JPH07301818A - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the surface of the connection terminal from being scratched during rubbing. [Structure] A transparent electrode 2 and a connection terminal 4 connected to each transparent electrode 2 through a lead wire 3 are formed on the upper surface of a lower substrate 1. Next, the conductive paste 6 is formed on the portion of the connection terminal 4 outside the seal material forming region 5. Further, the alignment film 7 is formed on the entire upper surface inside the seal material forming region 5. Then, a rubbing process is performed. In this case, since the connection terminals 4 on the outside of the seal material forming region 5 are covered with the conductive paste 6, the surface of the connection terminals 4 in this portion is not scratched. The surface of the conductive paste 6 may be scratched, and the surfaces of the connection terminals 4 and the wiring lines 3 in the seal material forming region 5 may be scratched, but there is no problem.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a liquid crystal display device, generally, two substrates made of glass, resin or the like having transparent electrodes and alignment films formed on opposite surfaces thereof are bonded to each other via a sealing material, and the inside of the sealing material is sealed. It has a structure in which a liquid crystal is sealed between both substrates. Further, in such a liquid crystal display device, in order to electrically connect to the outside, as an example, one end portion of the lower substrate is projected from one end portion of the upper substrate, and a connection terminal is provided on the upper surface of the protruding portion. There is something.

By the way, when manufacturing such a conventional liquid crystal display device, for example, a transparent electrode made of ITO and a connection terminal are formed at predetermined positions on the upper surface of the lower substrate,
Next, an alignment film made of polyimide resin or the like is formed on the upper surface of the portion corresponding to the liquid crystal enclosing region, and then the surface of the alignment film is rubbed by rubbing it in a certain direction with a rubbing cloth made of woven cloth or felt.

[0004]

However, in the conventional manufacturing method of such a liquid crystal display device, the transparent electrode is covered with the alignment film, but the connection terminal is not covered with the alignment film during the rubbing treatment. Since it is exposed, the surface of the connection terminal is also rubbed with a rubbing cloth,
The surface of the connection terminal may be scratched. In such a case, when one end of the flexible wiring board is thermocompression-bonded to the connection terminal via an anisotropic conductive adhesive, a crack is generated due to the pressure on the scratched portion of the connection terminal, causing a disconnection. There was a problem that it might happen. An object of the present invention is to provide a liquid crystal display device capable of preventing the surface of the connection terminal from being scratched during the rubbing treatment, and a method of manufacturing the same.

[0005]

The invention according to claim 1 is
A liquid crystal display device comprising a substrate having a transparent electrode and a connection terminal formed on each predetermined portion of one surface, wherein the connection terminal is covered with a conductive paste. According to a third aspect of the present invention, a transparent electrode and a connection terminal are formed on each predetermined portion of one surface of the substrate, an alignment film is formed on a predetermined portion of the upper surface thereof, and the connection terminal is covered with a conductive paste. In this state, the surface of the alignment film is rubbed.

[0006]

According to the present invention, since the connection terminal is covered with the conductive paste, the rubbing treatment in this state prevents the surface of the connection terminal from being scratched even if the surface of the conductive paste is scratched. be able to.

[0007]

1 to 3 show respective manufacturing steps of a liquid crystal display device according to an embodiment of the present invention.
Therefore, the structure of the liquid crystal display device of this embodiment will be described together with its manufacturing method with reference to these drawings in order.

First, as shown in FIG. 1, a set of seven transparent electrodes (segment electrodes) 2 and each transparent electrode 2 are formed at predetermined locations on the upper surface of a lower substrate 1 made of glass or resin. The connecting terminal 4 connected to the
Formed by TO. In this case, the connection terminals 4 are gathered at a predetermined one end of the lower substrate 1. Next, as shown in FIG. 2, a conductive paste 6 made of silver paste, carbon paste, or the like is formed by printing on a portion of the connection terminal 4 outside the seal material forming area 5, so that the outside of the seal material forming area 5 is formed. The connection terminal 4 in is covered with the conductive paste 6. Further, an alignment film 7 made of polyimide resin or the like is formed on the entire upper surface inside the seal material forming region 5. Next, the surface of the alignment film 7 is rubbed with a rubbing cloth made of woven cloth, felt, or the like in a certain direction for rubbing treatment. In this case, since the connection terminals 4 on the outside of the seal material forming region 5 are covered with the conductive paste 6, the surface of the connection terminals 4 in this portion is not scratched. In addition,
The surface of the conductive paste 6 may be scratched, and the connecting terminal 4 and the lead wire 3 in the seal material forming region 5 may be damaged.
Since it is exposed, the surface of the connection terminal 4 and the lead wire 3 in this portion may be damaged.

Next, as shown in FIG. 3, a sealing material 8 made of epoxy resin or the like is formed in the sealing material forming region 5.
Next, although not shown, spacers are scattered on the upper surface of the alignment film 7 inside the sealing material 8. Next, the sealing material 8
The upper substrate 9 is superposed on the upper surface of the. Although not shown, a transparent electrode (common electrode) made of ITO and an alignment film made of polyimide resin or the like are formed on the lower surface of the upper substrate 9 in advance. In this state, one end of the lower substrate 1, that is, the portion where the connection terminal 4 is formed is projected from one end of the upper substrate 9. Next, when the substrates 1 and 9 are thermocompressed from above and below, the sealing material 8 is cured, and the substrates 1 and 9 are bonded to each other via the cured sealing material 8. Here, it is desirable that the film thickness of the conductive paste 6 is equal to or less than the gap between the substrates 1 and 9 (usually about 2 to 10 μm) so that a gap defect does not occur during the bonding. Next, a liquid crystal (not shown) is injected between the substrates 1 and 9 inside the seal material 8 through a liquid crystal injection port (not shown) formed in the seal material 8, and then the liquid crystal injection port is sealed. Seal with a stopper (not shown). Thus, the manufacture of the liquid crystal display device of this embodiment is completed.

In the liquid crystal display device thus obtained, it is possible to prevent the surface of the connection terminal 4 from being scratched during the rubbing treatment, so that although not shown,
When one end of a flexible wiring board is thermocompression-bonded to the connection terminal 4 covered with the conductive paste 6 via an anisotropic conductive adhesive, cracks or disconnection due to scratches may occur in the connection terminal 4. Therefore, the reliability of the connection can be improved. It should be noted that even if the surface of the conductive paste 6 is scratched, there is no problem. Further, even if the surfaces of the connection terminals 4 and the routing wires 3 in the seal material forming region 5 are damaged, the connection terminals 4 are heated by, for example, one end of a flexible wiring board via an anisotropic conductive adhesive. At the time of crimping, neither heat nor pressure is applied to the connection terminal 4 and the lead wire 3 in the seal material forming region 5,
There is no problem with this. When the conductive paste 6 is made of a conductive material such as silver or carbon and a thermoplastic resin, one end of the flexible wiring board is heated to the connection terminal 4 directly through the conductive paste 6. It can also be crimped.

[0011]

As described above, according to the present invention, it is possible to prevent the surface of the connection terminal from being scratched during the rubbing process, and therefore, for example, one end of the flexible wiring board is attached to the connection terminal. When thermocompression bonding is performed via the anisotropic conductive adhesive, cracks or disconnections due to scratches do not occur in the connection terminals, and therefore the reliability of connection can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which a transparent electrode or the like is formed on the upper surface of a lower substrate when manufacturing a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a state in which a connection terminal is covered with a conductive paste and an alignment film is formed in the same manufacturing process.

FIG. 3 is a plan view showing a state in which an upper substrate is attached to a lower substrate via a sealing material in the same manufacturing process.

[Explanation of symbols]

 1 Lower Substrate 2 Transparent Electrode 3 Routing Wire 4 Connection Terminal 5 Sealing Material Forming Area 6 Conductive Paste 7 Alignment Film 8 Sealing Material 9 Upper Substrate

Claims (3)

[Claims] 1. A liquid crystal display device comprising a substrate having a transparent electrode and a connection terminal formed on each predetermined portion of one surface, wherein the connection terminal is covered with a conductive paste. 2. The liquid crystal display device according to claim 1, wherein the conductive paste is made of a conductive material and a thermoplastic resin. 3. A transparent electrode and a connection terminal are formed at predetermined locations on one surface of a substrate, an alignment film is formed at predetermined locations on the upper surface thereof, and the connection terminal is covered with a conductive paste. A method for manufacturing a liquid crystal display device, which comprises subjecting the surface of an alignment film to a rubbing treatment.