JP4848109B2 - Coating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating apparatus that forms a functional thin film on a substrate by ejecting liquid from a nozzle.
[0002]
[Prior art]
For example, in a manufacturing process of a semiconductor device or a liquid crystal display device, there is a film forming process for forming a functional thin film on a semiconductor wafer, a glass substrate, or the like. In this process, an ink jet type coating apparatus that sprays and applies a solution for forming a functional thin film on a substrate may be used. In this coating apparatus, a plurality of heads capable of ejecting a solution by an ink jet method along a direction perpendicular to the substrate transport direction are arranged above the substrate to be transported, and formed on these heads. The solution is sprayed and applied from the nozzle to the substrate.
[0003]
Since the solution sprayed onto the substrate is supplied from the solution tank, each head is connected to the solution tank by a separate pipe.
[0004]
[Problems to be solved by the invention]
Recently, large substrates are sometimes used in the manufacture of semiconductor devices and liquid crystal display devices. When a functional thin film is formed on a large substrate, a plurality of heads are juxtaposed above the substrate in order to spray and apply the solution uniformly over the entire surface of the substrate. For this reason, each head and the solution tank must be connected by pipes, so that the number of pipes disposed between the solution tank and the head increases. As a result, the number of pipes used increases, leading to an increase in cost. In addition, a large space is required to install this pipe, leading to an increase in the size of the apparatus and the inability to install the pipe. is there.
[0005]
In addition, the solution supplied from the solution tank to each head adheres to the nozzle surface of the head so as to cover a plurality of nozzles at the time of non-injection, and appropriate injection may not be performed at the start of the next injection, The solution sometimes dropped from the nozzle during spraying.
[0006]
A first object of the present invention is to provide a coating apparatus in which a head and a solution tank are not connected by piping.
[0007]
A second object of the present invention is to provide a coating apparatus capable of preventing a solution from dropping from a nozzle or adhering and staying on the lower surface of a head during non-ejection.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, in a coating apparatus for spraying and applying a solution for forming a functional thin film on a substrate using a nozzle, a plurality of ink jet heads on which the nozzle is formed, and the solution is supplied to these heads. A main pipe having a horizontal portion extending in the horizontal direction, a solution tank for supplying the solution to the main pipe, and an air vent provided in an upper portion of the horizontal portion of the main pipe A plurality of distribution pipes that connect the valve to each head and the main pipe and distribute the solution from the main pipe to the head; distribution valves provided in each of the plurality of distribution pipes; and a control device for controlling the opening and closing of the valve, the control device includes a control means controls so as to close the dispensing valve corresponding to the head to be removed among the plurality of heads That.
[0009]
According to a second aspect of the present invention, in the first aspect of the invention, the plurality of distribution pipes are connected to the horizontal portion, and the air vent valve is downstream of a connection portion of the plurality of distribution pipes. It is provided in the side .
[0012]
According to this invention, the plurality of heads are attached to the header in which the main pipeline is formed, and the main pipeline and each head are connected by the distribution pipes, so that each head and the solution tank are not connected by piping. I'm sorry.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
1 to 5 show a first embodiment of the present invention.
[0016]
The coating apparatus shown in FIGS. 1 and 2 has a base 1 having a substantially rectangular parallelepiped shape. Legs 2 are provided at predetermined positions on the lower surface of the base 1 to support the base 1 horizontally.
[0017]
Attaching plates 3 are fixed to both ends in the width direction of the upper surface of the base 1 along the longitudinal direction. A guide member 4 having a substantially rectangular cross section along the longitudinal direction is fixed to one end of the upper surface of each mounting plate 3 located inward in the width direction of the base 1.
[0018]
A table 5 is horizontally provided on the upper surface side of the pair of guide members 4. The table 5 has a substantially rectangular plate shape, and a slide member 6 having a substantially L-shaped cross section is fixed to a pair of opposed end portions on the lower surface thereof.
[0019]
Each slide member 6 is engaged with each guide member 4, whereby the table 5 is slidably supported along the longitudinal direction of the base 1. The table 5 is driven at a predetermined speed along the guide member 4 by a driving device (not shown).
[0020]
A substrate W as a coating material such as a glass substrate or a semiconductor wafer is detachably held on the upper surface of the table 5 by a holding means such as an electrostatic chuck or a suction chuck.
[0021]
That is, the substrate W is held on the upper surface of the table 5 so as to be transported along the longitudinal direction on the upper surface side of the base 1.
[0022]
A support body 7 formed in a gate shape is erected in the middle of the longitudinal direction of the base 1 so as to straddle the pair of guide members 4.
[0023]
At the upper part of the support 7, a header 9 made of a prism having a main pipe line 8 is provided horizontally. As shown in FIGS. 1, 3 and 5, one end of the header 9 is provided with a bubble vent valve 40 which communicates with one end of the main pipe line 8. The journals 10a and 10b are formed so as to protrude. The journals 10a and 10b are rotatably supported by a pair of bearings 12 provided on each support column 11 of the support 7, respectively.
[0024]
The main pipeline 8 is formed over substantially the entire length of the header 9 in the longitudinal direction, and the other end is opened on the end surface of one journal 10b.
[0025]
The journals 10 a and 10 b protrude from the support column 11 outward in the width direction of the base 1. As shown in FIG. 2, the rotary shaft 14 a of the motor 14 is detachably connected to the one journal 10 a via a joint 16. The motor 14 is held by a bracket 15 fixed to the column portion 11. The motor 14 is rotationally driven by a control device (not shown).
[0026]
Further, the tip of the solution supply pipe 17 is rotatably and liquid-tightly connected to the other journal 10 b by a rotary joint 18. That is, the main pipe line 8 and the solution supply pipe 17 communicate with each other via the rotary joint 18.
[0027]
Accordingly, by driving the motor 14, the header 9 is rotated at a predetermined angle. The header 9 may be manually rotated instead of the motor 14.
[0028]
The base end of the solution supply pipe 17 is connected to the lower end of a solution tank 19 that stores the solution to be sprayed onto the substrate W, so that this solution can be supplied to the main pipe line 8 formed in the header 9. It has become.
[0029]
As shown in FIG. 3 and FIG. 4, a plurality of ink jet heads 20 are set screws 21 along the longitudinal direction of the header 9 on one side surface of the header 9 that intersects the transport direction of the substrate W. It is fixed by. The length dimension formed by the plurality of heads 20 is set to be approximately equal to or slightly longer than the width dimension of the substrate W, and the entire substrate W to be transferred passes under the plurality of heads 20. ing.
[0030]
As shown in FIG. 4, the heads 20 and the header 9 are connected to each other by inverted U-shaped distribution pipes 22. The distribution pipe 22 communicates with the main pipeline 8 so that the solution in the solution tank 19 can be supplied from the main pipeline 8 to the head 20.
[0031]
Each distribution pipe 22 is provided with a distribution valve 23, and each distribution valve 23 is controlled to be opened and closed by a control device 41. As a result, for example, when the head 20 is maintained, by closing only the distribution valve 23 of the head 20 that needs maintenance, only the head 20 can be removed and the work can be performed. can do. The distribution valve 23 may be a manual type.
[0032]
Further, when the width dimension of the substrate W to which the solution is applied is reduced and the number of heads 20 to be used is reduced, it can be dealt with by closing the distribution pipe valve 23 of the distribution pipe 22 to which the head 20 is not connected. That is, even if the width dimension of the substrate W to which the solution is applied is changed, the distribution valve 23 is provided in the distribution pipe 22, and therefore it can be easily handled.
[0033]
As shown in FIG. 4, a plurality of nozzles 24 (only one is shown) are perforated at predetermined intervals along the longitudinal direction of the lower surface of each head 20, and the substrate W to be transported is a plate. For example, a solution that forms, for example, an alignment film, a resist, a color filter, or organic electronics luminescence as a functional thin film can be sprayed on the surface.
[0034]
As shown in FIG. 5, the solution tank 19 is connected to the top end of a supply pipe 25, and the base end of the supply pipe 25 is connected to a solution supply tank 26. The replenishment pipe 25 is provided with a replenishment valve 27, and by opening the replenishment valve 27, the solution can be replenished from the solution replenishment tank 26 to the solution tank 19.
[0035]
The solution tank 19 is provided with a liquid level gauge 28, which can detect the level of the liquid level of the solution stored in the solution tank 19. When the liquid level of the solution in the solution tank 19 is lowered by, for example, spraying the solution from the head 20 onto the substrate W, the control device 41 controls the replenishing valve 27 according to a detection signal from the liquid level gauge 28. Open. Thereby, the solution is supplied from the solution supply tank 26 to the solution tank 19.
[0036]
That is, the liquid level of the solution stored in the solution tank 19 is always kept at a predetermined level by the liquid level gauge 28, that is, substantially the same as or slightly below the level of the nozzle 24 formed on the lower surface of the head 20. It has come to droop.
[0037]
Further, an atmospheric pressure release valve 31 that opens the inside of the solution tank 19 to the atmospheric pressure is provided above the solution tank 19, and the opening and closing of the solution tank 19 is controlled by the control device 41.
[0038]
The solution tank 19 is connected to a gas supply pipe 32 for supplying an inert gas such as nitrogen gas or helium gas to the solution supply tank 19, and a gas valve 33 provided in the gas supply pipe 32 is connected to the solution tank 19. By opening with the control device 41, the inside of the solution tank 18 can be pressurized.
[0039]
Next, an operation when the coating apparatus having the above-described configuration is used will be described.
[0040]
When using this coating apparatus, as a preparation for use, the atmospheric pressure release valve 31 is closed and the gas valve 33 and the bubble release valve 40 are opened to supply an inert gas into the solution tank 19.
[0041]
Thereby, the inside of the solution tank 19 is pressurized, and the inside of the solution supply pipe 17, the main pipe 8 of the header 9 and the distribution pipe 22 is filled with the solution, and the gas in each of the pipes 17, 8, 22 is filled. Is discharged to the outside from the bubble release valve 40.
[0042]
As a result, it is possible to prevent inappropriate injection such as intermittent injection of the solution from the nozzle 24 by bubbles mixed in the solution at the time of injection of the solution described later.
[0043]
When the pipes 17, 8, and 22 are filled with the solution, the bubble release valve 40 and the gas valve 33 are closed, and the atmospheric pressure release valve 31 is opened. This completes the preparation for use.
[0044]
When the preparation for use is completed, the substrate W is held on the upper surface of the table 5 and the table 5 is driven along the longitudinal direction of the base 1 at a predetermined speed. When the substrate W reaches below the head 20 provided on the header 9, the solution is ejected from the nozzle 24 of the head 20 toward the substrate W. That is, the distribution valves 23 are opened, and the solution is supplied to the heads 20 through the distribution pipes 22 connected to the main pipeline 8. Then, the solution supplied to each head 20 is ejected from the nozzle 24 by the action of a piezoelectric element (not shown).
[0045]
Since the length dimension formed by the heads 20 arranged in parallel with the header 9 is set to be approximately equal to or slightly longer than the width dimension of the substrate W, the sprayed solution is applied to the entire surface of the substrate W. .
[0046]
As the solution is ejected from the nozzle 24, the liquid level of the solution in the solution tank 19 decreases. When the liquid level is lower than a predetermined level, that is, approximately equal to or slightly lower than the level of the nozzle 24 formed on the lower surface of the head 20, the liquid level gauge 28 detects the liquid level. The replenishing valve 27 is opened by the control device 41 connected to the surface meter 28, and the solution is replenished from the solution replenishment tank 26 to the solution tank 19.
[0047]
Thereby, the above solution a solution of liquid level in the tank 19 is always approximately equal to or slightly below the level of the nozzle 24 of the head 20, the level L ₁ of the nozzle 24 as shown in FIG. 5 in this embodiment Is maintained slightly below the liquid level L ₂ of the solution tank 19. Moreover, the liquid level of the solution tank 19 is opened to the atmospheric pressure by the atmospheric pressure release valve 31. Therefore, when the solution is not ejected from the nozzle 24, there is almost no pressure difference between the liquid level of the solution in the solution tank 19 and the open surface of the nozzle 24. Therefore, the solution drops from the nozzle 24 or the solution from the nozzle 24. Can be prevented from sticking and staying so as to cover the plurality of nozzles 24 on the lower surface of the head 20.
[0048]
If the solution is continuously ejected from the nozzle 24 for a long time, bubbles or the like contained in the solution may accumulate in the head 20. Accordingly, the motor 14 is driven during non-injection, and the header 9 is rotated together with the head 20 by approximately 180 degrees so that the nozzle 24 faces upward.
[0049]
As a result, the bubbles accumulated in the head 20 move upward in the solution and are discharged from the nozzle 24 to the outside. That is, since the header 9 provided with the head 20 can be rotated, bubbles accumulated in the head 20 can be easily removed.
[0050]
6 and 7 show a second embodiment of the present invention.
[0051]
In this embodiment, a header 9A made of a cylindrical tube having a main pipeline 8 inside is used in place of the header 9 made of a prism in the first embodiment. A mounting plate 34 is fixed to the header 9 </ b> A, and a plurality of heads 20 are fixed to the side surface of the mounting plate 34 in a row by set screws 21.
[0052]
Both end portions of the header 9A are rotatably supported, and one end of the header 9A is attached with a lid member 42 that closes one end of the main pipeline 8, and the other end is the first embodiment. The solution supply pipe 17 shown in the form is connected via a rotary joint 18.
[0053]
As described above, since the header 9A is a cylindrical tube, it is not necessary to form journals at both ends of the header 9A or to pierce the main tube 8 in the inside of the header 9A. be able to.
[0054]
【The invention's effect】
According to the present invention, the number of pipes connecting each head and the solution tank can be reduced, so that the apparatus can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a front view showing a coating apparatus according to an embodiment of the present invention.
FIG. 2 is a side view of the coating apparatus.
FIG. 3 is a front view showing a configuration of a header.
4 is a cross-sectional view taken along the line AA in FIG. 3;
FIG. 5 is a schematic diagram showing a piping system and control of a coating apparatus.
FIG. 6 is a front view of a header according to a second embodiment of the invention.
7 is a cross-sectional view taken along line BB in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base 7 ... Support body 8 ... Main pipe line 9 ... Header 40 ... Bubble release valve 10a, 10b ... Journal 12 ... Bearing 16 ... Joint 18 ... Rotary joint 19 ... Solution tank 20 ... Head 22 ... Distribution pipe 23 ... Distribution valve 26 ... Solution replenishment tank 27 ... Replenishment valve 28 ... Liquid level gauge 31 ... Atmospheric pressure release valve

Claims (2)

In a coating apparatus that sprays and applies a solution that forms a functional thin film on a substrate using a nozzle,
A plurality of inkjet heads on which the nozzles are formed;
A main line for supplying the solution to the heads, the main line having a horizontal portion extending in a horizontal direction ;
A solution tank for supplying the solution to the main line;
An air vent valve provided in an upper portion of the horizontal portion of the main pipeline;
A plurality of distribution pipes for connecting the heads to the main pipe and distributing the solution from the main pipe to the head;
A distribution valve provided in each of the plurality of distribution pipes;
A control device for controlling the opening and closing of these distribution valves,
The said control apparatus is controlled so that the distribution valve corresponding to the head removed among said several heads may be closed. The plurality of distribution pipes are connected to the horizontal portion,
The coating apparatus according to claim 1 , wherein the bubble removal valve is provided on a downstream side of a connection portion of the plurality of distribution pipes.

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