KR20080048337A - Substrate drying system - Google Patents

Abstract

A substrate drying system is provided to make a flow of compressed air ejected from air knifes parallel with the rubbing axis of an alignment layer, thereby preventing the rubbing axis from being changed by the force of the compressed air and water gathering by the force of the compressed air. A substrate drying system comprises a substrate(123), a conveying unit, and a pair of air knifes(135,137). An alignment layer is formed on the substrate. The surface of the alignment layer is rubbed. The conveying unit conveys the substrate in a state when a side of the alignment layer is put to face upward. The pair of air knifes are opposite to face each other with the substrate therebetween and eject compressed air to be parallel with the rubbing axis(125) of the alignment layer. The conveying unit exposes the upper and lower surfaces of the substrate and includes rollers(131) which rotate in a direction.

Description

Substrate drying system

1 is a flowchart illustrating a manufacturing process of a liquid crystal panel for a liquid crystal display device according to a process sequence.

2A to 2B are perspective views for explaining a general alignment film rubbing process.

3 is a process perspective view of a substrate drying apparatus including a general air knife.

4 is a flowchart illustrating a manufacturing process of a liquid crystal panel for a liquid crystal display according to an exemplary embodiment of the present invention according to a process sequence.

5 is a simplified cross-sectional view of a substrate drying apparatus including an air knife according to the present invention.

6 is a process perspective view showing a pair of air knives and a substrate passing therebetween.

<Description of the symbols for the main parts of the drawings>

123: substrate 125: rubbing shaft

131: roller 135, 137: upper, lower air knife

The present invention relates to a manufacturing apparatus for a liquid crystal display device, and more particularly, after the cleaning of the substrate, during the substrate drying process through the air knife for removing residual moisture of the substrate, the alignment film rubbing axis formed on the transverse electric field mode substrate This is to prevent the fluctuation problem in advance.

In general, the driving principle of the liquid crystal display device uses the optical anisotropy and polarization of the liquid crystal. Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

Therefore, when the molecular arrangement direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular arrangement direction of the liquid crystal by optical anisotropy to express image information.

1 is a perspective view schematically illustrating a liquid crystal panel of a general liquid crystal display device.

As shown in the drawing, a general liquid crystal panel 3 is bonded to the array substrate 31 and the color filter substrate 33 at predetermined intervals, and on one surface of the array substrate 31 facing the color filter substrate 33. The data line DL and the gate line GL defining the pixel area 39 are perpendicularly intersected with each other, and the thin film transistor 37 is formed at the intersection of the two lines DL and GL.

On one surface of the color filter substrate 33 facing the array substrate 31, a grid-like black matrix 41 and a color filter 43 are formed, and the color filter 43 and the black matrix 41 are formed. The transparent common electrode 45 is formed on the front surface of the color filter substrate 33.

The liquid crystal 35 is filled between the array substrate 31 and the color filter substrate 33.

At this time, although not shown, the thin film transistor 37 includes a gate electrode, an active layer, a source and a drain electrode.

Finally, an alignment layer 47 is formed on surfaces of the array substrate 31 and the color filter substrate 33 that face each other.

The liquid crystal display device 3 is an apparatus in which an image is represented by adjusting an amount of light passing through the liquid crystal layer 35 according to the arrangement characteristic of the liquid crystal exhibiting the optical anisotropy.

The arrangement characteristic of the liquid crystal molecules has a great influence on the optical characteristics of the liquid crystal display device 3. Therefore, controlling the alignment characteristics of the liquid crystal is a very important problem. In particular, the alignment layer 47 has the greatest influence on the molecular arrangement of the liquid crystal.

The alignment layer 47 is subjected to a rubbing treatment for giving a groove to the surface, and this rubbing process refers to rubbing the surface of the alignment layer in a predetermined direction by using a rubbing cloth wrapped around a roller.

When the surface of the alignment layer 47 is rubbed, the surface of the alignment layer 47 is shaped to have fine grooves.

2A to 2B are perspective views for explaining a general alignment film rubbing process.

The general alignment layer rubbing device includes a stage 17 for positioning the substrate 3, a rubbing roll 11 to which the rubbing cloth 15 is attached, and a support 13 for supporting the rubbing roll 11.

When the substrate 3 on which the alignment layer (not shown) is formed is placed on the stage 17, the rubbing roll 11 rotates at high speed, and the rubbing cloth 15 attached to the surface of the rubbing roll 11 is placed on the substrate. By rubbing the surface of the alignment film in contact with the alignment film on (3), the rubbing shaft 5 is formed on the surface of the alignment film.

In this case, FIG. 2A illustrates a case in which the substrate 3 of the twisted nematic (TN) mode is disposed. When the substrate 3 moves along the stage 17, the rubbing cloth 15 is attached. The rubbing roll 11 is positioned to form an acute angle of 45 ° with the moving direction of the substrate 3 to perform a rubbing process on the substrate 3.

That is, the substrate 3 in the twisted nematic mode drives the liquid crystal molecules perpendicular to the substrate 3, thereby rubbing the alignment layer formed on the common electrode and the pixel electrode, respectively, on the first and second substrates, although not shown. The axis is formed to form, for example, 45 ° with the gate wiring and the data wiring, and the rubbing axes of the respective alignment films are configured to be oriented perpendicular to each other.

On the other hand, in the case of the in-plane switching (IPS) mode substrate 23 of FIG. 2B, the rubbing shaft 25 is formed parallel to the moving direction of the substrate 23.

That is, since the substrate 23 in the transverse electric field mode drives the liquid crystal molecules in a horizontal direction with respect to the substrate 23, when the substrate 23 moves along the stage 17, the rubbing cloth 15 is moved. The attached rubbing roll 11 is positioned perpendicular to the moving direction of the substrate 23 to move the rubbing process on the substrate 23 while moving in the direction opposite to the moving direction of the substrate 23.

Therefore, the rubbing shaft 25 formed on the substrate 23 is formed in parallel with the moving direction of the substrate 23.

When the rubbing process is completed, a cleaning process and a drying process for removing the foreign matter adhering to the surface of the substrate 23 are carried out. At this time, the drying process is performed according to the recent increase in the size of the substrate 23. It is common to use 35, 37).

3 is a process perspective view of a substrate drying apparatus including a general air knife, wherein the substrate drying apparatus includes a pair of images facing each other with a roller 31 for moving the substrate 23 and the substrate 23 therebetween. And lower air knives 35 and 37.

The upper and lower air knifes 35 and 37 each have a bar shape and spray compressed air in a direction facing each other. At this time, the upper, lower air knife (35, 37) is to start the starting edge of the substrate 23 to move to the edge end opposite to the diagonal direction to spray the compressed air.

Accordingly, the cleaning process through the air knifes 35 and 37 may affect the rubbing shaft 25 of the alignment layer formed on the substrate 23 in the process of spraying compressed air onto the substrate 23. In particular, in the case of the alignment layer in the transverse electric field mode, the compressed air is injected by the air knives 35 and 37.

In more detail, the rubbing axis (5 in FIG. 2A) of the alignment layer formed on the substrate in the general twisted nematic mode (3 in FIG. 2A) has an acute angle of 45 ° with the moving direction of the substrate (3 in FIG. 2A). Since the air knives 35 and 37 proceed in a diagonal direction starting from one corner of the substrate (3 in FIG. 2A), the rubbing axis of the alignment film formed on the substrate (3 in FIG. 2A) is formed. Compressed air is injected in the same direction as 5). Therefore, the compressed air injected from the air knives 35 and 37 does not affect the alignment film rubbing axis (5 in FIG. 2A) in the twisted nematic mode.

However, since the rubbing axis 25 of the alignment layer formed on the substrate 23 in the transverse electric field mode is formed in parallel with the moving direction of the substrate 23, the air knives 35 and 37 are formed on the substrate 23. Starting from the corner and proceeding diagonally, compressed air injected from the rubbing shaft 25 of the alignment layer and the air knives 35 and 37 forms an acute angle of 45 °.

Therefore, a problem arises in that the rubbing shaft 25 is fluctuated due to the force of the compressed air injected from the air knives 35 and 37 and the water deflection phenomenon caused by the force of the compressed air.

The fluctuation of the rubbing axis 25 affects the contrast characteristic, that is, the contrast is calculated by dividing the white luminance by the black luminance. In the transverse electric field mode, the substrate first set by the rubbing axis 25 is used. Even if only 0 ° to 0.1 ° in parallel with the moving direction of (23) changes, the black luminance value increases, so that the contrast characteristic is reduced by that much.

The present invention is to solve the above problems, the first object is to prevent the variation of the alignment film rubbing axis formed on the transverse electric field mode substrate during the substrate drying process using an air knife to remove the residual moisture of the substrate .

In addition, another object of the present invention is to solve the problem of lowering the contrast due to the variation of the alignment film rubbing axis.

In order to achieve the above object, the present invention provides a substrate comprising: a substrate on which an alignment film on which a surface is rubbed is formed; Transport means for transporting a substrate placed with one surface on which the alignment layer is formed; A substrate drying apparatus including a pair of air knives facing each other with the substrate interposed therebetween and spraying compressed air to be parallel to the rubbing axis of the alignment layer.

The vehicle is characterized in that it comprises a roller that rotates in one direction, exposing the upper and lower surfaces of the substrate, the pair of air knife is characterized in that the bar (bar) shape including a nozzle.

In this case, the pair of air knives are each arranged to form a predetermined angle with the substrate, characterized in that the injection of compressed air containing high-purity air or nitrogen (N ₂ ) through the nozzle. do.

In addition, the pair of air knives are characterized in that the compressed air is injected in a direction opposite to the moving direction of the substrate, further comprising a rotating stage capable of rotating the substrate to the loader portion of the vehicle. It is done.

In addition, the vehicle is characterized in that seating the substrate via an external robot, the external robot is characterized in that it can be mounted on the vehicle by rotating the substrate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

4 is a flowchart illustrating a manufacturing process of a liquid crystal panel for a liquid crystal display according to an exemplary embodiment of the present invention according to a process sequence.

The first step st1 is a step of preparing a first substrate, which is a color filter substrate, and a second substrate, which is an array substrate. The second substrate includes a thin film transistor including a gate electrode, a semiconductor layer, a source and a drain electrode, and a pixel electrode serving as an electrode.

A color filter layer is formed on the first substrate to transmit only light of a specific wavelength band at a position corresponding to the pixel electrode of the second substrate, and a black matrix is formed at the boundary of each color of the color filter layer to cover the non-pixel region.

In addition, a common electrode for applying a voltage to the liquid crystal layer is formed under the color filter layer and the black matrix.

The second step st2 is a step of forming an alignment layer on the first and second substrates. The liquid crystal display device utilizes the electrical optical effect of the liquid crystal, and the electro-optical effect is determined by the anisotropy of the liquid crystal itself and the molecular arrangement state of the liquid crystal, and the control of the molecular arrangement of the liquid crystal is an image in the liquid crystal display device. This will greatly affect the stabilization of the display quality. Therefore, an alignment process is performed to even the initial arrangement of liquid crystal molecules.

This step forms an alignment film on each of the electrode portions in contact with the liquid crystals of the first and second substrates, and includes application and curing of the alignment film, and a rubbing treatment process. As the alignment layer, polyimide, which is an organic alignment layer, is mainly used.

In particular, the present invention is characterized by using a transverse electric field mode for driving the liquid crystal molecules in a horizontal direction with respect to the substrate, so that the rubbing axis of the alignment film formed on the substrate is formed parallel to the moving direction of the substrate.

The third step st3 is a step of printing the seal pattern. At this time, the seal pattern is formed by enclosing a sealant of a thermosetting or ultraviolet curable resin with an edge of any one of the two substrates by a dispenser or a screen printing method. In this case, the liquid crystal inlet through which the liquid crystal can be injected is formed in a portion of the edge of the seal pattern, and the vacuum inlet opened to facilitate the injection of the liquid crystal.

The fourth step st4 is a step of dispersing a spacer. Spacers of constant size are used to precisely and uniformly maintain a cell gap between the first and second substrates.

The fifth step st5 is a step of forming a liquid crystal cell through the bonding process of the first and second substrates after the spacer spreading process is completed.

As a result, a liquid crystal filling space connected to the liquid crystal injection hole and the vacuum suction hole formed at edges facing each other of the first and second substrates is formed.

The sixth step st6 is a step of cutting the prepared liquid crystal cell into a unit liquid crystal cell.

In general, a liquid crystal cell is formed of a plurality of liquid crystal cells on a large glass substrate, and then separated into one liquid crystal cell.

A seventh step st7 is to inject liquid crystal into the liquid crystal cell. In the initial manufacturing process of the liquid crystal display device, a process of cutting several cells at the same time and then cutting them into cell units is performed. However, as the cell size increases, the cells are cut into unit cells and then a liquid crystal is injected.

An eighth step st8 is a step of encapsulating the liquid crystal inlet and the vacuum inlet of the liquid crystal cell into which the liquid crystal is injected.

After the liquid crystal injection process is completed, the encapsulation process is a process to prevent the liquid crystal from flowing out of the liquid crystal cell injection port and the suction port configured for vacuum suction after the liquid crystal injection is completed. Irradiate with UV rays to prevent it.

At this time, if the injection hole and the suction hole are in contact with the outside while the liquid crystal is injected, defects may occur due to contamination, so care must be taken not to cause external contact during cell movement or process progress, and it should not be left outside for a long time. .

After the quality test, the liquid crystal cell that has undergone the above-described process is connected to a driving circuit to the liquid crystal cell, and then a polarizing plate and a plurality of modules are configured to complete the liquid crystal display device.

Since the first and second substrates constituting the liquid crystal cell of the liquid crystal display device are accompanied by a number of mechanical and chemical treatment processes, a cleaning process for cleaning the surface and a drying process for removing residual water are essential after each process. Follow.

A general substrate cleaning process involves spraying a cleaning liquid such as pure water onto a substrate through a rinsing spray unit, brushing off the surface through a brush, and applying ultrasonic waves using an ultrasonic unit. Proceeds to.

In this case, pure water is water, commonly referred to as D.I water (de ionixed water or semiconductor grade water), and after cleaning the substrate using the same, the remaining water must be removed to prevent stains such as water marks.

Equipment for this purpose is a substrate drying apparatus, such as spin dry (spin dry) method and air knife (air knife) method, but in recent years it is common to use air knife according to the larger substrate size.

5 is a simplified cross-sectional view of a substrate drying apparatus including air knives 135 and 137 according to the present invention, and is opposed to each other with a roller 131 for moving the substrate 123 and the substrate 123 therebetween. It includes a pair of upper, lower air knife (135, 137).

The upper and lower air knives 135 and 137 are positioned to face each other in a straight bar shape having nozzles (not shown) for injecting compressed air, respectively, so as to face the movement direction of the substrate 123. While moving in the opposite direction, compressed air such as clean dry air (CDA) or nitrogen (N ₂ ) is injected onto the substrate 123.

In this case, the pair of upper and lower air knives 135 and 137 are arranged to form a predetermined inclination with the moving direction of the substrate 123, respectively, so that the residual moisture can be quickly pushed out of the substrate 123 or dried.

Accordingly, the substrate 123 seated on the roller 131 and slidably moves is the dry and removed residual moisture on the surface of the substrate 123 through the upper and lower air knifes 135 and 137. The residual moisture on the surface of the substrate 123 passing between the 135 and 137 is dried and removed while being pushed toward the other edge from one edge closest to the first air knife 135 and 137.

In this case, since the upper and lower air knives 135 and 137 are arranged to have a predetermined inclination with the moving direction of the substrate 123, the compressed air injected from the upper and lower air knives 135 and 137 is the substrate 123. It flows in the direction parallel to the rubbing axis 125 of the alignment film formed in parallel with the moving direction of.

This will be described in more detail with reference to FIG. 6.

FIG. 6 is a process perspective view showing a pair of air knives 135 and 137 and a substrate 123 passing therebetween, wherein the upper and lower air knives 135 and 137 are formed on the substrate 123. Compressed air is sprayed in a direction parallel to the rubbing shaft 125.

That is, when the rubbing axis 125 of the alignment layer formed on the substrate 123 is formed parallel to the moving direction of the substrate 123, and the substrate 123 is moved by the roller 131, the air Knives 135 and 137 are positioned perpendicular to the moving direction of the substrate 123 and sprayed compressed air onto the substrate 123 while moving in a direction opposite to the moving direction of the substrate 123, and remain on the substrate. It will remove moisture.

In the substrate cleaning process, the array substrate (31 in FIG. 1) and the color filter substrate (33 in FIG. 1) are bonded to each other and are cut in the liquid crystal cell unit (st6). Unit cells (not shown) are defined, the unit cell defined on the large-area substrate 123 in order to change the surface dimensions of the unit cell (not shown) defined according to each model of the liquid crystal display device The number of (not shown) or the unit cell (not shown) is arranged differently.

That is, the alignment layer rubbing axis 125 of the unit cells (not shown) defined on the substrate 123 is formed differently for each substrate 123 according to each model, and a long side of the edge of the substrate 123 is large. And is divided into a rubbing shaft 125 formed along the short side (短 邊).

Therefore, in the present invention, the rubbing axis 125 of the alignment film formed on the substrate 123 is formed in parallel with the moving direction of the substrate 123, so that the air knives 135 and 137 of the alignment film formed on the substrate 123 are formed. Since compressed air must be sprayed in a direction parallel to the rubbing shaft 125, before the substrate 123 is transferred to the roller 131 for moving the substrate 123, various substrates configured according to each model ( The substrate 123 needs to be rotated so that the moving direction of the substrate 123 and the rubbing axis 125 of the alignment layer are parallel to each other.

This constitutes a separate rotating stage (not shown) in the load unit of the substrate 123 before transferring the substrate 123 to the roller 131 for moving the substrate 123, thereby providing a substrate 123. The rubbing axis 125 of the alignment layer formed on the substrate 123 and the moving direction of the substrate may be parallel to each other, or may be directly transferred onto the roller 131 by supporting the substrate 123 by an external robot (not shown) or the like. At this time, the moving direction of the substrate 123 and the rubbing axis 125 of the alignment layer formed on the substrate 123 are configured in parallel with the robot (not shown).

Therefore, the rubbing axis 125 of the alignment layer formed on the substrate 123 in the transverse electric field mode is formed in parallel with the moving direction of the substrate 123 so that the air knifes 135 and 137 are formed on the substrate 123. Since compressed air is sprayed in a direction parallel to the rubbing axis 125 of the formed alignment film, it does not affect the alignment film rubbing axis 125 of the substrate 123.

Therefore, by preventing the rubbing axis 125 fluctuation, the problem that the contrast due to the fluctuation of the existing rubbing axis (25 of FIG. 2b) is also reduced in advance.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

As described above, after cleaning the substrate according to the present invention, in the substrate drying process through the air knife for removing residual moisture on the substrate, the rubbing axis of the alignment film formed on the substrate with the compressed air injected from the air knife By spraying in parallel, there is an effect of preventing the problem that the rubbing axis is fluctuated by the force of the compressed air injected from the air knife and the water concentration caused by the force of the compressed air.

In addition, the problem that the contrast is lowered due to the fluctuation of the rubbing shaft also has an effect of preventing the problem.

Claims (9)

A substrate on which an alignment film on which a surface is rubbed is formed; Transport means for transporting a substrate placed with one surface on which the alignment layer is formed; A pair of air knives that face each other with the substrate therebetween and spray compressed air parallel to the rubbing axis of the alignment layer; Substrate drying apparatus comprising a. The method of claim 1, The transport means is a substrate drying apparatus, characterized in that it comprises a roller that rotates in one direction, exposing the upper and lower surfaces of the substrate. The method of claim 1, The pair of air knife is a substrate drying apparatus, characterized in that the bar (bar) shape including a nozzle. The method of claim 3, wherein And the pair of air knives are arranged to form a predetermined angle with the substrate, respectively. The method of claim 4, wherein Substrate drying apparatus, characterized in that for injecting compressed air containing high purity air or nitrogen (N ₂ ) through the nozzle. The method of claim 5, wherein And the pair of air knives spray compressed air in a direction opposite to the moving direction of the substrate. The method of claim 1, And a rotating stage capable of rotating the substrate in the loader portion of the vehicle. The method of claim 1, Substrate drying apparatus, characterized in that for mounting the substrate to the vehicle via an external robot. The method of claim 8, The external robot is a substrate drying apparatus, characterized in that to rotate on the substrate to be mounted on the vehicle.

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