KR101255703B1 - Method for manufacturing a liquid crystal panel - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of applying an alignment layer during a manufacturing process of a liquid crystal display device, and an object of the present invention is to apply an alignment layer using a slit nozzle and to form a seal pattern using a laser. A display device manufacturing method is provided. In order to achieve the above object, the liquid crystal panel manufacturing method according to the present invention comprises a cleaning step of manufacturing and then cleaning the upper substrate and the lower substrate of the liquid crystal panel; A firing step of applying an alignment layer to the upper substrate or the lower substrate using a slit nozzle and drying the alignment layer; A seal pattern forming step of forming a seal pattern using a laser on the alignment layer of the upper substrate or the lower substrate that has undergone the alignment layer firing step; And an alignment layer rubbing step of rubbing the upper or lower substrate through the seal pattern forming step in a predetermined direction to form a groove; And bonding the upper substrate and the lower substrate through the process to each other using a real material, and cutting the respective unit cells.

Description

 Liquid crystal panel manufacturing method {METHOD FOR MANUFACTURING A LIQUID CRYSTAL PANEL}

1 is an exemplary view showing a liquid crystal panel of a general liquid crystal display device.

Figure 2 is an exemplary view of a conventional alignment film coating device.

Figure 3 is an exemplary view showing a state in which the alignment film is applied by using the alignment film coating apparatus using a slit nozzle applied to the present invention.

4 is a left side cross-sectional view of the slit nozzle shown in FIG. 3.

5 is an exemplary view showing a state in which a seal pattern is formed on a substrate by using a seal pattern forming apparatus using a laser applied to the present invention.

6 is a flowchart illustrating one embodiment of a method for manufacturing a liquid crystal panel according to the present invention.

<Explanation of symbols for main parts of the drawings>

11 TFT substrate 12 C / F substrate

40: table 50: slit nozzle

60: alignment film 70: laser

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for applying an alignment film during a manufacturing process of a liquid crystal display device, and more particularly, to a method for applying an alignment film using a spray nozzle.

In general, a liquid crystal display (hereinafter referred to as "LCD") is a typical flat panel display that displays an image by adjusting an amount of light beam transmission to correspond to an image signal. In particular, LCDs are becoming more and more widespread due to light weight, thinness, and low power consumption. As such, LCDs are used as display devices for office automation devices and notebook computers. have.

1 is an exemplary view showing a liquid crystal panel of a general liquid crystal display device.

That is, the liquid crystal panel 10 of the liquid crystal display device shown in FIG. 1 includes a thin film transistor substrate (hereinafter, simply referred to as a TFT substrate) 11 for receiving a driving signal, a color filter substrate including a color filter layer ( Hereinafter, the liquid crystal layer 13 is interposed between the thin film transistor substrate and the color filter substrate.

The manufacturing process of the liquid crystal display device including the liquid crystal panel as described above is largely divided into three processes: substrate manufacturing process, liquid crystal panel manufacturing process, and module process.

First, the substrate manufacturing process is divided into a process of manufacturing a TFT substrate using a cleaned substrate and a process of manufacturing a C / F substrate. The TFT substrate manufacturing process includes a signal line and a plurality of thin film transistors on a lower glass substrate. And a process of forming a pixel electrode, and a process of manufacturing a C / F substrate refers to a process of sequentially forming a black matrix, a color filter layer, and a common electrode (ITO) on an upper glass substrate. In this case, the substrate manufacturing process again includes cleaning (PPCLN), moisture drying (DHP / DSP), photoresist coating, photo etching, solvent removal (VCD), thermal curing (SHP), exposure, and development (Developer). It can be broken down into hard bake and inspection processes.

Next, the liquid crystal panel process is a process of manufacturing a liquid crystal panel by bonding a TFT substrate and a C / F substrate and injecting a liquid crystal therebetween, wherein the liquid crystal panel process is again an alignment film forming process, a rubbing process, and a cell gap. It consists of many unit processes such as a cell gap forming process, an assembly process, a cell cutting process, a liquid crystal injection process, and a polarizing film attachment process.

Finally, the module process is a process of connecting the liquid crystal panel and the signal processing circuit part, and the module process is also made of a number of unit processes.

2 is an exemplary view of a conventional alignment film coating device.

As described above, in order to fabricate the liquid crystal display, a process of applying an alignment film to the substrate to determine an initial arrangement state of the liquid crystal molecules disposed between the TFT substrate 11 and the C / F substrate 12 is required.

That is, the molecular arrangement of the liquid crystal has a great influence on stabilizing the display quality of the liquid crystal display device. Therefore, it is necessary to give a single crystal order to the liquid crystal and to make a regular response in literally one unit. It is a role of the alignment film.

As described above, an alignment layer forming process is provided to arrange liquid crystal molecules inserted into the liquid crystal display device in a predetermined direction. Do rubbing work. An apparatus for applying the alignment film and a method of applying the alignment film by using the same will be described below.

That is, as shown in FIG. 2, in the conventional alignment film applying apparatus, the substrate 11 or 12 is fixedly placed on the table 40 for printing, and the alignment liquid is transferred onto the transfer plate 28 on the substrate. The printing roller 26 is coated on it. The printing roller 20 has a structure in which a first guide roller 27 and a second guide roller 29 are coupled to each other to transfer the alignment liquid.

In addition, the alignment liquid container 23 containing the alignment liquid is placed in the alignment liquid supply part 21 for supplying the alignment liquid. One side of the moving tube 22 is inserted into the alignment liquid container 23, and a dispenser 25 for discharging the alignment liquid moved along the moving tube 22 is coupled to the other side of the moving tube 22.

In addition, in the alignment liquid supply part 21, a nitrogen nozzle part 24 which applies pressure using nitrogen gas to raise the alignment liquid contained in the alignment liquid container 23 to the place where the dispenser 25 is located is provided. have.

The alignment liquid container 23 contains a solution in which a polyamic acid solid as a main material of the alignment film and a volatile solvent (NMP, γ-BL, BC, etc.) are mixed.

The alignment film coating apparatus of the liquid crystal display device having the above structure is to apply the alignment film on the substrate through the following process.

First, when the TFT substrate 11 or the C / F plate 12 of the liquid crystal display device for applying the alignment layer is fixed on the table 40, the alignment liquid container in which the alignment liquid is contained in the alignment liquid supply part 21. (23) is inserted and the said moving pipe 22 is inserted. In order to raise the alignment liquid in the alignment liquid supply part 21, nitrogen gas of a strong pressure is injected through the nitrogen nozzle part 24.

Then, a constant pressure is formed between the alignment liquid supply part 21 and the alignment liquid container 23, and this pressure acts as a pressure for raising the alignment liquid contained in the alignment liquid container 23.

The alignment liquid rising from the alignment liquid container 23 moves to the dispenser 25 along the moving tube 22.

The alignment liquid moved to the dispenser 25 is dropped between the first and second guide rollers 27 and 29, which can rotate in engagement with the printing roller 26, and the first guide roller 27 is The reciprocating motion is performed along the left and right of the second guide roller 29 so that the alignment liquid is evenly applied on the surface of the second guide roller 29.

Then, the alignment liquid applied to the surface of the second guide roller 29 is applied to the transfer plate 28 disposed on the surface of the printing roller 26, which is transferred by the rotation of the printing roller 26. The plate 28 applies an alignment liquid on the substrates 11 and 12 fixed on the table 40.

Subsequently, the substrates 11 and 12 to which the alignment solution is applied are heat-treated to remove the solvent, and polyimide of the polyamic acid component to form an alignment film.

When the alignment film is formed through the above process, an alignment film firing process of drying and curing the solvent by applying high temperature heat to the alignment film raw material solution is performed. Then, the surface of the baked alignment film is rubbed in a predetermined direction using a rubbing device. It is subjected to an alignment film rubbing process that produces.

After the alignment layer forming process is completed, a seal pattern serving as an adhesive on the edge of the upper substrate is formed in the remaining regions except for the liquid crystal injection hole, and the spacers are scattered on the lower substrate. After the substrates are opposed to each other, a cell cutting process of cutting the oppositely bonded substrates into unit cells as described above is performed.

Finally, when the liquid crystal is injected between the two substrates cut into the unit cells and the liquid crystal injection hole is sealed so that the liquid crystal does not flow out, the desired liquid crystal display device is completed.

On the other hand, the conventional alignment film applying apparatus as described above is a method of applying the alignment film to the substrate while the transfer plate 28 in contact with the substrate, the substrate 11, 12 by the pressure generated while the transfer plate 28 in contact with the substrate In addition to damaging the circuit configured, there is a problem that the static electricity generated by the contact.

In addition, in the manufacturing process of the conventional liquid crystal display device as described above, in order to form a seal pattern on the substrate on which the alignment layer is applied, exposure and etching processes must be performed.

In addition, as the substrate is enlarged, the alignment layer coating apparatus is also enlarged, and as each driving mechanism is made of a gear system, there is a problem in that the manufacturing accuracy of the equipment is lowered and foreign materials are generated due to friction of the driving unit.

In addition, there is a problem in that the manufacturing process is delayed because the transfer plate (APR resin plate) 28 must be replaced according to the production model, and the roller also has to be replaced when a pinhole occurs.

Accordingly, an object of the present invention for solving the above problems is to provide a liquid crystal display device manufacturing method capable of forming a seal pattern using a laser while applying an alignment layer using a slit nozzle.

In order to achieve the above object, the liquid crystal panel manufacturing method according to the present invention comprises a cleaning step of manufacturing and then cleaning the upper substrate and the lower substrate of the liquid crystal panel; A firing step of applying an alignment layer to the upper substrate or the lower substrate using a slit nozzle and drying the alignment layer; A seal pattern forming step of forming a seal pattern using a laser on the alignment layer of the upper substrate or the lower substrate that has undergone the alignment layer firing step; And an alignment layer rubbing step of rubbing the upper or lower substrate through the seal pattern forming step in a predetermined direction to form a groove; And bonding the upper substrate and the lower substrate through the process to each other using a real material, and cutting the respective unit cells.

In addition, the slit nozzle used in the alignment layer coating step is characterized in that the slit nozzle used in the upper substrate or lower substrate manufacturing step.

In addition, the laser is a femtosecond laser is irradiated for a fast time (Femto sec) irrespective of the material of the subject can be cut off the molecular ring of the subject before the molecular motion of the subject.

In addition, the laser is characterized in that the processing surface of the alignment film is processed to a uniform thickness.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

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

3 is an exemplary view showing a state in which the alignment film is applied using the alignment film coating apparatus using the slit nozzle applied to the present invention. 4 is a left side cross-sectional view of the slit nozzle shown in FIG. 3 and a left side cross-sectional view of the slit nozzle 50 shown in FIG.

As described above, a method for manufacturing a liquid crystal panel includes an alignment film disposed between a TFT substrate and a C / F substrate to determine an initial arrangement state of liquid crystal molecules on the substrate (the TFT substrate 11 or the C / F substrate 12). ) Is required, and in the liquid crystal panel manufacturing method according to the present invention, an alignment layer coating apparatus using a slit nozzle as shown in FIG. 3 is used as the alignment layer coating apparatus.

As shown in FIG. 3, the alignment film coating apparatus using the slit nozzle applied to the present invention includes a table 40 on which the substrate is placed, and a slit nozzle 50 for injecting the alignment liquid onto the substrate placed on the stage. It is composed.

In this case, the slit nozzle 50 is a slit nozzle used when manufacturing a TFT substrate or a C / F substrate, and is used by injecting an alignment liquid into a slit nozzle used for depositing photoresist for the substrates. Can be.

On the other hand, the slit nozzle 50 is a substrate 51, the alignment liquid supplied from the head 51 and the alignment liquid supplied from the head from the supply pipe 52 is connected to the solution tank (not shown) containing the alignment liquid It is comprised including the nozzle 53 used as the passage for injecting into 12).

At this time, the supply pipe 52 is connected to a solution tank (not shown) in which the alignment liquid to be applied to the substrate in a solution state and one end thereof, and transfers the alignment liquid in the solution state in the solution tank to the head 51. do.

The head 51 is a passage for receiving an alignment liquid in a solution state from the supply pipe 52 and delivering the same to the nozzle 53. The nozzle 53 has a slot shape.

Meanwhile, the alignment film applying apparatus using the slit nozzle may be configured such that the slit nozzle 50 sprays the alignment film while the substrates 11 and 12 placed on the table 40 move to the slit nozzle. Alternatively, the slit nozzle 50 may be sprayed on the substrate while the substrate is placed on the table 40 to spray the alignment layer.

As the material of the alignment liquid used as the alignment layer 60, a polyimide-based material excellent in printability, rubbing property, orientation direction, and chemical stability is used. In general, polyimide-based polymers are reacted with diamine and acid anhydride in a solvent to PAA or sol. Synthesize PI. Here, the alignment liquid material is PAA or sol. It is PI, and it becomes a polyimide through the process of drying after printing, and heat hardening.

FIG. 5 is an exemplary view showing a state in which a seal pattern is formed on a substrate using a seal pattern forming apparatus using a laser applied to the present invention, and an alignment layer using an alignment layer coating apparatus using a slit nozzle as shown in FIG. 3. In the present invention, the laser 70 is used to form the seal pattern 80 on the substrate subjected to the rubbing process after the coating of the 60.

That is, the seal pattern forming apparatus using the laser applied to the present invention uses a table 40 on which a substrate is placed and a laser 70 for generating a laser beam on the substrates 11 and 12 as shown in FIG. 5. It is configured to include.

The laser 70 is configured to include a control unit for controlling the intensity or pattern of the laser beam, and a laser irradiation unit for irradiating the laser generated from the control unit to the substrate, the control unit is a seal to be formed on the substrate Pattern information is included, so that the laser moves on the substrates 11 and 12 according to the information to process a portion corresponding to the seal pattern.

At this time, the laser 70 is a femtosecond laser, irradiated for a fast time (Femto sec) irrespective of the subject material, and breaks the molecular ring of the subject before the molecular motion of the subject occurs. By adjusting the power or pulse, the processed surface of the subject can be processed to a uniform thickness. That is, the femtosecond laser is only when the wavelength of the laser and the wavelength of the subject is absorbed and processed as heat is generated, and compared with the conventional laser having a characteristic of reflecting when the wavelength is not matched with the subject When its processing characteristics are excellent.

Hereinafter, a method of manufacturing a liquid crystal panel according to the present invention including a process of applying an alignment film using the alignment film applying apparatus using the slit nozzle described above and a process of forming a seal pattern using a laser will be described with reference to FIG. 6. do.

6 is a flowchart illustrating an embodiment of a method of manufacturing a liquid crystal panel according to the present invention.

First, the upper and lower substrates (TFT substrate and C / F substrate) of the liquid crystal panel are manufactured (S100). An array element is formed on the lower substrate 11 of the liquid crystal panel. The array element includes a plurality of thin film transistors. The thin film transistor is formed at a point where a gate line and a data line cross each other, and a gate electrode protruding from the gate line, a semiconductor layer formed at the gate electrode position, and source and drain electrodes contacting both sides of the semiconductor layer. It is made to include. A pixel electrode connected to the drain electrode is formed. Red, green, and blue color filters are formed on the upper substrate 12 of the liquid crystal panel, and black matrices are formed including boundary portions of the color filters. An overcoat layer and a common electrode are formed on the color filter and the black matrix.

Next, a cleaning process (S110) is performed to remove foreign substances on the upper substrate 12 and the lower substrate 11 formed as described above.

Next, an alignment layer coating process of forming polyimide (PI), which is an alignment layer raw material solution, on the upper surface of the upper substrate 12 or the lower substrate 11 using the alignment layer coating apparatus using the slit nozzle as shown in FIG. 3. Go through (S120).

Next, an alignment film firing step (S130) is performed in which a high temperature heat is added to the alignment film raw material solution to dry and cure the solvent.

Next, a seal pattern forming process of removing the alignment layer of a portion of the alignment layer corresponding to the seal pattern is performed using the seal pattern device using the laser as shown in FIG. 5 (S140).

Next, the alignment film rubbing process (S140) is performed by rubbing the surface of the baked alignment film using a rubbing device in a predetermined direction to form a groove. To this end, the substrate is inclined and rubbed using a rubbing roller. In this case, the inclination angle of the substrate is greater than 0 ° and less than 90 °, and the rubbing roller for rubbing on the substrate performs an alignment film rubbing process on the top or bottom of the inclined substrate.

Next, the upper substrate and the lower substrate on which the seal pattern is formed are opposed to each other using a sealant, and light is leaked out of a given margin so that precision of about several micrometers (μm) is usually required. S160).

Next, a cell cutting process of cutting the oppositely bonded substrates into unit cells is performed as described above (S170). The cell cutting process is to cut two completely bonded substrates to a required size. The scribing process of forming a line on the substrate and the brake process of impacting the scribed line to separate the substrate.

Finally, when the liquid crystal is injected between the two substrates cut into the unit cells and the liquid crystal injection hole is sealed so that the liquid crystal does not flow out, the desired liquid crystal panel is completed (S180).

That is, the present invention has the feature that the slit nozzle 50 is used in the alignment film formation process, and the laser 70 is used in the seal pattern removal process.

The liquid crystal panel manufacturing process according to the present invention as described above has an excellent effect of preventing damage to the patterns formed on the substrate by using the slit nozzle in the alignment film forming process.

In addition, the present invention has an excellent effect that by using a laser to form a seal pattern, a separate exposure and etching process can be omitted, thereby simplifying the manufacturing process of the liquid crystal panel as a whole.

In addition, the conventional coating method (Roll Coating) using a roller is difficult to manufacture equipment parts (Anilox Roll, Doator Roll, Printing Mask) according to the large size of the equipment and the maintenance is difficult because the parts are expensive, the present invention is a large production In addition to using advantageous slit nozzles, there is an excellent effect of not using large parts.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Claims (4)

A cleaning step of fabricating and cleaning the upper and lower substrates of the liquid crystal panel; A firing step of applying an alignment layer to the upper substrate or the lower substrate using a slit nozzle and drying the alignment layer; A seal pattern forming step of forming a seal pattern using a laser on the alignment layer of the upper substrate or the lower substrate that has undergone the alignment layer firing step; And An alignment layer rubbing step of rubbing the upper or lower substrate through the seal pattern forming step in a predetermined direction to form a groove; Bonding the upper substrate and the lower substrate through the alignment layer rubbing step using a real material and cutting each unit cell; wherein the alignment layer material is polyimide, and the slit nozzle Spraying in the direction of gravity to apply an alignment layer to the upper substrate or the lower substrate, the alignment layer rubbing step is to arrange the upper substrate or lower substrate inclined at an angle greater than 0 ° and less than 90 °, rubbing using a rubbing roller Liquid crystal panel manufacturing method characterized in that. The method of claim 1, The slit nozzle used in the alignment layer coating step is a slit nozzle used in the upper substrate or lower substrate manufacturing step characterized in that the liquid crystal panel manufacturing method. The method of claim 1, Wherein the laser is a femtosecond laser that is irradiated for a fast time (Femto sec) irrespective of a subject material and breaks the molecular ring of the subject before molecular motion of the subject occurs. The method of claim 1, Said laser processes the process surface of the said oriented film to uniform thickness, The manufacturing method of the liquid crystal panel characterized by the above-mentioned.

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