JP2001117082A - Mother substrate for liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mother substrate for a liquid crystal display panel which surely suppresses deflection of transparent plastic substrates by dispersing internal stress in a dummy film. SOLUTION: The dummy film 13 is formed in a dot shape in which plural dots are dispersed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motherboard for a liquid crystal display panel, and more particularly to a motherboard for a liquid crystal display panel in which a dummy film for preventing deflection is formed on a transparent plastic substrate having low rigidity.

[0002]

2. Description of the Related Art Conventionally, two transparent substrates on which a transparent electrode, an alignment film and the like are formed are bonded together via a peripheral sealing material, and a liquid crystal is filled in a gap between the two transparent substrates formed by the peripheral sealing material. In order to increase the productivity of the injected liquid crystal display panel, a motherboard for a liquid crystal display panel having a plurality of display regions formed thereon and a motherboard for an opposite liquid crystal display panel facing the motherboard are bonded to each other. However, a manufacturing method has been employed in which a plurality of liquid crystal display panels are manufactured at the same time by dividing the liquid crystal display panels into single liquid crystal display panels.

[0003] Conventionally, a plastic substrate has been used as the transparent substrate. This plastic substrate has great advantages in the fields of mobile phones, portable information terminals, and the like because of its advantages of being lighter and harder to break than glass substrates.

However, since the plastic substrate has a lower rigidity than a glass substrate, there is a problem in that the transparent substrate is bent by the transparent electrode formed on the transparent substrate.

For this reason, conventionally, a mother substrate for a liquid crystal display panel has been adopted in which a dummy film for preventing deflection is formed on a plastic substrate, which is made of a transparent conductive film of the same material as the transparent electrode.

That is, as shown in FIG. 4, the mother substrate 1 for a liquid crystal display panel has a transparent substrate 2 made of plastic, and a plurality of display areas 3 are uniformly formed on the transparent substrate 2. It is formed in a simple arrangement. Each display area 3 has a transparent conductive film of indium tin oxide (IT
O) and the like, and a frame-shaped peripheral sealing material forming position 5 is provided around each display area 3. The non-display area 6 other than the display area 3
Is formed with a dummy film 7 made of a transparent conductive film for preventing the transparent substrate 2 from bending.

By manufacturing a liquid crystal display panel using such a mother substrate 1 for a liquid crystal display panel, it is possible to make up for defects of a plastic substrate having poor rigidity and to manufacture a good liquid crystal display panel without bending. Was to be able to.

[0008]

However, conventionally, the dummy film 7 has been formed almost entirely on the non-display area 6 on the transparent plastic substrate 2. The dummy film 7 is formed of ITO formed at a temperature equal to or lower than the glass transition temperature of the plastic substrate. Since the ITO has elasticity, the dummy film 7 itself has internal stress. Therefore,
In a state where the dummy film 7 is formed on almost the entire surface, the internal stress of the dummy film 7 itself becomes large.
In this case, the internal plastic stress causes the transparent plastic substrate 2 to bend, causing a problem of overturning.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a motherboard for a liquid crystal display panel capable of reliably suppressing the bending of a transparent substrate by dispersing the internal stress of a dummy film. It is intended for.

[0010]

According to a first aspect of the present invention, there is provided a mother substrate for a liquid crystal display panel, wherein a dummy film made of a transparent conductive film is formed in a dot shape in which a plurality of dots are dispersed. It is in the formed point.

Since the internal stress of the dummy film can be dispersed by adopting such a configuration, the original function of the dummy film of preventing the transparent plastic substrate from bending can be effectively exhibited. it can.

A feature of the motherboard for a liquid crystal display panel according to the second aspect is that, in the first aspect, a dummy sealing material for preventing bending is formed on the non-display area of the transparent plastic substrate, and the dummy sealing material is formed. The point is that the dummy film is not formed below the formation range.

By adopting such a configuration, when a dummy sealing material for preventing the transparent plastic substrate from being bent is formed on the non-display area of the transparent plastic substrate, the dummy sealing material and the transparent plastic substrate are formed. Can be properly bonded.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a motherboard for a liquid crystal display panel according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a motherboard 10 for a liquid crystal display panel according to the present embodiment has a transparent plastic substrate 2. On the transparent plastic substrate 2,
Display regions 3 for forming a plurality of liquid crystal display panels are arranged at predetermined intervals and are arranged on each display region 3. Indium tin oxide (ITO) which is a transparent conductive film
Is formed. In the case of a color liquid crystal panel, R, G, B color elements and color filters may be formed below the transparent electrode 4.

A frame-shaped peripheral sealing material forming position 5 is provided around each display area 3. The peripheral sealing material forming position 5 includes a mother substrate 16 for the opposed liquid crystal display panel shown in FIG. Peripheral sealing material 12 in the bonding process of
Is formed.

Further, a non-display area 6 on the transparent plastic substrate 2 and outside each display area 3 includes:
A dummy film 13 made of ITO, which is a transparent conductive film of the same material as the transparent electrode 4 for preventing the transparent plastic substrate 2 from bending, is formed in a dot shape in which a plurality of dots are dispersed. Therefore, since the internal stress of the dummy film 13 is dispersed for each dot, the transparent plastic substrate 2 is not bent by the internal stress of the dummy film 13 itself. Note that the shape of each dot is preferably a substantially square from the viewpoint of making the stress in the upper, lower, left and right directions in FIG. 1 uniform. In this case, it is preferable to cut off the four corners of each dot as shown in FIG. 2 so that each dot does not damage the rubbing cloth during rubbing. The interval between the dots is 20 to 50 μm, and the total area of the dummy film 13 is 70% of the total area of the non-display area 6.
It is preferably set to about 90%.

Further, at the upper end and the lower end of the non-display area 6 in FIG. 1, a formation position of a dummy sealing material 15 shown in FIG. (Referred to as a sealing material forming position 14). At the dummy seal material forming position 14, the dummy film 13 is not formed, or even if it is formed once in the manufacturing process, it is removed by the time the dummy seal material 15 is formed.

Therefore, the transparent plastic substrate 2 and the dummy sealing material 15 can be properly bonded.

Next, the mother board 1 for the liquid crystal display panel
A method of manufacturing a liquid crystal display panel using 0, 16 will be described.

First, a plurality of display areas 3 are positioned at equal intervals on one surface of a transparent plastic substrate 2 made of polycarbonate or the like on which a hard coat layer, a gas barrier coat layer, an undercoat layer and the like are formed.
A transparent electrode 4 made of ITO is formed thereon. The transparent electrode 4 is formed by patterning a column electrode (not shown) in which a display electrode, a connection electrode, and a terminal electrode are formed in a single stripe for each display area 3, and a motherboard for an opposing liquid crystal display panel. The same number of stripe-shaped connection electrodes and terminal electrodes (not shown) as the row electrodes formed on the substrate 16 are formed by patterning.

In a non-display area 6 other than the display area 3, a transparent conductive film I of the same material as the transparent electrode 4 is formed.
The dummy film 13 made of TO is formed in a dot shape in which a plurality of dots are dispersed. At this time, the dummy film 13 is not formed by patterning at the dummy seal material forming position 14 where the dummy seal material 15 for preventing deflection is formed.

Then, after a polyimide resin is laminated on the transparent plastic substrate 2 except for a terminal portion (not shown) and a conductive connection portion between the substrates, a predetermined alignment film treatment is performed by rubbing or the like, thereby obtaining a liquid crystal display panel. The mother substrate 10 is formed.

Further, the motherboard 1 for a liquid crystal display panel
A transparent plastic substrate 2 similar to the transparent plastic substrate 2 is prepared.
And a transparent electrode 4 made of ITO is formed on each display region 3. Further, a dummy film 13 made of ITO, which is a transparent conductive film, is formed in the non-display area 6 other than the display area 3. And
After forming a row electrode (not shown) orthogonal to a column electrode of the motherboard 10 for a liquid crystal display panel together with a connection electrode on the transparent plastic substrate 2, a polyimide is laminated and an alignment film is formed by rubbing to form an alignment film. The mother substrate 16 for the opposing liquid crystal display panel which faces the mother substrate 10 is formed.

The motherboard 16 for the opposing liquid crystal display panel and the motherboard 10 for the liquid crystal display panel are
In the case of bonding, as shown in FIG. 3, a peripheral seal material 12 is formed at the seal material forming position 5 of the liquid crystal display panel mother substrate 10 and a dummy seal material 15 is formed at the dummy seal material forming position 14. After the spacers are scattered on the mother substrate 16 for the opposing liquid crystal display panel, the mother substrates 10 and 16 are overlaid with a jig (not shown) so that the surface on which the transparent electrode 4 is formed faces inside. An injection hole (not shown) for injecting liquid crystal when forming the peripheral sealing material 12 is formed.

Then, the two mother substrates 10 overlapping each other,
The peripheral seal member 12 is melted by heating the jig together with the jig, and the peripheral seal member 12 is cured while the mother substrates 10 and 16 are pressed against each other. Glue each other.

Then, the two mother substrates 10 bonded together,
16 is cut in units of one row of strips in which the display areas 3 are arranged in the horizontal direction, so that the injection holes formed in each peripheral sealing material 2 are exposed to the outside so that liquid crystal can be injected. Then, after injecting the liquid crystal from each injection hole, the injection hole is sealed with an ultraviolet curable resin. Lastly, the strip-shaped mother substrates 10 and 16 are separated for each single liquid crystal display panel.

Thus, a plurality of liquid crystal display panels are simultaneously formed.

Next, the quality test of the liquid crystal display panel manufactured using the motherboards 10 and 16 for the liquid crystal display panel according to the present embodiment and the liquid crystal display panel manufactured using the conventional motherboard 1 for the liquid crystal display panel will be described. Will be described.

In this test, (1) a bending measurement test for measuring the amount of warpage (mm) in the long side direction and the short side direction of the liquid crystal display panel, and (2) the dimension of the gap between the transparent plastic substrates 2 facing each other Three kinds of tests were carried out: a variation measurement test for measuring the variation, and (3) a peeling rate test for examining a peeling rate of the dummy seal material 15 generated when the mother substrates 10 and 16 in the bonded state were cut.

As the mother substrate 10 for one liquid crystal display panel in the present embodiment, a plastic substrate made of 0.1 mm polycarbonate was used as the transparent plastic substrate 2. In addition, the dots of the dummy film 13 made of ITO were approximately 1 mm × 1 mm square, and the distance between the dots was 50 μm. In addition, portions that cannot be formed into a substantially square shape, such as the end portions of the substrate, were handled by changing the shape of the dots. Further, the dummy sealing material 1
As No. 5, a dummy sealing material 15 having a width of 2 mm was used, and patterning according to the shape of the dummy sealing material 15 was performed at the dummy sealing material forming position 14 in the non-display area 6. In the peripheral sealing material 12, as a conductive connecting material between the substrates, conductive beads having a mean particle diameter of 6.0 μm formed by plating two layers of gold and nickel on resin beads made of a styrene-divinylbenzene copolymer are used. 2% by weight of beads are mixed and conductive filler is 5w
t% mixed. The thickness of the polyimide laminated on the transparent plastic substrate 2 was about 400 °.

The thickness of the transparent plastic substrate 2 and the dots of the dummy film 13 were similarly formed on the mother substrate 16 for the opposing liquid crystal display panel on the mother substrate 10 for the liquid crystal display panel. The spacers to be scattered on the mother substrate 16 for the opposing liquid crystal display panel have a surface layer made of a thermo-flexible resin, and have a core of styrene-divinylbenzene copolymer and an average particle diameter of 5.7 μm. Resin beads were used.

When the two mother substrates 10 and 16 are overlapped by a jig, the twist angle of the liquid crystal molecules is 240
After being arranged so as to be in a position and performing positioning, they were superposed. Then, the two mother substrates 10 overlapped,
By heating 16 at a temperature of 120 ° C., the peripheral sealing material 12 was cured. In addition, after injecting liquid crystal into the gap between the two mother substrates 10 and 16 bonded together by the peripheral sealing material 12, the two mother substrates 10 and 16 are pressurized at a predetermined pressure, so that extra liquid crystal in the gap is externalized. Released.

The above three types of quality tests were performed on the liquid crystal display panel manufactured using the liquid crystal display panel mother substrates 10 and 16 in the present embodiment to which the above specific numerical values were applied.

On the other hand, as the conventional motherboard 1 for a liquid crystal display panel, the motherboards 10 and 16 for the liquid crystal display panel of the present embodiment are the same as the motherboards 1 and 16 for the liquid crystal display panel except that the dummy film 7 is formed almost entirely on the non-display area 6. The configuration and specific numerical values were the same. The conventional motherboard 1 for a liquid crystal display panel
In the above, the dummy seal material 15 was also formed, but for comparison with the present embodiment, the dummy seal material 15 was formed on the dummy film 7.

In this embodiment and the related art, the dimensions of the liquid crystal display panel were formed to be 40 × 30 mm.

The results of tests performed on the two liquid crystal display panels are shown below.

[0038]

[Table 1]

As shown in Table 1, first, in the deflection measurement test, the liquid crystal display panel of the present embodiment has a warpage of 0.1 mm in the longitudinal direction, whereas the conventional liquid crystal display panel has a warpage of 0.1 mm. 3.0 mm, the amount of warpage in the longitudinal direction is 2.9 mm larger than that of the present embodiment. Further, the liquid crystal display panel of the present embodiment has a warpage in the short direction of 0 mm, whereas the conventional liquid crystal display panel has a warpage of 0.5 mm. Therefore, it can be seen that the liquid crystal display panel to which the present embodiment is applied is more excellent in preventing bending than the conventional one.

(2) In the variation measurement test, the liquid crystal display panel to which the present embodiment is applied is good without variation in the gap. The conventional liquid crystal display panel had a variation of 0.1 μm. Therefore, it can be seen that the liquid crystal display panel to which the present embodiment is applied is more excellent in the gap retention than the conventional liquid crystal display panel.

Further, in the (3) peeling rate test of the dummy seal material 15, the liquid crystal display panel to which the present embodiment is applied has a seal peeling rate of 1% or less.
The conventional liquid crystal display panel is as large as about 3%. Therefore, it can be seen that the liquid crystal display panel to which the present embodiment is applied is superior in the adhesion stability of the dummy seal material 15.

Therefore, according to the present embodiment, the dummy film 1
By forming the dots 3 in a dot shape in which a plurality of dots are dispersed, the internal stress of the dummy film 13 can be dispersed for each dot, so that the bending of the liquid crystal display panel can be prevented. In addition, the dummy film 1 is located in the formation range of the dummy seal material 15, that is, the dummy seal material formation position 14.
3 so that the dummy seal material 15 and the transparent plastic substrate 2 can be properly bonded to each other so that the function of the dummy seal material 15 for preventing the transparent plastic substrate 2 from being bent can be properly exhibited. Can be.

The present invention is not limited to the above embodiment, but can be variously modified as needed.

[0044]

As described above, according to the motherboard for a liquid crystal display panel according to the first aspect of the present invention, a good liquid crystal display panel without bending can be obtained.

According to the motherboard for a liquid crystal display panel according to the second aspect, the dummy sealing material and the transparent plastic substrate can be properly bonded to each other. Thus, the bending of the liquid crystal display panel can be more effectively suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a motherboard for a liquid crystal display panel according to the present invention.

FIG. 2 is an enlarged view showing a dummy film in the embodiment of the motherboard for a liquid crystal display panel according to the present invention.

FIG. 3 shows an embodiment of a motherboard for a liquid crystal display panel according to an embodiment of the present invention, in which a motherboard for a liquid crystal display panel and a motherboard for an opposing liquid crystal display panel are opposed to each other when they are bonded to each other. Sectional view

FIG. 4 is a diagram showing a conventional mother substrate for a liquid crystal display panel.

[Explanation of symbols]

 2 Transparent plastic substrate 3 Display area 4 Transparent electrode 6 Non-display area 10 Mother substrate for liquid crystal display panel 12 Peripheral sealing material 13 Dummy film 14 Dummy sealing material forming position 15 Dummy sealing material 16 Mother substrate for opposed liquid crystal display panel

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Okuda 1-2-1 Kamisakabe, Amagasaki City, Hyogo Prefecture Opterex Amagasaki Plant F-term (reference) 2H090 JA03 JA05 JA08 JA09 JB03 JC03 JC07 JD14 JD15 LA01

Claims (2)

[Claims] A plurality of display areas formed at predetermined intervals on a transparent plastic substrate, at least a transparent electrode is formed on each display area, and the transparent electrode is formed on a non-display area other than the display area. A motherboard for a liquid crystal display panel on which a dummy film made of a transparent conductive film for preventing bending of a plastic substrate is formed, wherein the dummy film is formed in a dot shape in which a plurality of dots are dispersed. Mother board for liquid crystal display panel. 2. A method according to claim 1, further comprising: forming a dummy sealing material for preventing deflection on the non-display area of the transparent plastic substrate, and not forming the dummy film below a formation area of the dummy sealing material. Claim 1.
A motherboard for a liquid crystal display panel according to item 1.