JP2006224089A - Device and method for coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide slit-coating-type coating device and coating method that are free from detection leakage and can realize reliable protection of a coating head, even in the case of very small foreign matter or protuberant part having a very small height of a substrate. <P>SOLUTION: This coating device include a moving means comprising a substrate holding plate for holding a coating substrate 10 and a coating head 2 for delivering a coating liquid from a slit-shaped opening. The substrate holding plate and the coating head 2 are relatively movable. The coating head 2 comprises a support part 9 having a rotary bearing provided on the moving direction side, a plate-shaped member 4, which is rotatably mounted in the rotary bearing and has a linear shape in its front end 5, a detection means 7 capable of sensing the rotary motion of the plate-shaped member 4, and a control means for controlling the movement of the coating head 2 based on the status of detection determined by the detection means 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a coating apparatus and a coating method capable of coating a coating liquid on a substrate such as glass with a uniform thickness. In particular, the present invention relates to a coating apparatus and a coating method capable of coating various liquid coating solutions such as a resist solution and a slurry on a flat substrate such as a plasma display or a liquid crystal display or a semiconductor wafer in a uniform thickness.

As a method of applying a coating solution such as a resist solution or an insulating material on a flat substrate used in a display unit of various electronic devices such as a liquid crystal display or a wafer for semiconductor manufacturing, a short side of the substrate or a wafer Using a coating head having a slit-shaped opening having a full length corresponding to the diameter of the liquid, a predetermined amount of coating liquid is discharged from the slit-shaped slit opening, while the coating head side or the substrate side is In recent years, many slit coat type coating apparatuses that form a uniform thin film by relatively moving at a constant speed have been adopted.

According to this slit coat type coating apparatus, the discharge amount of the coating liquid required to form a coating layer having a desired thickness (for example, a film thickness of 1.5 μm ± 5%) is 1.1 times that of the coating layer. Since it can be suppressed to the following, compared to punishing the coating layer using a conventionally used spin coat type coating device, the amount of the coating solution wasted is small, and the required amount of coating solution to be used is reduced. It can be greatly reduced.

However, since the slit coat type coating and feeding needs to form a uniform thin film by coating in one relative movement, the condition that the coating liquid is discharged with a uniform film thickness over the entire length of the slit opening, It is necessary to minimize the area of unstable application at the start and end of application.

As this die coating method, a non-contact type distance measuring sensor is attached to the coating head, the gap between the coating effective surface and the coating head opening is measured in advance using this sensor, and the deviation from the reference value is calculated. After that, the coating head is relatively moved based on the calculation result to apply the coating liquid, thereby forming a uniform coating layer that copes with substrate waviness, warpage, and thickness unevenness (Patent Literature). 1).

In addition, before applying the coating liquid, the surface to be coated of the substrate is scanned by a non-contact method with a laser scanning detector, and foreign matter is detected by detecting foreign matter of 100 to 200 μm. (See Patent Document 2).

Thus, according to the laser scanning detector, the presence or absence of a foreign substance can be detected by the interference waveform generated when the foreign substance is irradiated with laser light. However, more scanning time is required to increase detection accuracy in order to detect minute foreign matter. For this reason, there has been a problem that it takes a lot of time to detect foreign matter before coating. In this method, the size of the foreign matter that can be detected is several tens of μm, and there is a limit to detection.

It is possible to detect foreign matter on the surface of the substrate, but if the height of the substrate increases due to foreign matter existing between the substrate and the holding plate that holds and holds the substrate, an interference waveform Therefore, it is difficult to detect with the above-mentioned laser scanning detector. In this case, since it is not detected, if the coating operation is continued without any abnormality, the tip of the coating head opening and the substrate surface come into contact with each other, and when the coating head is moved relatively, the coating head opening When the substrate is pressed, the substrate is damaged.

Thus, the worker notices that foreign matter exists between the substrate and the holding plate only after the substrate is damaged, and the operator removes the foreign matter together with the substrate and restarts the coating process. However, when this substrate is removed, the tip of the coating head opening is also damaged.
This breakage of the tip portion causes the occurrence of streaky irregularities in the direction of movement of the coating solution, and therefore requires replacement with a new coating head. As a result, there has been a problem that the operation of the slit coat type coating apparatus and the entire substrate production line is stopped for a long time.
Furthermore, since the tip of the coating head opening needs to be precision processed, not only does it take a long time to process, but it also leads to a large loss, so it is necessary to avoid damage to the tip of the coating head as much as possible. .

Therefore, in Patent Document 2, in the slit coat type coating apparatus, by providing a plate-like member that moves together with the coating head, the foreign matter detection step before coating is omitted, and damage to the coating head due to foreign matter is prevented. Is disclosed.
Specifically, when the detection mechanism detects that the plate-like member vibrates when the foreign object contacts the plate-like member attached to the application head, the relative movement of the application head with respect to the substrate is forcibly stopped. It is disclosed to prevent breakage of the application head.
As described above, since it is not necessary to detect foreign matter before coating, the manufacturing cycle time can be shortened, and not only foreign matter existing on the substrate but also foreign matter existing between the substrate and the substrate holding board. Can be detected.

Further, as another means, it is disclosed that when a foreign object is detected, the coating head is prevented from being damaged by withdrawing the coating head from the substrate coating exemption (see Patent Document 3).
Patent Document 3 discloses that when a foreign object on a substrate is detected by the lowermost surface of the detection body, the detection body moves upward due to an action in contact with the foreign object, thereby detecting the foreign object.
Japanese Patent Laid-Open No. 10-421 JP 2000-24571 A JP 2002-1195 A

The foreign matter on the substrate is very small in size and is not firmly attached on the substrate. And the protruding part of the board | substrate by a foreign material is also very low height.
Therefore, it is difficult to detect the foreign matter or the raised portion of the substrate, and the foreign matter or the raised portion of the substrate may not be detected.
In particular, if the relative movement direction of the substrate and the coating head and the movement direction of the detection means provided in the coating head are substantially perpendicular, the force that pushes the foreign material and the raised portion of the substrate with the detection means is dispersed. May not be detected reliably.
In addition, as a detection means, even in a method of detecting vibration of a plate-like member fixed to the coating head, it is very difficult to detect minute foreign matter by vibration because the plate-like member is fixed to the coating head. Met.
Accordingly, the present invention provides a slit coat type coating apparatus and a coating method that ensure the protection of the coating head without causing any detection leakage even in the case of a minute foreign matter or a protruding portion having a minute height on the substrate. With the goal.

The invention described in claim 1 includes a substrate holding plate that holds the substrate to be coated and a coating head that coats the coating liquid from the slit-shaped opening, and the substrate holding plate and the coating head are relatively movable. In a slit coat type coating apparatus having means,
The application head is
A support portion having a rotary bearing provided on the moving direction side;
A plate-like member that is rotatably attached to the rotary bearing and has a straight end portion;
Detection means capable of detecting the rotational movement of the plate-like member;
A slit coat type coating apparatus comprising control means for controlling movement of the coating head based on the detection status obtained by the detection means.

The invention according to claim 2 is characterized in that the plate-like member is composed of a lower part whose tip is linear, and an upper part which can come into contact with the detecting means. It is a mold coating device.

The invention according to claim 3 is the slit coat type coating apparatus according to claim 2, wherein the plate-like member has an upper portion longer than a lower portion.

A fourth aspect of the present invention is the slit coat type coating apparatus according to the second or third aspect, wherein the upper part and the lower part of the plate-like member are composed of separate members.

The invention according to claim 5 is the slit coat type coating apparatus according to claim 4, wherein the specific gravity of the material constituting the upper portion is larger than the specific gravity constituting the lower portion.

The invention according to claim 6 is the slit coat type coating apparatus according to any one of claims 1 to 5, wherein the control means is to stop relative movement of the moving means. It is.

A seventh aspect of the present invention is the slit coat type coating apparatus according to any one of the first to fifth aspects, wherein the control means is a retracting movement of the coating head.

The invention described in claim 8 is a coating method characterized in that coating is performed on a substrate using the slit coat type coating apparatus according to any one of claims 1 to 7.

In the present invention, even if the foreign matter detection scanning of the substrate is not performed in advance before the coating solution is applied, if the foreign matter comes into contact with the plate-like member, the rotating force applied to the plate-like member is transmitted to the rotating shaft, and the In addition, foreign matter on the substrate can be eliminated, and even if foreign matter adhered to the back surface of the substrate is present, the rise of the substrate other than the foreign matter can be detected, so that the manufacturing cycle time can be shortened.
Further, it was possible to prevent the coating head from being damaged due to the protrusions due to the foreign matter on the substrate or the foreign matter existing between the substrate and the substrate holding plate.

Embodiments of the present invention will be described with reference to the drawings.
First, the first embodiment will be described.

FIG. 1 shows a state in which the slit coat type coating apparatus 1 is positioned on a substrate 10 on which foreign matter 11 exists.
The slit coat type coating apparatus 1 and the substrate 10 are movable relative to each other, and the following description will be made on the assumption that the substrate 10 is stationary and the coating apparatus 1 is movable in the right direction.

The slit coat type coating apparatus 1 has a coating head 2 having a slit-shaped opening, and a support unit 9 connected and integrated with the coating head 2. A plate-like member 4 that rotates about the rotation shaft 3 is provided. Below the plate-like member 4, there is provided a lower member 6 a having a tip portion 5 that is formed in a straight line parallel to the surface of the substrate 10 at the tip.
An upper member 6b is provided above the plate-like member 4, and a vibration sensor 7 for detecting vibration is provided at the tip of the upper member 6a.

The coating head 2 is provided with a slit having an opening at the tip, which is normally used, and the coating liquid is discharged through the slit to form a coating layer.

The lower member 6a constituting the plate-like member 4 is preferably made of a material having rigidity. If the lower member 6a does not have rigidity, the lower member 6a is deformed when it comes into contact with a foreign substance, and a force necessary for rotation is not applied, and the detection becomes impossible. The upper member 6b is also preferably made of a material having rigidity.
The lower member 6a and the upper member 6b are preferably made of a material having a small specific gravity. This is because if the specific gravity of the material constituting the lower member 6a and the upper member 6b is large, the plate-like member will not rotate even when it comes into contact with foreign matter.

Here, by making the length of the upper material 6b constituting the plate-like member longer than the length of the lower member 6a, it becomes easier to rotate with the force applied to the lower member 6a, and the foreign matter detection sensitivity can be increased. it can.

Furthermore, it is necessary to arrange the tip of the lower member 6a of the plate-like member 4 so as to be positioned on the side of the substrate 10 relative to the lip tip 8 of the coating head 2, that is, a position below the lip tip. Thus, by arranging the lower member 6a, even if there is a foreign object that cannot be detected by the lower member 6a, the tip of the lip of the coating head can be prevented from coming into contact with the foreign object and being damaged.

Next, a general vibration sensor can be used as the vibration sensor 7. For example, the vibration of the upper member 6 b is transmitted to the piezo vibrator using a piezo vibrator, and an electric signal generated by the piezo vibrator is transmitted. By detecting, it functions as a vibration sensor.

The operation after the vibration sensor 7 detects vibration will be described.
In one operation, when the vibration sensor 7 detects vibration, the application head 2 immediately stops moving relative to the substrate 10.
In other operations, when the vibration sensor 7 detects vibration, the coating head 2 is immediately retracted above the substrate 10 so that the foreign matter does not touch the tip of the coating head. At this time, the relative movement between the coating head 2 and the substrate 2 is not stopped, and the movement state may be kept as it is.
The relative movement between the coating head 2 and the substrate 10 continues the same operation regardless of whether or not a foreign object has been detected, so there is no need to modify the program relating to the relative movement.
Further, the substrate in which the foreign matter is detected can be continuously carried out as it is without applying any special change when the coating liquid is applied to a plurality of substrates by carrying it out in a subsequent process.

Next, a second embodiment will be described.
As shown in FIG. 2, the same detection can be performed by using a continuity sensor 20 that detects electrical continuity by changing the detection means to a vibration sensor.
The operation of the coating head after the foreign matter is detected by the continuity sensor may be performed in the same manner as in the first embodiment.

It is explanatory drawing which shows the principal part of the coating device of this invention. It is explanatory drawing which shows the principal part of the other coating device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Coating device 2 ... Coating head 3 ... Rotating shaft 4 ... Plate-shaped member 5 ... Tip part 6a ... Lower member 6b ... Upper member 9 ... Supporting part 10 ... Substrate 11 ... Foreign material

Claims (8)

A slit coat type coating apparatus comprising a substrate holding plate for holding a substrate to be coated and a coating head for coating the coating liquid from the slit-shaped opening, and having a moving means for relatively moving the substrate holding plate and the coating head. In
The application head is
A support portion having a rotary bearing provided on the moving direction side;
A plate-like member that is rotatably attached to the rotary bearing and has a straight end portion;
Detection means capable of detecting the rotational movement of the plate-like member;
A slit coat type coating apparatus comprising control means for controlling the movement of the coating head based on the detection status obtained by the detection means. 2. The slit coat type coating apparatus according to claim 1, wherein the plate-like member includes a lower part having a linear tip end part and an upper part capable of contacting the detecting means. The slit coat type coating apparatus according to claim 2, wherein the plate-like member has an upper portion longer than a lower portion. 4. The slit coat type coating apparatus according to claim 2, wherein the plate-like member has an upper part and a lower part made of different members. 5. The slit coat type coating apparatus according to claim 4, wherein the specific gravity of the material constituting the upper portion is larger than the specific gravity constituting the lower portion. 6. The slit coat type coating apparatus according to claim 1, wherein the control means is to stop relative movement of the moving means. 6. The slit coat type coating apparatus according to claim 1, wherein the control means is a retracting movement of the coating head. 8. A coating method comprising applying onto a substrate using the slit coat type coating apparatus according to any one of claims 1 to 7.

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