JP2010269245A - Coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus wherein a solution can efficiently be used. <P>SOLUTION: A submergible member 130 is disposed in a solution tank 102. The submergible member 130 is submerged in a solution 150 stored in the solution tank 102. The level of the submergible member 130 is controlled so that the level of the liquid surface 151 of the solution 150 is kept within a specified range. Thus, when the level of the liquid surface 151 of the solution 150 is kept at a higher position relative to the end part 109 of a solution feed pipe 108, or is kept within the specified range, the volume of the section in the solution tank 102 below the level to be maintained of the liquid surface 151 of the solution 150 can be reduced, and hence the amount of the solution 150 left unused for coating can be reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coating apparatus that applies a solution to an object such as a substrate.

  2. Description of the Related Art Conventionally, when manufacturing a liquid crystal display panel, a coating apparatus that sprays and applies a solution to a substrate by an inkjet method is used to form an alignment film or the like on a glass substrate. Such a coating apparatus sprays and coats a solution from a spray surface of each head formed by arranging a plurality of nozzles toward a glass substrate mounted on a substrate stage. In such a coating apparatus, the solution is stored in the solution tank, gas is sent to the solution tank, and the solution is supplied from the solution tank to the head via the solution supply pipe by the atmospheric pressure (for example, Patent Document 1).

JP 2004-223356 A

  Here, an example of a conventional solution supply means will be described with reference to FIG. Such supply means includes a solution tank 202 that stores a solution 250 to be supplied to the head 206. A solution supply pipe 204 is connected to the solution tank 202 through a lid at the upper end of the solution tank 202. The end of the solution supply pipe 204 on the solution tank 202 side extends to the vicinity of the bottom of the solution tank 202. The other end of the solution supply pipe 204 is connected to the liquid supply port of the head 206. The height (water head) of the liquid surface 251 of the solution 250 in the solution tank 202 is predetermined with respect to the lower surface (solution injection surface) of the head 206 when the solution 250 is spray-applied from the head 206 toward the glass substrate. Managed to keep in range. That is, if the liquid level detector (not shown) detects that the water head has fallen below the predetermined range due to consumption of the solution 250 by the head 206, the solution is supplied via the solution supply pipe 207 until the water head reaches the upper limit. The solution 250 is supplied into the tank 202.

  In such a solution tank 202, the volume, the cross-sectional area in the horizontal direction, and the amount of stored solution are limited for the following reasons. That is, it is necessary to fill each head 206 with the solution 205 prior to the application of the solution 250 to the substrate. Therefore, the solution tank 202 needs to have a capacity sufficient to supply the amount of solution 250 necessary for this at a time. In addition, the head is more easily managed when the head changes more slowly with respect to the consumption of the solution 250 by the head 206. Therefore, it is desired that the horizontal cross-sectional area of the solution tank 202 is large to some extent. Furthermore, when a problem such as mixing of bubbles into the nozzle occurs during the coating operation of continuously applying the solution 250 to a plurality of glass substrates, a pressurized gas is supplied into the solution tank 202, There is a case where a maintenance operation for forcibly supplying a predetermined amount of the solution 250 into the head 206 is performed. Therefore, it is desirable to manage the water head at a height position where the amount of the solution 250 necessary for the maintenance operation can be secured.

  For this reason, a relatively large amount (at least an amount necessary for the maintenance operation) of the solution 250 is stored in the solution tank 202. When the application of the solution 250 to all the substrates to be applied is completed, a large amount of the solution 250 remains in the solution tank 202 without being used for the application. Since the solution 250 remaining in the solution tank 202 is discarded without being used, the material is wasted.

  This invention is made | formed in view of such a situation, and provides the coating device which can use a solution efficiently.

  The coating apparatus according to the present invention includes a head for applying a solution to an object, a solution tank for storing the solution, a solution supply pipe for supplying the solution from the inside of the solution tank to the head, and the solution tank. And a settling member that is submerged in the solution.

  According to this configuration, the height of the liquid level of the solution is maintained within a predetermined range with respect to the head by sinking the settling member in the solution stored in the solution tank. The volume of the portion below the liquid level of the solution to be maintained can be reduced, in other words, the amount of solution not used for application can be reduced.

  In addition, the coating apparatus according to the present invention includes a detecting unit that detects a height of the liquid level of the solution, and a height of the settling member according to the height of the liquid level of the solution detected by the detecting unit. A control unit for adjusting

  According to this configuration, by adjusting the height of the settling member according to the level of the liquid level of the solution, the settling amount of the settling member with respect to the solution changes, and as a result, the height of the liquid level of the solution Is adjusted.

  From the same viewpoint, in the coating apparatus according to the present invention, the control unit adjusts the height of the settling member so that the liquid level of the solution is maintained within a predetermined range.

  In the coating apparatus according to the present invention, the solution tank has a shape in which the bottom surface is inclined downward toward the center.

  According to this configuration, it is possible to further reduce the volume of the portion below the liquid level of the solution that should maintain the height inside the solution tank, in other words, to reduce the amount of the solution that is not used for application. it can.

  Moreover, in the coating apparatus according to the present invention, the settling member has a shape in which the lower surface is along the bottom surface of the solution tank.

  According to this configuration, the lower surface of the settling member is shaped along the bottom surface of the solution tank, thereby further reducing the volume of the portion below the liquid level of the solution that should maintain the height inside the solution tank. And the amount of solution that is not used for coating can be reduced.

  According to the present invention, the solution is reduced by reducing the volume of the portion below the liquid level of the solution to be maintained in the inside of the solution tank, in other words, by reducing the amount of the solution not used for application. It can be used efficiently.

It is a figure which shows schematic structure of the coating device which concerns on embodiment of this invention. It is a figure which shows the structure of the part which supplies a solution to a head in a coating device. It is a figure which shows the state which moved the sedimentation member in the coating device below. It is a figure which shows the structure of the part which supplies the solution to a head in the conventional coating device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a coating apparatus according to an embodiment of the present invention. A coating apparatus 10 shown in FIG. 1 forms an alignment film by spray-coating a solution onto a glass substrate 20 by an inkjet method when manufacturing a liquid crystal display panel.

  The coating apparatus 10 includes a base 11, and a pair of rails 12 arranged at a predetermined interval are laid in the horizontal direction on the upper surface of the base 11. A substrate stage 13 is movably attached to the rail 12. The substrate stage 13 is moved in the horizontal direction (direction Y in FIG. 1) along the rail 12 by a drive source (not shown). A large number of support pins 14 are attached to the upper surface of the substrate stage 13. The glass substrate 20 is supported on the substrate stage 13 by the support pins 14.

  A plurality of heads 17 are provided above the movement path of the substrate stage 13 along the X direction orthogonal to the movement direction (Y direction) of the substrate stage 13. A plurality of nozzles (not shown) are arranged on the lower surface of the head 17 along the X direction. The lower surface serves as an ejection surface, and is placed on the substrate stage 13 that passes under the head 17. A solution (for example, a polyimide solution) for forming an alignment film on the upper surface of the glass substrate 20 is spray-coated toward the substrate 20 by an inkjet method.

  FIG. 2 is a diagram showing a configuration of means for supplying a solution to the head 17 in the coating apparatus 10. The solution supply means includes a solution tank 102, a lid 106, a solution supply tube 108, a solution storage tube 110, a gas supply tube 112, a liquid level confirmation tube 114, a liquid level detection unit 116, a first on-off valve 118, The second on-off valve 120, the third on-off valve 122, the control unit 124, and the settling member 130 are provided.

  The solution tank 102 is a substantially cylindrical container having a bottom portion whose bottom surface 103 is inclined downward toward the center. The solution tank 102 can be hermetically sealed by attaching a lid 106 to the top.

  A solution supply pipe 108 is connected to the solution tank 102 through the lid portion 106, and an end 109 on the solution tank 102 side of the solution supply pipe 108 extends to the vicinity of the bottom surface of the solution tank 102. . The other end of the solution supply pipe 108 is branched and connected to the liquid supply port of each head 17. The solution supply pipe 108 is for sending out the solution 150 from the solution tank 102 to the head 17, and is provided with a first on-off valve 118 at an intermediate portion.

  In addition, a solution storage tube 110 is attached to the solution tank 102 so as to penetrate the lid portion 106 and its end portion is positioned inside the solution tank 102. The solution storage pipe 110 connects the solution tank 102 and a storage tank (not shown), and sends the solution 150 from the storage tank to the solution tank 102. The second opening / closing valve 120 is provided in the middle portion. It has been.

  In addition, a gas supply pipe 112 is attached to the solution tank 102 so as to penetrate the lid portion 106 and its end portion is located inside the solution tank 102. The gas supply pipe 112 is for connecting the solution tank 102 and a gas supply mechanism (not shown), and sending nitrogen gas, which is a gas from the gas supply mechanism, to the solution tank 102. An on-off valve 122 is provided.

  Furthermore, one end of a liquid level confirmation tube 114 is attached to the bottom surface 105 of the solution tank 102. The liquid level confirmation pipe 114 extends in the horizontal direction from the bottom surface 103 of the solution tank 102 and further extends upward. A liquid level detector 116 is attached to a portion extending above the liquid level confirmation pipe 114. The liquid level detector 116 detects the height of the liquid level of the solution 150 in the liquid level confirmation tube 114. Here, the height of the liquid level 151 of the solution 150 stored in the solution tank 102 and the height of the liquid level of the solution 150 in the liquid level confirmation tube 114 coincide with each other. Accordingly, the liquid level detector 116 indirectly detects the height of the liquid level 151 of the solution 150 in the solution tank 102.

  The solution tank 102 is provided with a settling member 130 that can move in the vertical direction. In other words, a rod-like lifting member 125a that is moved up and down by a vertical drive unit 125 provided on the lid 106 and hangs down into the solution tank 102 through the lid 106 is connected to the settling member 130. The height of the settling member 130 can be adjusted via the elevating member 125a by driving the vertical drive unit 125. The lower surface 132 of the settling member 130 has a shape along the bottom surface 103 of the solution tank 102.

  The control unit 124 replenishes the solution 150 from a storage tank (not shown) to the solution tank 102, feeds nitrogen gas from the gas supply mechanism (not shown) to the solution tank 102, and adjusts the height of the settling member 130. I do.

  Next, the operation of applying the solution 150 to the glass substrate 20 of a predetermined lot will be described. In the present embodiment, the height (water head) of the liquid surface 151 of the solution 150 in the solution tank 102 is controlled at the normal application stage from the initial stage to the latter half of the predetermined lot and at the end stage of the lot. The way is different. Therefore, first, a normal application step will be described.

  First, the solution 150 is filled in each head 17. That is, since the solution 150 is not filled in the head 17 before the application is started, the solution 150 is supplied to each head 17 and the solution 150 is filled in the head 17. In this case, the solution tank 102 is filled with a sufficient amount of the solution 150 by supplying the solution 150 from a storage tank (not shown) via the solution storage pipe 110. In this state, pressurized nitrogen gas is supplied into the solution tank 102 via the gas supply pipe 112 for a predetermined time, and the solution 150 is pumped to the solution supply pipe 108 and each head 17. When the predetermined time has elapsed and the filling of the solution 150 into each head 17 has been completed, the control unit 124 reads the detection value by the liquid level detector 116 and stores the solution in the solution tank 102 via the solution storage tube 110. The solution 150 is replenished and adjusted so that the water head of the solution 150 in the solution tank 102 is within an allowable range (a predetermined range centered at a position of a distance L from the ejection surface of the head 17). At this time, the settling member 130 is raised by the vertical drive unit 125 and positioned at a position higher than the liquid level 151 of the solution 150.

  Thus, when each head 17 is filled with the solution 150, the glass substrate 20 to which the solution 150 is to be applied is sequentially supplied onto the substrate stage 13. During the movement of the substrate stage 13 on which the glass substrate 20 is placed, the solution 150 is discharged from each nozzle of the head 17 in accordance with the timing at which the glass substrate 20 passes under the head 17. At this time, since a predetermined amount of droplets of the solution 150 are discharged from each nozzle at predetermined time intervals, the droplets of the solution 150 are applied to the upper surface of the glass substrate 20 in a matrix. The droplets of the solution 150 applied to the glass substrate 20 wet and spread on the glass substrate 20, come into contact with each other, and are integrated to form a film.

  By performing such application, the solution 150 stored in the solution tank 102 is consumed, so that the water head of the solution 150 in the solution tank 102 is gradually lowered. Since the water head of the solution 150 is detected by the liquid level detector 116, the control unit 124 determines that the detection value by the liquid level detector 116 is within the allowable range of the water head (a position at a distance L from the ejection surface of the head 17. If it is determined that the lower limit of the (predetermined range) has been reached, the second on-off valve 120 is opened, and replenishment of the solution 150 into the solution tank 102 is started. The replenishment of the solution 150 is continued until the detection value by the liquid level detector 116 reaches the upper limit of the allowable range of the water head. When the control unit 124 determines that the detection value by the liquid level detector 116 has reached the upper limit of the allowable range of the head, the second opening / closing valve 120 is closed. In the normal application stage, the control unit 124 performs control to keep the water head of the solution 150 in the solution tank 102 constant within an allowable range as described above. During the above-described operation, the settling member 130 is raised by the vertical drive unit 125 and remains positioned at a position higher than the liquid level 151 of the solution 150.

Next, the lot end stage will be described.
When the solution 150 stored in the solution tank 102 is consumed at the end stage of the lot and the head of the solution 150 in the solution tank 102 reaches the lower limit of the allowable range, the solution 150 from the storage tank (not shown) Replenishment is not performed, that is, the settling member 130 is gradually lowered while the second on-off valve 120 is closed. That is, the control unit 124 controls the vertical driving unit 125 to gradually lower the settling member 130 and set the settling member 130 in the stored solution 150. When the settling member 130 moves downward in this way, the state changes from the state shown in FIG. 2 to the state shown in FIG. 3, and the solution 150 is pushed away by the settling member 130. As a result, the level of the liquid surface 151 of the solution 150 increases. And the head is maintained within an acceptable range. At this time, the control unit 124 monitors the detection value of the liquid level detector 116, and when it is determined that the detection value of the liquid level detector 116 has reached the upper limit of the allowable range of the water head, the descent member 130 is lowered. Stop.

  When the solution 150 in the solution tank 102 is further consumed and the water head reaches the lower limit of the allowable range again, the settling member 130 is lowered in the same manner as described above. By repeating such an operation, the solution 150 is applied up to the last glass substrate 20 of the current lot. Here, the timing of switching from the normal application stage control to the lot end stage control may be determined based on the volume of the precipitation member 130 (drainage amount) and the amount of the solution 150 required for the application of one glass substrate 20. . For example, if the volume (drainage amount) of the settling member 130 corresponds to the amount of the solution 150 required to apply 10 glass substrates 20, when the remaining 10 glass substrates 20 have reached the remaining lot. The control of the water head in the solution tank 102 may be switched from the normal application stage control to the lot end stage control.

  When the amount of the solution 150 required for coating all the glass substrates 20 in the current lot is equal to or less than the volume of the precipitation member 130, the above-described lot end stage control is performed from the first glass substrate 20 in the current lot. That is, control may be performed to keep the water head within an allowable range by lowering the sedimentation member 130.

  Thus, in the coating apparatus of this embodiment, the settling member 130 is disposed inside the solution tank 102, and the settling member 130 is submerged in the solution 150 stored in the solution tank 102. Furthermore, the height of the settling member 130 is adjusted so that the height of the liquid surface 151 of the solution 150 is maintained within the reference range. Accordingly, when the height of the liquid surface 151 of the solution 150 is maintained at a position higher than the end portion 109 of the solution supply pipe 108 or within the reference range, the height inside the solution tank 102 is increased. The volume of the portion below the liquid surface 151 of the solution 150 to be maintained can be reduced, in other words, the amount of the solution 150 that is not used for coating can be reduced.

  In addition, the bottom surface 103 of the solution tank 102 has a shape inclined downward toward the center, and the lower surface 132 of the settling member 130 has a shape along the bottom surface 103 of the solution tank 102. The volume of the portion below the liquid level 151 of the solution 150 to maintain the height inside can be reduced, and the amount of the solution not used for application can be reduced.

  In the above-described embodiment, the coating apparatus sprays and applies the solution 150 to the glass substrate 20 by the inkjet method. However, the present invention is similarly applied to the case where the solution 150 is applied to the glass substrate 20 by another method. be able to. Further, the application target of the solution 150 is not limited to the glass substrate 20 and may be another object.

  The coating apparatus according to the present invention enables efficient use of the solution and is useful as a coating apparatus.

DESCRIPTION OF SYMBOLS 10 Coating apparatus 11 Base 12 Rail 13 Substrate stage 14 Support pin 17 Head 20 Glass substrate 102 Solution tank 103 Bottom face of solution tank 106 Lid part 108 Solution supply pipe 109 End part of solution supply pipe 110 Solution storage pipe 112 Gas supply Pipe 114 Liquid level confirmation pipe 116 Liquid level detector 118 First on-off valve 120 Second on-off valve 122 Third on-off valve 124 Control unit 130 Sedimentation member 132 Lower surface of the sedimentation member

Claims (5)

A head for applying a solution to an object;
A solution tank for storing the solution;
A solution supply pipe for supplying the solution from the inside of the solution tank to the head;
A coating apparatus having a settling member disposed inside the solution tank and submerged in the solution. Detecting means for detecting the height of the liquid surface of the solution;
The coating apparatus according to claim 1, further comprising a control unit that adjusts a height of the settling member according to a height of a liquid level of the solution detected by the detection unit.   The said control part is a coating device of Claim 2 which adjusts the height of the said sedimentation member so that the height of the liquid level of the said solution may be maintained within the predetermined range.   The coating apparatus according to any one of claims 1 to 3, wherein the solution tank has a shape in which a bottom surface is inclined downward toward a center.   The coating apparatus according to any one of claims 1 to 4, wherein the sinking member has a shape in which a lower surface thereof extends along a bottom surface of the solution tank.

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