JP2008055356A - Solution applicator - Google Patents

Abstract

An object of the present invention is to provide a solution supply device that prevents clogging due to drying and solidification of a solution in a nozzle of an application head.
A transport table is mounted on a top surface and driven in a predetermined direction, and a plurality of nozzles disposed above the transport table and spraying and applying a solution onto the bottom surface of the substrate are opened. The coating head 12 is opened, a solvent is supplied to the inside to prevent the nozzle from drying, and the container 43 covers the lower surface of the coating head when no solution is supplied to the substrate. Is set so that the liquid level of the solvent supplied in the container does not contact the lower surface of the coating head, and a predetermined height is provided between the upper surface of the container and the lower surface of the coating head. The spacer 51 which forms a space part is provided.
[Selection] Figure 2

Description

  The present invention relates to a solution coating apparatus for spraying and supplying a solution in the form of droplets by an inkjet method and coating the substrate.

  Generally, in a manufacturing process of a liquid crystal display device or a semiconductor device, there is a film forming process for forming a circuit pattern on a substrate such as a glass substrate or a semiconductor wafer. In this film forming process, a functional thin film such as an alignment film or a resist is formed on the plate surface of the substrate.

  In the case of forming a functional thin film on a substrate, an ink jet type coating apparatus is used in which a solution for forming the functional thin film is ejected in the form of droplets from a nozzle and supplied and applied to the plate surface of the substrate.

  The coating apparatus includes a transport table for transporting a substrate. Above the transport table, a plurality of coating heads formed by opening the nozzles on the lower surface are orthogonal to the transport direction of the substrate. For example, it is provided in a staggered pattern along the direction. Thereby, a droplet-like solution is spray-applied on the upper surface of the substrate to be transported at a predetermined interval in a direction intersecting the transport direction from a plurality of nozzles. Such a technique is disclosed in Patent Document 1.

  As the solution for forming the functional thin film, a volatile solvent is used as a solvent for dissolving the solute. For this reason, for example, when the application of the solution to the substrate is stopped for a certain time or more when changing the type of the substrate, the solution is dried and solidified by the nozzle opened on the lower surface of the application head, and the nozzle is clogged.

Therefore, in order to prevent clogging of the nozzle, so-called dummy discharge is performed in which the solution is ejected from the nozzle every time a certain period of time has elapsed for stopping application of the solution.
JP 2004-223356 A

  If a dummy discharge is performed to prevent clogging of the nozzle, the quality of the solution discharged from the dummy changes due to dust or changes in viscosity due to contact with air. Can not. For this reason, the dummy discharged solution is wasted, which may increase the running cost. In particular, the solution used for forming the functional thin film is often very expensive, and therefore has a large effect on the cost.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a solution coating apparatus capable of preventing clogging of a nozzle without causing dummy discharge of the solution from the nozzle as much as possible.

The present invention is a solution coating apparatus for supplying and coating a solution on a substrate by an inkjet method,
A table on which the substrate is placed;
An application head having a plurality of nozzles which are disposed above the table and have a plurality of nozzles which are applied to the lower surface by spraying the solution onto the substrate in droplets;
Drive means for relatively driving the substrate and the coating head in a predetermined direction;
A container that covers the lower surface of the coating head when the upper surface is opened and a solvent that prevents drying of the nozzle is supplied therein, and the solution is not supplied and applied to the substrate;
When the lower surface of the coating head is covered by the container, the liquid level of the solvent supplied into the container is set to a height that does not contact the lower surface of the coating head, and the upper surface of the container and the coating head And a liquid level setting means for forming a space portion having a predetermined height between the lower surface of the liquid coating apparatus and the lower surface of the liquid coating apparatus.

  The liquid level setting means is interposed between the upper surface of the container and the lower surface of the coating head in an airtight state when the container covers the lower surface of the coating head, and is elastically held in the container by a spring. It is preferable to use a spacer.

  The liquid level setting means is configured to incline the container from a horizontal state to a predetermined angle before the container covers the lower surface of the coating head to allow a predetermined amount of solvent in the container to flow out, and then horizontally A tilting mechanism for returning is preferable.

  The liquid level setting means is preferably a discharge portion that is provided below the upper surface opening of the container by a predetermined dimension and discharges the solvent supplied into the container to maintain the liquid level at a predetermined height.

  The liquid level setting means is preferably provided on the table.

  According to this invention, when the solution is not discharged, the lower surface where the nozzle of the coating head is opened is covered with the container supplied with the solvent, so that the solvent is prevented from evaporating and the solution is prevented from drying and solidifying to the nozzle. it can. Therefore, the solution can be satisfactorily applied on the substrate.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 to FIG. 6 show a first embodiment of the present invention, and the coating apparatus shown in FIG. Legs 2 are provided at predetermined positions on the lower surface of the base 1, and the base 1 is supported horizontally by these legs 2.

  Mount plates 3 (only one is shown) are provided along the longitudinal direction at both ends in the width direction of the upper surface of the base 1. A first rail member 4 is provided on each of the upper surfaces of the mounting plates 3 along the longitudinal direction. On the upper surface of these first rail members 4, a conveying table 5 as a table is supported by slidably engaging a pair of receiving members 6 provided in parallel on both sides of the lower surface in the width direction. That is, the transfer table 5 is movable on the base 1 in the X direction along the first rail member 4 (one direction along the upper surface (horizontal plane) of the transfer table 5).

  A first X drive source 7 as a drive means is provided at one end in the longitudinal direction of the base 1. The first X drive source 7 rotationally drives a screw shaft 7 a that is screwed into a nut body (not shown) provided on the lower surface of the transport table 5.

  Accordingly, the transport table 5 is driven along the X direction indicated by an arrow in FIG. A glass substrate W used for the liquid crystal display device is supplied and positioned on the upper surface of the transfer table 5. The substrate W is held by suction on the transfer table 5 by means such as vacuum suction or electrostatic suction.

  A gate-shaped support body 8 straddling the pair of rail members 4 is erected in the middle of the base 1 in the longitudinal direction. A mounting plate 9 is installed on the upper portion of one side surface of the support 8 along the width direction of the base 1. A plurality of coating heads 12 for ejecting droplets of a solution that forms a functional thin film, for example, an alignment film, is formed on the mounting plate 9 by an inkjet method in the Y direction (along the horizontal plane, And a direction perpendicular to the one direction). In this embodiment, for example, five coating heads 12 are arranged in two rows in a staggered manner.

  As shown in FIGS. 3 and 4, the coating head 12 includes a head body 18. The head main body 18 is formed in a cylindrical shape, and its lower surface opening is closed by a flexible plate 19. The flexible plate 19 is covered with a nozzle plate 21, and a plurality of liquid chambers 22 are formed between the nozzle plate 21 and the flexible plate 19.

  Each liquid chamber 22 communicates with a main pipe portion 21A formed in the nozzle plate 21 via a branch pipe portion (not shown), and a solution is transferred from the main pipe portion 21A via the branch pipe portion to each liquid chamber 22. To be supplied. One end of the main pipe portion 21A is connected to a liquid supply hole 23 described later, and the other end is connected to a recovery hole 27 described later.

  The liquid supply hole 23 communicating with the liquid chamber 22 is formed at one longitudinal end of the head body 18. The solution for forming the functional thin film is supplied from the liquid supply hole 23 to the liquid chamber 22. Thereby, the inside of the liquid chamber 22 is filled with the solution.

  As shown in FIG. 4, a plurality of nozzles 24 are formed in the nozzle plate 21 in a zigzag pattern along the Y direction, which is a direction orthogonal to the transport direction of the substrate W. A plurality of piezoelectric elements 25 are provided on the upper surface of the flexible plate 19 so as to face the nozzles 24 as shown in FIG.

  Instead of transporting the substrate W by the transport table 5 in the X direction, the support 8 provided with the coating head 12 may be driven in the X direction.

  Each piezoelectric element 25 is supplied with a driving voltage by a driving circuit unit 26 provided in the head body 18. As a result, the piezoelectric element 25 expands and contracts and partially deforms the flexible plate 19, so that the solution is ejected as droplets from the nozzle 24 positioned opposite to the piezoelectric element 25, and the upper surface of the substrate W to be conveyed. Applied to feed. Therefore, a coating pattern in which droplet-like solutions are arranged in a matrix is formed on the upper surface of the substrate W. And this application | coating pattern adheres and it becomes one film | membrane when each solution of a droplet form flows and spreads.

  If the amount of voltage applied to the piezoelectric element 25 is changed to control the operation amount of the piezoelectric element 25, the amount of solution discharged from the nozzle 24 facing each piezoelectric element 25, that is, the size of the droplet is changed. be able to.

  The recovery hole 27 communicating with the liquid chamber 22 is formed at the other longitudinal end of the head body 18. The solution supplied from the liquid supply hole 23 to the liquid chamber 22 can be recovered from the recovery hole 27. That is, each head 12 can not only discharge the solution supplied to the liquid chamber 22 from the nozzle 24 but also recover the solution from the recovery hole 27 through the liquid chamber 22.

  As shown in FIG. 2, a mounting plate 31 is horizontally supported at the lower end portion of one end surface of the transport table 5 located on the coating head 12 side. A pair of second rail members 32 (only one shown) are laid along the X direction on the upper surface of the mounting plate 31 and spaced apart at a predetermined interval in the Y direction.

  An X movable body 33 is provided on the second rail member 32 so as to be movable along the X direction. The X movable body 33 is screwed with a screw shaft 34 whose axis is arranged along the X direction. The screw shaft 34 is rotationally driven by a second X drive source 35 such as a pulse motor disposed in a space 5 a formed in the transport table 5. Thereby, the X movable body 33 is driven along the X direction on the mounting plate 31 described above.

A Z drive source 36 such as a cylinder is disposed on the X movable body 33 with its axis line vertical. A flat Z-shaped movable body 37 is provided on the drive shaft 36 a of the Z drive source 36. The Z movable body 37 is driven in the vertical direction, which is the Z direction, by the Z drive source 36.
FIG. 2 shows a state in which the Z or the body 37 is driven in the upward direction by the drive shaft 36a of the Z drive source 36.

  The Z movable body 37 is provided with a first storage tank 38 and a second storage tank 39 along the X direction. The first storage tank 38 is provided with a flat blade 41 formed of an elastic member such as rubber so that the plate surface is vertical and the upper end portion protrudes. The blade 41 is set to have a length corresponding to the five coating heads 12 arranged along the Y direction.

  As shown in FIG. 2, if the height of the blade 41 is set to a height at which the upper portion of the blade 41 comes into contact with the lower surface of the coating head 12 by the Z drive source 36, the conveyance table 5 can be driven reciprocally. When the blade 41 passes through the lower surface of the coating head 12, the solution attached to the lower surface of the coating head 12 can be removed by rubbing the lower surface of the coating head 12.

  In the second storage tank 39, five containers 43 (only one shown) supported at a predetermined height in the storage tank 39 are arranged with five coating heads 12 provided on the support 8. It is arranged in a state corresponding to the state.

  As shown in FIGS. 5 and 6, the container 43 is formed with a liquid storage portion 44 opened on the upper surface. The opening surface of the liquid storage unit 44 is larger than the portion where the many nozzles 24 formed on the lower end surface of the coating head 12 are arranged, and moreover than the area of the nozzle plate 21 which is the lower end surface of the coating head 12. Is set too small.

  A liquid supply pipe 45 that supplies the solvent L to the liquid storage section 44 of the container 43 is connected to the bottom of the container 43. As the solvent L, the same type as that which melts the solute of the solution applied to the substrate W is used. The solvent L is supplied until it overflows from the upper surface opening of the liquid storage part 44 as shown in FIG.

  For example, the time required to fill up the liquid storage unit 44 based on the relationship between the flow rate of the solvent L supplied from the liquid supply pipe 45 and the volume of the liquid storage unit 44 is obtained in advance, and a margin value is added to the obtained time. The added time is counted by a timing device, and the solvent L is supplied only during that time, so that it can overflow.

  After the solvent L is once stored in the liquid storage unit 44, the solution L in the liquid storage unit 44 is reduced only by the amount of evaporation unless the solvent L is discharged. The counting time by may be shortened to a time that can compensate for the reduced amount of solvent L.

  Further, the overflowing solvent L flows into the storage tank 39. The solvent L flowing into the storage tank 39 is discharged from a discharge hole (not shown) provided at the bottom of the storage tank 39 and stored in a discharge tank (not shown). The discharge tank is provided with a full detection sensor. When the discharge tank is full with the solvent L, it can be detected to prompt replacement of the discharge tank.

  Accommodating holes 46 are formed in the upper four corners of the container 43 so as to open on the upper surface. A guide shaft 47 projects from the accommodation hole 46. A spring 48 is attached to the guide shaft 47. The spring 48 is set to a length protruding from the accommodation hole 46 in an uncompressed state as shown in FIG. 5, and is accommodated in the accommodation hole 46 by being compressed as shown in FIG. It has become so.

  The four guide shafts 47 have spacers 51 of a predetermined thickness inserted into the support holes 52 drilled at the four corners so that the guide shafts 47 can be moved vertically, and are elastically supported by the springs 48. Has been.

  The spacer 51 elastically supported by the spring 48 is in a state where the lower surface is lifted from the upper surface of the container 43. Accordingly, the solvent L supplied to the liquid storage unit 44 of the container 43 overflows from the upper surface opening of the liquid storage unit 44.

  As described later, when the container 43 covers the lower surface of the coating head 12 via the spacer 51 as described later, the liquid level of the solvent L stored in the liquid storage portion 44 of the container 43 is the coating head 12. To prevent contact with the lower surface of the plate. That is, the spacer 51 constitutes a liquid level setting means for setting the height between the liquid level and the lower surface of the coating head 12 so that the solvent L does not contact the lower surface of the coating head 12.

  The spacer 51 has an opening 54 having the same size as the liquid storage part 44 formed in the container 43. Packing 53 is provided on the upper and lower surfaces of the spacer 51 so as to surround the opening 54.

  When the container 43 is positioned so as to correspond to the lower end surface of the coating head 12 and driven in the upward direction by the Z drive source 36, the upper surface of the spacer 51 comes into airtight contact with the lower surface of the coating head 12 via the packing 53. To do. When the container 43 is further raised, the spacer 51 is lowered relative to the container 43 while compressing the spring 48 as shown in FIG. 6, and the lower surface thereof is airtight to the upper surface of the container 43 via the packing portion 53. Contact.

  As a result, a space S in which the opening 54 of the spacer 51 is airtightly closed is formed between the container 43 and the lower end surface of the coating head 12. When the airtight space S is formed, the space L is filled with the solvent L accommodated in the liquid storage portion 44 of the container 43. Therefore, the lower end surface of the coating head 12 is covered with the vaporized solvent L. Thus, drying of the nozzle 24 opened in the opening is prevented. That is, the progress of drying of the solution in the nozzle 24 stops when the concentration of the vaporized solvent L in the atmosphere in contact with the opening surface of the nozzle 24 becomes saturated.

  Note that the above-described coating apparatus drives and controls the first X drive source 7, the drive circuit 26, the second X drive source 35, the Z drive source 36, and the like, and a control (not shown) that performs overall control of the operation of the coating apparatus. Have the device.

  According to the coating apparatus configured in this way, for example, when the application of the solution to the substrate W is stopped for a long time in order to change the type of the substrate W, the lower surface of the coating head 12 is covered with the container 43, and the nozzle 24 Prevent the solution inside from drying out. For example, the control device (not shown) is configured to perform an operation such as a change in the type of the substrate W that is expected to stop the viscosity increasing to such an extent that the solution in the nozzle 24 is dried and the solution discharge from the nozzle 24 is hindered. In the case where an operation for selecting the type change of the substrate W is performed by an operator or the like, the control device executes the following operation.

  First, when the transport table 5 is stopped at a position away from the support 8 on which the coating head 12 is provided, the second X drive source 35 is operated to drive the X movable body 33 in the X direction. Positioning is performed so that the container 43 provided on the movable body 37 faces the lower surface of the coating head 12. In addition, the solvent L is accommodated in the liquid storage part 44 of the container 43.

  Next, the Z drive source 36 is operated to raise the container 43 together with the Z movable body 37. When the Z movable body 37 rises, the upper surface of the spacer 51 elastically supported by the guide shaft 47 on the upper surface side of the container 43 comes into airtight contact with the lower surface of the coating head 12 via the packing 53. Further, when the Z movable body 37 is raised, the spacer 51 is lowered relative to the container 43 against the biasing force of the spring 48. Accordingly, as shown in FIG. 6, the lower surface of the spacer 51 comes into airtight contact with the upper surface of the container 43 through the packing 53.

  Note that the Z drive source 36 continuously raises the Z movable body 37 (container 43) until the spacer 51 comes into contact with the lower surface of the coating head 12 from the state shown in FIG. 5 to the state shown in FIG. .

  In this way, when the upper surface of the spacer 51 comes into airtight contact with the lower surface of the coating head 12 and the lower surface comes into airtight contact with the upper surface of the container 43, the liquid is stored in the liquid storage unit 44 through the opening 54 formed in the spacer 51. An airtight space S having a height corresponding to the thickness of the spacer 51 is formed between the liquid surface of the solvent L and the lower surface where the nozzle 24 of the coating head 12 is opened.

  When an airtight space portion S is formed between the upper surface of the container 43 and the lower surface of the coating head 12, the space portion S is vaporized and filled with the solvent L contained in the liquid storage portion 44 and is saturated. It becomes. As a result, the vaporized solvent L prevents the nozzle 24 from drying, so that the solution in the nozzle 24 is prevented from being dried and solidified to clog the nozzle 24.

  That is, when the discharge surface of the nozzle 24 is stopped and the opening surface of the nozzle 24 is exposed to the atmosphere, the solution in the nozzle 24 is dried and increases in viscosity, or solidifies and becomes clogged. As a result, the solution in the nozzle 24 is prevented from being dried and solidified by the vaporized solvent L, so that it is not clogged.

The time required for the space portion S to be saturated by the atmosphere of the solvent L vaporized after the space portion S is formed differs depending on the volume of the space portion S.
Therefore, the volume of the space S is set so that the atmosphere concentration of the solvent L in the space S is saturated before the viscosity increases to such an extent that the solution in the nozzle 24 is dried and hinders discharge. If the size of the space portion S is set, clogging of the nozzle 24 can be reliably prevented.

  In this embodiment, the volume of the space S is increased according to the thickness of the spacer 51, that is, before the viscosity increases to the extent that the solution in the nozzle 24 is dried and hinders ejection. The atmospheric concentration of the solvent L in S is set to be saturated.

  Since the volume of the space S is defined by the thickness of the spacer 51, the space S can be set to a desired volume. Thereby, since the atmosphere of the solvent L in the same state can be created, the reliability of the clogging prevention effect of the nozzle 24 can be enhanced.

  If the concentration of the atmosphere of the solvent L is saturated in the space S, the drying of the solution in the nozzle 24 does not proceed further. That is, the solution in the nozzle 24 is dried until the concentration of the atmosphere in the space S becomes saturated. In this case, the degree of dryness is such that it does not pose a major problem in discharging the solution from the nozzle 24.

  If the degree of dryness of the solution is slight, the discharge state of the solution from the nozzle 24 does not become unstable, but when a functional thin film is formed, a dry solution is included. There is a possibility that the uniformity of the film is impaired.

  Therefore, several drops of the solution are ejected from the nozzle 24 at a timing when the concentration of the atmosphere of the solvent L in the space S becomes saturated by a control device (not shown). Accordingly, since the solution that has started to dry in the nozzle 24 is discharged, when the application of the solution to the substrate W is resumed, the non-dried solution can be discharged to improve the uniformity of the film.

  In order to efficiently bring the concentration of the atmosphere of the solvent L into the saturated state in the space S, it is preferable that the volume of the space S is as small as possible. However, when the thickness of the spacer 51 is made too thin in order to reduce the volume of the space S, the solution protrudes in a hemispherical shape from the lower surface of the coating head 12, which is the opening surface of the nozzle 24, by surface tension. The solution may come into contact with the solvent L stored in the liquid storage section 44 of the container 43, and the solvent L may enter the nozzle 24.

  Then, since the solution in the nozzle 24 is diluted with the solvent L, the concentration thereof is lower than the concentration of the solution in the other nozzles, so that the quality of the functional thin film formed on the substrate W may be deteriorated. is there.

  Therefore, although the thinner spacer 51 is preferable, even if the solution protrudes in a hemispherical shape from the opening surface of the nozzle 24 by the surface tension, the solution contacts the solvent L accommodated in the liquid storage portion 44. It is preferable to set the dimensions so that they do not occur.

  As described above, when the solution adheres to the lower surface of the coating head 12, when the container 43 is raised to form the space S, the solution comes into contact with the solvent L in the liquid storage unit 44, and the solvent There is a possibility that L may travel through the solution and enter the nozzle 24.

  Therefore, when the space S is formed, the blade 41 is brought into sliding contact with the lower surface of the coating head 12 just before that. As a result, the lower surface of the coating head 12 is cleaned and the solution is removed, so that the solvent L in the liquid storage unit 44 can be prevented from entering the nozzle 24 through the solution.

  7 and 8 (a) and 8 (b) show a second embodiment of the present invention which is a modification of the liquid level setting means. In this embodiment, a rotation shaft 57 is rotatably and horizontally mounted on a second storage tank 39 provided on the Z movable body 37. The rotary shaft 57 is rotationally driven by a rotational drive source 56.

  A container 43 </ b> A is connected and fixed to the rotating shaft 57 by a connecting member 58. A liquid storage part 44 to which the solvent L is supplied is formed in the container 43A, and a liquid supply pipe 45 for supplying the solvent L is connected to the container 43A. Further, a packing 59 is provided over the entire length on the upper end surface of the container 43A.

  When the lower surface of the coating head 12 is covered with the container 43A having the above-described configuration, first, if the rotation angle of the rotary shaft 57 is set so that the upper surface of the container 43A is horizontal, the storage is performed in the same manner as in the first embodiment and Saturday. The liquid L is supplied until the solvent L overflows from the upper surface thereof. Next, as shown in FIG. 8A, the rotation shaft 57 is rotated by the rotation drive source 56, the container 43 </ b> A is inclined at a predetermined angle, and a part of the solvent L contained in the liquid storage unit 44 (the liquid storage unit 44 is stored). The solution L) in the inverted triangular space above the liquid level of the solvent L inside is discharged.

  After discharging the solvent L, the container 43A is returned to the horizontal position as shown in FIG. As a result, a space S having a predetermined height is formed on the liquid level of the solvent L in the liquid storage section 44 according to the inclination angle of the container 43A when the container L is inclined and the solvent L is caused to flow out. The

  When the space S is formed in the liquid storage part 44 in this way, the container 43A is raised by the second Z drive source 36, and the upper surface is the lower surface of the coating head 12 indicated by a chain line in FIG. In an airtight manner through the packing 59.

  Here, the inclination angle of the container 43A can be determined using the condition that determines the thickness of the spacer 51 in the first embodiment. That is, after the solvent L has flowed out, the distance from the liquid level of the solvent L in the liquid storage unit 44 to the upper end of the container 43A is inclined so as to be equal to the thickness of the spacer 51 of the first embodiment. What is necessary is just to set an angle.

  As a result, the vaporized solvent L is filled in the space portion S having a predetermined height formed in the liquid storage section 44, so that the nozzle 24 of the coating head 12 can be prevented from drying. In addition, since the solvent L is vaporized to prevent the nozzle 24 from drying, the solvent L does not adhere to the nozzle 24. Therefore, when the application of the solution is resumed, the solvent L remaining on the nozzle 24 causes the solution to remain. It is also possible to prevent the concentration from becoming uneven.

FIG. 9 shows a third embodiment of the present invention which is a modification of the liquid level setting means. In this embodiment, a drainage hole 61 communicating with the liquid storage part 44 to which the solvent L is supplied is formed below the upper surface of the side wall of the container 43B by a predetermined dimension. A liquid supply pipe 45 for supplying a solvent is connected to the bottom of the container 43B, and a packing 62 is provided over the entire upper end surface.
The container 43B is fixed to the second storage tank 39 at a predetermined height, and does not need to be rotatably provided as in the second embodiment.

  According to such a configuration, when the solvent L is supplied into the liquid storage part 44 of the container 43B, the liquid discharge hole 61 is formed in the side wall, and thus the liquid level of the solvent L becomes higher than the liquid discharge hole 61. There is nothing. That is, a space portion S having a predetermined height is formed between the liquid surface of the solvent L and the upper surface of the container 43B in the upper part of the liquid storage unit 44 according to the height position of the drainage hole 61.

  Here, the height position of the discharge hole 61 can be determined using the condition for determining the thickness of the spacer 51 in the first embodiment. That is, the distance from the lower end of the discharge hole 61 to the upper end of the container 43A may be set so as to be equal to the thickness of the spacer 51 of the first embodiment.

  When the container 44B is raised and its upper surface is brought into airtight contact with the lower surface of the coating head 12 indicated by a chain line in FIG. 9 via the packing 62, the solvent L in the liquid storage unit 44 is vaporized, and the space S To charge.

  As a result, the nozzle 24 opened on the lower surface of the coating head 12 is prevented from drying, so that the nozzle 24 is not clogged by the solution, and the solvent L remains attached to the nozzle 24. Therefore, when the application of the solution is resumed, the concentration of the solution is prevented from becoming non-uniform.

  The operation of covering the lower surface of the coating head 12 with the container 43 has been described in the example executed when the operation set in the control device (not shown) is selected. However, the present invention is not limited to this. It may be executed when the possible time is exceeded.

  FIG. 10 is a fourth embodiment showing a modification of the third embodiment of the present invention. This embodiment is different from the third embodiment in that a communication pipe 65 communicating with the solution tank 65 is connected to the discharge hole 61.

  When the solvent L is supplied from the solution tank 65 to the liquid storage unit 44 by the pump 67 through the liquid supply pipe 45, the liquid level of the solvent L eventually reaches the discharge hole 61. The solvent L whose liquid level has reached the discharge hole 61 is discharged from the discharge hole 61 and is stored in the solvent tank 65 through the communication pipe 66.

  With this configuration, it is possible to reuse the solvent L that has overflowed from the discharge hole 61.

  Also, if the pump 67 is driven to circulate the solvent L, the liquid level of the solvent L in the liquid storage section 44 of the container 43B is always maintained at the height defined by the discharge hole 61. can do.

  FIG. 11 is a fifth embodiment showing a modification of the third embodiment of the present invention. In this embodiment, the liquid supply pipe 45 is connected to substantially the same height as the formation position of the discharge hole 61 in the container 43B, and the solvent tank 65 is disposed at a position higher than the connection position of the liquid supply pipe 45 with the container 43B. This is different from the third embodiment.

  With this configuration, the solvent L in the solvent tank 65 flows into the container 43B by its own weight simply by opening a not-illustrated on-off valve provided in the liquid supply pipe 45. Therefore, the solvent L shown in FIG. A driving source such as a pump for supplying the liquid into the liquid storage part of the container 43B becomes unnecessary, and the configuration of the supply means for the solvent L can be simplified.

  FIG. 12 is a sixth embodiment of the present invention showing a modification of the liquid level setting means. In this embodiment, a transparent window 70 is provided at the formation position of the discharge hole 61 in the third embodiment, and the liquid level detection sensor 71 is used through the transparent window 70 to enter the liquid storage portion 44 of the container 43C. The liquid level of the stored solvent L is detected.

  According to such a configuration, when the solvent L is supplied from the solvent tank 65 to the liquid storage unit 44 via the liquid supply pipe 45 by the pump 67, the liquid level of the solvent L in the liquid storage unit 44 eventually becomes liquid. The height of the surface detection sensor 71 is reached.

  The liquid level detection sensor 71 is an optical sensor that detects the presence or absence of the solvent L using, for example, a change in the refractive index of light, and when the liquid level of the solvent L reaches the height of the liquid level detection sensor 71, Since the refractive index of light changes, it can be detected. As described above, when the liquid level detection sensor 71 detects the liquid level of the solvent L, the signal is sent to a control device (not shown), and the control device issues a command to stop the pump 67 and stops the pump 67.

  In each of the above embodiments, the X movable body provided with the container is provided so as to be driven in the X direction by the second X drive source, and the container is opposed to the lower surface of the coating head by the second X drive source. However, since the container is provided on the transport table, the container may be positioned in the X direction with respect to the lower surface of the coating head.

The front view which shows the supply apparatus of the solution of 1st Embodiment of this invention. The enlarged view of the one end part of a conveyance table. The longitudinal cross-sectional view of the application head of a solution. The figure of the lower surface side of a coating head. Sectional drawing in the state which the container left | separated from the lower surface of the application head. Sectional drawing which shows the state which the container raised and contacted the lower surface of the coating head via the spacer. Sectional drawing which shows the attachment structure of the container which shows 2nd Embodiment of this invention. 7A is an explanatory diagram when the container shown in FIG. 7 is tilted to discharge a predetermined amount of the solvent in the container, and FIG. 8B is an explanatory diagram when the container from which the predetermined amount of solvent has been discharged is returned horizontally. Sectional drawing of the container which shows 3rd Embodiment of this invention. Sectional drawing of the container which shows 4th Embodiment of this invention. Sectional drawing of the container which shows 5th Embodiment of this invention. Sectional drawing of the container which shows 6th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 5 ... Transfer table, 12 ... Coating head, 24 ... Nozzle, 43, 43A, 43B ... Container, 44 ... Liquid storage part, 48 ... Spring, 51 ... Spacer, 53 ... Packing.

Claims (5)

A solution application apparatus for supplying and applying a solution to a substrate by an inkjet method,
A table on which the substrate is placed;
An application head having a plurality of nozzles which are disposed above the table and have a plurality of nozzles which are applied to the lower surface by spraying the solution onto the substrate in droplets;
Drive means for relatively driving the substrate and the coating head in a predetermined direction;
A container that covers the lower surface of the coating head when the upper surface is opened and a solvent that prevents drying of the nozzle is supplied therein, and the solution is not supplied and applied to the substrate;
When the lower surface of the coating head is covered by the container, the liquid level of the solvent supplied into the container is set to a height that does not contact the lower surface of the coating head, and the upper surface of the container and the coating head And a liquid level setting means for forming a space portion having a predetermined height with the lower surface of the solution coating apparatus.   The liquid level setting means is interposed between the upper surface of the container and the lower surface of the coating head in an airtight state when the container covers the lower surface of the coating head, and is elastically held in the container by a spring. 2. The solution coating apparatus according to claim 1, wherein the solution coating apparatus is a spacer.   The liquid level setting means is configured to incline the container from a horizontal state to a predetermined angle before the container covers the lower surface of the coating head to allow a predetermined amount of solvent in the container to flow out, and then horizontally 2. The solution coating device according to claim 1, wherein the solution coating device is a tilting mechanism for returning the solution.   The liquid level setting means is a discharge portion that is provided below the upper surface opening of the container by a predetermined dimension and discharges the solvent supplied into the container and maintains the liquid level at a predetermined height. The solution coating apparatus according to claim 1.   2. The solvent coating apparatus according to claim 1, wherein the liquid level setting means is provided on the table.

Images