JP5625299B2 - Coating device - Google Patents

Description

  The present invention relates to a coating apparatus that coats a coating liquid on the surface of a substrate or the like, and more particularly, to a coating apparatus that coats a thin film uniformly on the surface of a substrate using a low-viscosity coating liquid.

2. Description of the Related Art Conventionally, a die-type coating apparatus (coating apparatus) that applies (applies) a coating liquid directly to a substrate surface from a slit formed at the tip of a die head has been put into practical use. This die-type coating apparatus is used, for example, for coating a thin film of 10 μm or less with high precision (uniformity) in the electronics field.
Generally, a coating liquid reservoir called a manifold is formed inside the die head, and the coating liquid passes through a slit formed so as to communicate with the manifold. Discharged.

  One of the most important requirements for the die head is to quickly remove the air in the coating liquid in the manifold in order to apply uniformly without generating fine bubbles or the like. This is also important in preventing denaturation due to retention of the coating liquid.

  Conventionally proposed die heads for venting the coating liquid in the manifold include a manifold formed in a coat hanger shape as shown in Patent Document 1. However, this structure has a problem that it is impossible to vent the air in a short time because the coating liquid supply port and the port for venting air are close to each other.

  In order to solve the problem in Patent Document 1, in the coating apparatus shown in Patent Document 2, the upper part of the reservoir (manifold) is formed in an inclined shape so as to gradually increase from the central part of the slit toward both ends. doing. Vents (air vent pipes) are provided at both ends of the reservoir, and the air in the coating liquid is guided to both ends of the reservoir and is discharged from these vents.

In order to solve the above problems, the present invention proposes the following means.
The coating apparatus of the present invention is a coating apparatus including a die head that coats a base material with a coating liquid having a viscosity of 3 mPa · sec, and the die head extends in a horizontal direction inside the die head body and the die head body. A manifold for containing the coating liquid, a supply port for supplying the coating liquid, provided at an intermediate portion in the extending direction of the manifold, and an upper end formed below the manifold. The side communicates with the manifold, the lower end communicates with a discharge port formed on the bottom surface of the die head, the first end communicates with one end of the manifold in the extending direction, and the second A first air vent pipe with an open end; a second air vent pipe with a first end communicating with the other end of the manifold in the extending direction and a second end open; Have Inner diameters of the first air vent pipe and the second air vent pipe are 0.4 mm or more and 8.0 mm or less, respectively, and the second end of the first air vent pipe is formed by the first air vent pipe. The second end of the second air vent pipe is arranged at a position vertically below the first end of the second air vent pipe, and the second end of the second air vent pipe is the first end of the second air vent pipe. It is characterized by being arranged at a position of 0.2 m or more and 2.0 m or less vertically below one end.

  However, in the coating apparatus shown in the above-mentioned Patent Document 2, there is a case where air is not sufficiently removed from the end portion of the pool portion, which tends to cause coating defects.

  The present invention has been made in view of such problems, and prevents air from remaining in the coating liquid over the entire length of the manifold, thereby enabling uniform coating with higher accuracy. An object is to provide a coating apparatus.

In order to solve the above problems, the present invention proposes the following means.
The coating apparatus of the present invention is a coating apparatus including a die head that coats a base material with a coating liquid, and the die head is formed to extend in a horizontal direction inside the die head body and the die head body, A manifold that stores the coating liquid, a supply port that is provided at an intermediate portion in the extending direction of the manifold, and that is supplied with the coating liquid, and is formed below the manifold and has an upper end communicating with the manifold. A slit whose lower end communicates with a discharge port formed on the bottom surface of the die head, a first end communicates with one end in the extending direction of the manifold, and a second end is opened. A first air vent pipe and a second air vent pipe having a first end communicating with the other end in the extending direction of the manifold and a second end opened, First air vent And the inner diameter of the second air vent pipe is 0.4 mm or more and 8.0 mm or less, and the second end of the first air vent pipe is the first end of the first air vent pipe. The second end of the second air vent pipe is perpendicular to the first end of the second air vent pipe. It is characterized by being arranged at a position of 0.2 m or more and 2.0 m or less below the direction.

According to the present invention, the coating liquid supplied to the intermediate portion in the extending direction of the manifold through the supply port is formed on the bottom surface of the die head through the slit while moving along the extending direction toward both ends of the manifold. It is discharged from the discharged outlet. And the coating liquid discharged from the discharge outlet is applied to a base material.
During a predetermined period when the coating liquid is not applied to the base material, the coating liquid is supplied from the intermediate portion in the extending direction of the manifold through the supply port, and from each air vent tube at both ends in the extending direction of the manifold. Discharged.

At this time, the inner diameters of the first air vent pipe and the second air vent pipe are 0.4 mm or more and 8.0 mm or less, respectively, and the second end of the first air vent pipe is the first of the first air vent pipe. It is arranged at a position 0.2 m or more and 2.0 m or less vertically below the end, and the second end of the second air vent pipe is 0 below the first end of the second air vent pipe. .2m or more and 2.0m or less.
Therefore, the flow rate of the coating liquid flowing in the manifold is increased to prevent the coating liquid from accumulating, and the air is reliably removed from the entire coating liquid including the end in the extending direction of the manifold. Uniform coating can be performed with high accuracy.

In the coating apparatus, it is more preferable that the upper part of the inner surface of the manifold is formed so as to be positioned higher toward the respective end portions in the extending direction with the supply port as a center.
According to this invention, the air in the coating liquid can be easily collected at the end of the manifold where the first end of each air vent pipe communicates.

In the coating apparatus, it is more preferable that the manifold is formed to extend longer in the extending direction than the slit on one side and the other side in the extending direction.
According to this invention, it is possible to prevent the air collected at both ends in the extending direction of the manifold from flowing into the slits and perform uniform coating with higher accuracy.

  According to the coating apparatus of the present invention, air can be prevented from remaining in the coating solution over the entire length of the manifold, and uniform coating can be performed with higher accuracy.

It is a perspective view explaining the state which coats a base material with the die head of the coating device of 1st Embodiment of this invention. It is an A direction arrow directional view in FIG. FIG. 3 is a cross-sectional view taken along a cutting line B1-B1 in FIG. It is a figure which shows the result of having simulated the mode that air escapes from the manifold of the coating device in case the internal diameter of an air vent pipe is 8.0 mm. It is a figure which shows the result of having simulated the mode that air escapes from the manifold of the coating device in case the internal diameter of an air vent pipe is 6.0 mm. It is a figure which shows the result of having simulated a mode that air escapes from the manifold of the coating device in case the height difference of an air vent pipe is 0.2 m . It is a figure which shows the result of having simulated the mode that air escapes from the manifold of the coating device in case the height difference of an air vent pipe is 1.0 m . It is a figure which shows the result of having simulated a mode that air escapes from the manifold of the coating device in case the length of a manifold differs. It is a front view of the coating device of 2nd Embodiment of this invention. FIG. 10 is a cross-sectional view taken along section line B2-B2 in FIG.

(First embodiment)
Hereinafter, a first embodiment of a coating apparatus according to the present invention will be described with reference to FIGS. 1 to 8. As shown in FIG. 1, the die head 2 provided in the coating apparatus 1 of the present embodiment is of an extrusion type and is used for coating (coating) a coating liquid E on a substrate W. In the following figures, the flow path of the coating liquid E is mainly shown and described rather than each configuration of the die head 2.

As shown in FIGS. 1 to 3, the die head 2 includes a die head main body 5, a manifold 6 formed inside the die head main body 5, and a supply port 7 provided at an intermediate portion in the extending direction C in which the manifold 6 extends. A slit 8 formed below the manifold 6, a first air vent pipe 9 having a first end 9 a communicating with one end 6 a in the extending direction C of the manifold 6, and a first end 10 a has a second air vent pipe 10 communicating with the other end 6 b in the extending direction C of the manifold 6.
In addition, the base material W is arrange | positioned on the plane parallel to a horizontal surface, and let the direction where the base material W extends among the directions along a horizontal surface be an X direction, and let a perpendicular direction be a Y direction. At this time, the extending direction C of the manifold 6 is parallel to the Z direction perpendicular to the X direction and the Y direction, that is, parallel to the horizontal plane. Then, the coating liquid E is applied to the substrate W while the die head 2 and the substrate W move relatively in the X direction.
Moreover, the arrow in FIGS. 1-3 shows the direction through which the coating liquid E flows.

The die head body 5 is formed to extend in the extending direction C, for example, with aluminum or the like.
The cross section of the manifold 6 by a plane orthogonal to the Z direction is formed in a D-shaped semicircular shape having a linear portion along the Y direction, and the outer diameter L1 of the cross section is constant regardless of the position in the Z direction. It has become. The manifold 6 accommodates the coating liquid E supplied from a supply port 7 to which a supply pipe (not shown) is connected.
The slit 8 communicates with the manifold 6 at the upper end side, and communicates with the discharge port 13 formed at the bottom surface of the die head body 5 at the lower end side. The width of the slit 8 in the X direction and the length (land length) L2 in the Y direction are set to be constant regardless of the position in the Z direction. In the present embodiment, the length L3 in the Z direction between the slit 8 and the manifold 6 is set to be equal to each other.

The first end portion 9a of the first air vent tube 9 and the first end portion 10a of the second air vent tube 10 are upper portions of the inner surface at the respective end portions 6a and 6b in the extending direction C of the manifold 6 ( (Upper part in the Y direction). As shown in FIG. 1, the second end 9b of the first air vent tube 9 and the second end 10b of the second air vent tube 10 are each open to the atmosphere (second end (Part 10b is not shown). The inner diameter D1 of the first air vent pipe 9 and the inner diameter D2 of the second air vent pipe 10 are set to be 0.4 mm or more and 8.0 mm or less, respectively.
In the present embodiment, a first valve 14 and a second valve 15 for opening and closing the respective flow paths are respectively attached to intermediate portions of the first air vent tube 9 and the second air vent tube 10. . Then, below the second end portion 9b of the first air vent tube 9 and the second end portion 10b of the second air vent tube 10, the coatings discharged from the respective second end portions 9b and 10b are provided. A first waste liquid tank 16 and a second waste liquid tank 17 for receiving the working liquid E are disposed (the second waste liquid tank 17 is not shown).

In the 1st air vent pipe 9, the 2nd end part 9b is arrange | positioned vertically lower than the 1st end part 9a, The height difference H1 is set to 0.2 m or more and 2.0 m or less.
Similarly, in the 2nd air vent pipe 10, the 2nd edge part 10b is arrange | positioned vertically lower than the 1st edge part 10a, and the height difference H2 (not shown) is set to 0.2 m or more and 2.0 m or less. Has been.

Next, the process of applying the coating liquid E onto the substrate W using the coating apparatus 1 configured as described above will be described.
When the user supplies the coating liquid E from a supply pipe (not shown) with the first valve 14 and the second valve 15 closed, the coating liquid E extends from the manifold 6 through the supply port 7. It is supplied to the middle part in the direction C. The coating liquid E is formed on the bottom surface of the die head body 5 by flowing in the negative direction of the Y direction in the slit 8 while moving along the extending direction C in the manifold 6 toward both ends 6a and 6b. It is discharged from the discharged outlet 13. Then, the discharged coating liquid E is applied to the substrate W.

At a predetermined time during which the coating liquid E is not applied to the base material W (for example, after the application to the single base material W is completed), the user performs the first valve 14 and the second valve 15. In the open state. When the coating liquid E is supplied from the intermediate portion in the extending direction C of the manifold 6 through the supply port 7, the inner diameter D1 and the height difference H1 of the first air vent pipe 9 and the inner diameter D2 of the second air vent pipe 10 and the height difference thereof. Due to the siphon principle according to the difference H2, the frictional force of the inner wall of the pipe, and the pressure to supply the coating liquid E, the coating liquid E containing air passes through the manifold 6 from the air vent pipes 9 and 10 to the waste liquid tank 16, Each is discharged into the second waste liquid tank 17.
It is to be noted that one of the valves 14 and 15 is opened and the other is closed alternately, and the coating liquid E containing air is alternately discharged from the air vent pipes 9 and 10. Also good. By doing in this way, the coating liquid E containing air can be discharged | emitted from the manifold 6 efficiently.

  When the predetermined time is over, the user closes the first valve 14 and the second valve 15, respectively, supplies the coating liquid E from the supply pipe, and applies the coating liquid E to the substrate W. Repeat the coating procedure.

Next, the result of simulating using a computer how air escapes from the coating liquid E in the manifold 6 of the coating apparatus 1 configured as described above will be described.
Assume that the length L3 in the Z direction of the slit 8 and the manifold 6 is 3.1 m, the width in the X direction of the slit 8 is 80 μm, and the length in the Y direction is 80 mm. The coating liquid E is a Newtonian fluid having a viscosity of 3 mPa · second (s) and a density of 990 kg / m ³ , and the air in the coating liquid E has the same physical properties (viscosity, density, etc.) as the coating liquid E. Assume it is a particle.
Under this condition, a waste liquid time distribution, which is a time distribution required for discharging a certain number of air particles mixed in the coating liquid E from the first air vent pipe 9 or the second air vent pipe 10, was obtained. . And the waste liquid efficiency showing the ease of discharge | emission of the air particle was examined.

  4 and 5 show the simulation results when the inner diameters D1 and D2 of the air vent pipes 9 and 10 are changed, and FIGS. 6 and 7 show the height differences H1 and H2 of the air vent pipes 9 and 10. The simulation results are shown. 4 to 7, the horizontal axis indicates the time required for air particles to be discharged for each time zone, and the vertical axis indicates the amount of air discharged in each time zone with respect to the total number of air particles. The ratio of the number of particles is shown. For example, referring to FIG. 4, it can be seen that nearly 90% of the total number of air particles is exhausted in about 18 s, and it takes about 55 s to exhaust all the air particles (exceeding 55 s). No air particles).

In the air vent pipes 9 and 10, simulation results when the height differences H1 and H2 are 0.2 m are shown in FIG. 4 when the inner diameters D1 and D2 are 8.0 mm, and when the inner diameters D1 and D2 are 6.0 mm. Is shown in FIG.
When the inner diameters D1 and D2 are 6.0 mm, most of the air particles (about 98%) are discharged within 35 s. On the other hand, when the inner diameters D1 and D2 are 8.0 mm, there are about 5% of air particles discharged after 35 s or more. That is, it was found that the smaller the inner diameters D1 and D2, the shorter the time required until all the air particles were discharged, and the higher the waste liquid efficiency.
However, in practical use, if about 95% of air particles are discharged within 35 s, high-precision uniform coating can be performed. Therefore, the inner diameters D1 and D2 should be 8.0 mm or less. I understood.

Further, in the air vent pipes 9 and 10, simulation results when the inner diameters D1 and D2 are set to 8.0 mm. FIG. 6 shows a case where the height differences H1 and H2 are 0.2 m, and the height differences H1 and H2 are 1. The case of 0 m is shown in FIG.
It was found that the larger the height difference H1 and H2, the shorter the time required until all the air particles were discharged and the higher the waste liquid efficiency. However, in practical use, if approximately 95% of air particles are discharged within 35 s, high-precision uniform coating can be performed. Therefore, the height differences H1 and H2 should be 0.2 mm or more. I understood.
In the present embodiment, since the outer diameter L1 of the manifold 6 is 8.0 mm, the inner volume of the manifold 6 is 311488 mm ³ . And the sum total of the flow volume of the coating liquid E discharged | emitted from each air vent pipe 9, 10 is about 60000 mm < ³ > / s (The flow volume of the coating liquid E supplied from the supply port 7 also becomes equal to this value. ). For this reason, for example, the total volume of the coating liquid E discharged from the air vent pipes 9 and 10 during 35 s is about 6.7 times the internal volume of the manifold 6.

In the coating apparatus 1 in which the above-described simulation was performed, the coating apparatus 1 in which only the length L3 of the slit 8 and the manifold 6 was changed from 3.1 m to 2.5 m (in each of the air vent pipes 9 and 10, the inner diameter D1, FIG. 8 shows the result of simulation with D2 of 8.0 mm and height difference H1 and H2 of 1.0 m. From FIG. 7 and FIG. 8, when the length L3 is 3.1 m, the time required until all the air particles are discharged is shorter than when the length L3 is 2.5 m, and the waste liquid efficiency is improved. I found it expensive.
The coating apparatus 1 having a length L3 of 2.5 m allows air to be discharged from the coating liquid E of the entire manifold 6 even when the air in the coating liquid E is actually discharged, enabling highly accurate uniform coating. It has been confirmed. Therefore, even in the coating apparatus 1 with a length L3 of 3.1 m, which has a higher waste liquid efficiency, the air in the coating liquid E can be discharged efficiently and more effectively than in the case where the length L3 is 2.5 m. It was speculated that there was no problem.

As described above, according to the coating apparatus 1 of the present embodiment, the coating liquid E is supplied from the intermediate portion in the extending direction C of the manifold 6 through the supply port 7 and in the extending direction C of the manifold 6. The air is discharged from the air vent pipes 9 and 10 at both ends 6a and 6b.
At this time, the inner diameters D1 and D2 of the air vent pipes 9 and 10 are set to 0.4 mm or more and 8.0 mm or less, respectively. In the first air vent pipe 9, the second end portion 9b is perpendicular to the first end portion 9a. The height difference H1 is set to 0.2 m or more and 2.0 m or less, and the second end 10b of the second air vent pipe 10 is arranged vertically below the first end 10a. The height difference H2 is set to 0.2 m or more and 2.0 m or less.

When the inner diameter D1 of the first air vent pipe 9 or the inner diameter D2 of the second air vent pipe 10 is less than 0.4 mm, there is a problem that the coating liquid E is clogged in each of the air vent pipes 9 and 10 and exceeds 8.0 mm. Thus, it becomes impossible to effectively remove air from the coating liquid E.
On the other hand, if any of the height differences H1 and H2 is less than 0.2 m in the air vent pipes 9 and 10, air cannot be effectively removed from the coating liquid E, and any of the height differences H1 and H2 When it exceeds 2.0 m, it becomes difficult to arrange in a standard coating apparatus. Furthermore, by setting the height difference H1 and H2 to a certain level or more, air is mixed from both end portions 6a and 6b of the manifold 6 through the air vent pipes 9 and 10, and coating is performed in a state where air is mixed into the coating liquid E. Can be prevented.

  Accordingly, the flow rate of the coating liquid E flowing in the manifold 6 is increased to prevent the coating liquid E from staying, and the entire area including the end portions 6a and 6b in the extending direction C of the manifold 6 is from the inside of the coating liquid E. The air can be surely removed and uniform coating can be performed with higher accuracy.

  In addition, since the first end portions 9a and 10a of the air vent pipes 9 and 10 are connected to the upper part of the inner surface at the respective end portions 6a and 6b of the manifold 6, the coating liquid is supplied from the air vent pipes 9 and 10. The air in E can be easily removed.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 9 and FIG. 10. The same parts as those in the above embodiment are denoted by the same reference numerals and the description thereof will be omitted, and only differences will be described. explain.
As shown in FIGS. 9 and 10, the die head 22 provided in the coating apparatus 21 of the present embodiment includes a manifold 26 instead of the manifold 6 of the die head 2 of the embodiment.

  The manifold 26 is formed to extend longer in the extending direction C than the slit 8 on one side and the other side in the extending direction C. That is, in this embodiment, the slit 8 is formed to have a length L3 in the Z direction, and the length of the manifold 26 in the Z direction is a length L6 that is longer than the length L3 of the slit 8. . One end 26a and the other end 26b of the manifold 26 are formed to extend longer than the slit 8 by a length L7 in the Z direction.

Further, the upper portion of the inner surface 26c of the manifold 26 is formed so as to be positioned upward (upward in the vertical direction) toward the respective end portions 26a and 26b in the extending direction C with the supply port 7 as a center.
That is, the cross section of the manifold 26 by a plane orthogonal to the Z direction is formed in a D-shaped semicircular shape having a linear portion along the Y direction. The outer diameter of this cross section is the outer diameter L8 at the portion where the supply port 7 is provided in the Z direction, and the outer diameter L9 is larger than the outer diameter L8 at the end portions 26a and 26b.

As described above, according to the coating apparatus 21 of the present embodiment, air can be prevented from remaining over the entire length of the manifold 26 and applied uniformly with high accuracy, as in the above-described embodiment. it can.
Since the manifold 26 is formed to extend longer than the slit 8 on one side and the other side in the extending direction C, air collected at both ends 26a and 26b in the extending direction C of the manifold 26 is collected. It is possible to prevent the fluid from flowing into the slit 8 and perform uniform coating with higher accuracy.

  Moreover, since the upper part of the inner surface 26c of the manifold 26 is formed so as to be positioned higher toward the respective end portions 26a and 26b in the extending direction C, the first end portions of the air vent pipes 9 and 10 are formed. The air in the coating liquid E can be easily collected at the end portions 26a and 26b of the manifold 26 with which 9a and 10a communicate.

  Note that the manifold 26 of the coating apparatus 21 of the present embodiment has a feature that the manifold 26 extends longer in the extending direction C than the slit 8 and a feature that the upper portion of the inner surface 26c is positioned higher toward the end portions 26a and 26b. Had one. However, the manifold may be configured to include only one of the features.

As mentioned above, although 1st Embodiment and 2nd Embodiment of this invention were explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The structure of the range which does not deviate from the summary of this invention Changes are also included.
For example, in the said 1st Embodiment and 2nd Embodiment, the 2 air vent pipes of the 1st air vent pipe 9 and the 2nd air vent pipe 10 were connected to the both ends of the manifold, respectively. However, the third and subsequent air vent pipes may be further communicated with this manifold.

DESCRIPTION OF SYMBOLS 1,21 Application | coating apparatus 2,22 Die head 5 Die head main body 6 Manifold 6a One end 6b The other end 7 Supply port 8 Slit 9 First air vent pipe 9a First end 9b Second end 10 Second Air vent pipe 10a First end 10b Second end 13 Discharge port 26c Inner surface D1, D2 Inner diameter E Coating liquid W Substrate

Claims (3)

A coating apparatus comprising a die head for coating a substrate with a coating solution having a viscosity of 3 mPa · s ,
The die head is
The die head body,
A manifold formed in the die head body so as to extend in the horizontal direction and containing the coating liquid;
A supply port that is provided at an intermediate portion in the extending direction of the manifold and to which the coating liquid is supplied;
A slit formed below the manifold and having an upper end communicating with the manifold and a lower end communicating with an ejection port formed on the bottom surface of the die head;
A first air vent pipe having a first end communicating with one end of the manifold in the extending direction and a second end opened;
A second air vent pipe having a first end communicating with the other end of the manifold in the extending direction and a second end opened;
Have
The inner diameters of the first air vent pipe and the second air vent pipe are 0.4 mm or more and 8.0 mm or less, respectively.
The second end of the first air vent pipe is disposed at a position of 0.2 m or more and 2.0 m or less vertically downward from the first end of the first air vent pipe,
The second end of the second air vent pipe is disposed at a position of 0.2 m or more and 2.0 m or less vertically downward from the first end of the second air vent pipe. A characteristic coating apparatus.   The upper part of the inner surface of the said manifold is formed so that it may be located upwards so that it may go to each edge part of the said extension direction centering on the said supply port.   The coating apparatus according to claim 1, wherein the manifold is formed to extend longer in the extending direction than the slit on one side and the other side in the extending direction. .

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