KR20030066226A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

PURPOSE: A method for manufacturing a liquid crystal display is provided to improve the productivity by reducing a processing time before joining two substrates, and efficiently operate a production line by processing the substrates in balance. CONSTITUTION: Liquid crystal is dropped on a first substrate. A sealant is formed on a second substrate. The first substrate is chucked on a lower stage in a joining chamber and the second substrate is chucked on an upper stage in the joining chamber(31S-32S). The joining chamber is vacuumed firstly and a substrate receiver is placed under the second substrate, and then the joining chamber is vacuumed secondly(33S-34S). The substrate receiver is returned to the original position(36S). The first substrate and the second substrate are joined by applying a pressure(37S). The joined first and second substrates are unloaded(38S).

Description

Method for manufacturing liquid crystal display device

The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly, to a method for manufacturing a liquid crystal display device of a liquid crystal dropping method.

As the information society develops, the demand for display devices is increasing in various forms, and in recent years, the LCD (Lipuid Crystal Display Device), PDP (Plasma Display Panel), ELD (Electro Luminescent Display), and VFD (Vacuum Fluorescent) Various flat panel display devices such as displays have been studied, and some of them are already used as display devices in various devices.

Among them, LCD is the most widely used, replacing the CRT (Cathode Ray Tube) for mobile image display because of its excellent image quality, light weight, thinness, and low power consumption. In addition, it is being developed in various ways such as a television for receiving and displaying a broadcast signal, a monitor of a computer.

As described above, although various technical advances have been made in order for the liquid crystal display device to serve as a screen display device in various fields, the task of improving the image quality as the screen display device is often arranged with the above advantages. Therefore, in order to use a liquid crystal display device in various parts as a general screen display device, the key to development is how much high definition images such as high definition, high brightness, and large area can be realized while maintaining the characteristics of light weight, thinness, and low power consumption. It can be said.

Such a liquid crystal display may be largely divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel has a predetermined space and is bonded to the first and second glass substrates. And a liquid crystal layer injected between the first and second glass substrates.

The first glass substrate (TFT array substrate) may include a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing each gate line and data line, and a plurality of thin films that transmit signals of the data line to each pixel electrode by being switched by signals of the gate line Transistors are formed.

The second glass substrate (color filter substrate) includes a black matrix layer for blocking light in portions other than the pixel region, an R, G and B color filter layer for expressing color colors, and a common electrode for implementing an image. Is formed.

The first and second substrates are bonded to each other by a seal material having a predetermined space by a spacer and having a liquid crystal injection hole, so that the liquid crystal is injected between the two substrates.

In this case, in the liquid crystal injection method, when the liquid crystal injection hole is immersed in the liquid crystal liquid by maintaining the vacuum state between the two substrates bonded by the real material, love is injected between the two substrates by the osmotic phenomenon. When the liquid crystal is injected as described above, the liquid crystal injection hole is sealed with a sealing material.

However, the manufacturing method of such a liquid crystal injection type liquid crystal display device has the following problems.

First, after cutting into a unit panel, the liquid crystal injection hole is immersed in the liquid crystal liquid by maintaining the vacuum state between the two substrates, so that the liquid crystal injection takes a lot of time, the productivity is lowered.

Second, in the case of manufacturing a large-area liquid crystal display device, when the liquid crystal is injected by the liquid crystal injection method, the liquid crystal is not completely injected into the panel, which causes a defect.

Third, since the process is complicated and time-consuming as described above, several liquid crystal injection equipment is required, which requires a lot of space.

Therefore, in recent years, the manufacturing method of the liquid crystal display device using the method of dropping a liquid crystal is researched. Among them, Japanese Unexamined Patent Application Publication No. 2000-147528 discloses a technique using the following liquid crystal dropping method.

The manufacturing method of the conventional liquid crystal display device using the liquid crystal dropping method is as follows.

1A to 2E are cross-sectional views of a liquid crystal display device according to a conventional liquid crystal dropping method.

As shown in FIG. 1A, an ultraviolet curable material 1 is applied to the first glass substrate 3 on which the thin film transistor array is formed to have a thickness of about 30 μm, and the liquid crystal 2 is disposed inside the material 1 (a thin film transistor array). Dropping At this time, the real material 3 is formed without a liquid crystal injection hole.

The first glass substrate 3 as described above is mounted on the table 4 in the vacuum container C that is movable in the horizontal direction, and the entire lower surface of the first glass substrate 3 is mounted on the first adsorption mechanism 5. ) By vacuum adsorption.

As shown in Fig. 1B, the entire lower surface of the second glass substrate 6 on which the color filter array is formed is vacuum-adsorbed and fixed by the second adsorption mechanism 7, and the vacuum vessel C is closed and vacuumed. Then, the second adsorption mechanism 7 is lowered in the vertical direction so that the distance between the first glass substrate 3 and the second glass substrate 6 is 1 mm, and the first glass substrate 3 is mounted. The table 4 is moved in the horizontal direction to preliminarily position the first glass substrate 3 and the second glass substrate 6.

As shown in FIG. 1C, the second adsorption mechanism 7 is lowered in the vertical direction to bring the second glass substrate 6 into contact with the liquid crystal 2 or the actual material 1.

As shown in FIG. 1D, the table 4 on which the first glass substrate 3 is mounted is moved in the horizontal direction to adjust the position of the first glass substrate 3 and the second glass substrate 6.

As shown in FIG. 1E, the second adsorption mechanism 7 is lowered in the vertical direction to bond the second glass substrate 6 to the first glass substrate 3 through the actual material 1, and to press to 5 μm. .

As shown in FIG. 1F, the bonded first and second glass substrates 3 and 6 are taken out of the vacuum container C, and the ultraviolet rays are irradiated to the actual substance 1 to cure the actual substance 1 to provide a liquid crystal display device. Complete

However, the conventional method of manufacturing the liquid crystal display device of the liquid crystal dropping method has the following problems.

First, since the actual material is formed on the same substrate and the liquid crystal is dropped, the process time until joining the two substrates takes a lot.

Second, since a real material is applied to the first substrate and a liquid crystal is dropped, but no process is performed on the second substrate, an unbalance occurs between the processes of the first substrate and the second substrate to efficiently operate the production line. Difficult to do

Third, since the substance is applied to the first substrate and the liquid crystal is dropped, the substrate to which the substance is applied cannot be cleaned by the cleaning equipment USC before bonding. Therefore, it is not possible to deposit the actual material to be bonded to the upper and lower substrates, it is not possible to remove the particles, causing the actual contact failure occurs when bonding.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for manufacturing a liquid crystal display device of a liquid crystal dropping method which can improve the productivity by shortening the process time and maximizing the efficiency.

1A to 1F are schematic cross-sectional views showing a conventional liquid crystal display method of a liquid crystal display device.

2 is a process flowchart of a schematic liquid crystal display according to the present invention.

3A to 3E are schematic cross-sectional views showing the liquid crystal display device process of the liquid crystal dropping method according to the present invention.

4 is a flowchart of the bonding process according to the present invention

Explanation of symbols for the main parts of the drawings

10 vacuum vacuum chamber 11, 13 glass substrate

12: liquid crystal 14: real

15: upper stage 16: lower stage

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including: a first step of loading a first substrate on which liquid crystal is dropped and a second substrate on which an actual substance is formed into a combiner chamber; A second step of vacuuming, a third step of varying the pressures of the first and second substrates, and a fourth step of unloading the bonded first and second substrates. There is this.

Here, the first step may include adsorbing a first substrate to a lower stage in the adapter chamber and adsorbing a second substrate to the upper stage, and a second substrate on which the substrate receiver of the adapter is fixed to the upper stage. Positioning the lower side and fixing the first and second substrates by the electrostatic adsorption method, respectively.

In the second step of vacuuming the adapter chamber, the first substrate and the second substrate are adsorbed to the lower stage and the upper stage in the adapter chamber, respectively, and then vacuumed first, and the substrate receiver is fixed to the upper stage. It is preferred to place a second vacuum under the second substrate.

It is preferable that liquid crystal is dripped on the said 1st board | substrate, and a real thing is also apply | coated.

Preferably, the second step of evacuating the adapter chamber is vacuumed secondarily.

In the fourth step of unloading, it is preferable to load at least one of the first substrate or the second substrate to be subjected to the next bonding process to the upper or lower stage and to unload the bonded substrate.

The fourth step of unloading preferably includes adsorbing and raising the first and second substrates to which the upper stage is bonded, and unloading the bonded first and second substrates. .

The fourth step of unloading includes: adsorbing and raising the first and second substrates to which the upper stage is bonded, loading the first substrate to be subjected to the next bonding process, and loading the bonded substrates. 1, it is preferable to comprise the step of unloading the second substrate.

The fourth step of unloading includes loading a second substrate on which the next bonding process is to be performed on the upper stage, and unloading the bonded first and second substrates from the lower stage. desirable.

It is preferable to further include a liquid crystal spreading step for spreading the liquid crystal toward the real state before the fourth step of unloading.

After the fourth step of the unloading, it is preferable to further include a liquid crystal spreading step to spread the liquid crystal toward the real.

Preferably, the liquid crystal spreading process proceeds for at least 10 minutes.

Hereinafter, a method of manufacturing a liquid crystal display device according to the present invention having such a feature will be described in detail with reference to the accompanying drawings.

2 is a schematic process flowchart of the liquid crystal display according to the present invention, and FIGS. 3A to 3F are schematic cross-sectional views showing the process of the liquid crystal display according to the present invention.

A plurality of panels are designed on the first glass substrate 11 to form a thin film transistor array on each panel (11S), and a first alignment layer is formed on the entire surface to perform rubbing (12S).

A plurality of panels are designed on the second glass substrate 13 to correspond to each panel formed on the first glass substrate 11 to form a color filter array having a black matrix layer, a color filter layer, a common electrode, and the like on each panel. Then, a second alignment layer is formed on the entire surface (15S) and rubbing is performed (16S).

The first and second glass substrates 11 and 13 formed as described above are washed (13S and 17S), respectively.

As shown in FIG. 3A, the liquid crystal 12 is dropped into the washed first glass substrate 11 (14S).

Ag dots are formed on the washed second glass substrate 13 (18S), and the real material 14 is applied again (19S).

The first and second glass substrates 11 and 13 are loaded into the vacuum adapter chamber 10 so that the first and second glass substrates 11 and 13 are uniformly filled in the respective panels. It adheres and hardens the said substance (20S).

The bonded first and second glass substrates 11 and 13 are cut for each panel (21S).

Each cut panel is polished and the final quality is inspected to complete the liquid crystal display (22S).

Here, the bonding process is described in more detail as follows.

4 is a flowchart illustrating a bonding process of the liquid crystal display according to the present invention.

The bonding process according to the present invention comprises the steps of: loading two substrates into a vacuum combiner chamber, vacuuming the combiner chamber, bonding the two substrates, and unloading the bonded two substrates from the vacuum combiner chamber. It can be divided into steps.

First, before loading, the second glass substrate 13 coated with the actual material may be cleaned in an Ultra Sonic Cleaner (USC) to remove particles generated during the process. That is, since the liquid crystal is not dripped but the real thing and Ag dot are apply | coated to the 2nd glass substrate 13, cleaning is possible.

And, in the loading step, as shown in FIG. 3B, the second glass substrate 13 to which the sealant 14 is applied is directed so that the portion to which the sealant 14 is applied is directed downward. The first glass substrate 11 on which the liquid crystal 12 is dripped is fixed to the upper stage 15 of the vacuum cleaner chamber 10 by the vacuum suction method (31S). It is fixed (32S). At this time, the vacuum adapter chamber 10 maintains the standby state.

Specifically, the loader of the robot (not shown in the drawing) has a second glass substrate 13 coated with a sealant 14 so that the portion coated with the seal 14 faces downward. ) Mounts the second glass substrate and places it into the vacuum adapter chamber 10. In this state, the upper stage 15 of the vacuum adhering chamber 10 descends to fix the second glass substrate 13 by vacuum adsorption, and then rise. At this time, it can be fixed by the electrostatic adsorption method instead of the vacuum adsorption method.

The loader of the robot exits the vacuum combiner chamber 10, and the lower stage 16 in the vacuum combiner chamber 10 is placed on the first glass substrate 11 having the liquid crystal 12 dropped by the loader of the robot. ) To the top.

In the above description, although the liquid crystal 12 is dropped on the first glass substrate 11 having the thin film transistor array and the substance is formed on the second glass substrate 13 having the color filter array, the first glass substrate ( 11) a real substance can be applied, and a liquid crystal can be dripped onto the said 2nd board | substrate, and a liquid crystal can also be dripped and the real thing may be apply | coated to either of the two glass substrates. However, the board | substrate with which liquid crystal was dripped may be located in a lower stage, and the remaining board | substrate may be located in an upper stage.

Subsequently, a substrate receiver (not shown) is positioned directly below the second glass substrate 13 fixed to the upper stage 15 (33S). 2 The method of placing on a board | substrate is as follows.

First, the upper stage is lowered or the substrate receiver is raised to bring the second glass substrate and the substrate receiver into close proximity, and then the second glass substrate 13 is lowered on the substrate receiver.

Second, the upper stage is first lowered by a predetermined distance and the substrate receiver is secondly raised to bring the second glass substrate 13 and the substrate receiver into close proximity, and then the second glass substrate 13 is moved to the substrate receiver. Put on top.

Third, the upper stage is lowered, the substrate receiver is raised, or the upper stage is first lowered and the substrate receiver is raised secondly, so that the second glass substrate 13 and the substrate receiver have a predetermined distance. The upper stage then adsorbs the second glass substrate.

At this time, the reason why the substrate receiver is positioned below the second glass substrate 13 is that the stages 15 and 16 adsorb the first and second glass substrates by a vacuum adsorption method. Since the degree of vacuum in the adapter chamber becomes higher than the vacuum of each stage while making the chamber 10 into a vacuum state, the suction force of the first and second glass substrates 11 and 13 held by the stage is lost, in particular The second glass substrate adsorbed on the upper stage is to be prevented from falling off and falling on the first glass substrate 11.

Therefore, before the vacuum chamber is brought into the vacuum state, the second glass substrate 13 adsorbed on the upper stage is placed on the substrate receiver, or the upper stage and the substrate receiver on which the second glass substrate is adsorbed are spaced at a predetermined interval. The second glass substrate 13 may be positioned from the upper stage to the substrate receiver while positioning and vacuuming the chamber. In addition, when the vacuum chamber chamber starts to be vacuumed, there may be additional means for fixing the substrate since the substrate may move due to flow in the chamber at an initial stage.

Here, when the upper and lower stages adsorb the first and second glass substrates by the electrostatic adsorption method, the substrate receiver may be immediately vacuumed without having to be positioned below the upper stage.

The vacuum adhering chamber 10 is brought into a vacuum state (34S). Here, the vacuum degree of the vacuum adapter chamber 10 varies depending on the liquid crystal mode to be bonded, but the IPS mode is about 1.0 x 10 ^-3 Pa to 1Pa, and the TN mode is about 1.1 x 10 ^-3 Pa to 10 ^2. Let Pa.

In the above, the chamber 10 of the vacuum adapter may be vacuumed in two stages. That is, the substrate is adsorbed to the upper and lower stages, the door of the chamber is closed, and the first vacuum is started. The substrate receiver is positioned below the upper stage and the substrate adsorbed on the upper stage is placed on the substrate receiver or the substrate is held at a predetermined interval while the substrate is held at the substrate receiver. Is vacuumed second. At this time, the vacuum is faster at the time of the second vacuum than at the first vacuum, and the primary vacuum ensures that the vacuum degree of the vacuum adhering chamber is not higher than the vacuum suction force of the upper stage.

In addition, without separating the vacuum into primary and secondary, the substrate may be adsorbed to each stage and the chamber door may be closed, and then the vacuum may be started constantly to place the substrate receiver under the upper stage during the vacuum. At this time, the time point at which the substrate receiver is positioned below the upper stage should be positioned before the vacuum degree of the vacuum adapter chamber becomes higher than the vacuum suction force of the upper stage.

The reason why the vacuum of the vacuum adapter chamber is secondly carried out as described above is to prevent the vacuum adapter chamber from suddenly evacuating because the substrate in the chamber may be distorted or flowed.

When the vacuum adhering chamber 10 reaches the vacuum in a predetermined state, the upper and lower stages 15 and 16 are each of the first and second glass substrates 11 and 13 by an electrostatic charge (ESC) method. ) Is fixed (35S), and the substrate receiver is placed in its original position (36S).

Here, the electrostatic adsorption method includes at least two or more plate electrodes formed on the stage to supply negative / positive DC power to the plate electrodes and to adsorb them. That is, when a positive or negative voltage is applied to each of the flat plate electrodes, a negative or positive charge is induced on the stage and a conductive layer (a transparent electrode such as a common electrode or a pixel electrode is formed) is formed on the glass substrate by those charges. Therefore, the substrate is adsorbed by the Coulomb force generated between the conductive layer and the stage. At this time, a voltage of about 0.1 to 1 KV is applied when the surface on which the conductive layer of the substrate is formed is located on the stage side, and 3 to 4 KV when a surface on which the conductive layer of the substrate is formed is located on the side opposite to the stage. do. Here, an elastic sheet may be formed on the upper stage.

As shown in FIG. 3C, the first glass substrate 11 and the first glass substrate 11 and 13 are lowered by lowering the upper stage 15 while the two glass substrates 11 and 13 are loaded on the stages 15 and 16 by electrostatic adsorption. 2 is pressed in order to adhere the glass substrate 13 (37S). At this time, in the pressing method, the upper stage 15 or the lower stage 16 is moved in the vertical direction to press the two substrates, and at this time, the moving speed and the pressure of the stage are varied and pressed. That is, when the liquid crystal 12 of the 1st glass substrate 11 and the 2nd glass substrate 13 contact, or the real material 14 of the 1st glass substrate 11 and the 2nd glass substrate 13 is contacted, The stage is moved at a constant speed or constant pressure up to a point in time, and the pressure is gradually increased gradually from the point of contact to the desired final pressure. That is, the load cell is installed on the axis of the moving stage to recognize the point of contact, and the two glasses at a pressure of 0.1 ton at the time of contact, 0.3 ton at the middle stage, 0.4 ton at the last stage, and 0.5 ton at the final stage. The substrates 11 and 13 are bonded together (see FIG. 3D).

At this time, the upper stage presses the substrate by one axis, but may be installed so that each axis is equipped with a separate load cell (device for measuring pressure) by installing a plurality of axes to press independently on each axis. have. Therefore, when the lower stage and the upper stage are not horizontally aligned and the materials are not uniformly bonded, the shafts of the corresponding portions may be pressed at a relatively higher pressure or at a lower pressure so that the materials may be uniformly bonded.

When the bonding of the two substrates is completed by pressing, the adsorption is stopped by the electrostatic adsorption method (ESC off), and then the upper stage 15 is raised by raising the upper stage 15 as shown in FIG. 3E. Separate from the glass substrates 11 and 13.

Then, the bonded substrate is unloaded (38S). That is, when the bonding is completed, the upper stage 15 is raised and unloads the bonded first and second glass substrates 11 and 13 using the loader of the robot, or the bonded first and second glass substrates. The loader 11 of the robot unloads from the upper stage 16 after the upper stage 15 is lifted up by the upper stage 15.

At this time, in order to shorten the process time, one of the first glass substrate 11 or the second glass substrate 13 to be subjected to the next bonding process is loaded on the stage and the unbonded first and second glass substrates are unloaded. Can be. That is, a second substrate to be bonded next is placed on the upper stage 15 using a loader of a robot so that the upper stage fixes the second substrate by vacuum adsorption, and then on the lower stage 16. Unloading the bonded first and second substrates, or the upper stage 15 adsorbs the first and second glass substrates 11 and 13 to which the upper and lower substrates are bonded, and the loader of the robot moves to the first bonding process. After loading the glass substrate 11 on the lower stage, the bonded first and second glass substrates may be unloaded.

In the above, the liquid crystal spreading process of spreading the liquid crystals of the bonded substrates to the real side after bonding the substrates and before unloading may be further performed. Alternatively, after the unloading process is completed, if the liquid crystal does not spread, the liquid crystal spreading process may be further performed in order to spread the liquid crystal evenly toward the actual surface. At this time, the liquid crystal spreading step is performed for 10 minutes or more, and the liquid crystal spreading step can be performed in air or in vacuum.

The manufacturing method of the liquid crystal display device according to the present invention as described above has the following effects.

First, since a liquid crystal is dropped on the first substrate and a substance is formed on the second substrate, the process time before joining the two substrates is shortened, thereby improving productivity.

Second, since the liquid crystal is dropped on the first substrate and the real and Ag dots are applied on the second substrate, the process of the first substrate and the second substrate is balanced, so that the production line can be efficiently operated. .

Third, since the liquid crystal is dropped on the first substrate and the real and Ag dots are applied on the second substrate, the substrate is coated with the actual material in the cleaning equipment (USC) immediately before the bonding, so that the actual material is contaminated from particles. Can be prevented as much as possible.

Fourth, since the substrate receiver is positioned below the substrate and the adapter chamber is made in a vacuum state, the substrate adsorbed on the upper stage can be prevented from falling and the substrate is damaged.

Fifth, since the two substrates are bonded while recognizing the time point at which the two substrates are in contact with each other, the damage that the dropped liquid crystal may affect the alignment layer may be minimized.

Sixth, since the upper stage presses the substrate by a plurality of shafts that can press independently on each axis, when the lower stage and the upper stage are not horizontal to each other and the material is not uniformly bonded, It may be pressurized to a higher pressure or to a lower pressure so that the substance can be uniformly bonded.

Seventh, since vacuuming the adjoiner chamber over a second time, it is possible to prevent the chamber from suddenly vacuuming, thereby preventing the substrate from breaking and flowing due to a sudden vacuum.

Eighth, process time can be reduced by loading and unloading simultaneously.

Ninth, since the liquid crystal spreading step is performed, the process time of the liquid crystal display device can be shortened.

Claims (12)

A first step of loading the first substrate onto which the liquid crystal is loaded and the second substrate on which the substance is formed into the combiner chamber; Evacuating the adhering chamber; A third step of bonding the first and second substrates at variable pressures; And, And a fourth step of unloading the bonded first and second substrates. The method of claim 1, The first step includes adsorbing a first substrate to a lower stage in the adhering chamber and adsorbing a second substrate to an upper stage; Positioning the substrate receiver of the combiner under a second substrate fixed to the upper stage; And fixing the first and second substrates to each of the stages by an electrostatic adsorption method. The method of claim 2, In the second step of vacuuming the adapter chamber, the first substrate and the second substrate are adsorbed to the lower stage and the upper stage in the adapter chamber, respectively, and then vacuumed first, and the substrate receiver is fixed to the upper stage. And a second vacuum after the second substrate is placed below the second substrate. The method of claim 2, The liquid crystal display device of claim 1, wherein a liquid crystal is added to the first substrate and a substance is also applied. The method of claim 1, And a second step of vacuuming the adapter chamber is carried out in two vacuums. The method of claim 1, In the fourth step of unloading, at least one of the first substrate and the second substrate to be subjected to the next bonding process is loaded onto the upper or lower stage and the unbonded substrate is manufactured. Way. The method of claim 1, The fourth step of unloading includes the steps of: adsorbing and raising the first and second substrates to which the upper stage is bonded; And unloading the bonded first and second substrates. The method of claim 1, The fourth step of unloading includes the steps of: adsorbing and raising the first and second substrates to which the upper stage is bonded; Loading the first substrate on which the next bonding process is to be performed to the lower stage, And unloading the bonded first and second substrates. The method of claim 1, The fourth step of unloading may include loading a second substrate on the upper stage where a next bonding process is to be performed; And unloading the bonded first and second substrates from the lower stage. The method of claim 1, And a liquid crystal spreading step for spreading the liquid crystal toward the actual surface before the fourth step of unloading. The method of claim 1, And a liquid crystal spreading step for spreading the liquid crystal toward the real part after the fourth step of unloading. The method of claim 11 or 12, The liquid crystal spreading process is performed for at least 10 minutes or more.