JPH0146852B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a liquid crystal display cell.

A liquid crystal display cell is a device in which liquid crystal is sealed in a minute gap between a pair of electrode substrates that are adhesively polymerized via a sealing material. It is important to make the gap between the two electrode substrates uniform throughout the cell.

For this reason, conventionally, as shown in FIG. 1, in the sealing material 3 that seals between the electrode substrates 1 and 2 at the peripheral edge, a gap material ( beads or fibers) 4
It is considered that the two electrode substrates 1 and 2 are bonded and polymerized in a state where the electrode substrates 1 and 2 are placed in the substrate.

However, in the conventional liquid crystal display cell manufactured in this way, since the gap between the two electrode substrates 1 and 2 is defined only by the peripheral edge, adhesive polymerization of the two electrode substrates 1 and 2 (both electrodes The electrode substrate 1,
2 cannot be prevented from being bent and deformed inward, and as a result, the gap between both electrode substrates 1 and 2 at the center of the cell becomes smaller than the gap at the periphery, which is especially true for thin electrode substrates. This was more noticeable in thin cells using 1 and 2.

This invention has been made in view of the above-mentioned circumstances, and its purpose is to arrange a gap material in a liquid crystal enclosure by using an alignment film coated on the electrode formation surface of an electrode substrate. An object of the present invention is to provide a method for manufacturing a liquid crystal display cell in which the gap between both electrode substrates is uniform throughout the cell.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2 and FIG. 3e, 1 is an upper electrode substrate, 2 is a lower electrode substrate, and protective films 3, 3 are formed on the entire surface of the lower surface of the upper electrode substrate 1 and the upper surface of the lower electrode substrate 2, respectively. Transparent electrodes 4 and 5 are formed thereon. Note that 4a is an electrode terminal formed on the lower side edge of the upper electrode substrate 1. Further, the protective films 3, 3 are formed by the heat generated when bonding and polymerizing the electrode substrates 1, 2.
This is for capturing alkali ions (for example, Na ⁺ ) released from the glass substrates 1a and 2a constituting the glass substrates 2 and protecting an alignment film, which will be described later, from the alkali ions. 6 and 6 are alignment films that cover the electrode formation surfaces of both the electrode substrates 1 and 2, and 7 and 7 are the alignment films 6 that cover the electrode formation surface of one of the electrode substrates 1 and 2, for example, the lower electrode substrate 2. The gap material 7, 7 is, for example, a transparent glass bead, and is fixed to the alignment film 6 with its lower part embedded in the alignment film 6. are widely distributed. Further, 8 is a sealing material that seals the gap between the electrode substrates 1 and 2 at the peripheral edge thereof;
2 are opposed to each other with a gap equal to the diameter of the gap members 7, 7 protruding onto the lower electrode substrate 2, are adhesively polymerized via the seal material 8, and are surrounded by the seal material 8. A liquid crystal (not shown) is sealed in the gap a between the electrode substrates 1 and 2. In FIG. 2, reference numeral 9 denotes a liquid crystal injection port formed in a part of the sealing material 8, and this liquid crystal injection port 9 is sealed after the liquid crystal is injected.

That is, in the liquid crystal display cell of this embodiment, gap materials 7, 7 are fixed to one of the pair of electrode substrates 1, 2, and are fixed to an alignment film 6 covering the electrode forming surface, and the gap materials 7, 7 are dispersed. The materials 7, 7 define a gap between the electrode substrates 1, 2, and since the gap material 7 is also placed near the center of the liquid crystal enclosure, the electrode substrates 1, 2 can be prevented from being bent and deformed inwardly during adhesive polymerization (both electrode substrates 1 and 2 are adhesively polymerized while being pressurized from the outer surface side, so they will not be bent and deformed outward), and therefore, The gap between both electrode substrates 1 and 2 is uniform over the entire cell, and since the gap materials 7 and 7 are embedded and fixed in the alignment film 6, the gap between the electrode substrates 1 and 2 is uniform. It doesn't move or move.

In the above embodiment, the gap materials 7, 7 are widely distributed in the liquid crystal enclosure, but the gap materials 7, 7 may be arranged only near the center of the liquid crystal enclosure, or The gap materials 7, 7 may also be provided in the seal material 8.

Next, the third section regarding the manufacturing method of the liquid crystal display cell.
This will be explained with reference to Figures a to e.

Figure 3a shows the lower electrode substrate 2, which has a glass substrate 2a coated with SiO ₂ to form a protective film 3 for capturing alkali ions, and oxidized It is manufactured by forming the transparent electrode 5 from tin, indium oxide, or the like.

After manufacturing the lower electrode substrate 2, first, an alignment agent solution containing gap materials (beads) 7, 7 is sufficiently stirred and dropped onto the electrode forming surface of the lower electrode substrate 2. After coating the entire surface of the substrate with the alignment agent solution to an even thickness using a spinner coating method in which the electrode substrate 2 is rotated, this is dried to form an alignment film 6.
See Figure b]. In this case, when the alignment film 6 is for horizontally aligning a P-type nematic liquid crystal, the alignment agent is an organic resin such as polyimide, and the alignment film 6 is coated with a solution of this alignment agent using a spinner. , a method of baking at about 320℃ for about 20 minutes and then rubbing the surface (rubbing is simply rubbing lightly with cotton, etc., so it is necessary to use the gap material 7, 7).
(Rubbing treatment is possible even if there are protruding parts.) Further, when the alignment film 6 is for vertically aligning the N-type nematic liquid crystal, the alignment agent is DMOAP (NN-dimethyl-N
-octadecyl-3-aminopropoxyltrimethoxysilyl chloride) and chromium complexes, which have the property of making liquid crystal molecules stand vertically.
The alignment film 6 is formed by coating a solution of the alignment agent with a spinner and then baking (pre-baking is fine). Before forming film 6, SiO is applied to the electrode substrate surface.
(It is necessary to perform oblique evaporation such as

After this, first, as shown in FIG. 3c, the alignment film 6 on the seal portion (periphery of the electrode substrate) is removed by etching, and then, as shown in FIG.
The sealing material 8 is printed as shown in FIG. If the gap materials 7, 7 are also provided in the seal material 8, the gap materials 7, 7 may be mixed into the seal material 8 and then printed.

On the other hand, similarly to the lower electrode substrate 2, a protective film 3 is formed on the surface of the glass substrate 1a, and a transparent electrode 4 is formed on the protective film 3.
The upper electrode substrate 1 manufactured by forming the electrode is completely coated with the same alignment agent solution as the alignment agent solution coated on the lower electrode substrate 2 (however, the gap materials 7, 7 are not mixed) on the electrode forming surface. The alignment film 6 is formed by applying the same method and drying (baking).
After this, the alignment film 6 on the seal portion is removed by etching.

After this, both the electrode substrates 1 and 2 are placed facing each other and pressurized to polymerize the electrode substrates 1 and 2 through the gap materials 7 and 7, and then heated in this pressurized state to both the electrode substrates 1 and 2. The peripheral edges of the electrode substrates 1 and 2 are sealed with a sealing material 8, and then a liquid crystal is sealed in the gap a between the electrode substrates 1 and 2 whose peripheral edges are sealed with the sealing material 8. The liquid crystal display cell shown in Figure e is completed.

Note that when the alignment film 6 is made of a heat-resistant material such as polyimide, sealing using epoxy resin or the like as the sealing material 8 is possible, as well as sealing at high temperatures (400 to 500° C.) using fried glass or the like. It is. Further, the alignment film 6 is DMOAP
In the case of DMOAP or chromium complexes, it is sufficient to seal using epoxy resin as the sealing material 8. When using epoxy resin, the sealing temperature is about 130°C, which is not enough to dry DMOAP or chromium complexes. Since the temperature is approximately the same as that for the sealing process, the alignment film 6 that has been prebaked at the time of sealing can be completely dried. Further, the alignment film 6
If the electrode substrates 1 and 2 are pre-baked and completely dried during sealing, by polymerizing and pressurizing both electrode substrates 1 and 2, the gap materials 7 and 7 are formed into the alignment agent 6 on the upper electrode substrate 1 side. Since the gap members 7, 7 are also embedded, displacement of the gap members 7, 7 can be more reliably prevented.

That is, the method for manufacturing the liquid crystal display cell of this embodiment involves using an alignment agent solution in which gap materials 7, 7 of a predetermined diameter are mixed in a pair of electrode substrates 1, 2, and an alignment agent solution in which gap materials 7, 7 are not mixed. Both electrode substrates 1 and 2 on which alignment films 6 and 6 have been formed are polymerized through the gap materials 7 and 7, and pressure is applied to apply the gap materials 7 and 7 to the alignment film 6. According to this manufacturing method, the gap materials 7, 7 are formed simultaneously with the formation of the alignment film 6 coated on one electrode substrate 2. Since they can be placed on the electrode substrate surface, the spacing materials 7, 7 can be easily placed. Since the spacing material is arranged on one electrode substrate, the spacing material is less likely to overlap, and the spacing can be made uniform throughout the cell. Further, by drying the alignment agent solution after applying it, it is possible to prevent the gap materials 7, 7 from shifting during the process until the cell is completed.

In the above embodiment, beads are used as the gap material 7, but the gap material 7 may be made of glass fiber or the like, and the gap material 7 may be placed on either the upper or lower electrode substrate. good.

As described above, the method for manufacturing a liquid crystal display cell of the present invention is to mix a spacing material into the alignment material that covers the electrode forming surface of the electrode substrate and apply it to one of the electrode substrates. Place the gap material,
In addition, by pressurizing the pair of polymerized electrode substrates, the gap material is forced into the alignment film, so that it is possible to reliably prevent the gap material placed in the liquid crystal enclosing part from shifting. The gap between the substrates can be made uniform throughout the cell. Furthermore, according to the present invention, the gap material can be placed only on one substrate and fixed between the electrode substrates in the process of forming an alignment film, making it possible to efficiently produce a liquid crystal display cell with a uniform substrate gap. Can be manufactured well.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a conventional liquid crystal display cell, FIG. 2 is an exploded perspective view of a liquid crystal display cell showing an embodiment of the present invention, and FIGS. 3 a to 3 e are cross sections showing the manufacturing method in the order of steps. It is a diagram. 1, 2... Electrode substrate, 3... Protective film, 4, 5...
...Transparent electrode, 6...Alignment film, 7...Gap material, 8...
...Sealing material.

Claims (1)

[Claims] 1. A method for manufacturing a liquid crystal display cell in which a gap material is arranged between a pair of electrode substrates whose electrode forming surfaces are covered with an alignment film, and a liquid crystal is sealed between the pair of electrode substrates. a step of applying an alignment agent solution mixed with a gap material of a predetermined diameter to the surface of one of the electrode substrates to form an alignment film in which the gap material is disposed; The step of forming a sealing material on the peripheral edge, and superposing and pressurizing one electrode substrate on which an alignment film with the gap material disposed thereon and the other electrode substrate on which only an alignment film is formed, a step of pushing a gap material into the alignment film, a step of adhering and polymerizing the peripheral edges of both electrode substrates with the sealing material, and a step of placing a liquid crystal between the two electrode substrates whose peripheral portions are adhesively polymerized with the sealing material. A method for manufacturing a liquid crystal display cell, comprising the step of encapsulating the cell.