JPH03264916A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To prevent the need for providing holes in a film substrate to generate the failure or deformation of the substrate by bending one end of the one substrate to the outer side from a sealing member, exposing the transparent electrode extended from the sealing member on the front surface of the other substrate to the outer side and using this electrode as a terminal for external connection. CONSTITUTION:After two pieces of grooves 17 are formed at the end of the film substrate 11a extending from the sealing material 16 are formed, the substrate part 11c on the side outer than the grooves 17 is bent to expose the transparent electrodes 12 on the other film substrate 11 to form the terminal 18 for external connection. The bent substrate part 11c is fixed by using an adhesive. The stage for providing the hole for exposing the electrode on the counter substrate 11b prior to joining of the substrates 11a and 11b is omitted in this way. The terminal for external connection is formed by bending the end of the one substrate 11a and exposing the electrode 12 of the other substrate 11b.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid crystal display device used for a display device or a light shutter, and particularly to a liquid crystal display device using a flexible film substrate.

BACKGROUND OF THE INVENTION FIG. 2 shows a sectional view of a liquid crystal display device using a flexible film substrate (hereinafter simply referred to as a film substrate). Film substrates 1 on which transparent electrodes 2 buttons and alignment films 3 are formed are placed facing each other, and a liquid crystal 6 is sealed with a sealing material 6. Spacers 4 such as resin beads having a constant particle size are arranged in the liquid crystal layer. In order to connect to the housing and the drive circuit, one of the substrates extends outward from the sealing material, and is provided with an external connection terminal 8 with the transparent electrode 2 exposed.

Next, a method for manufacturing the liquid crystal display device having the above structure will be explained.

FIGS. 4a and 4b are plan views of two film substrates each having a transparent electrode 2 formed in a pattern. Reference numeral 1 denotes a transparent flexible film substrate, generally made of a material such as polyethylene terephthalate, polyether sulfon, polycarbonate, etc., and a transparent electrode 2 formed with an engineered τ0 film (indium tin oxide film). moreover,
Holes 9 are provided by punching or other methods to expose the electrodes on the other opposing film substrate 1.

In the case of liquid crystal display devices using glass substrates, it is possible to cut the two substrates one by one by scribing the surface with a diamond knife or applying pressure after bonding them together, so it is generally possible to cut them one by one using a sealant. A method is used in which a liquid crystal display device having the shape shown in FIG. 2 is obtained by cutting the bonded substrates one by one at different positions. However, since this more advanced cutting method cannot be applied to film substrates, it is necessary to make holes 9 in advance to expose the electrodes on the opposing substrate before bonding the substrates.

Next, an alignment film 3 is placed on the liquid crystal enclosed area on the surface of the film substrate 1.
After forming a spacer 4 thereon and forming a sealing material 6 to surround the liquid crystal filling area, the required amount of liquid crystal 5 is dropped onto one film substrate 1, and the other film substrate 1 is placed under vacuum. Paste inside.

FIG. 3 is a sectional view of a liquid crystal display device in which two substrates are bonded together. In the figure, 9 is a hole provided in advance for exposing the electrode on the opposing film substrate 1;
By cutting at the position indicated by Y, a liquid crystal display device shown in FIG. 2 is obtained.

Problems to be Solved by the Invention As mentioned above, in a liquid crystal display device using a film substrate, it is necessary to make holes in advance to expose the electrodes on the opposing substrate before bonding the film substrate. There is a problem in that the number of steps is increased compared to the case where the hole 9 is formed, and particles and cutting debris from forming the hole 9 adhere to the surface of the substrate, resulting in uneven substrate gap and poor sealing. The tensile strength of the casing and film substrate decreases, causing damage or abnormal deformation of the substrate during the process.

In order to omit the step of preparing holes in advance to expose the electrodes on the opposing substrate and to use the same construction method as for glass substrates, it is necessary to cut only one of the two bonded substrates. Generally, film substrates are not brittle and cannot be cut by applying pressure after scratching the surface with a diamond bite or the like. Further, it is very difficult to cut only one substrate with a cutter or the like without damaging the other substrate because there is only a gap of 6 to 10 μm between the side substrates.

Another method disclosed in Japanese Unexamined Patent Publication No. 64-48032 is a method in which a thin plate having conductivity on both sides is inserted between the upper and lower boards to connect it to an external drive circuit. Accordingly, it is necessary to insert a thin plate having conductivity on both sides into a gap of 6 to 10 μm between the upper and lower substrates.

The thin plates with conductivity on both sides used here are generally flexible substrates or metal foils, but in practice, the thickness of these is 10μ1 or more larger than the gap between the substrates, so by inserting them between the substrates, a sealing material can be formed. Tensile stress is generated in the process, resulting in a decrease in reliability. Furthermore, since elastic connectors generally used for connecting glass substrate liquid crystal display devices cannot be used, there are problems such as incompatibility of drive circuit boards.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device that does not require a step of forming holes in a film substrate, which may cause damage or deformation of the film substrate.

Means for Solving the Problems In order to achieve the above objects, the liquid crystal display device of the present invention has the following features:
Two flexible film substrates each having a transparent electrode are joined with a certain gap between them via a sealing member, and liquid crystal is sealed in the gap between the side substrates to form a liquid crystal panel. is bent outward from the sealing member to expose a transparent electrode extending outward from the sealing member on the surface of the other substrate, thereby forming an external connection terminal.

Function The liquid crystal display device of the present invention has a structure in which one substrate is bent to expose the transparent electrodes on the other substrate without cutting the other substrate, and the electrodes on the opposing substrate are exposed in advance before bonding the substrates. It is possible to omit the step of providing a hole for this purpose. i
Furthermore, the shape of the external connection terminal is the same as that of a conventional glass substrate liquid crystal display device, and the connection means and drive circuit board are compatible.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

The first national electric current is a cross-sectional view of a liquid crystal display device in which two film substrates 111L and 11b on which a transparent electrode GII 12 and an alignment film 13 are formed are bonded together with their electrode surfaces facing each other, and a liquid crystal 16 is sealed therein.

11&, 11b is 126μl thick! An ITO (indium tin oxide film) 12 is formed as a transparent electrode on a polyether sulfon film substrate. The alignment film 13 is a polyimide thin film, and after printing, the surface is subjected to a rubbing treatment. Next, resin beads with a diameter of 7 μl are sprinkled as spacers on one film substrate 11b, and an ultraviolet curing adhesive is formed as a sealing material 16 on the other film substrate 111L by screen printing in a shape surrounding the display area. do. Next, the liquid crystal 16 is placed on one film substrate 11.
A required amount of the sealing material 11b is dropped onto the other film substrate 111L, and after bonding with the other film substrate 111L in a vacuum, the sealing material 11b is cured by irradiation with ultraviolet rays to obtain the liquid crystal display device shown in the figure.

Next, the film substrates 11&, 11b are cut at the positions indicated by X in FIG. 1a using a mold to form the shape shown in FIG. The cutting position was a few degrees outside the sealing material 16 on the side where the transparent electrode 2 was extended as the external connection terminal 18, and on the outer edge of the sealing material 16 on the other sides. It is desirable to adjust this according to the required terminal length.

Next, as shown in FIG. 1C, two grooves 7 are formed in the end of the film substrate 111L where the sealing material 16 also extends, and then the substrate portion 11c outside the groove 1 is formed as shown in FIG. 1D. The transparent electrode 12 on the other film substrate 11b is exposed and the external connection terminal 18 is formed by bending it as shown in FIG. The bent substrate portion 110 is fixed using adhesive. 1st
The groove 7 in FIG. C is for facilitating the bending of the substrate, and can be easily formed by scribing the surface of the substrate with a sharp-tipped knife or the like. In addition, in general, the thinner the film substrate is, the easier it is to fold and bend.5Depending on the thickness of the substrate, it is possible to bend the substrate even with just one groove 7, and it is also possible to bend the substrate without forming a groove. may be possible.

In this embodiment, polyether sulfone is used as the film substrates 111L and 11b, but the invention is not limited to this. A method of filling the casing with a liquid crystal by forming a sealant 16 in a shape with an opening in a part, and after bonding two film substrates 11a and 11b, liquid crystal 16 is injected through the opening using a vacuum. can also be used.

As described above, according to this embodiment, an external connection terminal can be formed without providing a hole in the film substrate that would cause damage or deformation to the substrate.

Effects of the Invention According to the present invention, the step of forming holes for exposing the electrodes on the opposing substrate before bonding the substrates can be omitted, and the edge of one substrate can be bent and the edge of the other substrate can be bent. External connection terminals can be formed by exposing the electrodes of the substrate, and no irregularities in the gap between the substrates or poor sealing will occur due to particles or cutting debris adhering to the surface of the substrate during hole formation. In addition, the tensile strength of the film substrate is reduced and breakage or abnormal deformation during the process does not occur, so the process yield is improved. Furthermore, since the shape of the external connection terminal is the same as that of a conventional glass substrate liquid crystal display device, there is no need for special connection means and there is no increase in cost, which is of great industrial value.

[Brief explanation of drawings]

Figure 1&%a is a cross-sectional view sequentially explaining the manufacturing process of a liquid crystal display device according to an embodiment of the present invention, Figures 2 and 3 are cross-sectional views of a conventional liquid crystal display device, and Figures 4a and b 1 is a plan view of a film substrate applied to a conventional liquid crystal display device. 11! L, 11b...Film substrate, 11c
...Substrate part, 12 ...Transparent electrode, 1
3...Alignment film, 14...Spacer, 1
5. River...LCD, 16...Sealing material, 17...
...Groove, 18...-Terminal for external connection.

Claims (1)

[Claims] Two flexible film substrates each having a transparent electrode are joined with a certain gap between them via a sealing member, liquid crystal is sealed in the gap between both substrates to form a liquid crystal panel, and one end of one of the substrates is sealed. A liquid crystal display device characterized in that the transparent electrode is bent on the outside of the sealing member to expose a transparent electrode extending outside of the sealing member on the surface of the other substrate to serve as an external connection terminal.