KR102044418B1

KR102044418B1 - Method of fabricating lightweight and thin liquid crystal display device

Info

Publication number: KR102044418B1
Application number: KR1020120126902A
Authority: KR
Inventors: 홍기상; 황영근; 오재영; 이재원; 김진경
Original assignee: 엘지디스플레이 주식회사
Priority date: 2012-11-09
Filing date: 2012-11-09
Publication date: 2019-11-13
Also published as: KR20140060148A

Abstract

In the method of manufacturing a light weight thin liquid crystal display device according to the present invention, when an auxiliary substrate is used to process a thin glass substrate, HF or plasma treatment or an inorganic insulating film or a transparent oxide film is deposited on the surface of the auxiliary substrate to obtain surface roughness. In order to easily separate the auxiliary substrate from the liquid crystal panel in which the process is completed and bonded by increasing the surface roughness, the first and second auxiliary substrates and the thin first and second mother substrates are provided. Doing; Depositing a transparent oxide film on surfaces of the first and second auxiliary substrates; Crystallizing the transparent oxide film by performing heat treatment on the first and second auxiliary substrates on which the transparent oxide film is deposited; Attaching first and second auxiliary substrates on which the crystallized transparent oxide film is formed to each of the thin first and second mother substrates; Performing a color filter process on the first mother substrate to which the first auxiliary substrate is attached; Performing an array process on a second mother substrate to which the second auxiliary substrate is attached; Bonding the second mother substrate subjected to the array process and the first mother substrate subjected to the color filter process; And separating the first and second auxiliary substrates from the bonded first and second mother substrates.

Description

Lightweight thin liquid crystal display device manufacturing method {METHOD OF FABRICATING LIGHTWEIGHT AND THIN LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a manufacturing method of a liquid crystal display device, and more particularly, to a manufacturing method of a light weight thin liquid crystal display device.

In recent years, as the society enters a full-scale information age, the display field for processing and displaying a large amount of information has been rapidly developed, and recently, a thin film transistor (Thin) having excellent performance of light weight, thinness, and low power consumption has recently been developed. Film Transistor (TFT) Liquid Crystal Display (LCD) has been developed to replace the existing cathode ray tube (CRT).

The liquid crystal display device is largely composed of a color filter substrate and an array substrate, and a liquid crystal layer formed between the color filter substrate and the array substrate.

The color filter substrate distinguishes between a color filter composed of red (R), green (G), and blue (B) colors and the sub color filter and transmits the liquid crystal layer. It consists of a black matrix that blocks light and a transparent common electrode that applies a voltage to the liquid crystal layer.

The array substrate has gate lines and data lines arranged vertically and horizontally to define pixel regions. In this case, a thin film transistor as a switching element is formed in an intersection region of the gate line and the data line, and a pixel electrode is formed in each pixel region.

The color filter substrate and the array substrate configured as described above are joined to face each other by sealants formed on the outer side of the image display area to form a liquid crystal panel. The combination of the color filter substrate and the array substrate is the color filter substrate or the array substrate. It is made through a bonding key formed on the substrate.

Since the liquid crystal display is particularly used in portable electronic devices, it is possible to improve the portability of the electronic device only by reducing its size and weight. Moreover, in recent years, as the large-area liquid crystal display device is manufactured, the demand for such a light weight and a thin film becomes more intense.

There may be various ways to reduce the thickness or weight of the liquid crystal display, but there are limitations in reducing the essential components of the liquid crystal display in terms of its structure and current technology. Moreover, since these essential components are small in weight, it is very difficult to reduce the weight or weight of the entire liquid crystal display by reducing the weight of these essential components.

Therefore, the method of reducing the thickness and weight of the liquid crystal display device by reducing the thickness of the color filter substrate and the array substrate constituting the liquid crystal panel has been actively researched. The substrate is bent or broken during the process.

In order to solve this problem, a method of attaching an auxiliary substrate to a thin glass substrate and proceeding a process and then separating the thin glass substrate and the auxiliary substrate after the process is completed has been attempted. In this case, an adhesive is applied by attaching the auxiliary substrate to the thin glass substrate. There is a method of bonding directly in the air without using or using a medium.

In this case, the method of using the adhesive is not easy to remove because the adhesive should be removed when the auxiliary substrate is separated, or the adhesive strength of the adhesive should be reduced enough to separate the auxiliary substrate.

The method of direct bonding in the atmosphere is mainly caused by the OH-functional group adsorbed on the surface of the hydrophilic glass, and after completion of the process as the hydrogen bond formed by the OH-functional period attraction force is changed to covalent bond by high temperature during the process. The adhesion between the boards is increased, so separation is not easy. That is, in the method of directly bonding between substrates at atmospheric pressure, OH-functional groups are adsorbed on the surface of the hydrophilic glass, and hydrogen bonding is formed at the bonding interface due to the attraction of the OH-functional period. Such hydrogen bonds form covalent bonds at high temperatures of about 300 ° C., thereby increasing the bonding strength between the substrates.

In addition, there is a problem that the recycling efficiency of the auxiliary substrate is reduced due to damage of the surface of the auxiliary substrate by the chemical during the process. In other words, in order to increase the efficiency of using the auxiliary substrate, the separated auxiliary substrate should be recycled after the completion of the process, and the edge surface of the auxiliary substrate may be exposed to the outside and be damaged by chemicals during the process, making it difficult to recycle.

The present invention is to solve the above problems, in the case of using the auxiliary substrate for the progress of the process of the thin glass substrate, a light weight that can easily separate the auxiliary substrate from the liquid crystal panel of the cell state bonded to the process is completed An object of the present invention is to provide a method of manufacturing a thin liquid crystal display device.

Another object of the present invention is to provide a method for manufacturing a lightweight thin liquid crystal display device which can prevent breakage of a thin glass substrate when the auxiliary substrate is separated.

It is another object of the present invention to provide a method for manufacturing a lightweight thin liquid crystal display device which can prevent damage to the surface of an auxiliary substrate by chemicals during the process.

Other objects and features of the present invention will be described in the configuration and claims of the invention described below.

In order to achieve the above object, a method for manufacturing a lightweight thin liquid crystal display device of the present invention comprises the steps of providing a first, a second auxiliary substrate and a thin first, second mother substrate; Depositing a transparent oxide film on surfaces of the first and second auxiliary substrates; Crystallizing the transparent oxide film by performing heat treatment on the first and second auxiliary substrates on which the transparent oxide film is deposited; Attaching first and second auxiliary substrates on which the crystallized transparent oxide film is formed to each of the thin first and second mother substrates; Performing a color filter process on the first mother substrate to which the first auxiliary substrate is attached; Performing an array process on a second mother substrate to which the second auxiliary substrate is attached; Bonding the second mother substrate subjected to the array process and the first mother substrate subjected to the color filter process; And separating the first and second auxiliary substrates from the bonded first and second mother substrates.

In this case, the transparent oxide film is characterized in that it comprises indium tin oxide (ITO).

At this time, the ITO is characterized in that the content of SnO ₂ has a value of 0 to 15%.

The transparent oxide film is characterized in that the deposition to 50 ~ 1000Å thickness.

The transparent oxide film is characterized in that the deposition at a temperature of room temperature ~ 400 ℃.

The heat treatment is characterized in that proceeding at a temperature of 100 ℃ ~ 500 ℃.

The crystallized transparent oxide film is characterized in that the surface roughness has a value of 0.25nm ~ 10.0nm.

And separating the first and second auxiliary substrates from the bonded first and second mother substrates, and then cutting and cutting the first and second auxiliary substrates into a plurality of liquid crystal panels.

In addition, another method for manufacturing a lightweight thin liquid crystal display device of the present invention includes the steps of providing a first and a second auxiliary substrate and a thin first and second mother substrate; HF or plasma treatment on the surface of the first and second auxiliary substrates; Attaching the HF or plasma treated first and second auxiliary substrates to the thin first and second mother substrates, respectively; Performing a color filter process on the first mother substrate to which the first auxiliary substrate is attached; Performing an array process on a second mother substrate to which the second auxiliary substrate is attached; Bonding the second mother substrate subjected to the array process and the first mother substrate subjected to the color filter process; And separating the first and second auxiliary substrates from the bonded first and second mother substrates.

At this time, the first and second sub-substrate surface is treated with HF or dry etching using a fluorine gas of CF ₄ , C ₃ F ₈ , NH ₃ or SF ₆ characterized in that to proceed.

In this case, the first and second auxiliary substrates are characterized in that the HF treatment or dry etching using fluorine gas so that the surface roughness has a value of 0.25nm ~ 2.0nm.

N ₂ gas plasma treatment on the surface of the first and second auxiliary substrates.

In addition, another method for manufacturing a lightweight thin liquid crystal display device of the present invention comprises the steps of providing a first, a second auxiliary substrate and a thin first, second mother substrate; Depositing an inorganic insulating film of a silicon oxide film or a silicon nitride film on surfaces of the first and second auxiliary substrates; Attaching first and second auxiliary substrates on which the inorganic insulating layer is deposited to each of the thin first and second mother substrates; Performing a color filter process on the first mother substrate to which the first auxiliary substrate is attached; Performing an array process on a second mother substrate to which the second auxiliary substrate is attached; Bonding the second mother substrate subjected to the array process and the first mother substrate subjected to the color filter process; And separating the first and second auxiliary substrates from the bonded first and second mother substrates.

At this time, the inorganic insulating film is characterized in that the deposition to 100 ~ 1000Å thickness.

As described above, in the method of manufacturing a light weight thin liquid crystal display device according to the present invention, when the auxiliary substrate is used to process the thin glass substrate, the surface of the auxiliary substrate is subjected to HF or plasma treatment, or an inorganic insulating film or a transparent oxide film. By depositing and increasing the surface roughness (surface roughness) is completed the process can be easily separated from the auxiliary substrate from the liquid crystal panel of the bonded cell state. Accordingly, the cost and time used for the separation of the auxiliary substrate can be reduced, and the breakage of the substrate can be prevented during the separation of the auxiliary substrate, thereby improving the yield.

In addition, the method for manufacturing a lightweight thin liquid crystal display device according to the present invention can recycle the separated auxiliary substrate, thereby providing an effect of increasing the utility of the auxiliary substrate.

In addition, the method for manufacturing a light weight thin liquid crystal display device according to the present invention can implement a light weight thin liquid crystal display device using such a thin glass substrate, which can reduce the thickness or weight of a television or monitor model and a portable electronic device. Provide effect.

1A to 1D are perspective views sequentially illustrating a part of a process of a method of manufacturing a lightweight thin liquid crystal display device according to a first embodiment of the present invention.
2A to 2D are perspective views sequentially illustrating a part of processes of a method of manufacturing a lightweight thin liquid crystal display device according to a second embodiment of the present invention.
3A to 3D are perspective views sequentially illustrating a part of processes of a method of manufacturing a lightweight thin liquid crystal display device according to a third embodiment of the present invention.
4A to 4E are perspective views sequentially illustrating a part of processes of a method of manufacturing a lightweight thin liquid crystal display device according to a fourth embodiment of the present invention.
5A and 5B are photographs showing, for example, a surface of an auxiliary substrate separated from a liquid crystal panel.
6 is a flowchart schematically illustrating a method of manufacturing a lightweight thin liquid crystal display device according to the present invention;
7A to 7G are perspective views sequentially illustrating a method for manufacturing a lightweight thin liquid crystal display device according to the present invention.

Recently, as the use of liquid crystal display devices has been diversified and design aspects have been emphasized, interest in lightweight thin liquid crystal display devices has also increased, and interest in thinning substrates, which occupies the largest portion of the thickness of liquid crystal panels, has also increased. In addition, in 3D or touch panels, a retarder or a touch function protective substrate is added to the liquid crystal panel, thereby increasing the demand for thinning. However, in the case of thin substrates, there is a limitation in the process progress due to weakening of physical properties such as bending and rigidity.

In order to solve this problem, a method of separating the thin glass substrate and the auxiliary substrate after the process is completed by attaching the auxiliary substrate to the thin glass substrate and the process is completed, in particular, in the present invention, the vacuum force, van der Waals force (van The process is performed by attaching an auxiliary substrate to a thin glass substrate using der Waals' force, electrostatic force, or molecular bonding, and performing HF or plasma treatment or depositing an inorganic insulating film or a transparent oxide film on the surface of the auxiliary substrate. It is characterized in that the auxiliary substrate is easily separated from the liquid crystal panel in the cell state in which the process is completed by mitigating the adhesion.

Hereinafter, with reference to the accompanying drawings it will be described in detail a preferred embodiment of a method for manufacturing a lightweight thin liquid crystal display device according to the present invention can be easily carried out by those skilled in the art.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

The manufacturing process of the liquid crystal display device may be classified into a driving element array process of forming a driving element on a lower array substrate, a color filter process of forming a color filter on an upper color filter substrate, and a cell process.

As described above, there are various factors that determine the thickness and weight of the liquid crystal display device. Among them, the color filter substrate or the array substrate made of glass is the heaviest component among other components of the liquid crystal display device. Therefore, in order to reduce the thickness or weight of the liquid crystal display device, it is most efficient to reduce the thickness or weight of the glass substrate.

As a method of reducing the thickness or weight of the glass substrate, there is a method of etching the glass substrate to reduce its thickness or using a thin glass substrate. The first method is to reduce the thickness by further glass etching process after the completion of the cell, there are disadvantages of the defects and cost increase during the etching process.

In the present invention, a thin glass substrate having a thickness of about 0.1t to 0.4t is used to perform an array process, a color filter process, and a cell process. In this case, the thin glass substrate is attached to an auxiliary substrate to perform a thin process. Minimize the influence of the bending of the glass substrate and characterized in that the thin glass substrate is not damaged during the movement. In this case, t means mm, and 0.1t means a thickness of 0.1mm and 0.4t means a thickness of 0.4mm. In the following description, mm is expressed as t for convenience of explanation.

That is, a thin glass substrate having a thickness of about 0.1t to 0.4t causes a large warpage when the glass substrate is put into a general liquid crystal display manufacturing line, which causes severe deflection of the substrate. When loading and unloading the unit process equipment, there is a problem that warpage occurs suddenly even by a small impact, so that the positional error occurs frequently. .

Accordingly, in the present invention, the auxiliary substrate is attached before the thin glass substrate of 0.1t to 0.4t is introduced into the manufacturing line, thereby generating the same or improved warpage as the glass substrate having a thickness of about 0.7t used for a general liquid crystal display device. It is characterized in that it is possible to prevent the occurrence of problems, such as the substrate sag during the movement or unit process by having a characteristic.

1A to 1D are perspective views sequentially illustrating a part of a process of a method of manufacturing a lightweight thin liquid crystal display device according to a first embodiment of the present invention, and showing, for example, a bonding and detaching process of a thin glass substrate and an auxiliary substrate. have.

1A to 1D illustrate the bonding strength between the auxiliary substrate and the thin glass substrate by increasing the surface roughness by treating HF on the front surface of the auxiliary substrate or by performing a dry etch using fluorine (F) gas. It is characterized in that to facilitate the desorption between the auxiliary substrate and the thin glass substrate.

As shown in FIG. 1A, the auxiliary substrate 110 having a thickness of about 0.3t to about 0.7t is prepared before the thin glass substrate having the thickness of 0.1t to 0.4t is introduced into the manufacturing process of the array process and the color filter process.

At this time, the present invention is not limited to the thickness of the thin glass substrate and the auxiliary substrate 110.

Next, as shown in FIG. 1B, HF is treated on the entire surface 111 of the auxiliary substrate 110 to facilitate separation of the auxiliary substrate 110, or CF ₄ , C ₃ F ₈ , NH ₃ , SF. Dry etching using fluorine gas such as ₆ is performed.

As such, when HF is processed on the surface 111 of the auxiliary substrate 110 or dry etching is performed using fluorine gas, fluorine is etched to the surface 111 of the auxiliary substrate 110 to increase surface roughness. The bonding force by contact with the thin glass substrate can be weakened.

At this time, the surface roughness of the auxiliary substrate 110 may have a value of 0.25nm ~ 5.0nm, preferably may have a value of 0.25nm ~ 2.0nm.

Next, as shown in Figure 1c, to the thin glass substrate 100 is attached to the auxiliary substrate 110, the above-described HF is processed or dry etching. In this case, the thin glass substrate 100 and the auxiliary substrate 110 may be bonded together when the glass substrate is used as the auxiliary substrate 110 by contacting the two substrates 100 and 110 in an atmospheric state. The bonding force between 100 and 110) may be estimated by vacuum force, van der Waals force, electrostatic force, or molecular bond.

The process panel in which the thin glass substrate 100 having a thickness of 0.1t to 0.4t and the auxiliary substrate 110 having a thickness of 0.3t to 0.7t are bonded to the thin glass substrate 100 constituting the same ) And the auxiliary substrate 110 are made of the same glass material, so that the expansion rate is the same according to the temperature change, there is no problem that warpage occurs due to the expansion rate difference during the unit process.

In addition, the thin glass substrate 100 itself has a thickness of 0.1t ~ 0.4t, but as the secondary substrate 110 is bonded to form a process panel, the occurrence of warpage is significantly reduced and the thickness of the general 0.7t The level of warpage of the glass substrate having a level of less than or equal to that of the glass substrate having a lower level does not cause any problem in proceeding the unit process for the liquid crystal display device.

In this case, the thin glass substrate 100 may be a large area mother substrate on which a plurality of color filter substrates are arranged for a color filter process or a large area mother substrate on which a plurality of array substrates are arranged for an array process.

Thereafter, a color filter process or an array process is performed on the thin glass substrate 100 to which the auxiliary substrate 110 is attached to form a thin film transistor that is a color filter layer or a driving element in each panel region.

In addition, after the predetermined process is completed, as shown in FIG. 1D, the auxiliary substrate 110 must be separated from the thin glass substrate 100. In this case, due to the above-described HF treatment or dry etching using fluorine gas, Since the surface roughness of the auxiliary substrate 110 is increased, the bonding force between the substrates 100 and 110 may be alleviated, so that the auxiliary substrate 110 may be easily detached.

That is, when the bonding force between the thin glass substrate 100 and the auxiliary substrate 110 is strong, it is difficult to physically separate, so the bending phenomenon may occur in the thin glass substrate 100 during separation, but the aforementioned HF treatment When the surface roughness of the auxiliary substrate 110 is increased due to dry etching using fluorine gas, the bonding force between the thin glass substrate 100 and the auxiliary substrate 110 is lowered and the detachment of the auxiliary substrate 110 is performed. This can be done easily.

In addition, the auxiliary substrate 110 separated from the thin glass substrate 100 may be attached to a new glass substrate and recycled for a new process.

At this time, the method of processing the HF on the auxiliary substrate may have a partial processing method in addition to the above-described front surface treatment.

In addition, by changing the chemical properties of the surface of the auxiliary substrate through the N ₂ gas plasma treatment in addition to the above-described HF treatment method, it is possible to weaken the bonding force due to contact with the thin glass substrate, which is the following invention It will be described in detail through the second embodiment of the.

2A to 2D are perspective views sequentially illustrating a part of a process of a method for manufacturing a light weight thin liquid crystal display device according to a second embodiment of the present invention, and showing, for example, a bonding and detaching process of a thin glass substrate and an auxiliary substrate. have.

2A to 2D illustrate that the chemical property of the surface of the auxiliary substrate is changed through N ₂ gas plasma treatment to alleviate the adhesion between the auxiliary substrate and the thin glass substrate, thereby desorption between the auxiliary substrate and the thin glass substrate. It is characterized in that to facilitate.

As shown in FIG. 2A, the auxiliary substrate 210 of about 0.3t to about 0.7t is prepared before the thin glass substrate having the thickness of 0.1t to 0.4t is introduced into the manufacturing process of the array process and the color filter process.

In this case, the present invention is not limited to the thicknesses of the thin glass substrate and the auxiliary substrate 210.

Next, as shown in FIG. 2B, the N ₂ gas plasma is treated on the entire surface 211 of the auxiliary substrate 210 to facilitate separation of the auxiliary substrate 210.

Due to the N ₂ gas plasma treatment, the chemical properties of the surface 211 of the sub-substrate 210 are changed to weaken the hydrogen bond between the thin glass substrate and the sub-substrate 210, thereby making contact with the thin glass substrate. Adhesion is weakened.

Next, as shown in FIG. 2C, the N ₂ gas plasma-treated auxiliary substrate 210 is attached to the thin glass substrate 200. In this case, the thin glass substrate 200 and the auxiliary substrate 210 may be bonded to each other by contacting the two substrates 200 and 210 in the standby state when the glass substrate is used as the auxiliary substrate 210. The bonding force between 200 and 210 may be estimated by vacuum force, van der Waals force, electrostatic force, or molecular bond.

The thin glass substrate 200 having a thickness of 0.1t to 0.4t and the auxiliary substrate 210 having a thickness of 0.3t to 0.7t are bonded to each other substantially the same as the first embodiment of the present invention. The process panel is made of the same thin glass substrate 200 and the auxiliary substrate 210 is made of the same glass material, the expansion rate according to the temperature change is the same, so the warpage occurs due to the expansion rate difference during the unit process There is no problem at all.

In addition, the thin glass substrate 200 has a thickness of 0.1t to 0.4t per se, but is bonded to the auxiliary substrate 210 to form a process panel, thereby significantly reducing the occurrence of warpage and a thickness of 0.7t in general. The level of warpage of the glass substrate having a level of less than or equal to that of the glass substrate having a lower level does not cause any problem in proceeding the unit process for the liquid crystal display device.

In this case, the thin glass substrate 200 may be a large area mother substrate on which a plurality of color filter substrates are arranged for a color filter process or a large area mother substrate on which a plurality of array substrates are arranged for an array process.

Thereafter, a color filter process or an array process is performed on the thin glass substrate 200 to which the auxiliary substrate 210 is attached to form a thin film transistor that is a color filter layer or a driving element in each panel region.

In addition, after the predetermined process is completed, as shown in FIG. 2D, the auxiliary substrate 210 must be separated from the thin glass substrate 200, wherein the substrates 200 and 210 are separated by the N ₂ gas plasma treatment. Since the bonding force is alleviated, detachment of the auxiliary substrate 210 may be easily performed.

That is, when the bonding force between the thin glass substrate 200 and the auxiliary substrate 210 is strong, it is difficult to physically separate, so the bending phenomenon may occur in the thin glass substrate 200 when separating, but the auxiliary substrate 210 In the case where N ₂ gas plasma treatment is performed on the entire surface 211, the adhesion between the thin glass substrate 200 and the auxiliary substrate 210 decreases due to the chemical change of the surface 211 of the auxiliary substrate 210. The auxiliary substrate 210 may be easily attached or detached.

In addition, the auxiliary substrate 210 separated from the thin glass substrate 200 may be attached to a new glass substrate and recycled for a new process.

In this case, a method of treating the N ₂ gas plasma on the auxiliary substrate may include a partial processing method in addition to the above-described front surface treatment.

In addition, by depositing an inorganic insulating film of a silicon oxide film or a silicon nitride film on the surface of the auxiliary substrate in addition to the above-described method of processing the N ₂ gas plasma, it is possible to weaken the bonding force due to contact with the thin glass substrate, which is the following invention The third embodiment of the present invention will be described in detail.

3A to 3D are perspective views sequentially illustrating a part of a process of a method for manufacturing a lightweight thin liquid crystal display device according to a third exemplary embodiment of the present invention, and show a bonding and detaching process of a thin glass substrate and an auxiliary substrate. have.

3A to 3D illustrate an inorganic insulating film of a silicon oxide film or a silicon nitride film deposited on the entire surface of the auxiliary substrate to ease the adhesion between the auxiliary substrate and the thin glass substrate to facilitate detachment between the auxiliary substrate and the thin glass substrate. Characterized in that.

As shown in FIG. 3A, before the thin glass substrate having the thickness of 0.1t to 0.4t is introduced into the manufacturing process of the array process and the color filter process, the auxiliary substrate 310 having the thickness of about 0.3t to 0.7t is prepared.

In this case, the present invention is not limited to the thickness of the thin glass substrate and the auxiliary substrate 310.

Next, as shown in FIG. 3B, an inorganic insulating layer 315 is deposited on the entire surface of the auxiliary substrate 310 to have a thickness of 100 μs to 1000 μm to facilitate separation of the auxiliary substrate 310.

As the hydrogen bond between the thin glass substrate and the auxiliary substrate 310 is weakened by the deposition of the inorganic insulating film 315 having no OH-functional group on the auxiliary substrate 310, the sum of the contact with the thin glass substrate is reduced. You will be weakened.

Next, as shown in FIG. 3C, the auxiliary substrate 310 on which the inorganic insulating layer 315 is deposited is attached to the thin glass substrate 300. In this case, the thin glass substrate 300 and the auxiliary substrate 310 may be bonded to each other by contacting the two substrates 300 and 310 in the standby state when the glass substrate is used as the auxiliary substrate 310. The bonding force between 300 and 310 may be estimated by a vacuum force, a van der Waals force, an electrostatic force, or a molecular bond.

In this case, the thin glass substrate 300 may be a large area mother substrate on which a plurality of color filter substrates are arranged for a color filter process or a large area mother substrate on which a plurality of array substrates are arranged for an array process.

Thereafter, a color filter process or an array process is performed on the thin glass substrate 300 to which the auxiliary substrate 310 is attached to form a thin film transistor that is a color filter layer or a driving element in each panel region.

In addition, after the predetermined process is completed, as shown in FIG. 3D, the auxiliary substrate 310 must be separated from the thin glass substrate 300, wherein an inorganic insulating film 315 is deposited on the auxiliary substrate 310. Therefore, the adhesion between the substrates 300 and 310 is alleviated, so that the auxiliary substrate 310 can be easily detached.

In addition, the auxiliary substrate 310 separated from the thin glass substrate 300 may be attached to a new glass substrate and recycled for a new process.

In this case, a method of depositing an inorganic insulating film on the auxiliary substrate may include a partial deposition method in addition to the above-mentioned front deposition.

In addition to the above-described method of depositing an inorganic insulating film on the auxiliary substrate, a transparent oxide film may be deposited on the surface of the auxiliary substrate to increase surface roughness and to weaken the bonding force due to contact with the thin glass substrate. The fourth embodiment of the present invention will be described in detail.

4A to 4E are perspective views sequentially illustrating a part of a process of a method for manufacturing a lightweight thin liquid crystal display device according to a fourth exemplary embodiment of the present invention. For example, the bonding and desorption process of the thin glass substrate and the auxiliary substrate will be described. have.

At this time, Figures 4a to 4e is to deposit a transparent oxide film such as ITO (Indium Tin Oxide) on the entire surface of the auxiliary substrate to relax the adhesion between the auxiliary substrate and the thin glass substrate to remove the separation between the auxiliary substrate and the thin glass substrate It is characterized in that to facilitate.

As shown in FIG. 4A, the auxiliary substrate 410 of about 0.3 to 0.7t is prepared before the thin glass substrate of 0.1t to 0.4t is introduced into the manufacturing line of the array process and the color filter process.

In this case, as described above, the present invention is not limited to the thicknesses of the thin glass substrate and the auxiliary substrate 410.

Next, as shown in FIG. 4B, a transparent oxide film 415 such as ITO is deposited on the entire surface of the auxiliary substrate 410 to have a thickness of 50 kV to 1000 kV to facilitate separation of the auxiliary substrate 410.

In this case, the transparent oxide film 415 may be deposited at a temperature from room temperature to 400 ° C., and the deposition temperature may vary depending on the deposition method.

At this time, the condition of the transparent oxide film 415 deposited on the auxiliary substrate 410 should be crystallized by heat treatment after deposition, and the surface roughness after crystallization should be larger than the general glass surface (~ 0.2nm).

In this case, the transparent oxide film 415 does not have to have a general ITO composition, for example, ITO, but it is necessary to have a transmittance of 70 to 100%. If the transmittance is too low, there is a possibility of error in the sensing of the equipment because it is very different from the existing glass.

The specific resistance may have a value of 10 ⁻¹ to 10 ⁻⁸ Ωm, and the content of SnO ₂ may have a value of 0 to 15%. In the case of general ITO, the content of SnO ₂ is 10%, the compositional change of SnO ₂ content is 0-15%, and there is no significant change in the transmittance or the resistivity characteristics, and the surface roughness also has a larger value than glass.

Next, as shown in FIG. 4C, a predetermined heat treatment is performed on the auxiliary substrate 410 on which the transparent oxide film 415 is deposited to form a crystallized transparent oxide film 415 ′.

In this case, the heat treatment may be performed at a temperature of 100 ℃ ~ 500 ℃, as a result, the surface roughness of the crystallized transparent oxide film 415 'may have a value of 0.25nm ~ 10.0nm.

By controlling the heat treatment temperature, the surface roughness of the crystallized transparent oxide film 415 ′ may be adjusted, and thus the adhesion between the substrates may be controlled.

Next, as shown in FIG. 4D, the auxiliary substrate 410 on which the crystallized transparent oxide film 415 ′ is deposited is attached to the thin glass substrate 400. In this case, the thin glass substrate 400 and the auxiliary substrate 410 may be bonded by using the glass substrate as the auxiliary substrate 410 by contacting the two substrates 400 and 410 in an atmospheric state. The bonding force between 400 and 410 may be estimated by a vacuum force, a van der Waals force, an electrostatic force, or a molecular bond.

The thin glass substrate 400 having a thickness of 0.1t to 0.4t and the auxiliary substrate 410 having a thickness of 0.3t to 0.7t are substantially the same as the first, second and third embodiments of the present invention described above. ) Is a state in which the panel for the bonded state of the thin glass substrate 400 and the auxiliary substrate 410 constituting the same glass material is made of the same expansion rate according to the temperature change by the difference in expansion rate during the unit process There is no problem that warpage occurs, for example.

In addition, the thin glass substrate 400 has a thickness of 0.1t to 0.4t per se, but is bonded to the auxiliary substrate 410 to form a process panel, thereby significantly reducing the occurrence of warpage and a thickness of 0.7t in general. The level of warpage of the glass substrate having a level of less than or equal to that of the glass substrate having a lower level does not cause any problem in proceeding the unit process for the liquid crystal display device.

In this case, the thin glass substrate 400 may be a large area mother substrate on which a plurality of color filter substrates are arranged for a color filter process or a large area mother substrate on which a plurality of array substrates are arranged for an array process.

Thereafter, a color filter process or an array process is performed on the thin glass substrate 400 to which the auxiliary substrate 410 is attached to form a thin film transistor that is a color filter layer or a driving element in each panel region.

After the completion of the predetermined process, as shown in FIG. 4E, the auxiliary substrate 410 must be separated from the thin glass substrate 400, wherein the transparent oxide film 415 ′ crystallized on the auxiliary substrate 410. Since the deposition force is reduced between the substrates 400 and 410, the auxiliary substrate 410 may be easily detached.

That is, when the bonding force between the thin glass substrate 400 and the auxiliary substrate 410 is strong, it is difficult to physically separate, so the bending phenomenon may occur in the thin glass substrate 400 during separation, but the auxiliary substrate 410 When the crystallized transparent oxide film 415 'is formed on the thin film, the adhesion between the thin glass substrate 400 and the auxiliary substrate 410 is lowered, so that the auxiliary substrate 410 can be easily detached.

For reference, in the case of heat treatment after bonding between glass, the bonding strength is measured to be about 0.7 kgf, whereas in the fourth embodiment of the present invention, the surface roughness is increased by crystallization of the transparent oxide film 415, so that the bonding strength is about 0.6 kgf. Was measured.

In addition, the auxiliary substrate 410 separated from the thin glass substrate 400 may be attached to a new glass substrate and recycled for a new process.

In this case, the method of depositing a transparent oxide film on the auxiliary substrate may have a partial deposition method in addition to the above-mentioned full surface deposition.

As described above, according to the fourth embodiment of the present invention, the transparent oxide film 415 such as ITO is deposited on the auxiliary substrate 410, and then attached to the thin glass substrate 400 to separate the auxiliary substrate 410. 400 and 410 can be prevented from being damaged, and the separated auxiliary substrate 410 can be recycled, thereby increasing the utility of the auxiliary substrate 410.

That is, in the fourth exemplary embodiment of the present invention, the transparent oxide film 415 is deposited on the auxiliary substrate 410 to adjust the bonding force, and then heat-treated to form the crystallized transparent oxide film 415 '. If it is attached to the thin glass substrate 400, it can be bonded with a lower bonding force than direct bonding between existing substrates.

In the case where the thin glass substrate 400 is directly contacted and bonded to the auxiliary substrate 410 on which the crystallized transparent oxide film 415 'is formed, the attraction force of the OH-functional group on the surfaces of the substrates 400 and 410 is similar to that of the existing substrate. The coalescence can be made. At this time, the OH-working period attraction is formed when the gap between the substrates 400 and 410 is low. In the case of the auxiliary substrate 410 on which the crystallized transparent oxide film 415 'is formed, the surface roughness of the OH-acting period is increased compared to that of the general glass. The gap between 400 and 410 is higher than that of ordinary glass, so that the number of hydrogen bonds formed by the attraction force of the OH-action period is reduced, and as a result, the adhesion is lowered.

That is, when the transparent oxide film 415 is deposited on the auxiliary substrate 410, although it is initially in an amorphous state, crystallization proceeds through heat treatment. In this process, the surface grains agglomerate, increasing the surface roughness. The transparent oxide film 415 is deposited on the auxiliary substrate 410, and then the heat treatment temperature is controlled to form a crystallized transparent oxide film 415 ′ having various surface roughnesses. Accordingly, the substrates 400 and 410 may be formed. The cohesion between the two will also be able to vary.

Meanwhile, ITO crystallized using ITO as the transparent oxide film 415 is resistant to fluorine chemicals such as HF, NH ₄ F, and KHF ₂ at low concentrations (<3%) currently used as an etchant. Since the etching is resistant to halogen gas compounds, there is no damage to chemicals in the process, and thus the recycling efficiency of the auxiliary substrate 410 will be increased.

5A and 5B are photographs showing, for example, a surface of an auxiliary substrate separated from a liquid crystal panel, and are scanning electron microscope images of the surface of the auxiliary substrate.

5A is a scanning micrograph of the surface of the auxiliary substrate when the ITO is not deposited on the auxiliary substrate, and FIG. 5B is a scanning microscope picture of the surface of the auxiliary substrate when the crystallized ITO is formed on the auxiliary substrate.

Referring to the drawings, when ITO is not deposited on the auxiliary substrate, the surface of the auxiliary substrate is damaged by chemicals during the process, whereas when crystallized ITO is formed on the auxiliary substrate, the surface of the auxiliary substrate is crystallized by the ITO. It can be seen that this chemical can be protected.

Hereinafter, a method of manufacturing the light weight thin liquid crystal display device according to the present invention will be described in detail with reference to the bonding and desorption process of the thin glass substrate and the auxiliary substrate according to the fourth embodiment of the present invention. However, the present invention is not limited to the bonding and desorption process of the thin glass substrate and the auxiliary substrate according to the fourth embodiment.

6 is a flowchart schematically illustrating a method of manufacturing a lightweight thin liquid crystal display device according to the present invention.

7A to 7D are perspective views sequentially illustrating a method of manufacturing a lightweight thin liquid crystal display device according to the present invention.

6 illustrates a method of manufacturing a liquid crystal display device when the liquid crystal layer is formed by the liquid crystal dropping method, for example. However, the present invention is not limited thereto, and the present invention is a liquid crystal injection method. It is also applicable to the manufacturing method of a liquid crystal display device in this case.

As described above, the manufacturing process of the liquid crystal display device may be classified into a driving element array process of forming a driving element on a lower array substrate, a color filter process of forming a color filter on an upper color filter substrate, and a cell process.

At this time, in the present invention, an array process, a color filter process, and a cell process are performed using a thin glass substrate having a thickness of about 0.1t to 0.4t. In particular, the thin glass substrate is attached to an auxiliary substrate. This minimizes the effect of the warp of the thin glass substrate and is characterized in that there is no breakage of the thin glass substrate during movement.

That is, in the present invention, by attaching the auxiliary substrate before inserting the thin glass substrate of 0.1t to 0.4t into the manufacturing line, the same or improved warpage as the glass substrate having the thickness of about 0.7t used in the general liquid crystal display device It is characterized in that it can prevent the occurrence of problems such as substrate sag during the movement or unit process progress by having a generation characteristic.

First, as illustrated in FIG. 7A, auxiliary substrates 410a and 410b having 0.3t to 0.7t are prepared before the thin glass substrate having 0.1t to 0.4t is introduced into the manufacturing process of the array process and the color filter process. do.

In this case, for convenience of description, the auxiliary substrates 410a and 410b may include a first auxiliary substrate 410a attached to the thin glass substrate for color filter process and a second auxiliary substrate attached to the thin glass substrate for array process ( 410b).

As described above, the present invention is not limited to the thicknesses of the thin glass substrates and the auxiliary substrates 410a and 410b.

Next, as illustrated in FIG. 7B, the transparent oxide films 415a and 415b such as ITO may be 50 μm to 1000 μm on the front surface of the auxiliary substrates 410a and 410b to facilitate separation of the auxiliary substrates 410a and 410b. Deposition (S101).

In this case, the transparent oxide films 415a and 415b may be deposited at a temperature of room temperature to 400 ° C., and the deposition temperature may vary depending on the deposition method.

In this case, the conditions of the transparent oxide films 415a and 415b deposited on the auxiliary substrates 410a and 410b should be crystallized by heat treatment after deposition, and the surface roughness after crystallization should be larger than a general glass surface (˜0.2 nm).

In this case, as described above, the transparent oxide films 415a and 415b do not have to have a general ITO composition, for example, but need to have a transmittance of 70 to 100%. If the transmittance is too low, there is a possibility of error in the detection of the equipment because it is different from the existing glass.

Next, as shown in FIG. 7C, a predetermined heat treatment is performed on the auxiliary substrates 410a and 410b on which the transparent oxide films 415a and 415b are deposited to form crystallized transparent oxide films 415a 'and 415b'. (S102).

At this time, the heat treatment may be performed at a temperature of 100 ℃ ~ 500 ℃, as a result the surface roughness of the crystallized transparent oxide film (415a ', 415b') may have a value of 0.25nm ~ 10.0nm.

By controlling the heat treatment temperature, the surface roughness of the crystallized transparent oxide films 415a 'and 415b' may be adjusted, and thus the bonding strength between the substrates may be controlled.

Next, as shown in FIG. 7D, the auxiliary substrates 410a and 410b on which the crystallized transparent oxide films 415a 'and 415b' are deposited are respectively attached to the thin glass substrates 400a and 400b (S103). . At this time, when the thin glass substrates 400a and 400b and the auxiliary substrates 410a and 410b are bonded to each other when the glass substrate is used as the auxiliary substrates 410a and 410b, the two substrates 400a, 400b, 410a and 410b are in a standby state. The contact force between the two substrates 400a, 400b, 410a, and 410b may be estimated by a vacuum force, van der Waals force, electrostatic force, or molecular bond.

In this case, the thin glass substrates 400a and 400b may be large-area mother substrates in which a plurality of color filter substrates are disposed for a color filter process or large-scale mother substrates in which a plurality of array substrates are arranged for an array process. .

Thereafter, a color filter process or an array process is performed on each of the thin glass substrates 400a and 400b to which the auxiliary substrates 410a and 410b are attached, thereby forming a thin film transistor that is a color filter layer or a driving element in each panel region.

That is, after the auxiliary substrates 410a and 410b are attached to the thin glass substrates 400a and 400b in this manner, the thin glass substrate 400b for the array process to which the second auxiliary substrate 410b described above is attached ( Hereinafter, for convenience of description, an array substrate) is arranged on the array substrate 400b by an array process to form a plurality of gate lines and data lines defining pixel regions, and the gate lines and data in each of the pixel regions. A thin film transistor which is a driving element connected to the line is formed (S104). In addition, the pixel electrode is connected to the thin film transistor through the array process to drive the liquid crystal layer as a signal is applied through the thin film transistor.

In addition, the thin glass substrate 400a (hereinafter, referred to as a color filter substrate for convenience of description) to which the above-described first auxiliary substrate 410a is attached has a color that is implemented by the color filter process. In operation S105, a color filter layer including a green and blue subcolor filter and a common electrode are formed. In this case, when a liquid crystal display device having an in-plane switching (IPS) method is manufactured, the common electrode is formed on the array substrate 400b on which the pixel electrode is formed through the array process.

Subsequently, after the alignment films are printed on the color filter substrate 400a and the array substrate 400b, the alignment control force or the surface fixing force is applied to the liquid crystal molecules of the liquid crystal layer formed between the color filter substrate 400a and the array substrate 400b. The alignment layer is subjected to a rubbing process (ie, to provide a pretilt angle and an orientation direction) (S106 and S107).

A sealing material is applied to the rubbed color filter substrate 400a to form a predetermined failure turn, and a liquid crystal is dropped on the array substrate 400b to form a liquid crystal layer (S108 and S109).

On the other hand, the color filter substrate 400a and the array substrate 400b are formed on a large mother substrate, respectively. In other words, a plurality of panel regions are formed in each of the mother substrate of a large area, and a thin film transistor which is a color filter layer or a driving element is formed in each of the panel regions. However, for convenience of description, the drawings show only one liquid crystal panel.

In this case, the dropping method uses a dispenser to form a liquid crystal in an image display area of a first mother substrate having a large area where a plurality of array substrates 400b are disposed or a second mother substrate where a plurality of color filter substrates 400a are disposed. The liquid crystal layer is formed by dropping and dispensing, and by uniformly distributing the liquid crystals to the entire image display region by the pressure for bonding the first and second mother substrates.

Therefore, when the liquid crystal layer is formed on the liquid crystal panel by a dropping method, a failure turn should be formed in a closed pattern surrounding the outer portion of the pixel region so as to prevent the liquid crystal from leaking out of the image display region.

The dropping method can drop the liquid crystal in a short time compared to the vacuum injection method, and can form the liquid crystal layer very quickly even when the liquid crystal panel is enlarged. In addition, since only the required amount of liquid crystal is dropped on the substrate, the price competitiveness of the liquid crystal panel due to the disposal of the expensive liquid crystal is prevented, such as vacuum injection, thereby strengthening the product's price competitiveness.

Subsequently, as shown in FIG. 7E, the first mother substrate and the second mother substrate are applied by the sealing material by applying pressure while the liquid crystal is dropped and the first mother substrate and the second mother substrate on which the sealing material is applied are aligned. And the liquid crystals dropped by the application of pressure are uniformly spread over the entire liquid crystal panel (S110). By such a process, a plurality of liquid crystal panels in which a liquid crystal layer is formed are formed on the first and second mother substrates having a large area.

As shown in FIGS. 7F and 7G, the auxiliary substrates 410a and 410b should be separated from the first and second mother substrates having the plurality of liquid crystal panels formed therein, wherein the auxiliary substrates 410a, Since the crystallized transparent oxide films 415a 'and 415b' are formed on the 410b, the adhesion between the two substrates 400a, 400b, 410a, and 410b is alleviated, so that the auxiliary substrates 410a and 410b can be easily detached. (S111).

As a detachable method that can be applied to the auxiliary substrates (410a, 410b) or thin glass substrates (400a, 400b) by holding a vacuum pad (vacuum pad), the auxiliary substrates (410a, 410b) or thin glass substrates (400a, There is a method of lifting the 400b), wherein the adhesion between the two substrates 400a, 400b, 410a, and 410b is reduced due to the formation of the crystallized transparent oxide films 415a 'and 415b' on the surfaces of the auxiliary substrates 410a and 410b. It is not large and can be easily detached. In this case, air may be injected while making a gap between the auxiliary substrates 410a and 410b and the thin glass substrates 400a and 400b with a knife in order to facilitate detachment.

In addition, the auxiliary substrates 410a and 410b separated from the thin glass substrates 400a and 400b may be attached to a new glass substrate and recycled for a new process.

Subsequently, the liquid crystal display is manufactured by cutting and cutting the liquid crystal panel into a plurality of liquid crystal panels and inspecting each liquid crystal panel (S112). However, the present invention is not limited thereto, and the separation process of the above-described auxiliary substrates 410a and 410b may be performed after the above processing and cutting.

Many details are set forth in the foregoing description but should be construed as illustrative of preferred embodiments rather than to limit the scope of the invention. Therefore, the invention should not be defined by the described embodiments, but should be defined by the claims and their equivalents.

100,200,300,400,400a, 400b: thin glass substrate
110,210,310,410,410a, 410b: auxiliary board
415,415a, 415b: transparent oxide film
415 ', 415a', 415b ': crystallized transparent oxide film

Claims

Providing first and second auxiliary substrates and thin first and second mother substrates;
Depositing a transparent oxide film on surfaces of the first and second auxiliary substrates;
Heat-treating the first and second auxiliary substrates on which the transparent oxide film is deposited to crystallize the transparent oxide film to increase surface roughness;
Attaching first and second auxiliary substrates on which the crystallized transparent oxide film is formed to each of the thin first and second mother substrates;
Performing a color filter process on the first mother substrate to which the first auxiliary substrate is attached;
Performing an array process on a second mother substrate to which the second auxiliary substrate is attached;
Bonding the second mother substrate subjected to the array process and the first mother substrate subjected to the color filter process; And
Separating the first and second auxiliary substrates from the bonded first and second mother substrates,
The bonding force between the crystallized transparent oxide film and the thin first and second mother substrates is characterized in that the surface of the first and second auxiliary substrates and the thin first, second and second substrates are increased as the transparent oxide film is crystallized and the surface roughness increases. A method for manufacturing a lightweight thin liquid crystal display device, which is smaller than the bonding force between the second mother substrates.

The method of claim 1, wherein the transparent oxide film comprises indium tin oxide (ITO).

The method of claim 2, wherein the ITO has a SnO ₂ content of 0 to 15%.

The method of claim 1, wherein the transparent oxide film is deposited to a thickness of 50 kV to 1000 kV.

The method of claim 1, wherein the transparent oxide film is deposited at a temperature of room temperature to 400 ° C.

The method of claim 1, wherein the heat treatment is performed at a temperature of 100 ° C to 500 ° C.

The method of claim 1, wherein the crystallized transparent oxide film has a surface roughness of 0.25 nm to 10.0 nm.

The method of claim 1, further comprising separating the first and second auxiliary substrates from the bonded first and second mother substrates, and then cutting and cutting the first and second auxiliary substrates into a plurality of liquid crystal panels. Lightweight thin liquid crystal display device manufacturing method.

Providing first and second auxiliary substrates and thin first and second mother substrates;
Increasing surface roughness by HF or plasma treatment on the surfaces of the first and second auxiliary substrates;
Attaching the HF or plasma treated first and second auxiliary substrates to the thin first and second mother substrates, respectively;
Performing a color filter process on the first mother substrate to which the first auxiliary substrate is attached;
Performing an array process on a second mother substrate to which the second auxiliary substrate is attached;
Bonding the second mother substrate subjected to the array process and the first mother substrate subjected to the color filter process; And
Separating the first and second auxiliary substrates from the bonded first and second mother substrates,
The bonding force between the surface of the HF or plasma-treated first and second auxiliary substrates and the thin first and second mother substrates is characterized in that the surface of the first and second auxiliary substrates is HF or plasma-treated and thus the surface roughness is reduced. A method of manufacturing a light weight thin liquid crystal display device having a smaller adhesion force between the surfaces of the first and second auxiliary substrates and the thin first and second mother substrates before the HF or plasma treatment.

10. The method of claim 9, wherein the surface of the first and second sub-substrate is subjected to HF or dry etching using fluorine gas of CF ₄ , C ₃ F ₈ , NH ₃ or SF ₆ Liquid crystal display device manufacturing method.

11. The method of claim 10, wherein the first and second sub-substrates are light weight and thin, characterized in that for treating the HF or dry etching using fluorine gas so that the surface roughness has a value of 0.25nm ~ 2.0nm. Liquid crystal display device manufacturing method.

10. The method of claim 9, wherein the surface of the first and second auxiliary substrates is subjected to N ₂ gas plasma treatment.

Providing first and second auxiliary substrates and thin first and second mother substrates;
Depositing an inorganic insulating film having no OH-functional group of a silicon oxide film or a silicon nitride film on a surface of the first and second auxiliary substrates;
Attaching first and second auxiliary substrates on which the inorganic insulating layer is deposited to each of the thin first and second mother substrates;
Performing a color filter process on the first mother substrate to which the first auxiliary substrate is attached;
Performing an array process on a second mother substrate to which the second auxiliary substrate is attached;
Bonding the second mother substrate subjected to the array process and the first mother substrate subjected to the color filter process; And
Separating the first and second auxiliary substrates from the bonded first and second mother substrates,
The bonding force between the inorganic insulating film and the thin first and second mother substrates is formed by depositing an inorganic insulating film having no OH-functional group on the surfaces of the first and second auxiliary substrates. A method of manufacturing a light weight thin liquid crystal display device having a smaller bonding force between surfaces of the first and second auxiliary substrates and the thin first and second mother substrates before deposition of the inorganic insulating layer as the bond is weakened.

The method of claim 13, wherein the inorganic insulating film is deposited to a thickness of 100 kV to 1000 kV.