JPH062262B2 - Application method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coating method used in a manufacturing process of a liquid crystal display (LCD) or the like.

(Prior Art) A liquid crystal display attracts attention as a display device that replaces a cathode ray tube (CRT).

A liquid crystal display has a structure in which liquid crystal is injected between two glass substrates having electrodes and elements forming pixels on the surface. Each pixel is connected to a thin film transistor (TF
T) and active matrix systems that can be driven by elements such as metal / insulator / metal junction (MIM) are becoming mainstream because they can obtain high-quality screens.

The technique for forming the thin film transistor on the glass substrate is directly applied to the semiconductor manufacturing technique for forming an integrated circuit on a silicon wafer or the like. Applying the resist solution is also one of a series of steps. In this step, the glass substrate is set in the cup, the resist solution is dropped on the glass substrate, and then the cup is rotated and centrifugal force is applied to the surface of the glass substrate. The resist solution is evenly applied to.

(Problems to be Solved by the Invention) In the application of the resist solution described above, when the cup is rotated, the upper surface of the cup is closed with a lid to prevent the resist solution from scattering outside the cup. Further, a drain pipe is attached to the lower side wall of the cup so that the resist solution adhering to the side wall of the cup is discharged to the outside of the cup during rotation.

As described above, when the drain pipe is attached to the side wall of the cup, air or gas in the cup is discharged through the drain pipe due to the centrifugal force caused by the rotation, and the inside of the cup is in a reduced pressure state. Then, when application of the resist solution is completed and the glass substrate is taken out from the cup by removing the lid under reduced pressure,
Since the inside is depressurized, air suddenly flows into the cup,
There is a disadvantage that fine powder of the resist that is dried and solidified adheres to the surface of the glass substrate. It is possible to attach a glass introduction nozzle to the lid to eliminate this, but when the nozzle faces the cup, a turbulent flow is generated by this nozzle and the gas ejected from the nozzle causes the resist liquid applied on the glass substrate to flow. The thickness will be partially different.

Especially in the manufacture of liquid crystal displays, many transistors are embedded on a glass substrate (5 per square centimeter).
0 or more), and even if one of the transistors is defective, the entire substrate is defective. This is a decisive difference in yield between the production of an active matrix type liquid crystal display and the production of a semiconductor such as an LSI.

(Means for Solving the Problems) In order to solve the above problems, the present invention uniformly spreads a coating liquid on a surface of a plate-shaped object set on a vacuum chuck in an inner cup by centrifugal force due to rotation, and then Gas was introduced between the lid and the current plate to release the depressurized state in the inner cup, and then the lid was opened to take out the plate-shaped object.

(Function) When the upper cup opening of the inner cup is closed, the coating liquid is uniformly spread on the surface of the plate-shaped object in the inner cup by the centrifugal force caused by the rotation, and the inner cup is depressurized by the centrifugal force. . Therefore, when the processed plate-shaped object is taken out of the inner cup, gas is introduced into the inner cup to release the depressurized state.

(Example) Below, the Example of this invention is described based on an accompanying drawing.

FIG. 1 is a plan view of a coating film forming line incorporating a coating method according to the present invention, FIG. 2 is a sectional view of a coating apparatus used for carrying out the coating method according to the present invention in a state where a lid is raised, and FIG. FIG. 4 is a cross-sectional view of the coating apparatus with the lid closed.

The coating film forming line is provided with an inlet 1 for a plate-shaped object W such as a glass substrate at the most upstream portion (left end in FIG. 1), and a coating device 2 for carrying out the method of the present invention is provided downstream of the inlet 1. The vacuum drying device 3, the back surface cleaning device 4 for the workpiece W, and the hot plate 5 are sequentially arranged on the downstream side of the coating device 2.
The heating unit 5 including a ... Is arranged, and from the feeding unit 1 to the heating unit 5, the object to be processed W is conveyed while being supported by the lower surfaces of the front and rear ends of the object to be processed. The workpiece W is transported while being sequentially transferred on the hot plates 5a in a state where the lower surface of the workpiece W is supported by the conveyor device 7 that makes a crank motion in the vertical plane.

Next, details of the coating device 2 will be described with reference to FIGS. 2 and 3.

The coating device 2 has an outer cup 23 fixed to the outside of an inner cup 22 attached to a shaft 21 of the spinner device. The inner cup 22 and the outer cup 23 have their lower surfaces closed and their upper surfaces opened, so that the inner cup 22
A vacuum chuck 24 for adsorbing and fixing the object W to be processed is provided in the central portion, and a drain pipe 25 is attached to the lower portion of the side wall of the inner cup 22. Further, a drain recovery ring 26 is arranged inside the outer cup 23. The drain collecting ring 26 has an inner wall lower than the outer wall so that the tip of the drain pipe 25 is exposed and the bottom wall is inclined to one side, and the drain collecting pipe 27 is attached to the lowest position. An exhaust port 28 is formed on the closed lower surface of the outer cup 23.

On the other hand, arms 29 and 30 are arranged above the inner cup 22 and the outer cup 23 as shown in FIG. These arms 29, 30 are capable of linear movement, rotational movement, vertical movement, or a combined movement thereof so that they do not interfere with each other. Then, a noise for dropping a coating liquid such as a resist liquid is attached to the arm 29,
Attach the shaft 31 extending downward to the tip of the
A nozzle hole 32 is bored in the hole, and the nozzle hole 32 is connected to a pressurized air source such as nitrogen gas through a joint 33 and a hose 34 passing through the arm 30.

The shaft 31 has a bearing 35 and a magnetic seal 3.
A boss portion 37 is rotatably fitted to the inside of the boss portion 37, and a disc-shaped aluminum lid 38 for closing the upper opening of the inner cup 22 is attached to the boss portion 37.

Then, the rectifying plate 4 is attached to the lower surface of the lid 38 with screws 39.
0 is attached. The outer diameter of the straightening vane 40 is slightly smaller than the inner diameter of the inner cup 22, and the nozzle hole 32 is opened in the space formed between the lower surface of the lid 38 and the upper surface of the straightening vane 40.

In the above, in order to uniformly apply the resist solution to the surface of the object to be processed W such as a glass substrate, the upper surface of the inner cup 22 is opened and the arm 29 is attached to the surface of the object to be processed W fixed on the vacuum chuck 24. The resist solution is dripped from the nozzle attached to the arm 29, and then the arm 29 is retracted to move the arm 3 onto the inner cup 22 as shown in FIG.
The lid 38 is exposed by rotating 0. Then, as shown in FIG. 3, when the upper surface of the inner cup 22 is closed by lowering the arm 30 by the lid 38, the inner cup 22 is rotated by a spinner, and the resist solution is applied to the workpiece W by centrifugal force. Spread evenly on the surface of.

Since the inner cup 22 is in a depressurized state in the above process, the lid 38 and the rectifying plate 40 are first passed through the nozzle hole 32 in order to take out the object W to which the resist solution is uniformly applied. Nitrogen gas or the like is introduced into the space between. Then, the introduced gas spreads through the gap between the flow straightening plate 40 and the inner cup 22 into the inner cup, and the depressurized state is released. At this time, the gas from the nozzle holes 32 is not sprayed directly onto the resist liquid on the surface of the object to be processed W because of the flow straightening plate 40.

FIG. 4 and FIG. 5 are cross-sectional views of the coating apparatus for carrying out the second embodiment in a state where the lid body is raised and a state where the lid body is closed. In this embodiment, the arm 30 above the lid body 38 is shown. A lid 4 for closing the upper surface opening of the outer cup 23 on the lower surface of the tip.
When 1 is fixed and the coating liquid is applied by diffusion, the inner cup 22 is closed by the lid 38 and the outer cup 23 is closed by the lid 41 at the same time.

By doing this, the coating liquid collected in the outer cup will not be atomized and will not be scattered to the outside.Therefore, when the lid is opened and the object to be treated is taken out after the coating, it floats in the air. It is possible to prevent the solidified powder of the coating liquid from adhering to the surface of the object to be treated.

FIG. 6 and FIG. 7 are cross-sectional views of the coating apparatus for carrying out the third embodiment in a state where the lid body is raised and a state where the lid body is closed. In this embodiment, the upper surface opening of the outer cup 23 is closed. Dustproof plates 43 are attached to the lower surface of the lid 41 via spacers 42 at regular intervals. The dustproof plate 43 forms a gap 44 between the dustproof plate 43 and the outer peripheral surface of the boss portion 37 so that the dustproof plate 43 does not come into contact with the boss portion 37 when the boss portion 37 rotates as the inner cup 22 rotates. A gap 45 is also formed between the outer end 43 of the lid 41 and the inner peripheral surface of the skirt portion of the lid 41 to discharge the fine dust that has entered the space between the lid 41 and the dustproof plate 43. With such a configuration, when the lid is opened after application and the object to be treated is taken out, fine dust or the like that is connected between the upper and lower lids adheres to the surface of the object to be treated and becomes a defective product. Can be prevented.

(Effect) As described above, according to the present invention, the gas introducing nozzle is attached to the lid that closes the cup upper surface of the coating device, and the straightening plate is provided on the lower surface of the lid so as to be located below the gas introducing nozzle. Since the turbulent flow is unlikely to occur in the cup when the cup is rotated, and when the gas is introduced into the cup after the completion of coating, the introduced gas does not adversely affect the applied liquid.

[Brief description of drawings]

FIG. 1 is a plan view of a coating film forming line incorporating a coating method according to the present invention, FIG. 2 is a sectional view of a coating apparatus used for carrying out the coating method according to the present invention in a state where a lid is raised, and FIG. Is a cross-sectional view of the coating apparatus with the lid closed, and FIGS. 4 and 5 are cross-sectional views of the coating apparatus with the lid raised and the lid closed according to the second embodiment. FIG. 6 and FIG. 7 are cross-sectional views of the coating apparatus for carrying out the third embodiment with the lid raised and the lid closed. In the drawing, 1 is a loading portion of the plate-like object to be treated, 2 is a coating device,
22 is an inner cup, 23 is an outer cup, 38,
41 is a lid, 32 is a nozzle hole, 40 is a straightening plate, and W is a plate-shaped object.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michio Hashimoto 646 Seed, Yoshii-cho, Gotetsu-gun, Okayama 646 (72) Inventor Kazushi Kawakami 2397-1, Higashi-Misari, Yakage-cho, Oda-gun, Okayama

Claims (3)

[Claims] 1. A plate-shaped object to be processed such as glass is set on a vacuum chuck in an inner cup, a coating liquid is dropped on the surface of the plate-shaped object to be processed, and then the upper surface of the inner cup is closed with a lid. In addition, the vacuum chuck, the inner cup and the lid are integrally rotated with the straightening plate attached to the lower surface of the lid facing above the plate-shaped workpiece, and the coating is applied dropwise to the surface of the plate-shaped workpiece. The liquid was allowed to diffuse evenly, then gas was introduced between the lid and the current plate to release the depressurized state in the inner cup, and then the lid was opened to take out the plate-shaped workpiece. Characteristic coating method. 2. When rotating the vacuum chuck, the inner cup and the lid integrally, the outer cup disposed outside the inner cup is closed with another lid. The coating method according to claim 1, wherein: 3. When rotating the vacuum chuck, the inner cup and the lid integrally, the upper opening of the outer cup disposed outside the inner cup is closed by another lid and the other lid is closed. The coating method according to claim 1, wherein the dustproof plate attached to the lower surface is made to face the upper side of the lid that closes the upper opening of the inner cup.