JPH11190854A - Liquid crystal display device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely seal an injection hole for liquid crystal. SOLUTION: The peripheral parts of array substrates 2 which face each other are sealed with a sealing agent 5. For the sealing agent 5, the injection hole 6 is provided. The peripheral part of the injection hole 6 is coated with a 1st sealant 11 and after the sealant is cured, the liquid crystal 7 is injected through the injection hole 6. Then a 2nd sealant 12 is applied over the 1st sealant 11 to seal the injection hole 6. Even if liquid crystal 7 sticks on the 1st sealant 11, etc., at the peripheral part of the injection hole 6, the sealants 11 and 12 can be adhered strongly to each other. The step C between an end surface 2a of the array substrate 2 and an end surface 5a of the sealant 5 is filled with the 1st sealant 11 to suppress the staying of liquid crystal 7 at the step C, so that the injection hole 6 can securely be sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a liquid crystal display device in which liquid crystal is injected between opposing substrates and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal display device, peripheral portions of glass substrates opposed to each other are sealed with a sealant, and liquid crystal is injected between the substrates through an inlet provided in the sealant. A configuration in which a sealing agent is applied and sealed is known. After the liquid crystal is injected from the injection port, the end surface of the sealant near the injection port and the end surface of the glass substrate are wet with the liquid crystal. Therefore, a sealing material is applied after a liquid crystal near the injection port is removed by wiping with a nonwoven fabric, blowing it off with an air blow, or removing it by suction or the like.

[0003]

In the above-mentioned conventional configuration,
It is difficult to completely remove the liquid crystal near the injection port, and there is a small amount of liquid crystal between the end face of the sealant and the sealant or between the end face of the glass substrate and the sealant. It is in the state of doing. Further, when there is a step between the end face of the sealant and the end face of the glass substrate, the liquid crystal may accumulate at the step. In these states, the liquid crystal between the sealant and the sealant reduces the adhesive force between the sealant and the sealant, and the sealant peels off due to external stress or the like, or The so-called leak path is generated by liquid crystal collected between the end face of the sealant and the sealant or between the end face of the glass substrate and the sealant, so that air and contaminants enter the inside of the glass substrate from the injection port. However, there is a problem that causes display failure.

An object of the present invention is to provide a liquid crystal display device capable of reliably sealing an injection port and improving display quality, and a method of manufacturing the same.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method of sealing peripheral portions of opposing substrates with a sealant provided with an inlet,
The first sealant is brought into close contact with the periphery of the inlet, liquid crystal is injected between the substrates from the inlet, the second sealant is brought into close contact with the first sealant, and the inlet is sealed. Things.

[0006] In this configuration, the first sealant is
Adheres tightly to the sealant with the original adhesive force without the interposition of liquid crystal. When sealing the injection port with the second sealant, the liquid crystal adheres to the first sealant around the injection port and the like,
This liquid crystal is sandwiched between the first sealant and the second sealant, but is an adhesion between the sealants, and has a larger adhesive force than the adhesion between the sealant and the sealant. In addition, a decrease in the adhesive strength due to the liquid crystal is also suppressed.

In addition, the first sealing agent fills the step between the end surface of the substrate and the end surface of the sealing agent, or the first sealing agent smoothly fills the step between the end surface of one substrate and the end surface of the other substrate. Liquid crystal is prevented from accumulating in these steps, and the injection port is securely sealed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a liquid crystal display device and a method of manufacturing the same according to the present invention will be described below with reference to the drawings.

1 and 2, reference numeral 1 denotes a liquid crystal display device. The liquid crystal display device 1 is also called a liquid crystal panel, a liquid crystal display panel, or simply a panel. An array substrate 2 having electrodes for driving the substrate and a transparent substrate 3 also called an opposing transparent substrate or the like are provided. The substrates 2 and 3 are opposed to each other in parallel at a predetermined interval, and the vicinity of the outer peripheral portion is sealed, that is, bonded with a sealant 5 applied in a frame shape. In addition, an injection port 6 that connects the inside and the outside is formed in the sealant 5, and the liquid crystal 7 is injected inside through the injection port 6. Further, at both ends of the injection port 6, rising portions 8 from which the sealing agent 5 is raised are formed. The injection port 6 is sealed with a first sealant 11 and a second sealant 12.
That is, the first sealant 11 is provided around the inlet 6, that is, the end face 5 a of the rising portion 8 of the sealant 5 and each substrate 2.
The second sealant 12 is in close contact with the first sealant 11 so as to cover the inlet 6 in a frame-like manner on the end surfaces 2a, 3a of the third member 3 and the like.

Next, a manufacturing process of the liquid crystal display device 1 will be described.

First, after cleaning the array substrate 2 and the transparent substrate 3, an alignment film is applied and baked, and a rubbing process is performed.
After washing again, the sealant 5 is applied to the transparent substrate 3 for example.
Is applied using a dispenser. On the other hand, a spacer agent is sprayed on the array substrate 2 side using an electrostatic spraying device or the like. Thereafter, the array substrate 2 and the transparent substrate 3 are combined, and the sealant 5 is cured while applying pressure.

Before the liquid crystal 7 is injected, the injection port 6
The end face 5a of the rising portion 8 of the sealant 5 and the end faces of the substrates 2 and 3 except for the peripheral portion of the end, that is, the opening of the injection port 6 is left.
The first sealant 11 is applied to 2a, 3a and the like, and is cured by irradiating ultraviolet rays.

Thereafter, the liquid crystal 7 is injected into the inside from the injection port 6, and the liquid crystal 7 attached to the periphery of the injection port 6 is removed by wiping with a nonwoven fabric or the like.

Thereafter, the injection port 6 is covered from above,
Further, the second sealing agent 12 is applied so as to cover the first sealing agent 11, and is cured by irradiating ultraviolet rays or the like, thereby completing the sealing of the liquid crystal display device 1. In some cases,
Before applying the second sealant 12, pressure is applied to the substrates 2 and 3,
The liquid crystal 7 injected more than necessary is removed, and the second sealant 12 is removed.
After application, the pressure may be relaxed to allow the second sealant 12 to penetrate into the inlet 6.

A liquid crystal display device 1 is completed by attaching a deflecting plate, mounting a driving circuit on the periphery of each of the substrates 2 and 3, and combining the driving circuit with a backlight device.

As described above, according to the present embodiment, a pair of upper and lower glass substrates having an electrode pattern are joined to at least one substrate by the sealant formed around the substrate, and the liquid crystal is sealed therein. Liquid crystal display panel
Regarding the shape and forming method of the injection port seal near the injection port, the first sealant 11 was applied to the sealant 5 and cured before the liquid crystal 7 was injected.
, And can be firmly adhered to the sealant 5 with the original adhesive force. When the inlet 6 is sealed with the second sealant 12, the liquid crystal 7 is filled with the first sealant 11 around the inlet 6.
The liquid crystal 7 is adhered on the top and the like, and the liquid crystal 7 is sandwiched between the first sealant 11 and the second sealant 12. A larger adhesive force can be secured than the adhesive between the agent and the sealant, and a decrease in the adhesive force due to the liquid crystal 7 can be suppressed, so that the injection port 6 can be reliably sealed.
That is, the first applied and cured first liquid crystal 7 was injected.
The sealing agent 11 keeps the adhesive force with the sealing agent 5 to make the first
And peeling of the second sealants 11 and 12 can be prevented.

Further, by filling the steps between the end surfaces 2a, 3a of any one of the substrates 2, 3 and the end surface 5a of the sealant 5 with the first sealant 11, it is possible to suppress the accumulation of liquid crystal at these steps. Thus, the injection port 6 can be reliably sealed.

That is, as shown in FIG. 2, at the injection port 6 of the liquid crystal display device 1, the sealant 5
3 does not reach the end surfaces 2a, 3a, that is, the end surface 5a of the sealing agent 5 is retracted from the end surfaces 2a, 3a of the substrates 2, 3, and the step C
When the step occurs, the portion of the step C is
By filling the sealing material 11 with the sealing agent 11 and making it smooth, it is possible to suppress the generation of liquid crystal pools in which liquid crystal remains on the step C, prevent the occurrence of leak paths, and reliably seal the injection port 6.

As described above, the adhesion between the sealant 5 and the first and second sealants 11 and 12 is improved,
Since the occurrence of a leak path due to a step is suppressed and the injection port 6 can be reliably sealed, air bubbles, air and contaminants can be prevented from entering the panel, display defects of the liquid crystal display device 1 can be suppressed, and display quality can be suppressed. Can be improved.

Next, a second embodiment will be described.

In the second embodiment, as shown in FIG. 3, at the injection port 6 of the liquid crystal display device 1, a step D occurs between the end surfaces 2a and 3a of the substrates 2 and 3 instead of being flush. FIG.

That is, like the first embodiment shown in FIGS. 1 and 2, the liquid crystal display device 1 is also called a liquid crystal panel, a liquid crystal display panel, or simply a panel. The liquid crystal display device 1 includes an array substrate 2 having electrodes for driving, and a transparent substrate 3 also called an opposing transparent substrate. The substrates 2 and 3 are opposed to each other in parallel at a predetermined interval, and the vicinity of the outer peripheral portion is sealed, that is, bonded with a sealant 5 applied in a frame shape. Also, this sealing agent 5
Is formed with an inlet 6 communicating the inside and the outside, and a liquid crystal 7 is injected into the inside through the inlet 6 so that the sealant 5 is formed.
It is contained in. Also, at both ends of the injection port 6,
A rising portion 8 on which the sealing agent 5 has been raised is formed. Further, in this embodiment, extending portions 9 are formed from the rising portions 8 along the end faces 2a and 3a of the substrates 2 and 3, respectively. A step D is formed between the end face 2a of the array substrate 2 and the end face of the transparent substrate 3. The injection port 6 is sealed with a first sealant 11 and a second sealant 12. That is, the first sealant 11 is
, That is, the end surface 5a along the longitudinal direction of the extending portion 9 of the sealant 5 and the end surfaces 2a and 3a of the substrates 2 and 3 in a frame shape. Is in close contact with the first sealant 11 and covers the inlet 6.

Next, a manufacturing process of the liquid crystal display device 1 will be described with reference to FIG.

First, after cleaning the array substrate 2 and the transparent substrate 3, an alignment film is applied and baked, and a rubbing process is performed.
After washing again, the sealant 5 is applied to the transparent substrate 3 for example.
Is applied using a dispenser. At this time, the injection port 6
In the part, the sealant 5 is applied along the cut line 21 to be cut later. On the other hand, a spacer agent is sprayed on the array substrate 2 side using an electrostatic spraying device or the like. Thereafter, the array substrate 2 and the transparent substrate 3 are combined, and the sealant 5 is cured while applying pressure. Thereafter, the substrates 2 and 3 are cut along predetermined cut lines 21, 22, 23 and 24 shown in FIG. Note that at least the cut line 21 provided with the injection port 6 is cut so that each of the substrates 2 and 3 is cut one by one so that the end faces 2a and 3a are not flush with each other but have a step D.

Before the liquid crystal 7 is injected, the injection port 6
The end surface 5a of the extending portion 9 of the sealant 5 and the end surfaces of the substrates 2 and 3 except for the peripheral portion of the end, that is, the opening of the injection port 6 is left.
The first sealant 11 is applied to 2a, 3a and the like, and is cured by irradiating ultraviolet rays.

Thereafter, the liquid crystal 7 is injected into the inside from the injection port 6, and the liquid crystal 7 attached to the periphery of the injection port 6 is removed by wiping with a nonwoven fabric or the like.

After that, the inlet 6 is covered from above.
Further, the second sealant 12 is applied so as to cover the first sealant 11, and is cured by irradiating ultraviolet rays or the like.
As shown in (b) and (c), the sealing of the liquid crystal display device 1 is completed. In some cases, the second sealant 12
Prior to the application of the second sealant 12, pressure is applied to the substrates 2 and 3 to remove the liquid crystal 7 injected more than necessary, and the pressure is released after the second sealant 12 is applied. In some cases, it may penetrate into the entrance 6.

Then, the liquid crystal display device 1 is completed by attaching a deflecting plate, mounting a drive circuit on the periphery of each of the substrates 2 and 3 and combining the drive circuit with a backlight device.

According to the present embodiment, the first sealant 11 is applied to the sealant 5 and cured before the liquid crystal 7 is injected. And can be firmly adhered to the sealant 5 with the original adhesive force. When the inlet 6 is sealed with the second sealant 12, the liquid crystal 7 adheres to the periphery of the inlet 6 on the first sealant 11 and the like. First sealant 11 and second sealant
12 between the sealant and the sealant. In general, a larger adhesive force can be secured than the bond between the sealant and the sealant, and a decrease in the adhesive force due to the liquid crystal 7 can be suppressed. In addition, the injection port 6 can be reliably sealed. That is, the first sealant 11 applied and cured before the injection of the liquid crystal 7 maintains the adhesive force with the sealant 5, so that the sealants 11 and 12 can be prevented from peeling off.

Further, if there is a step D between the end surfaces 2a, 3a of the substrates 2, 3, it becomes difficult to remove the liquid crystal 7 before sealing, and the liquid crystal 7 accumulated in the step D is removed. Although the probability that a leak path is generated due to the failure is increased, the first sealant 11
By smoothly filling the step D between the end face 2a of the one substrate 2 and the end face 3a of the other substrate 3, the step D between the two glass substrates is smoothed, and the liquid crystal 7 accumulates on the step D. To prevent the liquid crystal 7 from being easily removed,
Can be reliably sealed.

As described above, the sealing agent 5 and the sealing agent
In addition to enhancing the adhesiveness to 11, 12 and suppressing the occurrence of a leak path due to a step, the injection port 6 can be reliably sealed, so that air bubbles, air and contaminants can be prevented from entering the panel, and the liquid crystal display A display defect of the device 1 can be suppressed, and display quality can be improved.

Furthermore, in the present embodiment, the extending portion 9 is applied to the injection port 6 of the sealant 5 along the end surfaces 2a and 3a of the substrates 2 and 3, that is, along the cut line 21. In other words, since each of the substrates 2 and 3 was cut along the longitudinal direction of the sealant 5 to form the injection port 6, the length of the extended portion 9 was changed to expose the cut line 21. The area of the contact portion between the sealing agent 5 and the sealing agents 11 and 12, that is, the bonding portion can be arbitrarily set and increased. Therefore, the sealant 5 and the sealants 11 and 12 can be reliably bonded together, and even when subjected to stress such as a temperature cycle or high temperature and high humidity, the sealant 5 and the sealants 11 and 12 can be used.
12 can be prevented from occurring, and the penetration of moisture and inorganic ions from the injection port 6 can be suppressed, and the reliability of the liquid crystal display device 1 can be improved.

In the embodiment shown in FIG. 4, the sealant 5 forms the rising portion 8 and further forms the extending portion 9 from the tip of the rising portion 8, but as shown in FIG. The entire length of the sealing agent 5 on the side where the injection port 6 is formed is applied along the cut line 21, and after the sealing agent 5 is cured, the sealing agent 5 can be cut along the center in the width direction. In this embodiment, since the width of the sealing agent 5 is reduced to half when cutting, the sealing agent 5 is applied in advance to double the thickness, and the width after cutting becomes the same as the other sides. The liquid crystal display device 1 is set in the same manner as in the embodiment shown in FIG.
To complete.

In the embodiment shown in FIG.
In addition to the effects of the embodiment shown in FIG. 4, since it is not necessary to form the rising portions 8 in the sealant 5, the outer size of the liquid crystal display device 1 can be reduced, and the liquid crystal display is small, lightweight and excellent in reliability. An apparatus 1 can be provided.

In each of the above embodiments, the first
It is preferable to use the same sealant as the sealant 11 and the second sealant 12 in order to improve the adhesiveness, but higher adhesiveness than the same sealant can be obtained. For example, a combination of different kinds of sealants is also possible.

If the viscosity of the sealant, especially the first sealant 11, is too small, it may penetrate into the inside of the panel. On the other hand, if the viscosity is too large, the sealant 5 and the first There is a possibility that a gap may be generated between the sealant 11 and the air. Therefore, the viscosity of the first sealant 11 is 1000
[MPaS] to 60000 [mPaS] or less, more preferably 3000 [mPaS] to 4000
It is preferably about 0 [mPaS] or less.

The injection port 6 is not limited to one location, but may be provided at a plurality of locations of the sealant 5.

The structure shown in FIGS. 4 and 5 in which the substrates 2 and 3 are cut along the longitudinal direction of the sealant 5 to increase the bonding area is applicable to the structure shown in FIGS. Can also. Also, the configuration shown in FIG. 3 does not necessarily need to adopt the configuration shown in FIGS.
As shown in (1), a configuration is employed in which the rising portion 8 of the sealing agent 5 is cut in a vertical direction or a direction similar to the vertical direction, so that the tact time in the seal application step and the cutting of the glass substrate can be facilitated.

The structure for cutting the substrates 2 and 3 along the longitudinal direction of the sealant 5 shown in FIGS. 4 and 5 so as to increase the bonding area is composed of the first sealant 11 and the second sealant 11. Stopper 12
In addition to the structure using the sealant, the sealing area between the sealant 5 and the sealant 5 can be increased by applying to the structure in which the injection port 6 is sealed using only the sealant after the liquid crystal 7 is injected. This has the effect of suppressing the occurrence of peeling between the agent 5 and the sealant, and improving the reliability of the liquid crystal display device 1.

[0040]

According to the present invention, the first sealant can be firmly adhered to the sealant with the original adhesive force without the intervention of the liquid crystal. When the inlet is sealed with the second sealant, the liquid crystal adheres to the first sealant around the inlet and the like, and the liquid crystal is mixed with the first sealant and the second sealant. Although it is sandwiched between the sealant 2 and the sealant, the bond between the sealants is higher than the bond between the sealant and the sealant. The inlet can be reliably sealed. In addition, the first sealing agent fills a step between the end surface of the substrate and the end surface of the sealing agent, or a smooth filling of a step between the end surface of one substrate and the end surface of the other substrate, so that these steps are eliminated. The accumulation of liquid crystal is suppressed, and the injection port can be reliably sealed.
As described above, since the adhesive of the sealant is enhanced and the injection port can be reliably sealed, it is possible to prevent air bubbles and contaminants from entering the inside of the sealant, thereby improving display quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view taken along a line BB in FIG. 2 showing one embodiment of a liquid crystal display device of the present invention.

FIG. 2 is a cross-sectional view of the liquid crystal display device, taken along the line AA in FIG. 1;

FIG. 3 is a sectional view showing a second embodiment of the liquid crystal display device of the present invention.

FIG. 4 is an explanatory view showing a manufacturing process of the liquid crystal display device.

FIG. 5 is an explanatory diagram of a manufacturing process of a liquid crystal display device showing another embodiment of the liquid crystal display device of the present invention.

FIG. 6 is an explanatory diagram of a manufacturing process of a liquid crystal display device showing still another embodiment of the liquid crystal display device of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 liquid crystal display device 2 array substrate as substrate 2a end face 3 transparent substrate as substrate 3a end face 5 sealant 7 liquid crystal 11 first sealant 12 second sealant

Claims (4)

[Claims] A substrate facing the substrate, a sealant for sealing peripheral portions of the substrates, an injection port provided in the sealant, a liquid crystal injected between the substrates from the injection port, A first sealant in close contact with the periphery of the inlet, and a second sealant in close contact with the first sealant and sealing the inlet.
A liquid crystal display device comprising: 2. The liquid crystal display device according to claim 1, wherein the first sealant fills a step between an end surface of the substrate and an end surface of the sealant. 3. The liquid crystal display device according to claim 1, wherein the first sealant smoothly fills a step between an end surface of one substrate and an end surface of the other substrate. 4. A sealing agent provided with an inlet is used to seal opposing peripheral portions of the substrates, and a first sealing agent is brought into close contact with a peripheral portion of the inlet, and a liquid crystal is interposed between the inlet and the substrate. And injecting a second sealant into close contact with the first sealant to seal the inlet.