JP2001235758A - Liquid crystal display panel and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To solve the problem that when a liquid crystal display panel is filled with a liquid crystal, a sealing material penetrates into the liquid crystal display area and a display defect occurs when the filling opening is sealed. In addition, the display quality of the liquid crystal display device is improved. A metal film is provided between a liquid crystal display area and an opening for injecting liquid crystal on at least one of two opposing substrates of a liquid crystal display panel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display panel and a method of manufacturing the same, and more particularly, to a liquid crystal display panel in which liquid crystal is injected into a liquid crystal display panel by a dip injection method.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been widely used as display devices for personal computers, televisions, digital cameras, etc., taking advantage of their advantages such as thinness and lightness, low voltage driving, and low power consumption. A liquid crystal display panel constituting a liquid crystal display device generally has a structure in which liquid crystal is sealed between two transparent substrates such as glass, and one substrate (CF substrate) has a black matrix, a color filter, a common electrode, and an alignment film. On the other substrate (TFT substrate), a thin film transistor (hereinafter, referred to as TFT), a gate bus line, a drain bus line, a pixel electrode, an alignment film, and the like are formed.

One method of injecting liquid crystal between two transparent substrates is a dip injection method.

In this method, a sealing material is applied to one of two transparent substrates so as to surround a display region while leaving an opening for injecting liquid crystal, and spheres or columnar spacers are scattered. The two substrates are fixed with this sealing material. Thereafter, when the pressure is returned to the atmospheric pressure in a state in which the liquid crystal injection opening is immersed in the liquid crystal in a vacuum, the liquid crystal is injected between the substrates due to the pressure difference.
Next, a liquid crystal display panel is completed by applying a thermosetting or ultraviolet curable resin (sealing material) to the opening and sealing the opening.

FIG. 4 illustrates an example of such a conventional liquid crystal display panel assembling process. As shown in FIG. 4A, one substrate 11 obtained by cutting the substrate 1 on which the sealing material 2 is applied while leaving the liquid crystal injection opening 3 along the scribe lines X and Y, and a gate bus at the end. The other substrate 12 on which the gate terminal 4 connected to the line and the drain terminal 5 connected to the drain bus line are formed is fixed, and liquid crystal is injected through the opening 3. The liquid crystal display panel 10 shown in FIG.
Becomes

[0006]

An opening 3 for injecting a liquid crystal.
After the liquid crystal is injected from the opening 3, a sealing material 7 is applied to the opening 3. To completely cover the opening 3, the inside of the opening 3 is so small that the sealing material 7 does not reach the display area. Must be infiltrated. For this reason, the sealing material 7 is hardened by applying heat or ultraviolet rays after the resin has penetrated and left for several seconds to several tens of seconds after applying the resin as the sealing material 7.

However, the viscosity of the sealing material 7 and the opening 3
Of the sealing material 7 depending on environmental conditions such as variations in width, temperature, humidity, etc., and the processing state of the glass surface when the substrate is glass.
There is a problem that the sealing material 7 penetrates into the display area 8 as shown in FIG. 3 which is a partially enlarged plan view of the opening 3 and a display defect occurs. In addition, the encapsulant 7 has been developed by narrowing the frame of the liquid crystal display panel in recent years (the area other than the display area has become narrower) and adopting a low-voltage driving liquid crystal material that is easily affected by the incorporation of the encapsulant 7.
The display failure due to the mixing of is also emerging as a problem.

In order to prevent the sealing material from entering the inside of the liquid crystal display panel, it has been proposed in Japanese Patent Application Laid-Open No. 05305333 to provide a flow path regulating bar near the opening. There is a problem that the width of the opening for injecting liquid crystal is substantially reduced, and the time for injecting liquid crystal is significantly increased.

[0009]

According to a first aspect of the present invention, there is provided a sealing material which surrounds a liquid crystal display region while leaving an opening for injecting liquid crystal in at least one of two substrates. Is applied in a frame shape, and a liquid crystal display panel in which two substrates disposed opposite to each other are fixed with a sealing material, between the opening on at least one of the two substrates and the liquid crystal display region. Wherein a metal film is provided. The invention according to claim 2 is characterized in that the material of the metal film is any one of aluminum, titanium, chromium, and silicon. According to a third aspect of the present invention, at least a thin film transistor, a gate bus line, and a drain bus line are formed on one of the two substrates, and a liquid crystal display is formed by leaving an opening for injecting liquid crystal on at least one of the two substrates. In a method of manufacturing a liquid crystal display panel in which a sealing material is applied in a frame shape so as to surround an area and two substrates disposed opposite to each other are fixed with the sealing material, an opening on the substrate, the liquid crystal display area, In the method, a metal film is formed in the same step as the gate bus line.

That is, according to the present invention, when a metal film is provided on a substrate between an opening for liquid crystal injection and a liquid crystal display area, the opening is sealed after the liquid crystal is injected into the liquid crystal display panel. As a result, the sealing material does not enter the liquid crystal display area due to the change in wettability between the liquid crystal display region and the display defect does not occur. Further, since the metal film is extremely thin, it does not hinder the liquid crystal injection. Furthermore, as the material of the metal film,
By using the same materials as the electrodes and wiring that make up the liquid crystal display panel, the electrodes of the conventional liquid crystal display panel,
Since it can be formed in the same process as the wiring, the number of manufacturing steps does not increase.

[0011]

Embodiments of the present invention will be described below. As shown in FIG. 1 (A) and FIG. 1 (B) which is a partially enlarged view of the opening 3 in FIG. 1 (A), in the present invention, between the opening 3 of the liquid crystal display panel 10 and the liquid crystal display area 8. The metal film 9 is formed on the surface of the substrate 12. As a material of the metal film 9, it is preferable to use a material used in a process of forming electrodes and wirings on a substrate in order not to actually increase the number of manufacturing steps of the liquid crystal display panel.
For example, in a liquid crystal display panel using a TFT, aluminum (Al), titanium (Ti), chrome (Cr), silicon (Si), and the like are given. The penetration speed of the sealing material 7 into the liquid crystal display panel 10 is lower in the metal film than in the glass, as long as the viscosity of the sealing material 7 and the size of the opening 3 are constant.

The surface of the substrate in the vicinity of the opening 3 of the conventional liquid crystal display panel has exposed glass, and in the case of glass, the sealing material 7 penetrates quickly, and the viscosity of the sealing material 7 is reduced.
The margin for the size of the opening 3 was narrow. Conventionally, the penetration speed of the sealing material 7 is about 200 μm / min with respect to the glass, and the penetration position where the distance a from the opening 3 is about 700 μm is set as the design center value. If the penetration speed varies by about 30% due to the variation in the width of the part 3, the penetration distance changes by about 210 μm, and the maximum penetration distance becomes 910 μm.

On the other hand, in the case of the metal film 9 according to the present invention, the penetration speed of the sealing material 7 is as low as about 50 μm / min. This is thought to be due to a change in the penetration rate due to the wettability between the glass and metal film and the sealing material. The distance b from the opening 3 to the inside of the metal film 9 is 650 μm.
When the width c is formed to a width of 150 μm from m, the sealing material 7
The maximum penetration distance is 750μ even if the penetration speed varies by 30%
m, and the design value is 700 μm as shown in FIG.
m. For this reason, the sealing material 7 does not enter the liquid crystal display area 8 of the liquid crystal display panel 10, and display defects do not occur. Although the sealing material 7 quickly penetrates into the exposed portion of the glass, the penetration speed of the portion of the metal film 9 is reduced, so the size and position of the metal film 9 formed on the substrate, that is, the distance b in FIG. , The width c of the sealing material 7 can be delicately controlled by design. Although the embodiment in which the metal film 9 is formed on the substrate 12 has been described, the metal film 9 may be formed on the substrate 11 or on both the substrates 11 and 12.

Next, the formation of the metal film according to the present invention is performed by using a TFT.
An example in which the formation of a gate electrode and a gate bus line on a substrate is performed in the same manufacturing process (hereinafter, referred to as a gate process) will be described with reference to FIG. 2 showing a manufacturing process of a liquid crystal display panel according to an embodiment of the present invention.

First, in step S1, the substrate is cleaned to remove dust, alkali, and the like on the glass substrate.
Next, as a step 2, a metal to be a gate film is formed on the substrate by sputtering or plasma CVD. In the embodiment of the present invention, aluminum is formed to a thickness of about 1000 angstroms, which is the same as the gate electrode and the gate bus line. . Next, a resist which reacts to ultraviolet rays is applied thereon by spin coating in step 3. Next, in step 4, ultraviolet light exposure is performed through an exposure mask 6. In addition to the gate electrode and the gate bus line, a metal film, which is a feature of the present invention, is formed on the opening 3 for liquid crystal injection.
A pattern to be formed in the vicinity is provided, and is exposed simultaneously with the pattern of the gate electrode and the gate bus line. Next, in step 5, the resist irradiated with the ultraviolet rays is immersed in a developing solution and removed. Next, in step 6, a portion of the aluminum film not covered with the resist is immersed in an etching solution and removed. Next, in step 7, the remaining resist is removed with a resist remover and then washed. Next, in step 8, it is checked whether or not a desired gate electrode, gate bus line, metal film, and the like are formed.

In the embodiment of the present invention, as the metal film 9, the distance b = the distance from the edge of the glass substrate of the opening 3 for injecting liquid crystal.
650 μm width 150 μm in the transverse direction, width 1 in the longitudinal direction
A 5 mm rectangular pattern is formed.

The gate process of the TFT substrate is completed as described above. To manufacture the TFT substrate, a gate insulating film, a TFT, a drain electrode, a drain bus line, a pixel electrode, an alignment A film or the like is formed. On the other hand, a black matrix, a color filter, a common electrode, an alignment film and the like are formed on a CF substrate facing the TFT substrate. Then, a sealing material such as an epoxy resin is applied to the CF substrate, and spacers are scattered, and then the two substrates are bonded. When the sealing material 2 is applied, the liquid crystal injection opening 3 is opened by 20 mm, and the liquid crystal is injected.
After injecting the liquid crystal, using a three-bond ultraviolet-curing sealing material (30Y-228), the sealing material 7 is cured by irradiating ultraviolet rays 250 seconds after the application of the sealing material 7. As a result, the flow of the sealing material 7 is kept close to the design value of 700 μm, so that the sealing material 7 does not enter the liquid crystal display area 8 of the liquid crystal display panel 10 and no display failure occurs.

[0018]

As described above, according to the present invention, when sealing the opening after injecting liquid crystal into the liquid crystal display panel, the sealing material is prevented from invading the liquid crystal display area, and display defects are reduced. The problems that occur are eliminated. In addition, there is no increase in the number of manufacturing steps for this, and this greatly contributes to improvement in display quality of the liquid crystal display device.

[Brief description of the drawings]

FIG. 1 is a plan view of a liquid crystal display panel according to an embodiment of the present invention.

FIG. 2 is a diagram showing a manufacturing process of the liquid crystal display panel according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating a problem of a conventional liquid crystal display panel.

FIG. 4 is a plan view of a conventional liquid crystal display panel.

[Explanation of symbols]

 2 Sealing material 3 Opening for liquid crystal injection 7 Sealing material 8 Liquid crystal display area 9 Metal film 10 Liquid crystal display panel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H089 JA11 LA22 LA32 LA48 NA19 NA24 NA55 NA60 PA13 QA12 QA13 TA06 TA09 2H092 JA26 JA39 JB27 KA16 KA18 MA05 MA14 MA15 MA16 MA17 MA35 MA37 NA25 NA29 PA04 5G435 AA14 AA17 EE06 KK LL04 LL08 LL14

Claims (3)

[Claims] 1. A sealing material is applied in a frame shape on at least one of two substrates so as to surround a liquid crystal display region while leaving an opening for injecting liquid crystal, and the two substrates disposed opposite to each other. A liquid crystal display panel in which substrates are fixed with the sealant, wherein a metal film is provided between the opening on at least one of the two substrates and the liquid crystal display region. Display panel. 2. The liquid crystal display panel according to claim 1, wherein a material of the metal film is any one of aluminum, titanium, chromium, and silicon. 3. A liquid crystal display area having at least one of a thin film transistor, a gate bus line, and a drain bus line formed on one of two substrates and leaving an opening for injecting liquid crystal on at least one of the two substrates. A method of manufacturing a liquid crystal display panel, in which a sealing material is applied in a frame shape so as to surround the liquid crystal display panel, and the two substrates disposed opposite to each other are fixed with the sealing material. A method for manufacturing a liquid crystal display panel, wherein a metal film is formed between the gate bus line and the region in the same step.