JP3079750B2 - Liquid crystal display panel manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal display panel, and more particularly to a method for forming an alignment film.

[0002]

2. Description of the Related Art FIGS. 3A and 3B are explanatory views of an alignment film in a liquid crystal display panel and a conventional rubbing treatment. A panel 1 used in a color liquid crystal display device has a polarizing plate 2 adhered to the lower surface. A black mask pattern 4, color pixels 5, an overcoat layer 6 covering them, a transparent electrode 7 extending in the left-right direction, and an alignment film 8
Is formed.

A conventional rubbing process for improving the rotation property of the liquid crystal is performed by using a proper tilt angle (rubbing angle) with respect to the substrate 3.
A rubbing cloth is adhered to a rubbing roller 9 which is disposed at α and rotates, and the alignment film 8 is rubbed with the tip of the fluff 10 of the rubbing cloth.

[0004]

As described above, in the conventional rubbing treatment, since the alignment film 8 is repeatedly rubbed with the fluff 10, dust such as a lint of the fluff 10 and shavings of the alignment film 8 is generated. The rubbing treatment becomes uneven due to the adhesion of the rubbing treatment to the alignment film 8 and the unevenness of the fluff 10, and as a result,
There is also a problem that display unevenness is apt to occur when incorporated in a device.

There is a method of removing dust adhered to the alignment film 8 by air blowing or washing. However, they have a drawback that the effect of the rubbing treatment is impaired due to the relatively strong dust adhering force, and the effect of the rubbing treatment is impaired.

[0006] Frequent replacement of the rubbing cloth reduces the generation of dust. However, the rubbing treatment gives rise to static electricity, and the adhesion of dust floating in the air is not prevented.
The new rubbing cloth has an unstable liquid crystal orientation and increases the product cost.

[0007]

The method of the present invention for preventing foreign matter from adhering to an alignment film by a rubbing process is shown in FIG.
According to the embodiment shown in FIG. 2, a transparent electrode is formed on the transparent substrate 3, and a relief plate 14 in which a large number of projections 18 are formed in many rows is formed in the alignment film forming region of the transparent substrate 3 on which the transparent electrode is formed. Or 21, and the projection row is inclined at a predetermined inclination angle to the transparent electrode.
(Orientation Angle) Transferring a resin so as to have α and curing the resin.

[0008] Further, another method of the present invention is as follows.
In the same manner as described above, a concave portion is formed on the letterpress 14 or 21, and the resin is transferred to the transparent substrate 3 to form an alignment film. When the resin is transferred to the transparent substrate 3, the letterpress 14, 21 is formed.
And moving the transparent substrate 3 to the pre-baking temperature of the resin when transferring the resin to the transparent substrate 3.

[0009]

According to the above-mentioned means, the resin alignment film itself is formed so as to have an orientation by utilizing the relief printing technique. Therefore, the conventional rubbing treatment using the rubbing fluff is unnecessary or only lightly performed, dust does not adhere to the alignment film, and the display quality and the manufacturing yield of the liquid crystal display panel are improved.

[0010]

1 (a) and 1 (b) are illustrations of first and second embodiments of the method of the present invention, and FIGS. 2 (a) and 2 (b) are third and fourth embodiments of the method of the present invention.
FIG. 4 is an explanatory diagram of the embodiment.

In FIG. 1A, which is a side view showing a main part of the resin transfer device, a transparent substrate 3 having a plurality of transparent electrodes (not shown) extending in the left-right direction for use in a color liquid crystal display panel has a bed. It is fixed to a slide table 12 which is guided by 11 and reciprocates toward a plate cylinder 13 which rotates.

A plate cylinder 13 rotating in the direction of the arrow in FIG.
14 is fixed and the metal roll rotates in the direction of the arrow in the figure.
15 is coated with a liquid polyimide resin 17 to a uniform thickness of, for example, 10 μm by a doctor roll 16 rotating in the opposite direction to the metal roll 15, and the resin 17 applied to the metal roll 15 is applied to the plate cylinder 13. Transfer to the surface of letterpress 14 by rotation
(Print).

FIG. 1B is a developed view of the surface of the letterpress 14,
In the first embodiment of the present invention, the surface of the relief plate 14 corresponding to the alignment film forming region of the transparent substrate 3 has a large number of protrusions 18 having a diameter of, for example, 50 to 75 μm and a height of about 10 μm.
Are aligned and protruded along each broken line at a predetermined rubbing angle α with respect to the rotation direction of the plate cylinder 13 (left-right direction in the figure).

Then, the plate cylinder 13 is rotated to rotate the surface of the letterpress 14.
Transfer the resin of metal roll 15 to (tip surface of projection 18),
When the plate cylinder 13 is further rotated and the slide table 12 is advanced, the alignment film forming region on the surface of the transparent substrate 3 on which the transparent electrodes are formed in the direction of movement of the slide table 12 has resin on the surface of the relief plate 14. Is transferred, and the resin is heated and cured (baked) to complete the formation of the alignment film.

In the first embodiment of the present invention, a large number of point-like resins transferred from the relief plate 14 to the surface of the transparent substrate 3 spread around the hardening process and become continuous between adjacent ones. The portion corresponding to the dashed line 1 (b) is thicker than the portion corresponding to the space between the dashed lines, and the same effect as the conventional rubbing process can be obtained.

Next, a second embodiment of the present invention will be described with reference to FIG. 1. In the second embodiment, the surface of the relief plate 14 corresponding to the alignment film forming region of the transparent substrate 3 has: Instead of the projections 18, for example, a number of recesses having a diameter of 50 to 75 μm and a depth of about 10 μm are formed in the rotation direction of the plate cylinder 13 (the left-right direction in the figure).
Is formed along each broken line at a predetermined rubbing angle α.

Using the relief plate 14 in which such a recess is formed,
When the resin is transferred to the surface of the transparent substrate 3 in the same manner as in the first embodiment, the resin is not transferred to the portion corresponding to the recess in the alignment film forming region of the transparent norm 3 but to the other portion. Become so.

The resin transferred to the transparent norm 3 in this manner fills the recess corresponding portions during the curing process. However, the portion corresponding to the broken line in FIG. 1B is thinner than the portion between the broken lines, and the same effect as the conventional rubbing process can be obtained.

In FIG. 2, which is a plan view of a main part of the resin transfer device, a transparent substrate 3 is fixed to a slide table 12 which reciprocates toward a plate cylinder 13, and a plate cylinder according to a third embodiment of the present invention. 13, the plate cylinder
13 In the direction of rotation (the direction of the broken line in the figure), for example, a diameter of 50 to 75
A plurality of projections 18 having a height of about 10 μm and having a height of about 10 μm are aligned, and a projecting plate 21 is fixed.

However, the rectangular transparent substrate 3 on which the transparent electrodes are formed in the longitudinal direction is fixed to the slide table 12 so as to be inclined by a predetermined rubbing angle α, and the transparent substrate 3 is adjusted in accordance with the inclination. The letterpress 21 corresponding to the alignment film forming region is also inclined.

Then, when a resin having a uniform thickness is applied to the surface of the metal roll 15 by a metal roll 15 and a doctor roll 16 shown by a dashed line, a part of the resin is removed from the plate cylinder.
When the plate 13 is further rotated and the slide 12 is moved forward, the alignment film forming region on the surface of the panel substrate 1 is transferred to the surface of the relief printing plate 21 (the tip surface of the projection 18) by the rotation of the printing plate 21.
The resin on the surface of the letterpress 21 is transferred, and the resin is heated and cured (baked) to complete the formation of the alignment film.

In the third embodiment of the present invention, a large number of dot-like resins transferred from the relief plate 21 to the surface of the transparent substrate 3 spread around the hardening process and become continuous between adjacent ones. The portion corresponding to the dashed line 1 (b) is thicker than the portion corresponding to the space between the dashed lines, and the same effect as the conventional rubbing process can be obtained.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 2. In the fourth embodiment, the surface of the relief plate 21 corresponding to the alignment film forming region of the transparent substrate 3 is provided with: Instead of the projections 18, for example, a number of recesses having a diameter of 50 to 75 μm and a depth of about 10 μm are formed in the rotation direction of the plate cylinder 13 (the left-right direction in the figure).
Are formed along the broken lines.

Using the relief printing plate 21 having such recesses,
When the resin is transferred to the surface of the transparent substrate 3 in the same manner as in the third embodiment, in the alignment film forming region of the transparent substrate 3, the resin is not transferred to a portion corresponding to the recess, and the resin is transferred to another portion. Become so.

The resin transferred to the transparent substrate 3 in this manner fills the recess corresponding portions during the curing process.
The portion corresponding to the broken line in FIG. 2 is thinner than the portion corresponding to the portion between the broken lines, and the same effect as the conventional rubbing process can be obtained.

Next, a fifth embodiment of the present invention will be described with reference to FIG. 1. The fifth embodiment is a modification of the second embodiment. A recess corresponding to the recess formed in the metal roll 15 is provided on the metal roll 15, the recess of the relief plate 14 is eliminated, the resin filled in the recess of the metal roll 15 is transferred to the relief 14, and the resin is transferred to the panel substrate 1. To be transferred to

Next, a sixth embodiment of the present invention will be described with reference to FIG. 2. The sixth embodiment is a modification of the fourth embodiment. A concave portion corresponding to the concave portion formed in the metal roll 15 is provided on the metal roll 15, the concave portion of the relief plate 21 is eliminated, the resin filled in the concave portion of the metal roll 15 is transferred to the relief plate 21, and the resin is transferred to the panel substrate 1. To be transferred to

In general, the curing treatment of a polyimide resin is divided into pre-baking for semi-curing and post-baking for complete curing. Therefore, in the seventh to twelfth embodiments of the present invention, a heater is accommodated in the slide base 12 to heat the panel substrate 1 to about 80 ° C.
In each of the sixth to sixth embodiments, the resin for forming the alignment film is transferred to the transparent norm 3 and the transferred resin is prebaked.

In the first to twelfth embodiments described above, the alignment characteristics with respect to the liquid crystal are almost the same as those of the conventional method. However, when it is desired to further enhance the alignment characteristics, a conventional rubbing treatment using a rubbing cloth may be performed lightly after forming an alignment film by the method of the present invention.

Further, as another embodiment of the present invention, when the resin for forming the alignment film of the letterpress 14 or 21 is transferred to the transparent substrate 3, the moving speed of the letterpress 14 or 21, the moving speed of the transparent substrate 3, Are different, for example letterpress 14 or 21
When the moving speed of the transparent substrate 3 is 100, the moving speed of the transparent substrate 3 is
By setting it to 100.01, an alignment film with higher stability is formed than when the two moving speeds are the same.

[0031]

As described above, the alignment film according to the method of the present invention does not need to be rubbed by rubbing fluff or only needs to be rubbed lightly. Therefore, there is an effect that the cleanliness of the alignment film is secured, and the display quality and the production yield of the liquid crystal display panel are improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of first and second embodiments of the method of the present invention.

FIG. 2 is an explanatory view of a third and a fourth embodiment of the method of the present invention.

FIG. 3 is an explanatory diagram of an alignment film and a conventional rubbing process in a liquid crystal display panel.

[Explanation of symbols]

 3 is a transparent substrate on which a transparent electrode is formed. 7 is a transparent electrode. 12 is a slide for fixing the transparent substrate. 14, 21 is a relief plate. 15 is a metal roll. 16 is a doctor roll. Protrusion

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1337-1/1337 530

Claims (4)

(57) [Claims] A transparent electrode (7) is formed on a transparent substrate (3),
A relief plate (1) having a large number of projections (18) formed in a large number of rows in an alignment film forming region of the transparent substrate (3) on which the transparent electrode (7) is formed.
4, 21) a method of manufacturing a liquid crystal display panel, wherein a resin is transferred to the transparent electrode (7) so that the projection row has a predetermined inclination angle, and the resin is cured. 2. A transparent electrode (7) is formed on a transparent substrate (3),
A relief plate (14, 2) having a large number of recesses formed in a large number of rows in an alignment film forming region of the transparent substrate (3) on which the transparent electrode (7) is formed.
A method of manufacturing a liquid crystal display panel, wherein a resin is transferred so that the recess row has a predetermined inclination angle with respect to the transparent electrode (7), and the resin is cured. 3. The transfer speed of the relief plate (14, 21) fixed to a rotating plate cylinder (13) when transferring the resin according to claim 1 to the transparent substrate (3). 3. The moving speed of the transparent substrate (3) moving in a direction perpendicular to the rotation axis of the plate cylinder (13) is different from the moving speed of the transparent substrate (3).
The manufacturing method of the liquid crystal display panel described in the above. 4. The method according to claim 1, wherein the step of transferring the resin according to claim 1 to the transparent substrate comprises heating the transparent substrate to a prebaking temperature of the resin. 3. The method for manufacturing a liquid crystal display panel according to claim 1.