JP2000029043A - Manufacture of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a liquid crystal with a simple process irrespective of kinds of devices and to moreover enhance precision of patterns. SOLUTION: The method for manufacturing the device comprises forming alignment films 2, 5 to define alignment of liquid crystal over entire areas of the surface of each of substrates 1, 4, of the side where transparent electrodes are formed, placing the substrates 1, 4 opposite to each other so as to hold the respective alignment films 2, 5 inside, sticking them together while holding a frame-shaped sealing member 6 in between, enclosing liquid crystal within a region inside the sealing member 6 between the alignment films 2, 5 of the substrates 1, 4, immersing the substrates 1, 4 in a solvent and the parts 2a, 5a of the alignment films 2, 5 which exist on the sides of the periphery of the substrates and outside the sealing member 6 are removed by dissolving them in the solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device is manufactured as follows. First, a pair of transparent substrates 1 and 4 (FIG. 4) each having a stripe-shaped transparent electrode (not shown) formed on each side.
Prepare). In a peripheral region of one substrate 1, an external connection terminal 7 in contact with the transparent electrode is formed for electrical connection with an external drive circuit. First, alignment films 2 and 5 for determining the alignment of the liquid crystal are formed on substantially the entire area of the surfaces of the substrates 1 and 4 on the side of the transparent electrodes except for the area around the substrates. The reason for excluding the area around the substrate is to expose the external connection terminals 7 in a completed state. Next, the pair of substrates 1 and 4 are opposed to each other so that the alignment films 2 and 5 are inside, and are bonded together with a frame-shaped seal member 6 interposed therebetween.
Then, the liquid crystal 3 is sealed in a region inside the seal member 6 between the alignment films 2 and 5 of the pair of substrates 1 and 4.

The alignment films 2 and 5 are formed by transferring an alignment film material (polyimide solution or its precursor) from the surface of the relief plate to the surface of the substrate by, for example, letterpress printing (Japanese Patent Laid-Open No. Hei. No. 31882).

[0004]

However, in the method using letterpress printing, the printing plate must be replaced with a pattern suitable for the substrate every time the type of liquid crystal display device changes. For this reason, there is a problem that the cost of the plate is increased, and a great deal of time is required for replacing the plate. Also, since the pattern accuracy is not good in the printing method,
There is also a problem that it is necessary to increase the design margin and the design restrictions of the liquid crystal display device become severe.

A method of printing an alignment film material on the entire surface of a substrate, and then printing an alignment film solvent on a peripheral region of the substrate to remove unnecessary portions (Japanese Patent Laid-Open No. Hei 5-307178) or a printing method is not used. In addition, a method is also known in which an alignment film material is applied to the entire surface of a substrate, and unnecessary portions existing in the peripheral region of the substrate are removed by optical ashing (Japanese Patent Application Laid-Open No. 5-323325). However, in these methods, the number of steps is increased, and the equipment and man-hours are further increased. Furthermore, since defects may occur due to defects in the mask, it is necessary to take into account the variation in the removed portions, and as in the above-described letterpress printing method, there is a problem that the design restrictions of the liquid crystal display device become severe. is there.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a liquid crystal display device which can manufacture a liquid crystal display device by a simple process irrespective of the model and can improve the pattern accuracy.

[0007]

According to a first aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising: a pair of substrates each having a transparent electrode formed on one surface; A method for manufacturing a liquid crystal display device for manufacturing a liquid crystal display device having an external connection terminal in contact with the transparent electrode in a peripheral region, wherein a liquid crystal is formed on the entire surface of the substrate on which the transparent electrode is formed. A step of forming an alignment film for determining the alignment of the substrate, a step of opposing the pair of substrates such that the alignment film is on the inside, and bonding the pair of substrates together with a frame-shaped seal member interposed therebetween; Enclosing a liquid crystal in a region inside the sealing member between the alignment films, and immersing the pair of substrates in a solvent to form a portion of the alignment film that is closer to the substrate than the sealing member. In the above solvent It characterized by having a step of removing by.

In the method of manufacturing a liquid crystal display device according to the first aspect, the pattern of the alignment film is formed in a self-aligned manner with respect to the sealing member. Therefore, a printing plate or a special mask pattern is not required, and a liquid crystal display device can be easily manufactured regardless of the model. As a result, productivity is increased. In addition, since the pattern of the alignment film is formed in a self-aligned manner with respect to the sealing member, the pattern accuracy is improved, and the restriction on the design of the liquid crystal display device is relaxed.

By the end of the last step, the external connection terminals are exposed in a region closer to the substrate than the seal member.
The external connection terminal is used to electrically connect to an external drive circuit as in the conventional case.

According to a second aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device according to the first aspect, wherein the solvent contains alkanolamine as a main component.

In the method for manufacturing a liquid crystal display device according to the second aspect, since the solvent contains alkanolamine as a main component, it is possible to avoid a problem that the above-described external connection terminal (usually containing aluminum) is corroded. it can.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a liquid crystal display device according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 3 shows a liquid crystal display device (completed state) to be manufactured as viewed from a direction perpendicular to the transparent glass substrates 1 and 4. A plurality of external connection terminals 7 are provided on two adjacent sides of one substrate (main substrate) 1.
The peripheral region of the main substrate 1 on which the external connection terminals 7 are provided does not overlap with the other substrate (counter substrate) 4 and is exposed. The external connection terminal 7 is made of a laminate of Al and Au, and is electrically connected to an external drive circuit.

This liquid crystal display device is manufactured as follows according to the flow shown in FIG. FIG.
As shown in (a), a TFT (thin film transistor) (not shown) for driving liquid crystal, an I
A striped transparent electrode made of TO (tin-added indium oxide) and in contact with the external connection terminal 7 is formed.
In addition, a color film (not shown),
A transparent electrode made of ITO is formed.

First, alignment films 2 and 5 for determining the alignment of liquid crystal are formed on the entire surface of each of the substrates 1 and 4 where the transparent electrodes are formed (S1). Specifically, polyimide (or a precursor thereof) as a material of the alignment film is applied to the entire surface of each of the substrates 1 and 4 on the side where the transparent electrode is formed, using, for example, a spinner. A method using a spinner is disclosed in, for example, JP-A-5-323355.
Subsequently, a firing step (S
2) An alignment treatment step (S3) for rubbing the polyimide surface and a cleaning step (S4) are performed.

Next, substrates 1 and 4 are aligned with alignment films 2 and 2, respectively.
5 are opposed to each other so as to be inside, and bonded together with a frame-shaped sealing member 6 made of a resin such as a thermosetting epoxy resin using diethylene glycol monomethyl ether or the like as a solvent (S5). Note that the seal member 6 has an inlet for injecting liquid crystal. Subsequently, a main firing step (S6) of main firing the above-mentioned polyimide is performed. Then, the liquid crystal 3 is injected into the region inside the sealing member 6 between the alignment films 2 and 5 of the substrates 1 and 4 (S7), and the injection port is sealed (S8).

Finally, the work (assembled product) including the substrates 1 and 4 is put into a cleaning step (S8). In this cleaning step, a dip type cleaning apparatus having a plurality of tanks is used.
Then, the work is immersed in an alignment film stripping solvent containing alkanolamine as a main component, and as shown in FIG. 2a and 5a are dissolved in the above solvent and removed. At the same time, each exposed portion of the work is cleaned. By this step, the external connection terminals 7 are exposed, and the surfaces of the external connection terminals 7 are cleaned.

Thus, the fabrication of the liquid crystal display device is completed.

According to this manufacturing method, the patterns of the alignment films 2 and 5 can be formed in a self-aligned manner with respect to the seal member 6. Therefore, a printing plate or a special mask pattern is not required, and a liquid crystal display device can be easily manufactured regardless of the model. As a result, productivity can be increased. In addition, since the pattern of the alignment film 2.5 is formed in a self-aligned manner with respect to the seal member 6, the pattern accuracy is improved, and the design limitation of the liquid crystal display device is relaxed.

In the above-mentioned alignment film forming step (S1),
A printing method may be used instead of the method of applying the material for the alignment film using a spinner. Even when using the printing method,
Since the material of the alignment film is printed on the entire surface of the substrate,
The same version can be used for all models, and the same effect can be obtained.

Further, since the alignment film removing solvent used in the above-mentioned cleaning step (S8) contains alkanolamine as a main component, it is possible to avoid a problem that the external connection terminal 7 is corroded.

The dip type cleaning device includes
What is used in the existing washing process can be used. Therefore, no new capital investment is required.

[0023]

As is clear from the above, according to the method of manufacturing a liquid crystal display device of the first aspect, the pattern of the alignment film can be formed in a self-aligned manner with respect to the sealing member. Therefore, a printing plate or a special mask pattern is not required, and a liquid crystal display device can be easily manufactured regardless of the model. As a result, productivity can be increased. In addition, since the pattern of the alignment film is formed in a self-aligned manner with respect to the sealing member, the pattern accuracy is improved, and the restriction on the design of the liquid crystal display device is relaxed.

According to the method for manufacturing a liquid crystal display device of the second aspect, the external connection terminal (usually containing aluminum)
Can be avoided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of a liquid crystal display device manufactured by a manufacturing method according to an embodiment of the present invention.

FIG. 2 is a process chart of a method for manufacturing the liquid crystal display device.

FIG. 3 is a view showing a liquid crystal display device manufactured by the above manufacturing method as viewed from a direction perpendicular to a substrate.

FIG. 4 is a diagram showing a cross section of a liquid crystal display device manufactured by a conventional manufacturing method.

[Explanation of symbols]

 1,4 transparent glass substrate 2,5 alignment film 7 external connection terminal

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tatsuo Shimazaki 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture F-term (reference) 2H089 JA11 KA15 MA04Y NA24 NA25 NA39 NA45 NA48 NA53 QA12 QA13 QA15 RA05 TA06 TA09 5C094 AA05 AA31 AA43 BA43 DA13 DB02 EA05

Claims (2)

[Claims] 1. A liquid crystal display device for manufacturing a liquid crystal display device comprising a pair of substrates each having a transparent electrode formed on one side thereof and having an external connection terminal in contact with the transparent electrode in a peripheral region of at least one of the substrates. Forming an alignment film for determining the alignment of the liquid crystal over the entire surface of the substrate on the side on which the transparent electrode is formed; and Opposing so as to be on the inside, bonding together with a frame-shaped sealing member interposed therebetween; enclosing liquid crystal in a region inside the sealing member between the alignment films of the pair of substrates; And dipping the substrate in a solvent to dissolve a portion of the alignment film closer to the periphery of the substrate than the seal member in the solvent to remove the portion. 2. The method for manufacturing a liquid crystal display device according to claim 1, wherein the solvent contains alkanolamine as a main component.