JP2823173B2 - Hard substrate 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 hard substrate coating apparatus used for manufacturing a liquid crystal display panel using a glass substrate and for applying a coating liquid such as a photoresist to a hard substrate in a thin and uniform manner. is there.

[0002]

2. Description of the Related Art In a manufacturing process of a liquid crystal plate, there is a process of applying a coating liquid such as a photoresist to a thin and uniform thickness on a hard substrate such as a glass substrate. For example, in the production of a color liquid crystal plate, a transparent electrode is formed on a glass substrate in advance,
After uniformly applying a red color mosaic liquid having the function of a photoresist, the color mosaic corresponding to the red color is cured by exposure, and an excess liquid is removed to form a red color mosaic. . The same processing is repeated for other colors such as green and blue. When a coating liquid to be a photoresist is applied as described above, it is necessary to strictly control this liquid to a uniform thickness (for example, about 2 μ ± 5%) and to apply the thin liquid. This is because if the thickness of the coating is non-uniform, the light transmittance becomes uneven, which leads to a deterioration in quality.

Conventionally, a spin coater has been used for this coating. In this spin coater, a coating liquid is dropped near a rotation center of a rotated substrate, and the liquid is applied by scattering using a centrifugal force. However, in the method using the spin coater, not only the time and labor efficiency for replacing the substrate are deteriorated, but also the amount of the liquid scattered and discarded increases. For this reason, there was a problem that the cost was increased.

In view of this, it has been considered to use an apparatus (so-called Gieser) for coating a substrate between a pair of upper and lower rollers disposed horizontally. In this device, the lower part of the micro rod bar, which is the lower roller, is immersed in the coating solution, and the substrate is sandwiched between the micro rod bar and the nip roller located above the micro rod bar. It is to be applied.

However, in this case, when the end of the substrate separates from the micro rod bar, the coating liquid remains thick on the substrate due to the surface tension and viscosity of the coating liquid, and tends to be thickly coated near the end of the substrate. This thick-coated portion cannot be properly processed in various processing steps such as exposure and cleaning set for a regular coating thickness, and residues such as debris and debris due to unprocessed thick-coated portion are not obtained. In a later step, it was mixed with the coating solution, resulting in a defective product. For this reason, there has been a problem that the yield of products is reduced.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent the formation of a thick coating near the end of a hard substrate when applying a coating solution using a geser, Is to improve the yield.

[0007]

According to the present invention, this object is achieved by sandwiching a hard substrate between a micro rod bar whose lower part is immersed in a coating solution tank and a nip roller arranged above and opposed to the micro rod bar. it makes lifting the hard substrate coating apparatus for applying a coating solution on the lower surface of the hard substrate, relative to the bottom surface of <br/> the hard substrate at a position apart in the feed direction of the hard substrate from the micro rod bar Arranged so that it can pass from the front end to just before the rear end of the hard substrate coated with the coating liquid
While moving away from the hard substrate, just before the rear end of the hard substrate.
Contacting the hard substrate lower surface increased when near passes extra
The present invention is achieved by a hard substrate coating apparatus including a scraper bar for removing a coating liquid .

Here, it is preferable that the scraping rod is rotated in a direction opposite to the substrate feeding direction to contact the lower surface of the substrate.
The scraping rod can be a micro rod bar or a cylinder made of a ceramic material so that the inside of the cylinder can be sucked to a negative pressure.

[0009]

The coating liquid is applied to the lower surface of the hard substrate by the Gieser, and remains thick on the lower surface of the substrate when the substrate is separated from the Gieser. When the substrate is fed a predetermined distance, the scraping bar rises and comes into contact with the lower surface thereof, and the excess coating liquid in the thickly coated portion is removed.

[0010]

FIG. 1 is an overall layout view of an embodiment of the present invention, and FIG.
3 is a cross-sectional view of the gieser, FIG. 3 is a cross-sectional view of the vicinity of a scraper bar, and FIG. 4 is an operation explanatory view of a main part taken along line III-III in FIG.

In FIG. 1, reference numeral 10 denotes a glass substrate;
Is a roller conveyor, and the glass substrate 10 is sent from left to right in the figure with the left and right edges of the lower surface thereof placed on rollers of the conveyor 12. Gieser 1 in the middle of the conveyor 12
4 are provided. The gisa 14 includes a microrod bar 16 having a small diameter and a circular cross section, a nip roller 18 having a large diameter facing above the microrod bar 16, and a coating solution tank 20 in which almost the entirety of the microrod bar 16 is left except for the upper part.

Here, the micro rod bar 16 is formed by winding a thin metal wire tightly around the surface of a rod having a circular cross section, and applying a coating liquid by utilizing a capillary phenomenon caused by a groove between the metal wires. It is.

As shown in FIG. 2, the coating liquid tank 20 has a long and shallow liquid reservoir 22 in a direction orthogonal to the direction in which the substrate 10 is fed.
The liquid reservoir 22 has a liquid supply pipe (not shown).
Supplies a new liquid, while the coating liquid is discharged from the liquid discharge port 26. The liquid supply pipe is located near one end of the reservoir 22
The drain port 26 opens to the bottom near the other end. Therefore, the coating liquid is suitable for flowing in the liquid reservoir 22 in the longitudinal direction thereof to homogenize the liquid. The depth of the coating liquid is monitored by a liquid level sensor (not shown), and is constantly maintained at a constant level.

The micro rod bar 16 is held horizontally so that its upper part is exposed from the liquid. That is, bearing portions 30 and 32 having concave portions that open upward in a semicircular arc are provided at both ends of the liquid reservoir portion 22, and the bearing portions 30 and 32 are provided.
The micro rod bar 16 is rotatably held between the micro rod bar 16 and a cap (not shown) which is covered from above.
The intermediate portion of the micro rod bar 16 is supported from below by a backup member 38 (see FIGS. 4A, 4B and 4C ). The backup member 38 is made of a hard synthetic resin having excellent slidability, and has a semicircular groove formed on the upper surface thereof along the longitudinal direction.
To prevent the micro rod bar 16 from bending. The height of the backup member 38 is adjusted by a number of adjustment screws 40 (see FIG.
4A, 4B, and 4C ), the fine adjustment can be performed from the lower surface of the coating solution tank 20.

One end (the end on the far side in FIG. 1) of the micro rod bar 16 protrudes rearward from the coating solution tank 20, and this protruding end is connected to an electric motor 44 by a detachable joint 42. This electric motor 44
Of the conveyor 12 is controlled so that the feed speed is equal to that of the conveyor 12. The surface of the nip roller 18 is made of conductive rubber, and is held so as to apply a predetermined clamping force to the glass substrate 10 with the glass substrate 10 sandwiched between the nip roller 18 and the micro rod bar 16.

Reference numeral 50 denotes a scraping bar. As the scraper bar 50, various types of structures can be used as shown in FIGS. The scraping bar 50A in FIG. 5A is formed of a metal rod such as stainless steel. The scraping bar 50B of FIG. 5B is a micro rod bar in which a thin metal wire 54 is densely wound around the outer periphery of a metal rod 52. FIG.
5C is a metal rod 52 of FIG. 5B.
Except that only the outer metal wire 54 is densely wound into a cylindrical shape. The scraping bar 50D in FIG. 5D is formed by a cylinder using a porous ceramic having air permeability.

As shown in FIG. 3, the scraping rod 50 is held in a cleaning liquid tank 56 so that its lower part is immersed in the cleaning liquid.
One end of the scraping bar 50 is rotated by a motor 60 via a joint 58 in a direction opposite to the direction in which the substrate 10 is fed. The motor 60 is held integrally with the cleaning liquid tank 56, and can be moved up and down by a guide rail 62 (only a part of which is shown in FIG. 3).

The cleaning liquid tank 56 is, for example, an air cylinder 6
4 is moved up and down. That is, this cleaning liquid tank 56
Until the vicinity of the rear end of the substrate 10 on which the coating liquid is applied by the greaser 14 approaches the scraping rod 50, it is lowered and scraped.
While the rod 50 is separated from the lower surface of the substrate 10,
When the vicinity of the rear end approaches the scraping rod 50, the cleaning liquid tank 56 rises and the scraping rod 50 contacts the lower surface of the substrate 10 while rotating in the direction opposite to the direction in which the substrate 10 is fed.
When the substrate 10 separates from the scraping rod 50, the cleaning liquid tank 56 descends and waits until the vicinity of the rear end of the next substrate 10 comes.

Next, the operation of this embodiment will be described. The glass substrate 10 sent from the left side to the right side in FIG. 2 by the roller conveyor 12 includes the micro rod bar 16 and the nip roller 1.
Enter between 8. Since the application liquid in the liquid reservoir 22 is attached to the surface of the micro rod bar 16 by the rotation thereof, the application liquid is applied to the lower surface of the glass substrate 10 with the rotation of the micro rod bar 16. During the coating, the entry side of the substrate 10 and the micro rod bar 1
A predetermined amount of the coating liquid R is held at the corner between the coating liquids 6 and 6 (FIG. 4A). Since the liquid level of the liquid reservoir 22 and the squeezing pressure by the nip roller 18 are controlled to be constant,
The thickness of the liquid applied to the lower surface of the glass substrate 10 can be controlled to be sufficiently thin and with high precision.

When the substrate 10 separates from the geser 14, a part of the coating liquid R accumulated between the substrate 10 and the micro rod bar 16 adheres to the substrate 10 due to surface tension or viscosity of the liquid. It becomes the thickly painted portion S (FIG. 4B). When the thick portion S approaches the scraping bar 50, the cleaning liquid tank 56 is raised by the air cylinder 64, and the scraping bar 50, which has been rotated in the opposite direction in advance, comes into contact with the lower surface of the substrate 10. As a result, the coating liquid of the thick coating portion S adheres to the scraping rod 50 and elutes into the cleaning liquid in the cleaning liquid tank 56 and is removed.

The scraping rod 50 used here may be the metal rod shown in FIG. 5A as described above,
The micro rod bar shown in (1) has better adhesion of the coating liquid and has a greater effect of removing the thickly coated portion S.

The scraping bar 50 shown in FIGS.
When formed by a cylinder having air permeability like C and 50D, it is desirable to suction the inside of the cylinder of the scraping rods 50C and 50D to a negative pressure. For example, as shown in FIG. 3, both ends of the scraping rods 50C and 50D are airtightly closed, and an airtight chamber 68 that sandwiches a small hole 66 provided in a part of the airtight chamber 68 is formed.

According to this embodiment, the scraping rods 50C, 5C
Since the coating liquid is sucked inward from the surface of 0D, the effect of removing the thick coating portion S is further enhanced.

Further, the scraping bar 50 may be removed from the thick-coated portion S after the distance L (FIG. 1) from the greaser 14 is increased and the thick-coated portion S is slightly dried.

In the present invention, the cleaning liquid tank 56 may be omitted, or only the scraping rod 50 may be moved up and down.

Further, when the scraping rod 50 is brought into contact with the substrate 10, the transport of the substrate 10 may be stopped.

[0027]

As described above, according to the present invention, a scraping rod is provided at a position distant from the gieser in the substrate feeding direction so as to be able to move up and down. Therefore, the product yield can be improved (claim 1).

If the scraping rod 29 is rotated in the direction opposite to the substrate feeding direction, the removal of the thick portion can be further improved (claim 2), and the scraping rod can be formed by a micro rod bar (claim 3). ), The effect can be further enhanced by forming the cylinder with a gas-permeable cylinder such as a ceramic material and sucking the inside of the cylinder with a negative pressure.

[Brief description of the drawings]

FIG. 1 is an overall layout diagram of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the gisa.

FIG. 3 is a cross-sectional view around a scraping bar.

FIG. 4 is an operation explanatory view of a main part taken along line III-III in FIG. 2;

FIG. 5 Sectional view showing various embodiments of a scraper bar

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Glass substrate 14 Gieser 16 Micro rod bar 18 Nip roller 50, 50A-D Scraping bar

Continued on the front page (72) Inventor Masafumi Ozaki 1005 Koizono, Ayase-shi, Kanagawa Prefecture Inside Fuji Mai Chromaix Co., Ltd. References JP-A-60-230658 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B05C 7/00-21/00 B05C 1/02 102 G03F 7/16 501

Claims (5)

(57) [Claims] 1. A hard substrate is sandwiched and sent between a micro rod bar whose lower part is immersed in a coating liquid tank and a nip roller opposed to and disposed above the micro rod bar. in hard substrate coating apparatus for applying a coating liquid, the hard substrate from the micro rod bar
Is temperature <br/> descending direction end to the lower surface of the hard substrate at a position apart in the feed direction of the front end of the hard substrate coated with a coating solution
While passing until the area immediately before the rear end, go down and
A hard substrate coating apparatus, comprising: a scraping bar which rises up when passing near the rear end of the hard substrate and comes into contact with the lower surface of the hard substrate to remove excess coating liquid . 2. The hard substrate coating apparatus according to claim 1, wherein the scraping bar contacts a rear lower surface of the hard substrate while rotating in a direction opposite to a feed direction of the hard substrate. 3. The hard substrate coating apparatus according to claim 2, wherein said scraping bar is formed by a micro rod bar. 4. The hard substrate coating apparatus according to claim 2, wherein said scraping bar is formed of a cylinder having air permeability, and suction means for sucking the inside of said cylinder to a negative pressure is provided. 5. A hard substrate coating apparatus according to claim 4 , wherein said scraping bar is formed of a multi-hard ceramic material.