JP2004233836A - Structure of liquid crystal display and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for decreasing contamination of a liquid crystal in a liquid crystal display manufactured by liquid crystal dropping (one-drop-fill (ODF)) techniques and for improving the quality and yield of the liquid crystal display. <P>SOLUTION: In a first step, a first substrate 110 having a conductive pattern layer 120 comprising peripheral circuits is supplied. The conductive pattern layer 120 is made of an indium tin oxide material. In a second step, a second substrate 150 having a black matrix layer 140 which prevents leaking of light from the liquid crystal display is supplied. A UV-curing seal 130 is applied on the first substrate 110. A liquid crystal material is dropped onto the first substrate 110. The first substrate 110 and the second substrate 150 are adhered in a vacuum chamber. The seal 130 is exposed to UV rays through the first substrate 110 to be preliminarily cured for a specified period. At last, the seal 130 is heated in a heating chamber. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid crystal display and a method for manufacturing a liquid crystal display.
[0002]
[Prior art]
2. Description of the Related Art Recently, liquid crystal displays (LCDs) have been widely applied to electric appliances due to rapid progress of optical technology and semiconductor technology. In addition, LCDs have been introduced in portable computers, personal digital assistants, and color televisions due to the advantages of high image quality, compact size, light weight, low driving voltage, and low power consumption. Is being replaced. LCDs are becoming the mainstream display devices.
[0003]
The main part of an LCD is a liquid crystal (LC) unit consisting of two parallel transparent substrates and an LC sealed to it. The mainstream of LCDs is thin film transistor (TFT) LCDs. The manufacturing process of the TFT-LCD is divided into the following four parts. That is, a TFT array process, a color filter (CF) process, an LC cell assembling process, and a liquid crystal module (LCM) process.
[0004]
The TFT array process is used to fabricate a TFT substrate. Each TFT is aligned with one pixel electrode. The CF process is used to manufacture a color filter substrate. Color filter layers comprising different color filter sheets are on the color filter substrate, and a black matrix layer surrounds each color filter sheet.
[0005]
The LC cell assembling process is used to assemble the TFT substrate and the CF substrate in parallel, and the bead spacers arranged therebetween maintain a constant distance between the TFT substrate and the CF substrate, that is, a cell gap. LC is injected into the cell gap and the inlet is sealed. Basically, each pixel electrode corresponds to one color filter sheet, and the black matrix layer covers a TFT and a metal line connecting different TFTs.
[0006]
The LCM process is used to attach a polarizer to a panel and electrically connect a driver IC to a panel circuit. Thereafter, the reflector and the backlight are assembled on the panel. After the burn-in step, the LCM process ends.
[0007]
Generally, the direction of the liquid crystal molecular axis controlled by the TFT determines whether or not each pixel transmits light. The color of each pixel is determined by the color of the color filter sheet. For example, when light passes through a red color filter sheet, a red spot is displayed on the panel. A full-color image can be displayed by mixing red, green, and blue.
[0008]
Since the molecular axis of the liquid crystal molecules between the pixel electrode and the color filter sheet must be accurately controlled, the color filter and the TFT substrate must be accurately aligned. The alignment tolerance is only within a few micrometers.
[0009]
Conventional LC injection is a complicated procedure in the TFT-LCD fabrication process. Liquid crystal dropping (ODF) simplifies the fabrication process. In the ODF process, an ultraviolet (UV) type seal is used to improve the yield. However, in the actual manufacturing process, many LCD panels are contaminated by the UV-type seal. The yield and quality of the TFT-LCD are reduced.
[0010]
[Problems to be solved by the invention]
It is an object of the present invention to provide a method and structure for reducing liquid crystal contamination in liquid crystal displays manufactured by liquid crystal dropping (ODF) technology.
It is another object of the present invention to provide a method and structure for improving the UV curing seal pre-curing conditions to reduce contamination problems.
It is still another object of the present invention to improve the quality and yield of liquid crystal displays by improving the problem of liquid crystal contamination.
[0011]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a method for manufacturing a liquid crystal display using a liquid crystal dropping technique. The method includes the following steps. First, a first substrate having a conductive pattern layer formed by a peripheral circuit is provided. The conductive pattern layer is made of an indium tin oxide material. Second, a second substrate is provided having a black matrix layer to avoid light leakage of the liquid crystal display. The UV-curable seal is then arranged on the first substrate. A liquid crystal material is dropped on the first substrate. The first substrate and the second substrate are bonded together in a vacuum chamber. The seal is exposed to ultraviolet light from the first substrate to pre-cure the seal for a predetermined time. Finally, the seal is heated in the heating chamber.
[0012]
The first substrate is a thin film transistor glass substrate, and the second substrate is a color filter glass substrate. The peripheral circuit is a peripheral drive circuit arranged in a non-display area of the liquid crystal display.
The UV-curable seal may be arranged on the second substrate instead of the first substrate. The liquid crystal material may be dropped on the second substrate instead of the first substrate.
[0013]
In another embodiment, the present invention provides a structure of a liquid crystal display manufactured by a liquid crystal dropping technique. The structure includes a first substrate, a conductive pattern layer, a second substrate, a black matrix layer, a liquid crystal layer, and a UV-curable seal. The conductive pattern layer is formed on the first substrate. The conductive pattern layer includes a peripheral circuit made of indium tin oxide (ITO) material. The black matrix layer is formed on the second substrate to prevent light leakage from the liquid crystal display. The UV-curable seal forms a chamber between a conductive pattern layer for storing liquid crystal by bonding a first substrate to a second substrate and a black matrix layer. The UV-curable seal is pre-cured by ultraviolet light from the first substrate via the conductive pattern layer for a predetermined period, and then heated in a heating chamber to be completely cured.
[0014]
The above aspects and many of the advantages associated with the present invention will be better understood and more readily appreciated by reference to the following detailed description when considered in conjunction with the accompanying drawings.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The following description is of the presently contemplated mode of carrying out the invention. This description is not to be taken in a limiting sense, but merely to illustrate the general principles of the invention. The scope of the invention should be determined by reference to the appended claims.
[0016]
FIG. 1 shows a detailed sectional view of a sealed portion of a TFT-LCD according to one embodiment of the present invention. As shown in the drawing, the TFT-LCD has a first substrate 110 and a second substrate 150, both of which are transparent glass materials. Conventionally, the conductive pattern layer 120 is hidden behind the black matrix layer 140. The conductive pattern layer 120 includes a peripheral driving circuit of the TFT-LCD. The peripheral driving circuit is formed by a metal layer made of copper, aluminum, or chromium, and is disposed in a non-display area.
[0017]
In the TFT-LCD according to the present embodiment, the LCD is filled with LC using an ODF process. The ultraviolet-curable seal 130 is easily pre-cured by ultraviolet rays.
The conductive pattern layer 120 is formed on a first substrate 110 that is a TFT substrate, and the black matrix layer is formed on a second substrate 150 that is a color filter substrate. The seal is arranged around the periphery of the substrate, and then the liquid crystal 160 is dropped at the center of the substrate by an ODF process. Finally, the two substrates are pressure sealed in a vacuum chamber. The seal is exposed to ultraviolet light for about 30 seconds to pre-cure the seal surface, after which the seal is completely cured in the heating chamber. Liquid crystal is dropped, and a seal is arranged on one of the first substrate 110 and the second substrate 150 during the ODF process. The seal and the liquid crystal may be worn in any order or may be worn simultaneously. What is important is that after the bonding step, the two substrates are sent to a vacuum chamber in which the internal air is evacuated. The seal is then exposed to UV light for about 30 seconds, and then heated for about 60 minutes to fully cure.
[0018]
The periphery of the LCD is covered with a black matrix layer 140 to avoid light leakage caused by backlight or localization errors. Accordingly, since the black matrix layer 140 does not transmit ultraviolet rays, the ultraviolet-curable seal is not pre-cured by the ultraviolet rays from the second substrate 150. In particular, the black matrix is very thin and very narrow in a TFT-LCD smaller than 17 inches. The only way to expose the seal to ultraviolet light is from the first substrate 110. The conventional first substrate having the conductive pattern layer 220 and the metal circuit made of aluminum, copper, or chromium, ie, the TFT substrate, is not completely transparent. Therefore, the conductive pattern layer forms a mesh layer.
[0019]
FIG. 2 is a front view of a sealed portion of the TFT-LCD according to the present embodiment. The conductive pattern layer 220 is formed as a transparent square. The seal 230 is arranged in this area. The black matrix layer 240 is under the seal 230 and the conductive pattern layer 220, and completely covers the seal 230. The liquid crystal 260 is arranged on the left side of the drawing.
[0020]
The seal must be completely exposed to UV light to improve the pre-cure step. That is, the conductive pattern layer 220 must be completely transparent. The conductive pattern layer according to the present invention is made of a transparent material such as an indium tin oxide (ITO) material. In the prior art, since the conductive pattern layer is only partially transparent, only a part of ultraviolet rays can be transmitted. Therefore, the portion where ultraviolet rays cannot reach the seal is not pre-cured. Therefore, the sealing surface is wet. In a vacuum chamber, when pressure is applied to the substrate, the liquid crystal contacts the seal and the wet seal contaminates the liquid crystal.
[0021]
In this embodiment, a conductive pattern layer which is a completely transparent layer is formed using an ITO material. The seal can be completely pre-cured by UV light. Contamination caused by a wet seal can be avoided. LCD quality and yield are improved and defect rates are reduced.
[0022]
It will be appreciated by those skilled in the art that the above preferred embodiments of the present invention are illustrative of the invention rather than limiting the invention. It is intended to cover various modifications and similar arrangements within the spirit and scope of the appended claims, the scope of which is given the broadest interpretation to encompass all such modifications and similar structures. Should.
[Brief description of the drawings]
FIG. 1 is a detailed sectional view showing a sealed portion of a liquid crystal display according to an embodiment of the present invention.
FIG. 2 is a front view of a sealed portion of a liquid crystal display according to an embodiment of the present invention.
[Explanation of symbols]
110 First substrate 120 Conductive pattern layer 130 UV curable seal 140 Black matrix layer 150 Second substrate 160 Liquid crystal 220 Conductive pattern layer 230 UV curable seal 240 Black matrix layer 260 Liquid crystal

Claims (12)

A method for manufacturing a liquid crystal display using a liquid crystal dropping technique,
Providing a first substrate having a conductive pattern layer formed by a peripheral circuit comprising an indium tin oxide material;
Providing a second substrate having a black matrix layer to avoid light leakage of the liquid crystal display;
Arranging a UV-curable seal on the first substrate;
Dropping a liquid crystal material on the first substrate;
Bonding the first substrate and the second substrate in a vacuum chamber;
Exposing the seal to ultraviolet light from the first substrate for a predetermined time to pre-cure the seal;
Heating the seal;
A method for producing a liquid crystal display, comprising: The method according to claim 1, wherein the first substrate comprises a glass substrate of a thin film transistor. 2. The method according to claim 1, wherein the second substrate comprises a glass substrate of a color filter. 2. The method according to claim 1, wherein the peripheral circuit includes a peripheral driving circuit disposed in a non-display area of the liquid crystal display. The method according to claim 1, wherein a vacuum chamber is used to exhaust air from between the first substrate and the second substrate. 2. The method according to claim 1, wherein the step of arranging the ultraviolet-curable seal on the first substrate is replaced with the step of arranging the ultraviolet-curable seal on the second substrate. 2. The method according to claim 1, wherein the step of dropping the liquid crystal material on the first substrate is replaced with the step of dropping the liquid crystal material on the second substrate. A liquid crystal display manufactured using a liquid crystal dropping technique,
A first substrate;
A conductive pattern layer formed on a first substrate and formed by a peripheral circuit made of indium tin oxide material;
A second substrate;
A black matrix layer formed on the second substrate to avoid light leakage from the liquid crystal display;
A liquid crystal layer formed by liquid crystal dropping technology,
An ultraviolet-curable seal for bonding a first substrate and a second substrate to form a chamber between a conductive pattern layer for storing a liquid crystal layer and a black matrix layer, wherein the ultraviolet-curable seal is A seal that is pre-cured by ultraviolet light from the first substrate through the conductive pattern layer for a predetermined time, and is completely cured by being heated in the heating chamber;
A liquid crystal display comprising: 9. The liquid crystal display of claim 8, wherein the first substrate comprises a thin film transistor glass substrate. 9. The liquid crystal display according to claim 8, wherein the second substrate comprises a color filter glass substrate. 9. The liquid crystal display according to claim 8, wherein the peripheral circuit includes a peripheral driving circuit arranged in a non-display area of the liquid crystal display. The vacuum chamber is used to evacuate air between the first substrate and the second substrate after the UV-curable seal bonds the first substrate to the second substrate. The liquid crystal display as described.

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