid stored in the tank and imparts ultrasonic vibrations to the nozzle lower end through the liquid, the lower end of the cleaning tank and the cleaning liquid, wherein the lower end of the cleaning tank and the storage area are viewed in the first horizontal direction, It is characterized in that the tip is finished in a shape that narrows toward the ultrasonic vibrator.

Another aspect of the present invention is a coating device, comprising: a coating processing unit for discharging a dispersion-based coating liquid from a nozzle from a first horizontally extending slit-shaped discharge port formed at the lower end of the nozzle to apply the dispersion-based coating liquid to an object to be coated; , the nozzle cleaning device for cleaning the nozzle is provided.

In the invention constituted as described above, when the ultrasonic vibrator operates, ultrasonic vibrations generated by the ultrasonic vibrator are imparted to the lower end of the nozzle through the liquid stored in the liquid tank, the lower end of the cleaning tank, and the cleaning liquid stored in the cleaning tank. Thereby, the dispersed material is removed from the vicinity of the discharge port of the nozzle, and is collected at the tip portion of the storage area. Since this storage area has a tapered shape, the amount of cleaning liquid stored in the storage area and the time required for storage are smaller than those of a conventional cleaning tank having a rectangular cross-sectional shape, reducing running cost In addition, the time required for nozzle cleaning can be shortened.

In addition, in the lower end of the washing tub having a tapered shape, the outer surface thereof is inclined obliquely upward from the tip portion of the lower end of the washing tub. For this reason, bubbles generated in the liquid in the liquid tank during application of ultrasonic vibrations, after reaching the lower end of the cleaning tank, further rise in the liquid along the outer surface and are discharged from the liquid tank. Thereby, adhesion of the bubble to a washing tank is suppressed effectively, and the propagation efficiency of an ultrasonic vibration improves.

As described above, since the shape of the lower end of the washing tank and the storage region when viewed from the first horizontal direction is narrowed toward the ultrasonic vibrator, the nozzle for discharging the dispersion-based coating liquid can be cleaned efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows typically the application|coating apparatus equipped with one Embodiment of the nozzle washing|cleaning apparatus which concerns on this invention.
FIG. 2 : is a side view which shows typically the application|coating apparatus shown in FIG.
3 : is a top view which shows schematically arrangement|positioning of each part of the application|coating apparatus shown in FIG.
4 : is a perspective view which shows typically a slit nozzle.
5 is a perspective view showing the configuration of a cleaning unit that is an embodiment of the nozzle cleaning apparatus according to the present invention.
FIG. 6 is a diagram showing the configuration of a piping system and an electric system connected to the cleaning unit shown in FIG. 5 .
FIG. 7 is a flowchart showing a nozzle cleaning operation performed by the cleaning unit shown in FIG. 5 .

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows typically the application|coating apparatus equipped with one Embodiment of the nozzle washing|cleaning apparatus which concerns on this invention. Moreover, FIG. 2 is a side view which shows typically the coating apparatus shown in FIG. In addition, FIG. 3 is a top view which shows schematically arrangement|positioning of each part of the coating device shown in FIG. 1, 2, 3 and subsequent drawings, in order to clarify their directional relationship, an XYZ Cartesian coordinate system with the Z direction as the vertical direction and the XY plane as the horizontal plane is appropriately attached, and if necessary The dimensions or numbers of each part are exaggerated or simplified. In addition, in FIG.2 and FIG.3, the structure of a part, such as a nozzle support body, is abbreviate|omitted.

The coating device 1 is a coating device called a slit coater that applies a coating liquid to the surface 31 of the substrate 3 which is an example of the to-be-coated object using the slit nozzle 2 . The coating liquid is a dispersion-based coating liquid in which a dispersion-based material such as a pigment or microcapsule is dispersed. Further, as the cleaning liquid for cleaning the dispersion-based coating liquid adhering to the slit nozzle 2, in this embodiment, PGMEA (propylene glycol monomethyl ether acetate), thinner (ether solvent or ketone organic solvent) etc.), a mixed solution of PGMEA and PEGME (polyethylene glycol monomethyl ether: polyethylene glycol monomethyl ether) is used. Moreover, the board|substrate 3 is a glass substrate which has a rectangular shape in planar view. In addition, in this specification, the "surface 31 of the board|substrate 3" means the main surface of the side to which the coating liquid is apply|coated among the both main surfaces of the board|substrate 3.

The coating apparatus 1 is the stage 4 which can hold|suck and hold the board|substrate 3 in a horizontal attitude|position, and apply|coating which apply|coats to the board|substrate 3 hold|maintained by the stage 4 using the slit nozzle 2 It includes a processing unit 5 , a nozzle maintenance unit 6 that performs maintenance processing on the slit nozzle 2 , and a control unit 100 that controls each of these units.

The stage 4 is comprised of stones, such as granite which has a substantially rectangular parallelepiped shape. On the (-Y) direction side of the upper surface (+Z side), it has a holding surface 41 which is processed into a substantially horizontal flat surface and holds the substrate 3 . A large number of vacuum adsorption ports (not shown) are dispersedly formed on the holding surface 41 . By adsorbing the board|substrate 3 by these vacuum suction ports, the board|substrate 3 is horizontally hold|maintained at a predetermined position at the time of a coating process. In addition, the holding|maintenance aspect of the board|substrate 3 is not limited to this, For example, you may comprise so that the board|substrate 3 may be hold|maintained mechanically. Moreover, in the stage 4, the nozzle adjustment area|region RA is formed in the (+Y) direction side from the area|region occupied by the holding surface 41. As shown in FIG. As will be described later in this nozzle adjustment area RA, a nozzle maintenance unit 6 having an embodiment of the nozzle cleaning apparatus according to the present invention is disposed.

4 is a perspective view schematically showing a slit nozzle. The slit nozzle 2 has two nozzle bodies 23 and 25 and a nozzle shim 27 sandwiched between these nozzle bodies 23 and 25 from the Y direction. The nozzle bodies 23 and 25 are respectively extended and installed in the X direction with the same width. The nozzle body 23 has a trapezoidal lower end 23a and a rectangular upper end 23b in YZ cross section. The nozzle body 25 has a trapezoidal lower end 25a and a rectangular upper end 25b in the YZ cross section. The surfaces of the inner sides (the nozzle core 27 side) of the nozzle bodies 23 and 25 are planes parallel to the ZX plane, respectively. On the other hand, the surface of the outer side (the opposite side of the nozzle shim 27) of the lower end parts 23a, 25a of the nozzle bodies 23 and 25 is an inclined surface which inclines so that it may approach the nozzle shim 27 as it goes downward, respectively. Accordingly, the lower end 2a (nozzle lip portion) of the slit nozzle 2 constituted by the lower end portions 23a and 25a of the nozzle bodies 23 and 25 has a shape that tapers downward. Then, in the lower end portion 2a, a slit-shaped discharge port 21 is extended in the X direction, and the coating liquid supplied by pressure from a coating liquid supply unit (not shown) flows from the discharge port 21 to the substrate 3 . It is discharged to the surface 31 . Thereby, the coating liquid is apply|coated to the surface 31 of the board|substrate 3 .

Returning to FIG. 1, description of the structure of the application|coating apparatus 1 is continued. The application|coating processing part 5 has the nozzle support body 51 which supports the slit nozzle 2 . The nozzle support body 51 includes a support member 51a extending parallel to the X direction from above the stage 4, and supporting the support member 51a from both sides in the X direction to raise and lower the support member 51a. It has two raising/lowering mechanisms 51b. The support member 51a is a bar member made of carbon fiber reinforcing resin or the like and having a rectangular cross section. The lower surface of the supporting member 51a serves as a mounting location 510 for the slit nozzle 2 , and the supporting member 51a removably supports the slit nozzle 2 at the mounting location 510 . In addition, as a mechanism for attaching and detaching the slit nozzle 2 to the attachment point 510 of the support member 51a, various fastening mechanisms, such as a latch or a screw, can be used suitably.

The two lifting mechanisms 51b are connected to the both ends of the longitudinal direction of the support member 51a, and have an AC servomotor, a ball screw, etc., respectively. By these lifting mechanisms 51b, the support member 51a and the slit nozzle 2 fixed thereto are raised and lowered in the vertical direction (Z direction). Thereby, the distance between the discharge port 21 opened at the lower end of the slit nozzle 2 and the substrate 3 , that is, the relative height of the discharge port 21 with respect to the substrate 3 is adjusted. In addition, although the position of the vertical direction of the support member 51a is abbreviate|omitted, for example, the scale part provided in the side surface of the raising/lowering mechanism 51b, and the side surface of the slit nozzle 2 facing the said scale part. It can be detected by a linear encoder constituted by a detection sensor installed on the back.

As shown in FIG. 1 , the nozzle support body 51 configured in this way has a cross-linked structure spanning the holding surface 41 disposed along the X direction over the left and right (X direction) both ends of the stage 4 . The application|coating processing part 5 has the slit nozzle moving part 53 which moves this nozzle support body 51 in a Y direction. The slit nozzle moving unit 53 relatively moves the nozzle support 51 as a crosslinked structure and the slit nozzle 2 supported thereon along the Y direction with respect to the substrate 3 held on the stage 4 . It functions as a means of relative movement. Specifically, the slit nozzle moving unit 53 includes a guide rail 52 for guiding the movement of the slit nozzle 2 in the Y direction in each of the (±X) side, and a linear motor 54 serving as a driving source. and a linear encoder 55 for detecting the position of the discharge port 21 of the slit nozzle 2 .

The two guide rails 52 are provided in the both ends of the X direction of the stage 4, and are respectively extended and provided in the Y direction so that the nozzle adjustment area|region RA and the area|region in which the holding surface 41 may be included. And the two guide rails 52 guide the movement of the two lifting mechanisms 51b in the Y direction, respectively. The two linear motors 54 are provided on both sides of the stage 4 and are AC coreless linear motors each having a stator 54a and a mover 54b. The stator 54a is provided on the side surface of the stage 4 in the X direction along the Y direction. On the other hand, the mover 54b is fixedly provided outside the lifting mechanism 51b. The two linear motors 54 drive the two lifting mechanisms 51b in the Y direction by the magnetic force generated between the stator 54a and the mover 54b, respectively.

Moreover, each linear encoder 55 has the scale part 55a and the detection part 55b, respectively. The scale part 55a is provided along the Y direction under the stator 54a of the linear motor 54 fixed to the stage 4 . On the other hand, the detection part 55b is fixed to the outer side further of the mover 54b of the linear motor 54 fixed to the lifting mechanism 51b, and is arrange|positioned opposite to the scale part 55a. The linear encoder 55 detects the position of the discharge port 21 of the slit nozzle 2 in the Y direction based on the relative positional relationship between the scale unit 55a and the detection unit 55b.

The slit nozzle moving part 53 comprised in this way drives the nozzle support body 51 in the Y direction, between the upper side of the nozzle adjustment area|region RA, and the upper side of the board|substrate 3 hold|maintained on the stage 4. The slit nozzle 2 can be moved. Then, the coating device 1 relatively moves the slit nozzle 2 with respect to the substrate 3 while discharging the coating liquid from the discharge port 21 of the slit nozzle 2, whereby the surface 31 of the substrate 3 is to form a coating layer on Moreover, the area|region (frame-shaped area|region) of a predetermined width from the edge part of each side of the board|substrate 3 becomes an uncoated area|region which does not become the application|coating object of a coating liquid. Therefore, in the board|substrate 3, the rectangular area|region excluding this non-coating area|region becomes the application|coating area|region RT to which the coating liquid should be apply|coated (FIG. 3). For this reason, the coating liquid is discharged from the discharge port 21 which moves the upper section of the application area|region RT of the board|substrate 3 among the moving sections of the slit nozzle 2 .

In addition, during a period in which the coating process is not performed on the stage 4 , such as a water supply period (transport/export period of the substrate 3 ) of the coating device 1 and the substrate 3 of the external transport mechanism, the slit The nozzle 2 is evacuated from the holding surface 41 of the board|substrate 3 to the nozzle adjustment area|region RA which deviated to the (+Y) direction side (state shown in FIG. 1). And the nozzle maintenance unit 6 performs various maintenance with respect to the slit nozzle 2 located in nozzle adjustment area|region RA.

As shown in FIG. 2, the nozzle maintenance unit 6 is installed in the nozzle adjustment area RA of the (+Y) direction side (even side in the same figure) in the area occupied by the holding surface 41 . has been The nozzle maintenance unit 6 has a function of cleaning the slit nozzle 2 and removing the deposits adhering to the slit nozzle 2 . Here, various substances which can be adhered to the slit nozzle 2 are mentioned as a deposit|attachment used as a removal object. For example, this deposit contains the coating liquid itself, the solidified material in which the solute of the coating liquid was dried and solidified, and a dispersion material, etc. are included. In particular, the dispersion material is dispersed in the coating liquid and has a physical property of being insoluble in the cleaning liquid.

5 is a perspective view showing the configuration of a cleaning unit as an embodiment of the nozzle cleaning apparatus according to the present invention. FIG. 6 is a diagram showing the configuration of a piping system and an electric system connected to the cleaning unit shown in FIG. 5 . The cleaning unit 62 is a device for removing residual deposits that have not been completely removed by the cleaning unit 61 from the slit nozzle 2 using a cleaning liquid and ultrasonic vibration. The cleaning unit 62 is disposed on the (+Y) direction side with respect to the cleaning unit 61 (refer to FIGS. 2 and 3 ).

The cleaning unit 62 includes a cleaning tank 66 , a liquid tank 67 , and an ultrasonic vibrator 68 . As shown in FIG. 5, the washing tank 66 has a box structure with an upper opening, and can store the washing|cleaning liquid which wash|cleans the lower end part 2a of the slit nozzle 2 in the inside. In more detail, it is comprised as follows.

The washing tank 66 has a cross section of a substantially L-shape or a substantially V-shape when viewed from the X-direction, and has an angled bottom wall 661 extending in the X-direction. The bottom wall 661 is formed by bending the central portion of the Y direction of the flat plate member extending in the X direction, and the outer side of the bent portion, that is, the ridge portion 661a is disposed in a state facing the (-Z) direction. has been The bending angle is set to a value substantially equal to the angle θ (refer to FIG. 4 ) in the YZ plane of the lower end 2a of the slit nozzle 2 . For example, when the angle θ is 90°, the angle of the ridge portion 661a is also about 90°, and the bottom wall 661 has an equilateral ridge-shaped external appearance. Further, in the bottom wall 661, when viewed from the (+X) direction, the wing portion 661b is installed obliquely upward by about 45° in the clockwise direction, extending from the ridge portion 661a, and in a counterclockwise direction. A wing portion 661c is provided extending from the ridge portion 661a obliquely upward by about 45°. And the upper end of the blade parts 661b, 661c is spaced apart in the Y direction only by the distance W6 slightly wider than the width (Y-direction size) W2 of the slit nozzle 2, as shown in FIG. In addition, the length (X-direction size) L6 of the blade parts 661b and 661c is slightly longer than the length (X-direction size) L2 of the slit nozzle 2 .

In addition, with respect to the upper ends of the wing portions 661b and 661c, while having a rectangular cross section, a pair of rods extending by a distance L6 slightly longer than the length (X-direction size) L2 of the slit nozzle 2 are provided. The members 662b and 662c are respectively connected. More specifically, as shown in Fig. 5, the lower right side of the rod-shaped member 662b is connected to the upper end of the wing portion 661b, while the lower left side of the rod-shaped member 662c is the wing portion 661c. It is connected to the upper part.

A pair of side walls 663 and 663 is arranged so as to sandwich the bottom wall 661 and the rod-shaped members 662b and 662c connected in this way from the X direction. Therefore, at the lower end of the washing tank 66 (hereinafter referred to as “the lower end of the washing tank 664”), a slit is formed in the region surrounded by the bottom wall 661 , the rod-shaped members 662b and 662c and the sidewalls 663 and 663 . The cleaning liquid for cleaning the lower end portion 2a of the nozzle 2 can be stored, and the region functions as an example of the “storage region” of the present invention. In addition, below, the said area|region is called "retention area 665". The tip portion 665a corresponding to the lowermost end of the storage region 665 has a groove-shaped structure provided extending in the X direction in a state of being finished with an arc-shaped concave portion in the YZ plane orthogonal to the X direction. .

6, one end of the supply pipe 691 is connected to an inlet (not shown) provided on the side wall 663 on the (+X) side of the washing tank 66, and the washing tank ( One end of a drain pipe 692 is connected to an outlet (not shown) provided on the bottom wall 661 of the 66 . And the other end of the supply pipe 691 is connected to a cleaning liquid supply source which is one of the utilities of the factory where the coating device 1 is installed. A valve 693 is interposed in the supply pipe 691 . For this reason, when the valve 693 is opened according to a command from the controller 100 , the cleaning liquid is supplied from the cleaning liquid supply source to the cleaning tank 66 through the supply pipe 691 , and is stored in the storage area 665 .

In order to control the storage amount of the washing liquid in the storage area 665 , an overflow pipe 666 is erected from the bottom wall 661 . The overflow pipe 666 is connected to a drain recovery unit (not shown) via a drain pipe 694 . A valve 695 is interposed in the drain pipe 694 . For this reason, when the valve 695 is opened according to a command from the control unit 100 , excess washing liquid is removed from the storage area 665 through the overflow pipe 666 , and a predetermined amount of the washing liquid is removed from the storage area 665 . can be stored, and the lower end 2a of the slit nozzle 2 can be always cleaned with an appropriate amount of cleaning liquid. On the other hand, when draining the cleaning liquid used in the nozzle cleaning process, the valve 696 interposed in the drain pipe 692 is opened according to a command from the controller 100 , and the used cleaning liquid is discharged through the drain pipe 692 . It is recovered by the drainage recovery unit.

In addition to nozzle cleaning with such a cleaning liquid, the cleaning unit 62 further increases cleaning performance by adding ultrasonic vibrations. Therefore, the liquid tank 67 and the ultrasonic vibrator 68 are provided. The liquid tank 67 has a box structure with an upper opening formed by a bottom wall that forms a rectangle whose planar size when viewed from the (+Z) direction is larger than that of the cleaning tank 66, and four side walls that stand up from the periphery of the bottom wall. has In the interior 671 of the liquid tank 67 , the ultrasonic vibrator 68 is accommodated, and cooling water 672 for cooling the ultrasonic vibrator 68 is stored. In the liquid tank 67, the opening 673 is opened from above the inside 671 to be larger than the cleaning tank 66 when viewed from the (+Z) direction. And as shown in FIG. 6, the washing|cleaning tank lower end part 664 of the washing|cleaning tank 66 is immersed in the cooling water 672 stored in the liquid tank 67. As shown in FIG.

The ultrasonic vibrator 68 is electrically connected to the vibrator driving unit 681 . For this reason, when the vibrator driving unit 681 drives the ultrasonic vibrator 68 according to a command from the control unit 100, the ultrasonic vibrations generated in the ultrasonic vibrator 68 are transmitted to the washing tank 66 through the cooling water 672. is granted Further, when the lower end 2a of the slit nozzle 2 is immersed in the cleaning liquid stored in the storage area 665 of the cleaning tank 66, the ultrasonic vibration is applied to the lower end 2a through the cleaning liquid. As a result, in addition to the cleaning action by the cleaning liquid, ultrasonic vibration is imparted to the outer surface of the lower end 2a of the slit nozzle 2 . As a result, residual deposits such as the dispersion material DM adhering to the lower end portion 2a are effectively removed from the slit nozzle 2 .

Regarding the nozzle cleaning operation (nozzle cleaning combining cleaning liquid and ultrasonic vibration) by the cleaning unit 62 , the nozzle cleaning operation by the cleaning unit 61 (scraping treatment by the scraper 65) is performed once You may carry out every time, and you may carry out after carrying out only for a plurality of times. That is, the execution timing of nozzle cleaning by the cleaning unit 62 can be determined according to the amount of the residual deposit remaining after the nozzle cleaning operation by the cleaning unit 61 . In addition, the nozzle cleaning operation by the cleaning unit 62 is executed by the control unit 100 controlling each unit of the apparatus as follows according to a cleaning program stored in advance in the storage unit (not shown) of the control unit 100 . .

7 is a flowchart showing a nozzle cleaning operation performed by the cleaning unit shown in FIG. 5 , and includes diagrams schematically illustrating one step of the cleaning operation. The control unit 100 determines that nozzle cleaning by the cleaning unit 62 is unnecessary even after the nozzle cleaning operation by the cleaning unit 61 while the amount of residual deposits remaining is small (“NO” in step S1 ) ). On the other hand, if the control unit 100 determines that nozzle cleaning combining the cleaning liquid and ultrasonic vibration is necessary (“YES” in step S1), the following process (steps S2 to S10) is performed to perform the cleaning unit 62 Execute the nozzle cleaning operation. Here, in the step of executing step S1, a predetermined amount of the cleaning liquid is stored in the storage area 665 and the valves 693, 695, and 696 are all closed, and preparation of nozzle cleaning by the cleaning liquid and ultrasonic vibration is prepared. Assume it is complete and continue with the operation description.

In step S2 , the control unit 100 drives the ultrasonic vibrator 68 by the vibrator driving unit 681 to generate ultrasonic vibrations from the ultrasonic vibrator 68 . Then, the ultrasonic vibration is propagated to the cleaning tank 66 through the cooling water 672 .

Subsequently, the control unit 100 controls the slit nozzle moving unit 53 to move the slit nozzle 2 to a position immediately above the cleaning unit 62 . Subsequently, the control unit 100 controls the lifting mechanism 51b, and as shown in the operation explanatory diagram enclosed by the broken line in FIG. 7 , the lower end 2a of the slit nozzle 2 is the The slit nozzle 2 is lowered until it is immersed in the cleaning liquid stored in the storage area 665 (step S3). As a result, the outer surface of the lower end portion 2a comes into contact with the cleaning liquid and receives ultrasonic vibration while receiving the cleaning action by the cleaning liquid. As a result, residual deposits such as the dispersion material DM adhering to the lower end 2a of the slit nozzle 2 are effectively removed from the slit nozzle 2 . Here, as described above, in the present embodiment, the storage region 665 is finished in a shape that tapers toward the ultrasonic vibrator 68 when viewed from the X direction. That is, the tip portion 665a of the storage region 665 faces the discharge port 21 of the slit nozzle 2 , and the inner bottom surface of the bottom wall 661 (the valley side of the wing portions 661b and 661c) is an inclined surface. and face the outer surfaces of the lower ends 23a and 25a of the nozzle bodies 23 and 25, respectively. As a result, as schematically shown in the enlarged view of FIG. 5 , the residual deposits removed as described above, particularly the dispersion material DM as an insoluble solid, are stored by the inner bottom surface of the bottom wall 661 . It is guided and gathered to the tip portion 665a of the region 665 .

Moreover, during application of the ultrasonic vibration described above, bubbles B are generated in the cooling water 672 and move to the outer surface of the bottom wall 661 of the washing tank 66 . In this embodiment, in particular, the bottom wall 661 is finished in a shape that tapers toward the ultrasonic vibrator 68 when viewed from the X direction. That is, the outer side surface of the bottom wall 661 (the mountain side surface of the blade parts 661b, 661c) is an inclined surface. Accordingly, the bubble B, which has moved to the outer surface of the bottom wall 661 , floats along the inclined surface, and is discharged from the cooling water 672 to the outside air. That is, adhesion of the bubble B to the bottom wall 661 of the washing tank 66 is suppressed effectively. Thereby, the conventional problem (the fall of the propagation efficiency of ultrasonic vibration due to bubble adhesion to a washing tank) can be effectively eliminated, and the residual deposit|attachment by ultrasonic vibration is removed with high efficiency.

When the nozzle cleaning by the cleaning liquid and ultrasonic vibration is completed, the control unit 100 controls the lifting mechanism 51b to raise the slit nozzle 2 from the cleaning tank 66 (step S4). Subsequently, the control unit 100 stops the driving of the ultrasonic vibrator 68 by the vibrator driving unit 681 (step S5). In this way, when cleaning with the cleaning liquid stored in the storage area 665 is completed once, the control unit 100 increments the number of consecutive cleanings by “1” (step S6).

While this number of consecutive cleanings has not reached the preset number of times (“NO” in step S7 ), the control unit 100 returns to step S1 to repeat the nozzle cleaning operation by the cleaning unit 62 . On the other hand, when the nozzle cleaning operation by the cleaning unit 62 is continuously performed for a prescribed number of times using the cleaning liquid stored in the storage area 665 as it is, the control unit 100 reduces the cleaning performance of the cleaning liquid and removes the It is determined that the amount of the dispersion material (DM) is gathered. Therefore, the control unit 100 opens the valve 696 and collects the dispersed material DM collected in the tip portion 665a of the storage area 665, together with the used cleaning liquid, through the drainage pipe 692 to the drainage recovery unit. do. Further, the control unit 100 opens the valve 693 to supply the cleaning liquid fresh from the cleaning liquid supply source to the cleaning tank 66 through the supply pipe 691 as a rinse liquid. Thereby, the storage area 665 is washed out by the washing liquid (rinsing liquid) (rinsing process, step S8).

After the rinsing process is performed for a certain period of time, the control unit 100 closes the valve 696 while maintaining the open state of the valve 693 to start storage of the cleaning liquid in the storage area 665 . Also, at the same time or later when the valve 696 is closed, the control unit 100 opens the valve 695 . After that, when it is detected that the excess cleaning liquid is drained from the storage area 665 through the overflow pipe 666, the control unit 100 closes the valves 693 and 695 to complete the storage of the cleaning liquid (step S9). . Here, as for the overflow of the cleaning liquid, the cleaning liquid flowing through the drain pipe 694 may be detected by a sensor, or may be detected based on the elapsed time from the start of storage of the cleaning liquid (closing of the valve 696 ).

When the storage of the fresh cleaning liquid in this way is completed, the control unit 100 clears the number of consecutive cleanings (step S10), and then returns to step S1 to repeat the nozzle cleaning process.

As described above, according to the present embodiment, since the storage region 665 is finished in a shape that narrows toward the ultrasonic vibrator 68 when viewed from the X direction, the following effects are obtained. The amount of cleaning liquid stored in the storage area 665 , the time required for discharging the used cleaning liquid from the storage area 665 , and the time required for storage of the cleaning liquid into the storage area 665 are conventional It becomes smaller than the washing tank which has a rectangular cross-sectional shape, and reduction of a running cost and shortening of the time (so-called tact time) required for nozzle washing can be aimed at. Further, the residual deposits removed from the slit nozzle 2, particularly the dispersion material DM, are collected along the inner bottom surface of the bottom wall 661 at the tip portion 665a of the storage region 665, so that the dispersion material DM is formed. Spreading over the entire inner bottom surface of the bottom wall 661 can be prevented. In addition, the dispersed material DM collected in this way can be washed in the X direction together with the cleaning liquid by the rinse process, and can be reliably discharged from the cleaning tank 66 . Further, as shown in the partially enlarged view of FIG. 5 , the tip portion 665a has a groove structure extending in the X direction in a state of being finished with an arc-shaped concave in the YZ plane orthogonal to the X direction. The contact resistance of the tip portion 665a with respect to DM is suppressed. Thereby, it is possible to perform washing|cleaning of the slit nozzle 2 more efficiently.

Moreover, the following effect is also acquired by having the shape which the edge of the washing|cleaning tank lower end part 664 narrows toward the ultrasonic vibrator 68. As shown in FIG. The outer surface of the bottom wall 661 finished in a shape in which air bubbles B generated in the cooling water 672 during operation of the ultrasonic vibrator 68 are tapered toward the ultrasonic vibrator 68 when viewed from the X direction. It is discharged from the cooling water 672 to the outside air along (the mountain side of the wing portions 661b and 661c). Accordingly, ultrasonic vibration can be applied to the slit nozzle 2 while excluding the influence of the bubbles B together with the cleaning with the cleaning liquid. As a result, residual deposits can be removed with higher efficiency.

As mentioned above, in the said embodiment, the lower end part 2a of the slit nozzle 2 corresponds to an example of the "nozzle lower end part" of this invention. Moreover, the cooling water 672 corresponds to an example of "liquid" of this invention. In addition, the tip portion 665a of the storage region 665 corresponds to an example of the "groove" of the present invention, and the bone side of the wing portion 661b provided on the (-Y) direction side with respect to the tip portion 665a. Corresponding to an example of the "first storage slope" of the present invention, the trough side of the wing portion 661c provided on the (+Y) direction side with respect to the tip portion 665a is the "second storage slope" of the present invention. corresponds to an example of Moreover, the surface of the outer side of the lower end parts 23a, 25a of the nozzle bodies 23 and 25 corresponds to an example of "1st lip surface" and "2nd lip surface" of this invention, respectively. In addition, while the X direction corresponds to the "first horizontal direction" of the present invention, and the Y direction corresponds to the "second horizontal direction" of the present invention, the (-Y) direction side and the (+Y) direction side are They correspond to "the one side of a 2nd horizontal direction" and "the other side of a 2nd horizontal direction" of this invention, respectively. The (-Z) direction corresponds to "downward" of the present invention.

In addition, this invention is not limited to above-mentioned embodiment, Unless it deviates from the meaning, it is possible to make various changes other than what was mentioned above. For example, in the above embodiment, a washing liquid is used as the rinsing liquid used in the rinsing process. That is, the liquid of the same component is used for the rinse liquid and the cleaning liquid. However, a liquid different from the cleaning liquid, for example, DIW (deionized water) may be used for the rinse liquid.

Further, as shown in Figs. 6 and 7, the washing tank 66 may have an opening capable of immersing at least the lower end 2a of the slit nozzle 2 to be cleaned with respect to the washing liquid stored therein. . For this purpose, the length (X-direction size) of the opening at the upper end of the cleaning tank 66 is greater than the length (X-direction size) of the lower end 2a of the nozzle 2, and the width of the opening (Y-direction size) About W6, you may make it larger than the width (Y-direction size; code|symbol W2a shown in FIG. 4) of the lower end part 2a of the nozzle 2.

In the above embodiment, the bottom wall 661 of the cleaning tank 66 is bent and formed, but the bottom wall 661 and the rod-shaped members 662b and 662c are integrally formed or the cleaning tank ( 66) The whole may be manufactured by integral molding. That is, the manufacturing method of the washing tank 66 is arbitrary.

Moreover, in the said embodiment, although the YZ cross-sectional shape of the front-end|tip part 665a corresponded to the "groove" of this invention is finished in arc shape, it is not limited to the said shape, For example, you may finish in rectangular shape.

Further, about the substrate 3 to be applied, a glass substrate for a liquid crystal display device, a semiconductor substrate, a glass substrate for a PDP, a glass substrate for a photomask, a substrate for a color filter, a substrate for a recording disk, a substrate for a solar cell, an electronic paper Various substrates such as substrates for precision electronic devices such as substrates for use, rectangular glass substrates, flexible substrates for film liquid crystals, and substrates for organic EL can be used.

INDUSTRIAL APPLICATION This invention is applicable to the nozzle washing|cleaning apparatus which wash|cleans the nozzle which discharges a dispersion system coating liquid, and the coating apparatus in general equipped with the said nozzle washing|cleaning apparatus.

1: Applicator 2: Slit nozzle
2a: (nozzle) lower part 3: substrate
21: discharge port (of the nozzle) 62: cleaning unit (nozzle cleaning device)
66: washing tank 67: liquid tank
68: ultrasonic vibrator 661: bottom wall
661a: umbilical region (of the bottom wall) 661b, 661c: wing region
664: washing tank lower part 665: storage area
665a: tip (in the storage area) 672: coolant (liquid)
681: vibrator driving unit B: bubble
DM: dispersion material X: first horizontal direction
Y: second horizontal direction

Claims (7)

A nozzle cleaning apparatus for cleaning a nozzle that discharges a dispersion-based coating liquid from a first horizontally extending slit-shaped discharge port formed at the lower end of the nozzle, comprising:
a cleaning tank having a lower end of the cleaning tank in which a storage area for storing the cleaning liquid for cleaning the lower end of the nozzle is formed, and an opening through which the lower end of the nozzle can be immersed in the cleaning liquid stored in the storage area;
a liquid tank installed below the cleaning tank in a state in which the lower end of the cleaning tank is immersed in the liquid while storing the liquid;
and an ultrasonic vibrator for generating ultrasonic vibrations in the liquid stored in the liquid tank and applying ultrasonic vibrations to the nozzle lower end through the liquid, the lower end of the cleaning tank, and the cleaning liquid;
The nozzle cleaning apparatus, characterized in that the lower end of the cleaning tank and the storage area are finished in a shape that is narrowed toward the ultrasonic vibrator when viewed in the first horizontal direction. The method according to claim 1,
Nozzle cleaning in which a rinse liquid and a cleaning liquid for rinsing the storage area are supplied from one side in the first horizontal direction, and the rinse liquid and the cleaning liquid are discharged from the storage area on the other side in the first horizontal direction Device. The method according to claim 1 or 2,
The storage area is
a groove extending in the first horizontal direction;
a first storage inclined surface installed on one side of the second horizontal direction perpendicular to the first horizontal direction with respect to the groove and inclined toward the groove;
A second storage inclined surface installed on the other side of the second horizontal direction with respect to the groove and inclined toward the groove
have,
A nozzle cleaning apparatus for guiding a solid material insoluble in the cleaning liquid contained in the dispersion-based coating liquid to the groove by the first storage inclined surface and the second storage inclined surface. 4. The method according to claim 3,
The nozzle is finished in a shape that is tapered downward, and a first lip surface inclined toward the lower surface of the lower end of the nozzle from one side in the second horizontal direction with respect to the discharge port, and the second lip surface with respect to the discharge port When it has a second lip surface inclined toward the lower surface of the lower end of the nozzle from the other side in the horizontal direction,
and the cleaning tank is arranged such that the groove faces the discharge port, the first storage inclined surface faces the first lip surface, and the second storage inclined surface faces the second lip surface. 4. The method according to claim 3,
The nozzle cleaning apparatus in which the said groove|channel is finished in the arc shape when seen in the said 1st horizontal direction. 5. The method according to claim 4,
The nozzle cleaning apparatus according to claim 1, wherein the groove is finished in an arc shape when viewed in the first horizontal direction. a coating processing unit for discharging the dispersion-based coating liquid from the nozzle through a first horizontally extending slit-shaped discharge port formed at the lower end of the nozzle to apply the dispersion-based coating liquid to the substrate;
The nozzle cleaning apparatus according to claim 1 or 2, which cleans the nozzle.
An application device comprising a.

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