JPH0458217A - Production of liquid crystal display element - Google Patents

Abstract

PURPOSE:To obviate the generation of any steps at all in marks by simultaneously forming flattening protective films to cover at least two position recognition marks provided at the corners of substrates on the outer side of sealing layers of respective glass substrates at the time of forming oriented films. CONSTITUTION:The position recognition marks 6a, 6b consist of ITO (In2O3- SnO2) and at least two pieces thereof are formed simultaneously with striped transparent electrodes not shown in Fig. in the suitable positions on the outer side of the sealing layers 5 on the glass substrates 1a, 1. The flattening protec tive films 7a, 7b are the oriented films and are so formed as to cover the respec tive position recognition marks 6a, 6b with the films in the central part thereof. The steps of the recognition marks 6a, 6b are gently coated with the flattening protective films 7a, 7b and, therefore, the sticking of dust, etc., t the position recognition marks themselves does not arise at all even if the films are subjected to an orientation treatment by rubbing. Then, the automatic registration by an image recognizing and registering device using a TV monitor while observing the position recognition marks with transmitted light or reflected light is easily executed.

Description

[Detailed Description of the Invention] [Summary] The purpose of the present invention is to improve the precision and workability of aligning upper and lower glass substrates and shaping and cutting the substrates, as well as to improve yield and reduce costs in a method for manufacturing liquid crystal display elements. A striped transparent electrode and an alignment film are formed on two glass substrates, and the alignment film faces the two glass substrates, and each of the transparent electrodes forms a matrix intersection. After placing a spacer between the two substrates and sealing them with a sealing layer made of adhesive, the glass substrate is cut to shape on the outside of the sealing layer. In a method of manufacturing a liquid crystal display element in which liquid crystal is injected and sealed into a gap-like space, at least two position recognition marks are simultaneously formed on the substrate surface outside the sealing layer when forming a transparent electrode on the glass substrate. Then, when forming the alignment film, the method for manufacturing a liquid crystal display element is configured such that a flattening protective film is simultaneously formed to cover the position recognition mark.

[Industrial application field]

The present invention relates to a method for manufacturing a liquid crystal display element, particularly a display panel (empty cell) before liquid crystal injection.

In recent years, the development of display devices has been remarkable, and in particular, flat displays have rapidly become popular due to their thinness and light weight. Among them, liquid crystal display devices have a low driving voltage and are inexpensive, so they are being actively introduced into the field of office automation equipment such as personal computers and word processors.

BACKGROUND ART As liquid crystal display elements have become larger and more precise, their manufacturing technology has become increasingly sophisticated, and there is a need to develop manufacturing methods with even higher precision and higher work efficiency.

[Conventional technology]

Liquid crystal display devices, especially graphic display liquid crystal display devices, are STN (Super Twisted Ne5a).
By using tic) type liquid crystals, it has become possible to increase the size and capacity, but in order to manufacture this, the liquid crystal display panel (called an empty cell) before injecting liquid crystal is first processed with high precision. , and it is necessary to manufacture it efficiently.

Figure 4 is a diagram showing the panel configuration of a liquid crystal display element, showing the state of an empty cell before liquid crystal is injected; (a) is a top view, (b) is a partially enlarged view, and (c) is a sectional view.

In the figure, la and lb are transparent glass substrates on which they are placed.

For example, striped transparent electrodes 2a and 2b made of well-known ITO (InJ3SnO2) are formed. Orientations l13a and 3b are formed on the transparent electrodes 2a and 2b in the display area, respectively. The alignment film.

For example, after coating with a polyimide resin film, alignment treatment is performed by rubbing with a cloth such as nylon.

As shown in the figure, the two glass substrates 1a and lb formed in this manner have alignment films 3a and 3b facing each other, and
The respective transparent electrodes i1a and lb are orthogonally arranged so as to form a matrix intersection, and a spacer 4.
For example, a small sphere made of polyester resin is sandwiched and sealed with a sealing layer 5 made of adhesive. A part of the seal layer 5 is provided with a liquid crystal injection port 50 through which liquid crystal will be injected later.

60 is a position recognition mark, for example, 2 as shown in the figure.
It is a double rectangle and 1. For example, the outer rectangle 60a is on the upper glass substrate 1a, and the outer rectangle 60a is on the lower glass substrate 1b.
is provided with an inner quadrangle 60b. These position recognition marks 60 are formed by transparent electrodes 2a, 2 on each substrate.
When forming the substrate b, for example, at least two are simultaneously formed at the diagonal corners of the substrate as shown.

When the two glass substrates 1a+Ib are bonded together in the above arrangement, the position recognition mark 60 is formed by, for example, placing the position recognition mark 60b on the lower substrate inside the large rectangle of the position recognition mark 60a on the upper substrate. The small rectangles can be manually aligned under a microscope, or automatically aligned using an image recognition alignment device using a TV monitor, and then mechanically clamped, or using ultraviolet curing resin or the like. After temporary adhesion, the seal layer 5 is cured by heating to form an empty cell. The position recognition mark 60 can be recognized by utilizing the fact that the reflectance is different from that of the glass substrate.

In addition, if the glass substrate 1 is to be cut into shapes after bonding both substrates together, for example, the position recognition mark 60 is read by an automatic cutting device, and the position recognition mark 6 is
0 and the seal layer 5, each cutting line, for example, the dashed line X for the upper substrate.

-L, Xz-Xt, and the lower board are dotted lines Y, -Y
. After that, the liquid crystal injection port 50 is hermetically sealed to produce a display liquid crystal display element.

[Problem to be solved by the invention]

However, the conventional position recognition marks 6 (6a, 6b) mentioned above.

For example, since it is formed at the same time as the transparent electrodes 2 (2a, 2b) made of ITO, it usually has a thickness of 100 to 200 nm, and due to the step difference during the alignment process of the alignment film 3 (3a, 3b). Rubbing cloth and other debris may adhere to the surface.

FIG. 3 is a diagram showing an example in which dust has adhered to a conventional position recognition mark, in which FIG. 3(a) is a top view and FIG. 3(b) is a sectional view. An alignment film 3 (3a, 3b) made of, for example, a polyimide resin film is provided on the transparent electrode in the display area inside the seal layer 5 (not shown). In the figure, 8o
was attached to the position recognition mark 6a on the upper glass substrate 1a. For example, it is fiber waste from a rubbing cloth, and 90 is attached to the position recognition mark 6b of the lower glass substrate ib. For example, fiber scraps from rubbing cloth.

Note that the same reference numerals are given to the same parts as those explained in the above drawings, and the explanation of the same parts will be omitted.

In this way, dust 80 or 90 is placed on the position recognition mark 6.
If it adheres, image recognition by the position recognition device becomes inaccurate or impossible, which reduces the accuracy of bonding and cutting of substrates, leading to deterioration of product quality and yield. A problem had arisen and a solution was needed.

[Means to solve the problem]

The above problem is solved by forming a striped transparent electrode 2 on two glass substrates 1 and an alignment film 3 thereon, so that the alignment film 3 faces the two glass substrates 1, and The electrodes 1 are orthogonally arranged so as to form a matrix intersection, a spacer 4 is sandwiched between the two plates, and the glass substrate 1 is sealed with a sealing layer 5 made of adhesive, and the glass substrate 1 is cut into shapes outside of the sealing layer 4. After that, in the method for manufacturing a liquid crystal display element in which liquid crystal is injected and sealed into a gap-like space formed between the two glass substrates 1, when forming a transparent electrode 2 on the glass substrate 1, simultaneously forming at least two position recognition marks 6 on the substrate surface outside the sealing layer 4;
Next, when forming the alignment film 3, the problem can be solved by a method of manufacturing a liquid crystal display element in which a flattening protective film 7 is simultaneously formed to cover the position recognition mark 6.

[Effect]

According to the method of the present invention, when forming the alignment film 3, the at least two position recognition marks 6 provided on the corners of each glass substrate 1, for example, outside the sealing layer 4, are covered for planarization protection. Since the film 7 is formed at the same time,
There is no step in the position recognition mark 6, and even if the alignment process is performed by rubbing, no dust 80 or 90 such as rubbish from the rubbing cloth will adhere, and positioning can be easily performed with high precision. be.

〔Example〕

FIG. 1 is a diagram showing an embodiment method of the present invention, in which (a) shows a glass substrate 1a (for example, an upper substrate), and (b) shows a glass substrate 1b (for example, a lower substrate).

Figure (c) shows the state in which the upper and lower substrates are aligned and bonded together. In addition, (a) is a top view of each, (
b) is a cross-sectional view of each.

In the figure, 6a and 6b are position recognition marks, for example,
At least two of them are made of ITO (InJsSnO,) and are placed at appropriate positions outside the sealing layer 5 on the glass substrates 1a and lb, for example, at diagonal corners of the substrate.
It is formed at the same time as a striped transparent electrode (not shown), and the thickness is, for example, 100 to 200 nm, and the external dimensions are 0.2 mm (6a) to 0.1 mm (6a).
b) Approximately.

7a and 7b are flattening protective films, which are formed on the knee at the same time as an alignment film (not shown), for example, a polyimide resin film, and have a circular shape of, for example, 5 mmφ, and each position recognition mark is formed in the center of the circular shape. 6a, 6b thickness 110
It is formed simultaneously with the alignment film by, for example, transfer printing so as to cover it with a film of about 0 nm.

As can be seen from the cross-sectional views in (a) and (b) of the same figure, the steps between the position recognition marks 6a and 6b are gently covered with the flattening protective films 7a and 7b, so even if alignment treatment by rubbing is performed, There is no possibility that dust or the like will adhere to the position recognition mark itself. Therefore, it becomes possible to automatically align the position recognition mark with high precision and within a short time using an image recognition alignment device using a TV monitor while observing the position recognition mark using transmitted light or reflected light. The bonding accuracy and board shaping and cutting accuracy have been greatly improved compared to conventional examples, and work efficiency has also been greatly improved.

FIG. 2 is a diagram showing another embodiment of the method of the present invention, and two modified examples are shown in FIG. 2 (A) and (B).

In the same figure (a), the flattening protective films 7''a and 7'b are not circular but square, and in the same figure (b), the position recognition mark 6
'a, 6' and b are circular instead of square. It is clear that all of the above methods satisfy the purpose of the method of the present invention and produce the same effects as the above embodiments.

Note that the same reference numerals are given to the same parts as those explained in the above countries, and the explanation of the same parts will be omitted.

Furthermore, it goes without saying that the position recognition mark 6 is not limited to the above-mentioned shape, and any easy-to-use shape such as a cross, a star, or a triangle may be used as appropriate.

Furthermore, the position of the position recognition mark 6 is not limited to the corner of the board, but may be placed at an appropriate location outside the display screen, that is, outside the seal layer 5, and the number of position recognition marks 6 is at least two. Although it is possible to align the side substrate and determine the position of each cutting line, it goes without saying that the number of cutting lines may be three or more if necessary.

The above-described embodiment methods are merely examples, and it goes without saying that preferred materials and configurations, or combinations thereof may be used as appropriate, as long as they comply with the spirit of the present invention.

〔Effect of the invention〕

As explained above, according to the method of the present invention, when forming the alignment film 3, each glass substrate 1.

For example, since the flattening protective film 7 is simultaneously formed to cover at least two position recognition marks 6 provided at the corners of the substrate outside the seal layer 5, the position recognition marks 6 do not have any level difference. First, even if the orientation treatment by rubbing is performed, the dust 80 and 90 such as fiber waste of the rubbing cloth will not adhere.

Therefore, positioning is easily possible with high accuracy and within a short time, and the accuracy of bonding and cutting of substrates is greatly improved compared to conventional methods, and work efficiency is also greatly improved. This greatly contributes to improving the quality and yield of liquid crystal display elements and lowering prices.

2 (2a, 2b) are transparent electrodes, 3 (3a, 3b) are alignment films, 4 are spacers, 5 is sealing layers, 6 (6a, 6b), 6'(6'a,6'b) are position recognition Mark, 7 (7a, 7b), 7' (7°a + 7'
b) is a flattening protective film, and 80.90 is dust.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example method of the present invention, FIG. 2 is a diagram showing another example method of the invention, FIG. 3 is a diagram showing an example of dust attached to a conventional position recognition mark, FIG. 4 is a diagram showing the panel configuration of a liquid crystal display element. In the figure, 1(la, lb) are glass substrates, Italy 1 Method Σ Showing 4 Figures $ 2 Figures (a) (I)

Claims (1)

[Claims] Striped transparent electrodes (2) are placed on two glass substrates (1).
) and an alignment film (3) formed thereon, such that the alignment film (3) faces the two glass substrates (1), and each of the transparent electrodes (1) forms a matrix intersection. The glass substrate (
After cutting 1) to shape outside the seal layer (4),
In the method for manufacturing a liquid crystal display element in which liquid crystal is injected and sealed into a gap-shaped space formed between the two glass substrates (1), when forming a transparent electrode (2) on the glass substrate (1). At least two position recognition marks (6) are simultaneously formed on the substrate surface outside the sealing layer (4), and then, when forming the alignment film (3), the position recognition marks (6) are A method of manufacturing a liquid crystal display element, comprising simultaneously forming a flattening protective film (7) covering the element.