KR20060065167A - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

Disclosed are a liquid crystal display device and a method of manufacturing the same, which can prevent touch and gravity failure.

Since it is difficult to fill an appropriate amount of liquid crystal in the past, touch failure or gravity failure occurred.

The present invention forms a seal pattern having a protrusion, and when cutting the substrate after the liquid crystal is filled, by cutting the protrusion to make the internal pressure of the liquid crystal panel equal to the external atmospheric pressure, thereby preventing poor touch or poor gravity Product reliability can be improved.

Poor touch, poor gravity, liquid crystal, protrusions, liquid crystal display

Description

Liquid crystal display device and manufacturing method thereof             

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

2 is a view schematically showing a general liquid crystal panel.

3A to 3E are diagrams sequentially illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention.

Figure 4 is a view showing a state in which the internal pressure of the liquid crystal panel is adjusted by the manufacturing process of Figure 3d.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a manufacturing method thereof capable of preventing touch and gravity failure.

In general, a flat panel display includes a plasma display panel, a field emission display, a light emitting diode, and a liquid crystal display device. .

Among these, the liquid crystal display is widely used because of its thinness, light weight and low power consumption. The liquid crystal display displays a predetermined image by controlling the light transmittance of the liquid crystals by displacing the liquid crystals between the two substrates according to the electric field according to the digital data signal. Such a liquid crystal display device includes a liquid crystal panel for displaying an image and a driving unit for applying a driving signal to the liquid crystal panel. The liquid crystal panel includes first and second substrates bonded to each other with a predetermined space, and a liquid crystal filled between the first and second substrates. Spacers are formed therein to maintain a constant space between the first and second substrates. The liquid crystal panel is completed by pressing the first and second substrates together with a seal pattern formed of a sealant applied along the outer edges of the first and second substrates. A liquid crystal injection hole may or may not be formed in the seal pattern depending on the method of filling the liquid crystal.

The liquid crystal filling method and the liquid crystal dropping method include filling the liquid crystal into the first and second substrates.

In the liquid crystal injection method, when the liquid crystal injection hole of the liquid crystal panel bonded to have an internal space by the seal pattern having the liquid crystal injection hole is immersed in the liquid crystal liquid, the liquid crystal is injected into the internal space of the liquid crystal panel by osmotic pressure. Subsequently, the liquid crystal injection hole is sealed with a sealing material.                         

However, when the liquid crystal panel is completed by the liquid crystal injection method, productivity is reduced because a lot of time is required for the liquid crystal injection. In particular, as the area of the liquid crystal panel increases, the amount of liquid crystal for injecting the liquid crystal rapidly increases, which takes more time.

In addition, since the liquid crystal is injected only through the liquid crystal injection hole, the liquid crystal is not sufficiently injected into the deep inside of the liquid crystal panel, which causes a defect.

In addition, the process is complicated and process equipment for each process is required, which increases process time or process cost.

Therefore, in recent years, a liquid crystal dropping method for reducing a process time and a process cost in a liquid crystal panel having a large area has been studied.

Such a liquid crystal dropping method is well known and will be described schematically below.

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

As shown in FIG. 1A, a seal pattern 2 is formed using a seal material along an edge of the first substrate 1 on which the thin film transistor array is formed.

As shown in FIG. 1B, the liquid crystal 3 is dropped into the seal pattern 2 (part of the thin film transistor array). In this case, the seal pattern 2 is formed without a liquid crystal injection hole.

As shown in FIG. 1C, the second substrate 4 on which the color filter array is formed is aligned with the first substrate 1.                         

As shown in FIG. 1D, the second substrate 4 is moved in the vertical direction to be in contact with the first substrate 1, and then pressed to bond the first and second substrates 1 and 4 to each other.

As shown in FIG. 1E, ultraviolet rays are irradiated onto the bonded first and second substrates 1 and 4 using an ultraviolet illuminator 5 to cure the seal pattern 2 to cure the liquid crystal panel 6. To complete).

As described above, when the liquid crystal panel 6 is manufactured by the liquid crystal dropping method, the process is simplified, the cost is low, and the process time is reduced. Therefore, in the case of a liquid crystal panel having a large area, the liquid crystal dropping method is mainly used. It is used.

However, even when a liquid crystal panel is manufactured by using the liquid crystal dropping method, it is difficult to drop the optimum amount of liquid crystal onto the liquid crystal panel when the area of the liquid crystal panel is enlarged.

2 is a view schematically showing a general liquid crystal panel.

As shown in FIG. 2, the liquid crystal panel 6 includes a first substrate 1, a second substrate 4, and a liquid crystal 3 filled between the first and second substrates 1 and 4. do. The first multi-layer 8 is formed on the first substrate 1, and the second multi-layer 7 is formed on the second substrate 4. The first multi layer 8 may include a gate line, a gate insulating layer, a data line, a pixel electrode, and a protective layer. The second multi layer 7 may include a color filter, a black matrix, an overcoat layer, and a common electrode. A seal pattern 2 for bonding and supporting is formed along edges of the first and second substrates 1 and 4. Although not shown, a plurality of spacers are formed in the liquid crystal panel 6 to maintain a constant gap between the first and second substrates 1 and 4.

In this way, a plurality of multi-layers 8, 7 are formed in the liquid crystal panel 6, and each layer is formed in accordance with each mask process. In this case, each layer having a desired thickness is formed according to each mask process set.

However, even if each mask process is set correctly, if the mask processes are repeatedly performed to continuously generate liquid crystal panels, the process is performed in an incorrect setting state. Accordingly, each layer formed by each mask process is not formed to a desired thickness. That is, multiple layers having different thicknesses are formed for each liquid crystal panel. Of course, the thickness of the seal pattern and the spacers is also different for each liquid crystal panel for the same reason as described above. Thus, as the thicknesses of the multi-layers, seal patterns, or spacers are different for each liquid crystal panel, the internal space of each liquid crystal panel is also different.

As described above, the liquid crystal is dropped into the inner space of the liquid crystal panels having different thicknesses of the multi layers, the seal pattern, or the spacer. In this case, the optimum amount of liquid crystal to be dropped for the same liquid crystal panels is determined. If the predetermined amount of liquid crystal is dropped into liquid crystal panels having different internal spaces, the amount of liquid crystal may be insufficient for each liquid crystal panel, or may overflow. That is, when the internal space of the liquid crystal panel becomes large, the liquid crystal is insufficient even if the predetermined liquid crystal amount is dropped. On the contrary, when the internal space of the liquid crystal panel becomes small, the liquid crystal panel overflows due to the predetermined liquid crystal amount.

As described above, as the amount of liquid crystal is insufficient or overflows, a variation occurs in the internal pressure of each liquid crystal panel, and a touch defect or a gravity defect occurs due to such a deviation.

The touch failure occurs when the amount of liquid crystal is insufficient, and when the liquid crystal panel is touched, unevenness occurs along the touched portion. Gravity failure occurs when the amount of liquid crystal overflows. When the liquid crystal panel is placed vertically, the surplus liquid crystal is oriented downward by gravity and the lower portion becomes white.

It is an object of the present invention to provide a liquid crystal display device and a method of manufacturing the same, which can prevent a touch failure or a gravity failure by temporarily exposing a liquid crystal panel filled with liquid crystals to atmospheric pressure.

According to a preferred embodiment of the present invention for achieving the above object, a liquid crystal display device, the first substrate; A second substrate; A liquid crystal filled between the first and second substrates; And a seal pattern having a protrusion which is joined to the first and second substrates and is open to adjust the internal pressure of the first and second substrates to an external atmospheric pressure.

According to another preferred embodiment of the present invention, a method of manufacturing a liquid crystal display device may include forming a seal pattern having a protrusion on a first substrate; Dropping liquid crystal onto the first substrate; Bonding the first substrate to the second substrate with the seal pattern therebetween; Cutting the protrusion to adjust internal pressure between the bonded first and second substrates; And sealing the cut protrusion.

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

3A to 3E are diagrams sequentially illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIG. 3A, the seal pattern 22 is formed on the first substrate 21 on which the thin film transistor array is formed using a seal material.

The seal pattern 22 may be an ultraviolet curable resin. Although a thermosetting resin may also be used, the seal pattern having a thermosetting resin may contaminate the liquid crystal because it is vulnerable to heat and melts during the seal pattern curing process, which is a post process. Accordingly, the seal pattern 22 of the present invention preferably uses an ultraviolet curable resin.

The first substrate 21 includes gate lines and data lines, and a pixel region is defined by the intersection of the gate lines and the data lines. A thin film transistor and a pixel electrode are formed in the pixel region. The thin film transistor includes a gate electrode, a semiconductor layer (including a channel layer and an ohmic contact layer), and a source / drain electrode. The gate electrode is connected to the gate line, the source electrode is connected to the data line, and the drain electrode is connected to the pixel electrode.

The seal pattern 22 may be formed by a dispenser method or a screen printing method using a screen mask. The seal pattern 22 is formed along an outer edge of the first substrate 21.

The display area and the non-display area are divided by the seal pattern 22. That is, the inside of the seal pattern 22 is a display area, and the outside is a non-display area. Pads for connecting to the driving unit generating the driving signal should be formed on the left and upper edges of the first substrate 21, so that the seal pattern 22 has a margin more than the right and lower edges of the first substrate 21. ) May be formed.

The seal pattern 22 may correspond to an edge region of the second substrate 25 that is later bonded to the first substrate 21. The seal pattern 22 adheres the first and second substrates 21 and 25 and prevents the liquid crystal from flowing out.

The seal pattern 22 has a protrusion 23 protruding laterally in a predetermined region. Although only one protrusion 23 is illustrated in FIG. 3A, a plurality of protrusions 23 may be formed as necessary. The protrusion 23 is to be cut in part in a later process, which will be described later in detail.

As shown in FIG. 3B, when the seal pattern 22 is formed on the first substrate 21, the liquid crystal 24 set in the seal pattern 22 of the first substrate 21, that is, the display area. Dropping

The total amount of the liquid crystal 24 to be dropped may be preset according to the area of the substrate. The liquid crystal 24 may be dropped in a droplet form.

As shown in FIG. 3C, the second substrate 25 having the color filter array is aligned with the first substrate 21, and then the second substrate 25 is pressed to press the first and second substrates ( 21, 25).

In this case, the liquid crystal 24 is uniformly formed on the entire surface of the display area while being compressed between the first substrate 21 and the second substrate 25. In addition, while the upper portion of the seal pattern 22 is also compressed by pressing the second substrate 25, the thickness of the seal pattern 22 is adjusted.

Since the pad for connecting to the driving unit is formed on the first substrate 21, it is larger than the area of the second substrate 25. The seal pattern 22 is in contact with the outer edge of the second substrate 25. Therefore, a display area is defined by the first and second substrates 21 and 25 inside the seal pattern 22 and by the first substrate 21 outside the seal pattern 22. The non-display area is defined.

The second substrate 25 is provided with color filters at positions corresponding to the pixel region, a black matrix is formed between the color filters, and a common electrode is formed on the color filters and the black matrix. In addition, an overcoat layer may be further formed on the color filters and the black matrix before the common electrode is formed to compensate for the thickness variation between the color filters and the black matrix formed on the same plane.

Although not shown in FIG. 3C, ultraviolet light may be irradiated onto the bonded first and second substrates 21 and 25 by using an ultraviolet lighting device to cure the seal pattern 22. By hardening the seal pattern 22 to bond the first and second substrates 21 and 25 more firmly, and by the hardened seal pattern 22, the first and second substrates 21 and 25. The interval between them can be kept constant.

Although not shown in FIGS. 3A to 3C, a plurality of first substrates 21 may be formed in a disc.

In recent years, in terms of process simplification and process cost reduction, a multifaceted technique has been proposed for producing several substrates from a single disc. Using this multi-faceted technique, a plurality of first substrates may be formed on one disc. The plurality of first substrates are joined to the plurality of second substrates correspondingly cut in advance, and then are cut into respective first substrates.

As shown in FIG. 3D, when cutting the first substrate 21, a part of the protrusion 23 of the seal pattern 22 is simultaneously cut and opened.

The protrusion 23 is formed to protrude outward of at least the second substrate 25. Accordingly, the protrusion 23 may be simultaneously cut when the first substrate 21 having a larger area than the second substrate 25 is cut.

In the previous process, a seal pattern 22 is formed between the bonded first and second substrates 21 and 25, and the liquid crystal 24 is filled in the seal pattern 22. In this case, as shown in FIG. 4, when a part of the protrusion 23 of the seal pattern 22 is cut off, the cut protrusion 23 causes the gap between the first and second substrates 21 and 25. The inside of the will be in circulation with the outside. That is, when the first and second substrates 21 and 25 are pressed together and adhered to each other, the internal pressure between the first and second substrates 21 and 25 becomes low. When a part of the protrusion 23 of the seal pattern 22 is cut, the internal pressure between the first and second substrates 21 and 25 is controlled by an external atmospheric pressure.

The external atmospheric pressure is higher than the internal pressure between the first and second substrates 21 and 25. The external atmospheric pressure flows into the interior between the first and second substrates 21 and 25 through the cut protrusion 23, so that the internal pressure between the first and second substrates 21 and 25 is increased. As the external pressure is controlled, the internal pressure between the first and second substrates 21 and 25 becomes atmospheric. In this case, the opening time of the protrusion 23 may be appropriately adjusted. An important point is that the internal pressure between the first and second substrates 21 and 25 should be opened until the same as the external atmospheric pressure. will be. Since this may vary depending on the area of the liquid crystal panel, it may be optimized through experiments according to the area of each liquid crystal panel.

However, if the protrusion 23 is opened for a long time, the process time is increased, and thus, between the first and second substrates 21 and 25 in the shortest time by increasing the number of appropriate protrusions. Its internal pressure must be designed so that it can be adjusted to the external atmospheric pressure. Accordingly, as the internal pressure between the first and second substrates 21 and 25 becomes equal to the atmospheric pressure, touch failure or gravity failure can be prevented.

In particular, when the amount of liquid crystal is insufficient, due to the internal pressure between the first and second substrates 21 and 25, the liquid crystal 24 is interposed between the first and second substrates 21 and 25 at a high pressure. Will come into contact. In this case, when the first and second substrates 21 and 25 are touched, a touch failure occurs in which stain occurs along the touched portion.

As in the present invention, when the internal pressure between the first and second substrates 21 and 25 is equal to the external atmospheric pressure, the internal pressure between the first and second substrates 21 and 25 is reduced. It can be alleviated to prevent touch failure.

As described above, the liquid crystal panel having the first and second substrates 21 and 25 may have various layers (eg, a seal pattern 22, a spacer, a gate line, a data line, a pixel electrode, a color filter, a common electrode, etc.). ), And each of these layers is hardly formed to the same thickness in every liquid crystal panel. As a result, deviation occurs in the internal space of each liquid crystal panel. In this case, when each liquid crystal panel is filled with a predetermined liquid crystal amount, the liquid crystal amount may be excessive or insufficient depending on each liquid crystal panel. As a result, a touch failure or a gravity failure tends to occur in the related art.

In the present invention, after joining the first and second substrates 21 and 25, a part of the protrusion 23 of the seal pattern 22 is cut, so that the interior between the first and second substrates 21 and 25 is cut. The pressure can be adjusted to the external atmospheric pressure to prevent touch failure or gravity failure.

Meanwhile, as shown in FIG. 3E, when the internal pressure between the first and second substrates 21 and 25 is equal to the external atmospheric pressure, the protrusion 23 of the cut seal pattern 22 is sealed. Seal using (26). As such, the liquid crystal panel is completed by sealing the protrusion 23 of the seal pattern 22 with the sealing material 26.

Accordingly, the liquid crystal panel includes a liquid crystal filled between the first substrate 21 on which the thin film transistor array is formed, the second substrate 25 on which the color filter array is formed, and the first and second substrates 21 and 25. And a protrusion 23 which is open to bond the first and second substrates 21 and 25 to each other and to adjust the internal pressure of the first and second substrates 21 and 25 to an external atmospheric pressure. The seal pattern 22 which has is provided.                     

At least one protrusion may be provided on the seal pattern 22. As described above, when one or more protrusions are provided, the internal pressures of the first and second substrates 21 and 25 may be adjusted to the external atmospheric pressure more easily by simultaneously opening each of the protrusions.

The protrusion 23 may be partially cut at the same time when the first substrate 21 is cut. As described above, a plurality of first substrates 21 are formed on the original plate by a multi-faceted technique, and when forming each of the first substrates 21, part of the protrusions 23 can be simultaneously cut.

As such, when the first substrate 21 is cut, a portion of the protrusion 23 is also cut at the same time, so that an additional process is not required, and thus it may be economical in terms of process cost.

As described above, according to the present invention, the internal pressure between the first and second substrates is equal to the external atmospheric pressure by cutting a part of the protrusions in the seal pattern having the protrusions for joining the first and second substrates. To prevent poor touch or poor gravity.

Therefore, product reliability can be improved by completing the liquid crystal display panel without defect.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present 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 (10)

A first substrate; A second substrate; A liquid crystal filled between the first and second substrates; And A seal pattern having a protrusion which bonds the first and second substrates and is openable to adjust the internal pressure of the first and second substrates to an external atmospheric pressure Liquid crystal display comprising a. The liquid crystal display device of claim 1, wherein the seal pattern has at least one protrusion. The liquid crystal display device according to claim 1, wherein when the first substrate is cut from the disc, the protrusions are cut at the same time. The liquid crystal display device according to claim 1, wherein an internal pressure between the first and second substrates is equal to an external atmospheric pressure by the cut protrusion. The liquid crystal display of claim 1, wherein the protrusion protrudes in the lateral direction. Forming a seal pattern having protrusions on the first substrate; Dropping liquid crystal onto the first substrate; Bonding the first substrate to the second substrate with the seal pattern therebetween; Cutting the protrusion to adjust internal pressure between the bonded first and second substrates; And Sealing the cut protrusion Method of manufacturing a liquid crystal display device comprising a. The method of claim 6, wherein the seal pattern has at least one protrusion. 7. A method according to claim 6, wherein when the first substrate is cut from the disc, the protrusions are cut at the same time. The method of claim 6, wherein an internal pressure between the first and second substrates is equal to an external atmospheric pressure by the cut protrusions. The method of claim 6, wherein the protrusion protrudes in the lateral direction.

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