JP3527853B2 - Manufacturing method 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]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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 one surface thereof.
Prepared). In the peripheral area of one substrate 1, an external connection terminal 7 is formed in contact with the transparent electrode for electrical connection with an external drive circuit. First, the alignment films 2 and 5 for determining the alignment of the liquid crystal are formed on substantially the entire surface of the substrates 1 and 4 on the transparent electrode side except the region around the substrates. The reason for excluding the area around the substrate is to expose the external connection terminals 7 in the 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 the frame-shaped seal member 6 is sandwiched between them.
Then, the liquid crystal 3 is sealed in the region inside the seal member 6 between the alignment films 2 and 5 of the pair of substrates 1 and 4.

The above-mentioned alignment films 2 and 5 are formed by transferring the alignment film material (polyimide solution or precursor thereof) from the surface of the relief plate to the surface of the substrate by, for example, a relief printing method (Japanese Patent Laid-Open Publication No. Hei 5- 31882 publication).

[0004]

However, in the method of letterpress printing, the printing plate must be replaced with a pattern suitable for the substrate each time the model of the liquid crystal display device is changed. Therefore, there is a problem that the cost of the plate becomes high and that it takes a lot of time to replace the plate. In addition, since the pattern accuracy is not good with the printing method,
There is also a problem that it is necessary to increase the design margin, and the design limitation of the liquid crystal display device becomes severe.

It is to be noted that a method of printing an alignment film material on the entire surface of the substrate and then printing an alignment film solvent on the peripheral region of the substrate to remove unnecessary portions (Japanese Patent Laid-Open No. 5-307178) or a printing method is not used. Further, there is also known a method (Japanese Patent Laid-Open No. 5-323325) in which an unnecessary portion in the peripheral area of the substrate is removed by optical ashing after the entire surface of the substrate is coated with the alignment film material. However, in these methods, the number of steps is increased, and the equipment and man-hours are further increased. Furthermore, since a defect may occur due to a defect in the mask, it is necessary to take into consideration the variation in the removed portion, and similar to the method by the above-mentioned letterpress printing, there is a problem that the design limitation of the liquid crystal display device becomes severe. is there.

Therefore, an object of the present invention is to provide a method of manufacturing a liquid crystal display device which can manufacture the liquid crystal display device by a simple process regardless of the model and can improve the pattern accuracy.

[0007]

In order to achieve the above object, a method for manufacturing a liquid crystal display device according to claim 1 is directed to
A pair of substrates which are opposed to each other
The one that has external connection terminals in the peripheral area of the surface
A method of manufacturing a liquid crystal display device for manufacturing a liquid crystal display device, comprising the steps of forming an alignment film for determining the alignment of liquid crystals over the entire surface of the substrates facing each other; And facing each other such that the alignment film is on the inside, and sandwiching with a frame-shaped seal member,
A step of encapsulating liquid crystal in a region inside the seal member between the alignment films of the pair of substrates, and immersing the pair of substrates in a solvent so that the alignment film of the alignment film is closer to the substrate than the seal member. Remove the part existing on the side by dissolving it in the above solvent
The alignment film pattern to the sealing member
Formed in a self-aligned manner and exposed the above external connection terminals
It is characterized by having a step of

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

By the end of the last step, the external connection terminals are exposed in the region on the substrate peripheral side of the seal member.
This external connection terminal is used to electrically connect to an external drive circuit as in the conventional case.

The liquid crystal display device according to a second aspect of the present invention is an opposing device.
At least one of the substrates is opposite.
Hold the external connection terminal in the peripheral area of the
The opposite side of each board so that the connection terminals are exposed
Of the liquid crystal formed on the entire area of the
Of the alignment film for determining the orientation and the alignment film of the pair of substrates
The frame-shaped seal member sandwiched between
And a liquid crystal enclosed in a region on the side of
Is aligned with the board peripheral side of the seal member.
Is characterized by.

In the liquid crystal display device according to the second aspect, the alignment film is
The pattern is aligned with the board peripheral side of the seal member.
Can improve the pattern accuracy of the liquid crystal display device.
It Therefore, the restrictions on the design of the liquid crystal display device are eased.
Be done.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for manufacturing a liquid crystal display device of the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 3 shows a liquid crystal display device (finished state) to be produced as viewed from a direction perpendicular to the transparent glass substrates 1 and 4. A plurality of external connection terminals 7 are arranged 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 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. Note that FIG.
As shown in (a), a TFT (thin film transistor) (not shown) for driving a liquid crystal or I
A stripe-shaped transparent electrode made of TO (tin-doped 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 crystals are formed on the entire surface of each substrate 1 and 4 on which the transparent electrodes are formed (S1). Specifically, the polyimide (or its precursor) that is the material of the alignment film is applied to the entire surface of each substrate 1, 4 on the side where the transparent electrodes are formed, using, for example, a spinner. The method using a spinner is disclosed in, for example, Japanese Patent Laid-Open No. 5-323355.
Then, a firing step (S for temporarily firing the polyimide)
2) The alignment treatment step (S3) of rubbing the surface of the polyimide and the cleaning step (S4) are performed.

Next, the substrates 1 and 4 are respectively aligned with the alignment films 2 and 2.
5 are made to face each other inside, and a frame-shaped sealing member 6 made of a resin such as a thermosetting epoxy resin using diethylene glycol monomethyl ether as a solvent is sandwiched and bonded (S5). The seal member 6 has an injection port for injecting liquid crystal. Then, a main firing step (S6) of performing main firing of the poiliimide is performed. Then, the liquid crystal 3 is injected into the region inside the seal member 6 between the alignment films 2 and 5 of the substrates 1 and 4 (S7), and the injection port is sealed (S8).

Finally, a work (assembled product) including the substrates 1 and 4 is put into a cleaning process (S8). In this cleaning process, a dip type cleaning device having a plurality of tanks is used.
Then, the work is dipped in an alignment film peeling solvent containing alkanolamine as a main component, and as shown in FIG. 1B, a portion of the alignment films 2 and 5 located on the substrate peripheral side of the seal member 6. 2a and 5a are dissolved in the above solvent and removed. At the same time, each exposed portion of the work is washed. By this step, the external connection terminal 7 is exposed and the surface of the external connection terminal 7 is washed.

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

According to this manufacturing method, the pattern of the alignment films 2 and 5 can be formed in self-alignment with the seal member 6. Therefore, a printing plate and a special mask pattern are not required, and the liquid crystal display device can be easily manufactured regardless of the model. As a result, productivity can be improved. 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 restrictions on the design of the liquid crystal display device are alleviated.

In the above-mentioned alignment film forming step (S1),
A printing method may be used instead of the method of applying the material of 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 achieved.

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

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

[0023]

As is apparent from the above, in the method of manufacturing a liquid crystal display device according to the first aspect, the pattern of the alignment film can be formed in self-alignment with the seal member. Therefore, a printing plate and a special mask pattern are not required, and the liquid crystal display device can be easily manufactured regardless of the model. As a result, productivity can be increased. Moreover, since the pattern of the alignment film is formed in a self-aligned manner with respect to the seal member, the pattern accuracy is improved and the design limitation of the liquid crystal display device is alleviated.

The liquid crystal display device according to a second aspect of the invention is an alignment film.
The pattern of is aligned with the board peripheral side of the seal member .
Can improve the pattern accuracy of the liquid crystal display device.
It Therefore, the restrictions on the design of the liquid crystal display device are eased.
Be done.

[Brief description of 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 drawing of the manufacturing method of the liquid crystal display device.

FIG. 3 is a diagram showing a liquid crystal display device manufactured by the above manufacturing method as seen 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

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-167712 (JP, A) JP-A-8-137113 (JP, A) JP-A-9-138411 (JP, A) JP-A-9- 283508 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/13-1/141

Claims (2)

(57) [Claims] 1. A liquid crystal display device is manufactured by using a pair of substrates which are opposed to each other and have external connection terminals in a peripheral region of a surface of at least one of the substrates which is opposed to each other. A method of manufacturing a liquid crystal display device, the step of forming an alignment film for determining the alignment of the liquid crystal over the entire area of the surfaces of the substrates facing each other; A step of facing each other so as to face the inside, and pasting together with a frame-shaped seal member sandwiched therebetween; a step of enclosing a liquid crystal in a region inside the seal member between the alignment films of the pair of substrates; The substrate is immersed in a solvent, and a portion of the alignment film on the substrate peripheral side of the sealing member is dissolved and removed in the solvent to remove the pattern of the alignment film.
In addition to the above
A method of manufacturing a liquid crystal display device, which comprises a step of exposing a part connection terminal . 2. A pair of substrates facing each other, at least
Also, one of the substrates is externally connected to the peripheral area of the opposite surface.
A terminal is provided and is provided in the entire area of the surface of the substrate facing each other except the peripheral area so as to expose the external connection terminal,
A frame-shaped seal part sandwiched between the alignment film for determining the alignment of the liquid crystal and the alignment films of the pair of substrates.
And a liquid crystal filled in the area inside the sealing member.
For example, the pattern of the alignment film and the substrate peripheral side of the seal member
A liquid crystal display device characterized by being matched.