JPH11142851A - Method of manufacturing liquid crystal display panel and liquid crystal display panel - Google Patents

Abstract

(57) [Problem] To provide the same alignment film pattern position and shape with respect to upper and lower substrates, and to be able to share the alignment film printing plate between the upper and lower substrates, thereby improving the equipment operation rate, the quality, and the equipment cost. The aim is to reduce. SOLUTION: An alignment film pattern 101a, 1 corresponding to each chip formed on the upper and lower substrates 102a, 102b is provided.
01b to the center line B in the vertical (or horizontal) direction of the substrate.
Xa (or BYa) and BXb (or BYb) are arranged symmetrically so that the alignment film pattern having the same shape is located at the same position on the upper and lower substrates when the upper and lower substrates are bonded together with the alignment film printing surface inside. Formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is excellent in productivity,
The present invention relates to a method for manufacturing a liquid crystal display panel having a high yield and a liquid crystal display panel.

[0002]

2. Description of the Related Art In recent years, liquid crystal panels of various sizes and shapes have been produced and put to practical use with the expanding use of liquid crystal panels.

In the production of this liquid crystal panel, an alignment film material made of polyimide or the like is first applied to the substrate surface in a slightly wider area than the display area and cured by heating to align the liquid crystal molecules. The rubbing method of rubbing the surface with a cloth is generally widely used.

A general conventional example of an alignment film pattern on a liquid crystal display panel substrate and an alignment film forming method will be described with reference to the drawings.

First, FIG. 6 shows a cross section of a general TFT active matrix type color liquid crystal display panel, and basically, a thin film transistor (TF) is provided for each dot.
T) A lower substrate 2a on which a pixel electrode 5 made of a transparent conductive film, a signal wiring, and a mounting terminal are formed, and a color filter film 7 made of red, green, and blue resins are formed for each dot. It is formed from the upper substrate 2b on which the common transparent electrode 6 is formed. An alignment film 1a, 1b is formed on the inner surface of each substrate, and a liquid crystal 3 is sealed between them. A sealing material 10 for adhering the upper and lower substrates around the periphery and sealing the liquid crystal is provided.
Is arranged. Note that a fiber spacer 9 for forming an appropriate liquid crystal layer thickness is sealed in the sealing material 10.

Generally, in the production process, the size of the lower and upper substrates 2a and 2b is larger than the panel size shown in FIG. 6 at the time of preparation and before bonding of the upper and lower substrates. In many cases, a plurality of panels are arranged on one substrate and cut into a predetermined panel shape after bonding the upper and lower substrates.

FIG. 7A is a plan view of a lower substrate in which an alignment film is formed by letterpress printing in a conventional example, and FIG. 7B is a plan view of an alignment film formed by letterpress printing. It is a top view of a board. 7 (a) and 7 (b) are diagrams as viewed from the alignment film forming surface.

In the figure, BXa and BYa denote lower substrate 10 respectively.
AXa and AYa denote the vertical and horizontal center lines of the panel region 104 on the lower substrate side, respectively.
“a” and “PYa” indicate the vertical and horizontal center lines of the alignment film pattern 103a formed on the lower substrate, respectively. Further, B
Xb and BYb indicate the vertical and horizontal center lines of the upper substrate 102b, respectively, and PXb and PYb indicate the vertical and horizontal center lines of the alignment film pattern 101b formed on the upper substrate, respectively.

In general, as shown in FIG. 7A, the panel region 104 of the lower substrate is asymmetric with respect to the display screen due to the arrangement of the mounting electrodes on one side or the like (in recent years, particularly, with a narrower frame, the panel region 104 is particularly remarkable. AXa and AYa are PX
a and PYa do not coincide with each other, and a shift shown by d in the figure occurs.

In addition, several notches C for conducting the counter electrode are provided only on one or two sides to arrange the mounting electrodes on one side.

Further, a region within a predetermined width from the outer periphery of the four sides of the lower substrate 102a is a region where the performance and quality can be secured. Generally, in order to effectively use this region, a panel on the lower substrate side with respect to the outer shape of the substrate is used. The chip arrangement is determined such that the regions 104 are evenly located.

On the other hand, the alignment film 1 of the upper substrate shown in FIG.
01b has a position and a shape that coincide with the alignment film pattern 101a formed on the lower substrate when bonded so that the lower substrate and the alignment film surface face each other (in the drawing: Lpa1 = Lpb2, Lpa2 = Lpb1).

Therefore, in this conventional example, AXa is B
It is located symmetrically with respect to Xa (FIG. 7: La1 = La
Each panel position is arranged as shown in 2), PXa of the alignment film 101a on the lower substrate side is not symmetric with respect to BXa (in FIG. 7: Lpa1 ≠ Lpa2), and the shape is not symmetric with respect to PXa. Similarly, in the orientation film 101b on the upper substrate side, PXb is not symmetric with respect to BXb, and the shape is PXb.
Is not symmetric with respect to The symmetry in the vertical direction has been described above, but the same relation is arranged in the horizontal direction.

[0014]

However, FIG.
As can be seen from (a) and (b), in the configuration of the above-described conventional example, since the positions and shapes of the alignment films on the lower substrate 102a and the upper substrate 102b are different, it is necessary to separate the alignment film print patterns. is there. That is, it was necessary to prepare two types of printing relief plates for the alignment film.

In the conventional example, when one alignment film printing machine is used for production, it is necessary to switch the orientation film printing plate of the lower substrate 101a and the upper substrate 101b even in the case of one model production. Frequent replacement of the printing plate causes the time required for switching work and maintenance to become extremely long, which deteriorates the equipment operation rate.In addition, the residence time of one of the substrates becomes longer before the upper and lower substrates are bonded to each other. There were major problems with productivity, quality, and yield, such as adhesion of foreign matter and adsorption of contaminants.

On the other hand, when the upper and lower substrates are separately printed by two alignment film printers, the above problem is solved.
Since it is difficult to completely match the alignment film application state on the upper and lower substrates, the alignment film thickness after curing often differs between the upper and lower substrates, causing an asymmetry of the electric field at the time of display.
This tends to cause quality problems such as a printing phenomenon and display unevenness due to the residual C component, and also causes a cost problem that an enormous equipment cost is required.

[0017]

In order to solve this problem, according to the present invention, an alignment film pattern corresponding to each chip formed on upper and lower substrate surfaces has a symmetrical shape at least in a vertical or horizontal direction. This is a manufacturing method in which an alignment film pattern having the same shape is located at the same position on the upper and lower substrates when the upper and lower substrates are bonded together with the printing surface inside.

According to this configuration, the alignment film pattern position and shape with respect to the upper and lower substrates are the same, and the alignment film printing plate can be shared by the upper and lower substrates.

Therefore, since it is not necessary to switch the plates, not only the facility operation rate is improved, but also the lower substrate and the upper substrate can be alternately printed, and the substrate before lamination does not stay. Quality issues are also reduced. Therefore, it is possible to produce a liquid crystal display panel having excellent productivity and quality. Further, a large capital investment such as providing an alignment film printing apparatus for each of the upper and lower substrates is not required.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIGS. 1A and 1B show Embodiment 1.
5 shows a print state of an alignment film on a lower substrate and an upper substrate of the liquid crystal display panel in FIG. Here, a case where four liquid crystal panels are manufactured from a pair of substrates is shown. The center line PXa of the alignment film pattern 101a on the lower substrate 102a
Are symmetric with respect to the center line BXa of the lower substrate 102a (FIG. 1).
Middle: the chip position on the substrate is determined so that Lpa1 = Lpa2), and the alignment film pattern 101
a is provided with a notch C similar to the upper side on the lower side in the figure so as to be symmetric with respect to PXa.

On the other hand, the alignment film pattern 101b on the upper substrate 102b coincides with the alignment film pattern 101a formed on the lower substrate when the lower substrate and the alignment film face each other so as to face each other (see FIG. 1). : Lpa1 = Lpb2)
Are arranged as follows.

By doing so, the center line PXb of the alignment film pattern 101b on the upper substrate is also
(In FIG. 1: Lpb1 = Lp)
b2), and the alignment film pattern 101b is also PXb
With respect to.

By setting the position of the chip on the substrate and the shape of the alignment film as described above, the position of the alignment film with respect to the outer shape of the substrate,
The shape becomes the same between the upper and lower substrates, and the formation of the alignment film on the upper and lower substrates can be performed using the same printing plate with the same printing apparatus.

Therefore, since it is not necessary to switch the plate, not only the facility operation rate is improved, but also the lower substrate 10
2b and the upper substrate 102a can be alternately printed, so that there is no stagnation of the substrates before bonding and the quality problem is reduced. Therefore, a liquid crystal display panel having excellent productivity and quality can be manufactured. Further, a large capital investment such as providing an alignment film printing apparatus for each of the upper and lower substrates is not required.

(Embodiment 2) However, in Embodiment 1, the position of the panel region 104 on the lower substrate 102a is vertically asymmetric (La1 ≠ La2 in FIG. 1).
If the panel area is relatively large, the outer shape of the lower substrate and the outer shape of the panel are partially close to each other, and the wiring electrodes and T
In some cases, the performance is out of the guaranteed performance range such as FT.

The second embodiment solves the problem of the first embodiment, and FIG. 2A and FIG.
FIG. 3B shows the state of printing the alignment film on the lower substrate and the upper substrate of the liquid crystal display panel, and FIGS.
Shows a method of printing an alignment film on the lower substrate and the upper substrate.

In the second embodiment, similar to the first embodiment, four liquid crystal panels are manufactured from a pair of substrates. The feature is the alignment film pattern 1 of each chip.
01a and 101b are symmetric in the vertical direction in the figure, and have the same shape on the upper substrate and the lower substrate.

The difference from the first embodiment is the printing position of the alignment film pattern on the substrate. Compared with the first embodiment, the alignment film pattern 101a is shifted downward in the drawing on the lower substrate 102a side and on the upper substrate 102b side in the drawing. Then, the alignment film pattern 10
1b is printed in the upward direction in the figure, both being shifted by d.

An outline of this printing method will be described with reference to FIG. This printing is performed by the same printing apparatus using the same printing plate as in the first embodiment, but the upper and lower substrate positions are shifted by 5 mm in the opposite direction with respect to the cylindrical plate cylinder 202 around which the printing plate 201 is wound. By displacing, the alignment films are printed at different positions on the upper and lower substrates.

The alignment film pattern thus formed is obtained by inverting the upper substrate with BXb as an axis and bonding the upper and lower substrates with the alignment film printing surface inside, and the alignment film pattern formed above and below is positioned. , And the shapes match (Fig. 2
Middle: Lpa1 = Lpb2).

In the second embodiment, the printing apparatus needs a function of switching the position of the substrate or the alignment film.
In addition to the advantages of the first embodiment, since the panel region 104 can be positioned substantially near the center of the lower substrate 102a, a region having stable performance such as a wiring electrode and a TFT can be used. Further, it is possible to manufacture a panel size larger than that of the first embodiment even with the same substrate size.

Embodiment 3 FIG. 4 shows a cross section of a liquid crystal display panel according to Embodiment 3 of the present invention. The components are the same as in FIG. 6 shown in the conventional example,
The positional relationship between the end positions of the alignment films 1a and 1b and the dummy pattern 7 'made of a color filter film is different.

The dummy pattern 7 'made of a color filter film is formed on the black matrix 11 outside the display area, and is provided for improving alignment unevenness and liquid crystal layer thickness unevenness which are likely to occur at the end of the display area. .

However, on the other hand, projections due to liquid pools and the like and local thickening are likely to occur at the ends of the alignment films 1a and 1b during printing of the alignment films. In the conventional example in which this portion and the dummy pattern 7 'overlap, if a protrusion at the end of the alignment film or a local increase in film thickness occurs, the effect immediately becomes a liquid crystal layer thickness unevenness, and display unevenness around the display area occurs. Cheap.

However, in the third embodiment, the positions of the end portions of the alignment films 1a and 1b are extended to a portion having no dummy pattern 7 'made of a color filter film, or the dummy pattern 7' is partially deleted. By displacing the positional relationship, it is possible to enlarge a protrusion which is likely to be generated at the edge of the alignment film and a margin for locally increasing the film thickness.

This effect is effective not only for the alignment film 1b on the upper substrate but also for the protrusion and local thickening of the alignment film 1a on the lower substrate.

As described above, the following effects can be obtained. The film thickness of the dummy pattern 7 'made of a color filter film is 1.5
μm and the thickness of the liquid crystal layer in the display area is 5.0 μm, so that the protrusion at the edge of the alignment film and the local thickness increase margin can be reduced from 5.0 μm to 6.5 μm, and the The yield in manufacturing can be greatly improved.

(Embodiment 4) FIG. 5 shows a cross section of a liquid crystal display panel according to Embodiment 4 of the present invention. The components are the same as in FIG. 6 shown in the conventional example,
The positions of the end portions of the alignment films 1a and 1b are different from the configuration and the positional relationship of the dummy pattern 7 'made of a color filter film.

In the first embodiment, the pattern of the alignment film 1 is limited in symmetry in order to use the printed pattern of the upper and lower substrates, and a liquid crystal panel having a high yield as in the third embodiment is obtained. Therefore, there is also a restriction on the positional relationship with the dummy pattern 7 '.

In the fourth embodiment, when the distance from the display area to the seal 10 located at the end of the panel is relatively long, the above two restrictions are satisfied.

In the fourth embodiment, the dummy patterns located at the ends of the alignment films 1a and 1b are deleted. However, a dummy pattern 7 'made of a color filter film is further formed on the seal 10 side, and beads are formed. By providing the portion supported by the spacer 8, it is possible to prevent the thickness unevenness of the liquid crystal layer from occurring.

In the above embodiment, the color TF
Although a T liquid crystal panel is taken as an example, a liquid crystal panel using another mode is similarly effective.

Further, in the embodiments, only the alignment film printing pattern has been described for the sake of simplicity. However, the present invention relates to a device formed on the substrate before printing the alignment film, such as an electrode wiring pattern and a display pixel. On the other hand, this means that the formation position is previously arranged so as to correspond to the alignment film print pattern.

[0044]

As described above, according to the present invention, the alignment film pattern corresponding to each chip formed on the upper and lower substrate surfaces has a symmetrical shape at least in the vertical or horizontal direction, and the alignment film printed surface is on the inner side. By forming the alignment film patterns having the same shape at the same position on the upper and lower substrates when the substrates are bonded, the alignment film printing plate and the printing apparatus can be shared by the upper and lower substrates.

Therefore, since it is not necessary to switch the plates, not only the facility operation rate is improved, but also the lower substrate and the upper substrate can be alternately printed, and the substrate before laminating does not stay. Quality issues are also reduced. Therefore, a liquid crystal display panel having excellent productivity and quality can be manufactured.

Further, by shifting the position of the edge of the alignment film and the position of the dummy pattern composed of the color filter film,
It is possible to reduce the influence on the display due to the protrusion or local thickness increase that is likely to occur at the edge of the alignment film, and to contribute to the production of a liquid crystal panel with high quality and high yield.

[Brief description of the drawings]

FIG. 1 is a plan view of a lower substrate (a) and an upper substrate (b) after printing an alignment film according to the first embodiment of the present invention.

FIG. 2 is a plan view of a lower substrate (a) and an upper substrate (b) after printing an alignment film according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a method for printing an alignment film on a lower substrate (a) and an upper substrate (b) in Embodiment 2 of the present invention.

FIG. 4 is a cross-sectional view of a part of a color TFT liquid crystal display panel according to Embodiment 3 of the present invention.

FIG. 5 is a partial cross-sectional view of a color TFT liquid crystal display panel according to a fourth embodiment of the present invention.

FIG. 6 is a cross-sectional view of a part of a conventional color TFT liquid crystal display panel.

FIG. 7 is a plan view of a lower substrate (a) and an upper substrate (b) after an alignment film is printed in a conventional example.

[Explanation of symbols]

1a Alignment film of lower substrate 1b Alignment film of upper substrate 2a Lower substrate after splitting 2b Upper substrate after splitting 3 Liquid crystal 4 Thin film transistor (TFT) 5 Pixel electrode 6 Common transparent electrode 7 Color filter film 8 Bead spacer 9 Fiber spacer Reference Signs List 10 sealant 11 black matrix 101a alignment film pattern on lower substrate 101b alignment film pattern on upper substrate 102a lower substrate 102b upper substrate 103a display area on lower substrate 103b display area on upper substrate 104 lower panel side panel area 201 Alignment film printing plate 202 Plate cylinder BXa Vertical center line of lower substrate BYa Horizontal center line of lower substrate PXa Vertical center line of alignment film pattern formed on lower substrate Pya Horizontal line of alignment film pattern formed on lower substrate AXa Vertical center line of panel area on lower substrate side AYa Panel area on lower substrate side BXb The vertical center line of the upper substrate BXb The horizontal center line of the upper substrate BXb The vertical center line of the alignment film pattern formed on the upper substrate PXb The horizontal center line of the alignment film pattern formed on the upper substrate PYb Center line

Claims (6)

[Claims] 1. One or more chips are formed on one substrate, and an alignment film pattern corresponding to each chip formed on upper and lower substrate surfaces has a symmetrical shape at least in a vertical or horizontal direction. A method for manufacturing a liquid crystal display panel, comprising: forming an alignment film pattern having the same shape at the same position on the upper and lower substrates when the upper and lower substrates are bonded together with the surface inside. 2. One or more chips are formed on one substrate, and an alignment film pattern corresponding to each chip formed on upper and lower substrate surfaces is symmetric at least with respect to a vertical or horizontal center line of the substrate. 2. The method for manufacturing a liquid crystal display panel according to claim 1, wherein an alignment film pattern having the same shape and the same shape is formed at the same position on the upper and lower substrate surfaces as viewed from the alignment film printing surface. 3. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the alignment films for the upper and lower substrates are formed using the same or the same pattern of printing plates. 4. An alignment film for the upper and lower substrates, using the same or the same pattern of printing plates, and the positions of the plate and the substrate when printing the alignment film on the upper substrate and when printing on the lower substrate. 2. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the liquid crystal display panel is formed by printing while being shifted in a symmetric direction of the alignment film pattern. 5. A color liquid crystal display panel having a dummy pattern formed of a color filter film near a display area, wherein at least one edge of an alignment film pattern is located outside the dummy pattern. 6. A color liquid crystal display panel having a dummy pattern made of a color filter film on at least a part of an outer side of a region where an alignment film pattern corresponding to each chip on a substrate surface is formed.