JP2937549B2 - Coating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus used in a manufacturing process of a liquid crystal display (LCD).

[0002]

2. Description of the Related Art As a display device replacing a cathode ray tube (CRT), an electrode or an element forming a pixel is formed on the surface.
A liquid crystal display having a structure in which liquid crystal is injected between two glass substrates has attracted attention. As the above-mentioned pixels, an active matrix system driven by an element such as a thin film transistor (TFT) or a metal / insulator / metal junction (MIM) is becoming mainstream because a high-quality screen can be obtained.

The technique of forming the above-mentioned thin film transistor and the like on a glass substrate directly applies a semiconductor manufacturing technique of forming an integrated circuit on a silicon wafer and the like. The application of a resist solution is also one of a series of steps, in which a resist solution is dropped onto a glass substrate set on a vacuum chuck in an inner cup, and then the vacuum chuck and the inner cup are integrated by a spinner. By rotating the resist, the resist liquid is uniformly applied to the surface of the glass substrate by centrifugal force.

[0004] A part of the dropped coating liquid scatters on the inner wall of the inner cup due to centrifugal force. If this coating solution is left as it is, it is dried and solidified, and becomes small fragments and adheres to the surface of the glass substrate. In order to prevent this, the present applicant first attached a drain pipe to the outer peripheral wall of the inner cup, discharged excess coating liquid to the recovery passage via the drain pipe, and opened the inner cup and the outer cup. By covering the top surface with the lid, the coating liquid once collected is sucked out and floats in the form of a mist, etc., and the floating coating liquid particles adhere to the surface of the glass substrate and cause spot-like defects. Proposed technology to prevent.

However, 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 centrifugal force caused by rotation, and the inside of the cup is reduced in pressure. When the application of the resist solution is completed and the lid is removed under reduced pressure to remove the glass substrate from the cup, air flows into the cup rapidly due to the reduced pressure, and the fine powder of the resist that has dried and solidified Disadvantageously adheres to the glass substrate surface.

In order to solve this problem, the present applicant further attaches a circular rectifying plate having a dimension to enter the cup with a predetermined space between the rectifying plate and the lid, on the lower surface of the lid of the inner cup. A technique for opening a gas introduction nozzle in the space was proposed.

[0007]

The shape of a glass substrate as a plate-like workpiece is generally square (rectangular). If the circular current plate approaches the upper surface of such a square glass substrate and is rotated, a turbulent flow is generated due to a difference in these shapes, and the thickness of the resist solution applied on the glass substrate is partially increased. Have different results.

Therefore, it is conceivable to make the current plate a square in accordance with the glass substrate. However, if the current plate is made a square, a turbulent flow is generated due to a difference in shape between the current plate and the inner peripheral shape of the inner cup. As a result, the distance between the current plate and the inner peripheral surface of the inner cup is widened, and the coating liquid is scattered upward from this portion.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an apparatus for applying a resist liquid to a rectangular or other rectangular object to be processed. At the same time, a rectifying plate having a similar size and a larger size than the object to be processed is attached to the lower surface of the lid so as to maintain a constant distance between the rectifying plate and the lid. The cleaning liquid supply nozzle and / or the gas introduction nozzle faced the space between them, and a scattering prevention ring having a similar size opening and a larger size than the plate-like workpiece was provided on the inner periphery of the cup.

[0010]

With the upper surface of the rotating cup closed by the lid, the coating liquid dropped on the surface of the workpiece is rotated and the cup is rotated to uniformly spread the coating liquid. Turbulence does not easily occur on the surface of the object to be treated, without the gas ejected from the surface.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a plan view of a film forming line incorporating the coating apparatus according to the present invention, FIG. 2 is a cross-sectional view of the coating apparatus in a state in which a lid is raised, and FIG. FIG. 4 is a cross-sectional view of the coating apparatus with the lid closed, and FIG. 5 is an enlarged view of a main part of FIG.

The coating film forming line has an upstream portion on the left side of FIG. 1, and an input portion 1 for a glass substrate W as a rectangular plate-like workpiece is provided on the upstream portion. A coating unit 2 according to the present invention is arranged, and a heating unit 5 having a vacuum drying unit 3, a back surface cleaning unit 4 for a glass substrate W, a hot plate 5a... Is transported from the charging section 1 to the heating section 5 while the lower surfaces of the front and rear ends of the glass substrate W are supported by the transport apparatus 6, and the heating section 5 performs a crank motion in a vertical plane. While the lower surface of the glass substrate W is supported by 7, each hot plate 5 a is sequentially transferred, and finally the glass substrate W is transported while the temperature is adjusted by the cooling plate 5 b.

The coating device 2 has an outer cup 23 disposed outside an inner cup 22 attached to a shaft 21 of a spinner device. Inner cup 22 is bottom plate 22
a and a side plate 22b.
Are constituted by a bottom plate 23a, a main body 23b, and a side plate 23c that penetrate through.

The bottom plate 22a of the inner cup 22
Vacuum chuck 2 for holding glass substrate W by suction at the center of
4, a drain pipe 25 is attached to the lower portion of the side plate 22b, while an annular drain recovery passage 27 is formed in the main body 23b, and the drain pipe 25 is recovered through a narrow portion 28 of the recovery passage 27. It faces the passage 27. The drain pipe 25 may be a slit or an eave-like object having a plurality of holes.

Arms 29 and 30 are disposed above the inner cup 22 and the outer cup 23 as shown in FIG. The arms 29 and 30 can be moved linearly, rotationally, vertically, or a combination thereof, so that they do not interfere with each other. A nozzle for dropping a coating solution such as a resist solution is attached to the arm 29, a shaft 31 extending downward is attached to the tip of the arm 30, and a nozzle hole 32 is formed in the shaft 31.
Hoses 33, 34 passing through the joint and arm 30
And a nitrogen gas supply source and a cleaning liquid supply source.

A boss 37 is rotatably fitted to the shaft 31 via a bearing 35 and a magnetic seal 36. The boss 37 has a disk shape for closing the upper opening of the inner cup 22. Eggplant aluminum lid 38
Is installed. Further, a lid 39 for closing an upper surface opening of the outer cup 23 is fixed to a lower surface of a distal end of the arm 30 above the lid 38.

A rectifying plate 41 for preventing turbulent flow in the inner cup 22 is attached to the lower surface of the lid 38 by screws 40. As shown in FIG. 3, the current plate 41 has a size slightly larger than the glass substrate W and has a similar shape.

A plurality of locking portions 42 are provided at the upper end of the inner peripheral surface of the inner cup 22, and a block 44 is fixed to these locking portions 42 with screws 43. An anti-scattering ring 45 is attached. The scattering prevention ring 45 is located above the rectifying plate 41 with the lid 38 closed, and forms an opening 46 for preventing interference when the rectifying plate 41 rises. The shape of the opening 46 is slightly larger than the outer diameter of the current plate 41 and has a similar shape.

The lid 39 is fitted to the outer periphery of a cylindrical body 51 attached to the lower surface of the distal end of the arm 30 through a hole 50 formed in the center, and a Teflon bearing 52 fixed to the periphery of the hole 50.
The cover 39 is held slidably up and down by engaging a guide post 53 implanted in the cylindrical body 51.

When the lid 38 is closed and the inner cup 22, the glass substrate W, and the rectifying plate 41 are rotated to diffuse the coating solution dropped on the glass substrate W by centrifugal force, as shown in FIG. It is necessary that the glass substrate W and the rectifying plate 41 completely overlap in the same phase, or the rectifying plate 41 faces the glass substrate W with a predetermined angle shifted in consideration of the rotational speed.

For this purpose, a notch 54 is formed on the outer periphery of the lid 38, and a pin 55 projects upward from the lid 38, and a receiving member 56 with which the pin 55 is engaged is connected to the lid 39.
It is attached to. That is, since the cover 39 is prevented from rotating by the guide post 53 and the relative position with respect to the glass substrate W is fixed, the cover member 38 is lifted up in the receiving member 56 in the state of FIGS. 38 are engaged with the cover 55 and the glass substrate W of the current plate 41.
The relative position to is also determined.

Thereafter, when the arm 30 is lowered, the outer peripheral end of the lid 39 is placed on the upper end of the side plate 23c of the outer cup 23 as shown in FIG. And screw 4 in this state
Notch 54 is located immediately above 3. Therefore, when the lid 38 is lowered in this state, the notch 54 of the lid 38 engages with the head of the screw 43 as shown in FIG. 4, and the positional relationship between the glass substrate W and the current plate 41 is as shown in FIG. It becomes as shown in.

In the above, in order to uniformly apply the resist solution on the surface of the glass substrate W, the upper surfaces of the inner cup 22 and the outer cup 23 are opened and an arm is provided on the surface of the glass substrate W fixed on the vacuum chuck 24. The resist solution is dropped from a nozzle attached to the nozzle 29, the arm 29 is then retracted, and the arm 30 is rotated on the inner cup 22 and the outer cup 23 as shown in FIG. I do.

As shown in FIG. 4, if the upper surface of the inner cup 22 is closed by the lid 38 by lowering the arm 30 and the upper surface opening of the outer cup 23 is closed by the lid 39, a vacuum is applied by the spinner. The chuck 24 and the inner cup 22 are rotated integrally, and the resist solution is uniformly diffused and applied to the surface of the glass substrate W by centrifugal force.

In the above processing, since the inside of the inner cup 22 is in a reduced pressure state, if the glass substrate W is taken out by opening the lid as it is, the air in the inner cup is disturbed and the resist solution is spotted on the glass substrate. It may adhere to the W surface. In order to take out the glass substrate W coated with the resist solution uniformly, first, nitrogen gas or the like is introduced into the space between the lid 38 and the rectifying plate 41 through the pipe 33 and the nozzle hole 32 connected to the nitrogen gas supply source. And then release the pressure reduction state. At this time, the gas from the nozzle hole 32 is not directly blown onto the resist liquid on the surface of the glass substrate W because of the presence of the current plate 41.

Thus, a predetermined number of glass substrates W
After the resist solution is uniformly applied to the inner cup 22, a part of the excess coating solution adheres to the inner peripheral surface of the inner cup 22 or the like. If this is left as it is, it is dried and solidified, scatters in the atmosphere, and adheres to the surface of the glass substrate W, so that cleaning is performed.

Cleaning is performed by closing the inner cup 22 and the outer cup 23 with the lids 38 and 39 with the glass substrate W removed. That is, the pipe 34 connected to the cleaning liquid supply source
The cleaning liquid is supplied to the space between the lid 38 and the current plate 41 via the nozzle hole 32.

Then, as shown in FIG. 5, the cleaning liquid flows on the surface of the current plate 41 due to the centrifugal force, and a part of the cleaning liquid reaches the inner peripheral surface of the inner cup 22, and the coating liquid adhered to this inner peripheral surface is washed away. Is discharged into the collection passage 27 through the drain pipe 25, and another part is communicated with the communicating portion P 1 between the outer periphery of the lid 38 and the upper end of the inner cup 22,
2 A gap P between the outer surface and the inner surface of the outer cup 23
The coating liquid is discharged to the collection passage 27 through the second passage 2, and during this time, the coating liquid attached to the inner peripheral surface of the narrow portion 28 of the collection passage 27 is washed away.

[0029]

According to the present invention as described above,
A large rectifying plate similar in shape to the object to be processed is attached to the lower surface of the lid that closes the upper surface of the cup of the coating device, and a cleaning liquid supply nozzle and / or a gas introduction nozzle are provided in a space between the rectifying plate and the lid. In addition, a scattering prevention ring with a large opening similar to the object to be processed is provided on the inner circumference of the cup, so that when the cup is rotated, turbulence does not easily occur in the cup, and the coating is completed Later, when the gas is introduced into the cup, the introduced gas does not directly hit the surface of the object to be treated, so that the film thickness can be kept uniform. The washing liquid can be guided to the inner peripheral wall of the cup as a guide.

[Brief description of the drawings]

FIG. 1 is a plan view of a film forming line incorporating a coating apparatus according to the present invention.

FIG. 2 is a cross-sectional view of the coating apparatus in a state where a lid is raised.

FIG. 3 is a view taken in the direction of arrows AA in FIG. 2;

FIG. 4 is a sectional view of the coating apparatus in a state where a lid is closed.

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is a sectional view of a main part in a state where a lid is raised.

FIG. 7 is a cross-sectional view of a main part in a state where the lid is lowered halfway.

[Explanation of symbols]

2 ... Coating device, 22 ... Inner cup, 23 ... Outer cup, 38,39 ... Lid, 41 ... Rectifier plate, 45 ... Scatter prevention ring, 46 ... Opening, 52 ... Bearing, 53 ... Guide post, 55 ... Pin, 56 receiving member.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-87664 (JP, A) JP-A-1-176473 (JP, A) JP-A-3-293055 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) B05C 11/08 B05D 1/40 G03F 7/16 502 G11B 5/842 H01L 21/027

Claims (2)

(57) [Claims] 1. A plate-shaped workpiece is set in a cup rotated by a spinner, a coating liquid is dropped on the surface of the plate-shaped workpiece, and then the upper surface of the cup is closed with a lid to rotate the cup. In the coating apparatus, the coating liquid dropped to spread the coating liquid uniformly on the surface of the plate-like workpiece, the plate-like workpiece has a rectangular shape, and a plate-like coating is formed on the lower surface of the lid. A rectifying plate having a larger size and a similar shape than that of the processing object is attached so as to maintain a constant distance between the rectifying plate and the lid, and a cleaning liquid supply nozzle and / or a cleaning liquid supply nozzle is provided in a space between the rectifying plate and the lid. A coating apparatus, wherein a gas introduction nozzle is faced, and a scattering prevention ring having a similar size opening as a plate-shaped workpiece is formed on the inner periphery of the cup. 2. The cup rotated by the spinner is an inner cup, and an outer cup that does not rotate is disposed outside the inner cup, and respective lids that close the upper surfaces of the inner cup and the outer cup are raised. The coating device according to claim 1, wherein the coating device engages with the concave and convex portions at the set positions.