JP4792787B2 - Coating device with cleaning device - Google Patents

Description

  The present invention relates to a coating apparatus with a cleaning device including a cleaning device for cleaning a tip portion of a slit nozzle for forming a highly accurate coating film on a square glass substrate, such as a color filter for a liquid crystal display.

As a method for producing a color filter used in a liquid crystal display or the like, a pigment dispersion method is often used in which a photosensitive material in which a pigment is dispersed in advance is applied to a square glass substrate, and a lattice pattern is obtained by exposure and development. Yes.
In this method, as a method of applying the photosensitive material on the glass substrate, conventionally, a certain amount of the photosensitive material is dropped on the center of the glass substrate, and then the glass substrate is rotated at a constant speed to spread the liquid thinly and uniformly. Spin coating was common. However, this method has a problem in that a large amount of material is used and the central portion of the glass substrate is thickened during rotation.
Therefore, in recent years, as a coating method that compensates for these drawbacks and is easy to cope with an increase in the size of the glass substrate, a desired film thickness is directly applied to the entire surface of the glass substrate using a slit nozzle. This is a die coating method.
However, in the above method, when applying on the glass substrate, the photosensitive material dries and adheres to the tip of the slit nozzle, which peels off and remains as a foreign matter on the glass substrate. It was.

In the prior art, the longitudinal direction of the slit nozzle tip is cleaned at once using a cleaning head in which a plurality of cleaning nozzles are ejected in a fan shape from two rectangular fluids mixed with cleaning chemicals and inert gas. There was a method to do (refer patent document 1).
However, in the above method, since the cleaning head is long in the longitudinal direction of the slit nozzle, cleaning may be uneven depending on the cleaning position.
Therefore, a cleaning liquid spout for spraying a mist-like cleaning liquid and a gas spout on the top thereof are provided, and a device set shorter than the longitudinal direction of the slit nozzle is ejected while moving along the longitudinal direction of the slit nozzle. Thus, there is a method of cleaning the inclined portion at the tip of the slit nozzle (see Patent Document 2).
However, in the above method, although the cleaning power is high and the amount of the cleaning chemical used can be reduced, it is not possible to obtain a high drying property only by jetting from the upper gas jet nozzle, and when using a cleaning chemical with low volatility, The tip of the slit nozzle could not be completely dried by the cleaning by the above operation. For this reason, it is necessary to perform a step of supplying only the gas again after the cleaning is completed to dry the tip of the slit nozzle (that is, two operations including cleaning), and the tact time per cleaning is increased. There was a problem.
JP 2002-355596 A JP 2004-113934 A

  The present invention solves the problems of the prior art, and the object of the present invention is to provide a cleaning chemical solution having low volatility in a coating apparatus with a cleaning apparatus including a cleaning apparatus for cleaning the tip of the slit nozzle. Even when washed with a strong striking force, the dryness is very high, vertical stripe unevenness caused by the remaining cleaning chemical solution can be eliminated, and it adheres to the tip of the slit nozzle by one washing each time. An object of the present invention is to provide a coating apparatus with a cleaning device that can improve the yield and reduce the tact time by completely removing foreign substances.

That is, in order to achieve the above object, according to the present invention, first, in the invention of claim 1, coating with a cleaning device comprising a cleaning device that cleans the tip portion of the slit nozzle while moving along the longitudinal direction of the slit nozzle. In the device
The cleaning device includes one or more two-fluid nozzles that eject two fluids, which are a mixture of NMP that is a cleaning chemical and nitrogen that is an inert gas , on the outside of the slit nozzle tip, and the cleaning device progresses in the two-fluid nozzle. Two sets of one or more liquid cutting nozzles arranged on the side of the direction of travel opposite to the direction and ejecting nitrogen , which is an inert gas , are arranged in the longitudinal direction of the slit nozzle. A cleaning head composed of a cleaning unit that is arranged in parallel with the longitudinal direction of the slit nozzle so as to sandwich the outside, and an exhaust unit that is positioned below the cleaning unit and forcibly exhausts the generated mist waste liquid comprising a said two-fluid nozzle located in the upper portion of the liquid cutting nozzle, liquid blocking nozzles for jetting nitrogen is the inert gas toward the slit nozzle, sandwiching the slit nozzle Unnecessarily is paired, in which it was washed device with a coating device, characterized in that is Kin設parallel to the longitudinal direction of the slit nozzle.

According to the coating apparatus with a cleaning apparatus according to the present invention, the following effects can be obtained.
That is, in the coating apparatus with a cleaning device having a cleaning device for cleaning the tip of the slit nozzle, cleaning is performed while moving along the longitudinal direction of the slit nozzle while jetting two fluids mixed with a cleaning chemical and an inert gas, In addition, cleaning with a very high drying property can be performed with a liquid cutting nozzle provided with a certain inclination in the longitudinal direction and depth direction of the slit. As a result, it is possible to completely remove the dry fixed foreign matter at the tip of the slit nozzle and to suppress vertical stripe unevenness due to the remaining cleaning liquid, thereby improving the yield. In addition, since the tip of the slit nozzle can be completely dried and kept clean by washing with one operation each time, the tact time can be shortened.
Further, the inert gas is ejected toward the inclined surface of the slit nozzle, whereby an inert gas curtain is formed, and the inert gas is ejected from the two-fluid mist ejected from the two-fluid nozzle and the liquid cutting nozzle. It becomes possible to completely prevent the active gas from rolling up to the upper part of the slope of the slit nozzle and being contaminated.
That is, it is possible to provide a coating apparatus with a cleaning device that is an object of the present invention.

FIG. 1 shows a coating apparatus of the present invention having an apparatus for cleaning the tip of a slit nozzle. As shown in FIG. 1, the slit nozzle 1 is composed of a manifold side block 3 and an anti-manifold side block 2 which are metal structures. A manifold 4 for storing the coating liquid is provided inside the slit nozzle 1, and the coating liquid is supplied from the coating liquid supply port 7, passes through the slit 5, and is discharged to the outside. A lip 6 that is a flat surface is formed near the exit of the slit 5.
In the slit nozzle 1, when the coating liquid is discharged to the outside, the coating liquid wraps around and adheres to the slit nozzle tip 8 including the lip 6, which is dried and solidified to become foreign matter. In addition, when the foreign matter is washed and removed, if the drying property is poor, the cleaning chemical solution enters the slit 5 due to a capillary phenomenon, and vertical stripe unevenness occurs when this is mixed in the coating solution and applied.

As shown in FIG. 5, the cleaning device in the coating apparatus with a cleaning device of the present invention has a cleaning head 23. The cleaning head 23 is composed of a cleaning unit and an exhaust unit. The cleaning unit is arranged in parallel with the two-fluid nozzle 10 and the two-fluid nozzle 10, and the liquid draining nozzle 18 is disposed in the direction opposite to the apparatus traveling direction, which will be described later. The liquid blocking nozzle 11 is provided on the upper part, and the exhaust part is located at the lower part of the cleaning part, and has a fixed base 16 and an exhaust duct 22.
As shown in FIG. 1, a manifold 13 for mixing two fluids connected to the cleaning chemical solution supply port 12 and the inert gas supply port 15 is formed inside the two-fluid nozzle 10. The two-fluid mist mixed in the manifold 13 is ejected from the two-fluid ejection port 14 toward the slit nozzle tip 8.
An inert gas supply port 17 and a liquid blocking slit 24 connected to the inert gas supply port 17 are provided inside the liquid blocking nozzle 11, and the inert gas supplied from the inert gas supply port 17 is supplied from the liquid blocking slit 24. It is ejected toward the middle stage of the slope 25 of the slit nozzle 1. As a result, a curtain of inert gas is formed, and the two-fluid mist ejected from the two-fluid nozzle 10 and the inert gas ejected from the liquid cutting nozzle 18 roll up to the upper part of the inclined surface 25 and completely prevent contamination. It becomes possible to prevent.

As shown in FIG. 2, a manifold 20 connected to an inert gas supply port 21 is formed inside the liquid cutting nozzle 18, and the inert gas stored in the manifold 20 is slit from the liquid cutting slit 19. It is ejected toward the middle of the inclined surface 25 of the nozzle tip 8 and the slit nozzle 1.
As shown in FIG. 3, the longitudinal direction of the liquid cutting slit 19 is opposite to the apparatus traveling direction of the two-fluid nozzle 10 on the side closer to the slit nozzle tip 8 (lower side in FIG. 3) with respect to the longitudinal direction of the slit nozzle 1. It inclines so that it may become a direction side, and the inclination angle X exists in the range of 55 degrees-75 degrees. Further, the depth direction of the liquid cutting slit 19 is inclined so that the side closer to the manifold 20 with respect to the longitudinal direction of the slit nozzle 1 is opposite to the device moving direction of the two-fluid nozzle 10, The angle Y is in the range of 50 ° to 70 °. When the range of the inclination angle X and the inclination angle Y is within the above range, the two-fluid mist adhering to the inclined surface 25 of the slit nozzle 1 can be completely removed.

The two-fluid nozzle 10, the liquid cutting nozzle 18, and the liquid blocking nozzle 11 that constitute the cleaning unit described above are set in two sets, and are arranged close to each other in parallel to the longitudinal direction of the slit nozzle 1 so as to sandwich the outside of the slit nozzle tip 8. Yes.
In the lower part of the cleaning unit, as described above, an exhaust unit including the fixed base 16 for supporting the cleaning unit and the exhaust duct 22 for discharging the generated mist waste liquid is provided.

The supply of the cleaning chemical and the inert gas will be described.
As shown in FIG. 5, the cleaning chemical liquid 74 is supplied to the two-fluid nozzle 10 by first opening the ball valve 68 and opening the air operated valve 72 to pressurize the cleaning chemical liquid tank 73 with the clean air 67. By supplying the operation valve 66, the cleaning chemical liquid supply port 12 supplies the cleaning chemical liquid. The flow rate of the cleaning chemical liquid 74 is adjusted by the flow rate adjusting valve 75, and the flow rate value at that time is displayed on the flow meter 64. A filter 65 for collecting foreign matter is provided between the flow rate adjusting valve 75 and the air operated valve 66.
The pressure of the clean air 67 for pressurizing the cleaning chemical tank 73 is adjusted by the pressure reducing valve 69, and the pressure value at that time is displayed on the pressure gauge 70. A filter 71 for collecting foreign matter is provided between the air operated valve 72 and the pressure gauge 70.

The inert gas 59 is supplied to the two-fluid nozzle 10 by opening the ball valve 60 and opening the air operated valve 55. The flow rate is adjusted by the flow rate adjusting valve 54, and the flow rate value at that time is displayed on the flow meter 53.
The inert gas 59 is supplied to the liquid draining nozzle 18 by opening the ball valve 60 and opening the air operated valve 58. The flow rate is adjusted by the flow rate adjusting valve 57, and the flow rate value at that time is displayed on the flow meter 56.
The inert gas 59 is supplied to the liquid blocking nozzle 11 by opening the ball valve 60 and opening the air operated valve 52. The flow rate is adjusted by the flow rate adjusting valve 51, and the flow rate value at that time is displayed on the flow meter 50.
The pressure of the inert gas 59 is adjusted by the pressure reducing valve 61, and the pressure value at that time is displayed on the pressure gauge 62. Between the air operated valves 52, 55 and 58 and the pressure gauge 62, a filter 63 for collecting foreign matter is provided.

  The mist waste liquid accumulated in the cleaning head 23 is discharged to the outside through the exhaust duct 22 by the forced exhaust device 77. The discharged mist waste liquid is collected in the waste liquid trap tank 76.

  As shown in FIG. 4, the coating liquid tank 38 for supplying the coating liquid 39 to the slit nozzle 1 is pressurized by clean air 37 by opening the ball valve 36. The pressure of the clean air 37 is adjusted by the pressure reducing valve 35, and the pressure value at that time is displayed on the pressure gauge 34. A filter 33 for collecting foreign matter is provided between the pressure gauge 34 and the coating liquid tank 38. The coating liquid 39 is supplied to the slit nozzle 1 by opening the air operated valve 31. A primary filter 32 for collecting foreign matter is provided between the coating liquid tank 38 and the air operated valve 31, and a secondary filter 30 is provided between the air operated valve 31 and the slit nozzle 1. Yes.

  FIG. 7 shows a basic configuration and a schematic operation of the coating device 86 with a cleaning device of the present invention. As shown in FIG. 7, a coating device 86 with a cleaning device includes a cleaning unit including the cleaning head 23 and the linear motion unit 90, and a cleaning chemical solution and inert gas supply mechanism. It comprises a stage 82, a standby pod 80 storing an organic solvent 81, and the like. As shown in FIG. 6, the cleaning head 23 is fixed to a linear motion unit 90 driven by a motor. The movement of the cleaning head 23 is the same as that described in the following examples, and the description thereof is omitted in the embodiment.

As an example of the coating apparatus with a cleaning device of the present invention, a case where the tip of the slit nozzle is cleaned when a photosensitive material is applied with the slit nozzle in a manufacturing process of a color filter for a liquid crystal display will be described.
As the photosensitive material to be applied, a commercially available resin black resist was used, and NMP (N-methyl-2-pyrrolidone (or 1-methyl-2-pyrrolidinone was also acceptable)) was used as a cleaning chemical. Moreover, nitrogen was used for the inert gas. Further, the glass substrate on which the coating film was formed was non-alkali glass, and the size was 680 mm × 880 mm × t 0.7 mm.
As shown in Table 1, liquid draining nozzles having various inclination angles were attached and evaluated in advance. In the table, ◯ indicates that no cleaning chemical liquid residue is found on the slope of the slit nozzle, Δ indicates that some cleaning chemical liquid residue is observed, and x indicates that cleaning chemical liquid residue is observed. From this result, it was found that the cleaning chemical solution can be completely removed if the inclination angle X in the longitudinal direction is 55 ° to 75 ° and the inclination angle Y in the depth direction is 50 ° to 70 °.

  Based on the above results, the two-fluid nozzle has three circular two-fluid nozzles, and the liquid draining nozzle has slits with an inclination angle X in the longitudinal direction of 65 ° and an inclination angle Y in the depth direction of 60 °. Each of the three sites was arranged.

The actual operation is shown in detail below.
As shown in FIGS. 6 and 7, the glass substrate 85 put in from a loader unit (not shown) is placed on the application stage 82 of the application device 86 with a cleaning device by a transfer robot (not shown) and is vacuum-sucked. The ball valves 36, 60, 68 and the air operated valve 72 are opened in advance, and the coating liquid tank 38 and the cleaning chemical tank 73 are constantly pressurized. The slit nozzle 1 is in a standby state with the slit nozzle tip 8 stored in a standby pod 80 in an atmosphere of an organic solvent 81 at the standby position A, and a glass substrate 85 is placed on the coating stage 82. Then, it rises to the standby upper position B, and then translates to the application start upper position C. Next, it is lowered to the coating start position D, and in this state, the air operated valve 31 is opened to form the coating bead 83, and then it is translated to the coating end position E while forming the coating film 84 while discharging the resin black resist. When the slit nozzle 1 moves to the application end position E, the air operated valve 31 is closed and the discharge of the resin black resist is stopped. Next, the coating finishes ascending to the upper position F, then moves parallel to the cleaning upper position G, and then descends to the cleaning position H.

The cleaning head 23 stands by at the cleaning head standby position I (FIG. 6), and at the same time as the movement of the slit nozzle 1 to the cleaning position H is completed, the forced exhaust device 77 is activated to start exhausting, and then the air operation is performed. Nitrogen is ejected from the liquid blocking slit 24 by opening the valve 52, and then nitrogen is ejected from the liquid draining slit 19 by opening the air operated valve 58. When the nitrogen ejection from the liquid blocking slit 24 and the liquid cutting slit 19 is stabilized, nitrogen is supplied to the two-fluid nozzle 10 by opening the air operated valve 55, and then NMP is 2 by opening the air operated valve 66. The two-fluid mist supplied to the fluid nozzle 10 and mixed inside the two-fluid nozzle 10 is ejected from the two-fluid ejection port 14 toward the slit nozzle tip 8.
When the ejection of the two-fluid mist is stabilized, the linear motion unit 90 is driven, and the cleaning head 23 starts cleaning while moving in parallel along the longitudinal direction of the slit nozzle 1. When the cleaning head 23 moves to the cleaning head cleaning end position J, the linear motion unit 90 stops and the slit nozzle 1 rises again to the cleaning upper position G. Next, the robot moves in parallel to the standby upper position B, then descends to the standby position A, and waits with the slit nozzle tip 8 stored in the standby pod 80 again.
At the same time that the slit nozzle 1 rises to the cleaning upper position G, the linear motion unit 90 is driven, and the cleaning head 23 starts parallel movement to the cleaning head standby position I. At the same time, the air operated valve 66 is closed and the supply of NMP is stopped. Next, the air operated valve 55 is closed and the supply of nitrogen for the two fluids is stopped, then the air operated valve 58 is closed and the supply of nitrogen for draining is stopped, and then the air operated valve 52 is closed and the supply of nitrogen for shutting off the liquid is stopped. Thereafter, the forced exhaust device 77 is stopped when the mist-like waste liquid in the cleaning head 23 is completely discharged to the outside. When the cleaning head 23 moves to the cleaning head standby position I, the linear motion unit 90 stops.
On the other hand, the glass substrate 85 coated with the resin black resist by the coating device 86 with a cleaning device is transported to the next process by a transport robot (not shown).

  With the above operation, the glass substrate was continuously applied and washed each time. As a result, the dryness of the lip tip after the slit nozzle cleaning was very good visually, and there was no occurrence of vertical stripe unevenness due to the remaining cleaning liquid. In addition, the slit nozzle tip was kept very clean even after continuous application, and no foreign matter due to dry adhesion was generated in the foreign matter inspection of the glass substrate after application.

It is explanatory drawing showing the side section of the 2 fluid nozzle part and slit nozzle of the washing head concerning the present invention. It is explanatory drawing showing the side cross section of the liquid cutting nozzle part and slit nozzle of the washing head concerning the present invention. It is a top view of the liquid cutting nozzle concerning this invention. It is explanatory drawing showing the slit nozzle concerning this invention, and the supply system of a coating liquid. It is explanatory drawing showing the perspective view of the cleaning head and slit nozzle concerning this invention, and the supply system of a cleaning chemical | medical solution and an inert gas. It is explanatory drawing which showed the washing | cleaning apparatus and slit nozzle in one Example of the coating device with a washing | cleaning apparatus concerning this invention. It is explanatory drawing which represented the operation | movement of the slit nozzle of the coating device with a washing | cleaning apparatus concerning this invention by the side surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Slit nozzle 5 ... Slit 8 ... Slit nozzle tip part 10 ... 2 fluid nozzle 11 ... Liquid blocking nozzle 14 ... 2 fluid ejection port 16 ... Fixed base 18 ... -Liquid cutting nozzle 19 ... Liquid cutting slit 23 ... Cleaning head 24 ... Liquid blocking slit 25 ... Slope 86 ... Coating device with cleaning device

Claims (1)

In a coating device with a cleaning device, comprising a cleaning device for cleaning while moving the tip of the slit nozzle along the longitudinal direction of the slit nozzle,
The cleaning device includes one or more two-fluid nozzles that eject two fluids, which are a mixture of NMP that is a cleaning chemical and nitrogen that is an inert gas , on the outside of the slit nozzle tip, and the cleaning device progresses in the two-fluid nozzle. Two sets of one or more liquid cutting nozzles arranged on the side of the direction of travel opposite to the direction and ejecting nitrogen , which is an inert gas , are arranged in the longitudinal direction of the slit nozzle. A cleaning head composed of a cleaning unit that is arranged in parallel with the longitudinal direction of the slit nozzle so as to sandwich the outside, and an exhaust unit that is positioned below the cleaning unit and forcibly exhausts the generated mist waste liquid comprising a said two-fluid nozzle located in the upper portion of the liquid cutting nozzle, liquid blocking nozzles for jetting nitrogen is the inert gas toward the slit nozzle, sandwiching the slit nozzle Unnecessarily been paired, the cleaning device with a coating apparatus characterized by being Kin設parallel to the longitudinal direction of the slit nozzle.

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