JPH0894985A - Production of liquid crystal display device - Google Patents

Abstract

PURPOSE: To provide a process for production of liquid crystal display elements which widens the effective display area without increasing the size. CONSTITUTION: This process comprises producing the liquid crystal display elements by adhering an original plate consisting of two sheets of translucent base materials respectively formed with electrode patterns for at least one piece of the liquid crystal display elements while holding a specified spacing by a sealant layer 21 formed around at least one patterns of two sheets of the original plates and respectively cutting two sheets of the original plates at the outer periphery of the sealant layer 21. The second sealant 22 is injected into the spacing between two sheets of the transparent substrates between the end edges of the transparent substrates 1a, 1b formed by cutting the sealant layer 21 after cutting of the original plates and solidifying the part.

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. More specifically, the present invention relates to a method for manufacturing a liquid crystal display element, which can expand an effective display area without increasing the size of the liquid crystal display element.

[0002]

2. Description of the Related Art A liquid crystal display device is usually provided with two large transparent original plates such as glass plates, each having a plurality of electrode film patterns and alignment films for a liquid crystal panel, and a seal around one transparent original plate pattern. An agent layer is provided by screen printing, etc., and a spacer is sprinkled on the other transparent original plate to overlap the two transparent original plates, and a spacer is used to maintain a constant gap and two transparent original plates are stuck by the sealant layer. I'm wearing it. After that, the transparent original plate is cut at the outer periphery of the sealant layer, and a liquid crystal material is injected into the inner gap surrounded by the sealant layer to form each liquid crystal display panel.

The gap between the above-mentioned sealant layer and the cutting line of the transparent original plate becomes a non-display area outside the liquid crystal layer and becomes a dead space, so the narrower it is, the more preferable it is. For simplification of the process, a scribe break method is adopted in which a line is put in the cut portion and the wire is broken. Therefore, it is not possible to cut at a clean end face and at a position where it comes into contact with the sealing agent layer, and the distance between the sealing agent layer and the cutting line, that is, the edge of the liquid crystal display panel is at least 0.3 in terms of shape quality. ~ 0.5 mm is required.

On the other hand, the sealant layer holds the liquid crystal material inside by adhering the two transparent substrates together, prevents moisture from entering from the outside, and causes the liquid crystal material to undergo a chemical reaction such as hydrolysis. It prevents it from changing. Therefore, in terms of reliability, the width of the sealant layer is usually at least 1 mm.
The above is necessary, and considering the manufacturing tolerance, the distance between the edge of the substrate and the inside of the sealant layer (liquid crystal layer side) is at least 1.
A width of about 8 to 2 mm is provided.

[0005]

As described above, according to the conventional method of manufacturing a liquid crystal display element, a dead space having a width of about 2 mm is generated at the peripheral edge of the liquid crystal display panel, and an effective display for the size of the liquid crystal display panel is made. There is a problem that the area becomes smaller, which violates the demand for miniaturization of electronic components.

An object of the present invention is to solve the above problems and to provide a method of manufacturing a liquid crystal display device capable of expanding an effective display area without increasing the size of the liquid crystal display device.

[0007]

According to the method of manufacturing a liquid crystal display element of the present invention, an original plate made of two translucent substrates on which at least one electrode pattern for the liquid crystal display element is formed is used. A liquid crystal display device is prepared by bonding a sealant layer provided around the pattern on at least one of the two master plates with a fixed gap therebetween, and then cutting the two master plates at the outer periphery of the sealant layer. A method for producing a second sealing agent after cutting the original plate, and injecting a second sealing agent into a gap between the two transparent substrates between an edge of the transparent substrate formed by the cutting and the sealing agent layer. It is characterized by solidifying.

The seal portion formed by the seal agent layer and the second seal agent is 1.5 from the edge of the transparent substrate.
It is preferable to provide the sealing agent layer so as to be in the range of mm or less because the effective display area can be widened for a liquid crystal display panel having a certain size.

[0009]

According to the present invention, since the seal portion is provided by the conventional sealant layer and the second sealant provided on the edge side after cutting of the transparent substrate, the width of the sealant layer is reduced to the edge side. You can get it. Moreover, in order to cut the transparent substrate, a second gap is created between the sealant layer and the edge of the transparent substrate.
Since the sealing portion is injected by injecting the sealing agent, the width of the essential sealing portion can be brought close to the edge of the liquid crystal display panel. As a result, it is possible to secure a seal width that can prevent the entry of moisture, maintain reliability, and increase the effective display area.

[0010]

The method for producing the liquid crystal display device of the present invention will be described below with reference to the accompanying drawings.

FIG. 1A is a plan view of a liquid crystal display panel portion manufactured by an embodiment of the method for manufacturing a liquid crystal display element of the present invention, and FIG. 1B is a sectional view taken along the line I-I of FIG. FIG. 2 is a diagram schematically showing an example in which the liquid crystal display panel is made of a large transparent original plate, and FIG. 3 is a flow chart of an embodiment of the method for producing the liquid crystal display device of the present invention.

1A and 1B, 1a and 1b
Each is a transparent substrate made of glass or plastics, and the inner surfaces facing each other are provided with electrode patterns, alignment films, etc., respectively, which are not shown, and spacers (not shown) are provided to maintain a constant gap. The sealant layer 21 and the second sealant 22 are adhered to each other at the peripheral edge portion thereof to form the seal portion 2. A liquid crystal layer 4 is formed by injecting a liquid crystal material into the gap between the two transparent substrates from a liquid crystal injection port 3 in which the seal portion 2 is not provided. After the injection of the liquid crystal material, the injection port 3 is a sealant. A liquid crystal display panel 6 is formed by sealing with 5. A polarizing plate (not shown) and the like are provided on both sides of the transparent substrates 1a and 1b, and a circuit substrate and a backlight are further provided to form a liquid crystal display element.

In the liquid crystal display device of the present invention, the peripheral sealing portion 2 for adhering the two transparent substrates 1a and 1b has a sealing agent layer 21 and a second sealing agent 22 in which the width of the conventional sealing agent layer is narrowed. And is characterized in that the width of the entire seal portion 2 is brought close to the edges of the transparent substrates 1a and 1b. It is preferable that the seal portion 2 is contained within a range of 1.5 mm from the edges of the transparent substrates 1a and 1b. That is, these liquid crystal display panels are shown in FIG.
As shown in FIG. 3, a large transparent original plate 10 on which a plurality of liquid crystal display panels can be formed is provided with an electrode pattern for each liquid crystal display panel, an alignment film, etc. (none of which are shown), and is attached by a sealant layer 21. After that, the transparent original plate 10 is cut along the cutting line A on the outer periphery of the sealing agent layer 21. Therefore, the cutting line A, that is, the distance between the edges of the transparent substrates 1a and 1b of each liquid crystal display panel 6 and the sealant layer 21 cannot be eliminated. Moreover, this space becomes a dead space, and when the liquid crystal material is injected, the liquid crystal material also enters this space to waste the liquid crystal material, and the work of removing the liquid crystal material becomes difficult. In the present invention, the width of the conventional sealant layer is from 1 mm or more to 0.3 by making the void portion which becomes the dead space a part of the seal portion.
The width is narrowed to about 0.5 mm, and the effective display area is widened by bringing the entire seal portion 2 closer to the edge side of the transparent substrate.

After cutting each liquid crystal display panel, by filling the gap between the edges with the second sealing agent 22, the second sealing agent 22 has a width of about 0.4 to 1.0 mm, and the sealing portion is sealed. Even if the sealing agent layer 21 which has been used conventionally is narrowed, the width of about 1 mm can be secured as the entire sealing portion 2 and the functions of the sealing portion 2 such as the adhesive strength and the moisture resistance are sufficient. Is being demonstrated. The place where the second sealant 22 is provided is a place which has been a dead space in the past as described above. In the present invention, the dead space is utilized to widen the effective display area.

As the sealing agent layer 21, a thermosetting resin such as an epoxy resin which has been conventionally used or an ultraviolet curable resin can be used. As the second sealant, thermosetting resin such as epoxy resin, amino resin, melamine resin, phenol resin, room temperature curable resin such as silicone resin, ultraviolet curable resin, thermoplastic resin such as acrylic resin, low melting point, etc. Although glass or the like can be used, among these, a thermosetting resin such as an epoxy resin and an ultraviolet curable resin are particularly preferable. In addition, the sealing agent layer 2
It is preferable to use the same type of material for the first and second sealing agents 22 because the reliability of the sealing property is improved and the width of the sealing portion 2 as a whole can be narrowed.

As described above, the width of the sealant layer 21 is 0.
When the thickness is about 3 to 0.5 mm, the adhesive strength of the transparent substrates 1a and 1b can be sufficiently maintained, and the second sealing agent 22 has a thickness of 0.
If it is about 4 to 0.8 mm, the reliability of the seal portion 2 can be sufficiently obtained, and the width of the seal portion 2 is 1.5 mm or less, preferably 0.7 to 1.5 mm, more preferably 0.8 to
It is about 1.2 mm. This is because if it is too narrow, the sealing function will not be exerted, and if it is too wide, the object of the present invention to widen the effective display area cannot be achieved.

Next, the manufacturing method of the liquid crystal display device of the present invention will be described with reference to FIG.
A description will be given based on the flowchart.

First, cleaning I is carried out by an appropriate method such as cleaning with an organic solvent or shower cleaning in order to remove dirt from the two original glass plates (step A).

Next, ITO or Sn is formed on each surface of the two glass original plates by vapor deposition or sputtering.
A pattern such as a transparent electrode film made of O ₂ or the like is formed for each liquid crystal display panel 6 (see FIG. 1). Further, an alignment film (not shown) made of polyimide resin (PI), polyamino acid resin, or the like is formed on the surface of the transparent electrode film by screen printing or the like and cured (step B).

Next, the orientation film formed on the original glass plate in step B is rubbed to align the orientation of orientation (step C), washed II and dried (step D).

Next, from the position corresponding to the cutting line around the pattern of the liquid crystal panel of one original plate, for example, 0.5 to
The sealant layer 21 is formed by printing a sealant with a width of about 0.3 to 0.5 mm on the inside of about 0.7 mm (step E). Further, an electrode film for connecting the terminals of the electrode film of one substrate to the other substrate side is printed on the other original plate by silver dot printing (step F), and spacers are further scattered (step G).

Next, the two glass original plates 10 are aligned and overlapped so that the electrode films are inside and the corresponding electrode films face each other, and the sealant layer 21 of each liquid crystal display panel is cured. Bond (step H).

Next, the original glass plate 10 on which a plurality of liquid crystal display panel patterns are formed is cut outside the sealant layer 21 by scribe break to form individual liquid crystal display panels 6 (step I).

Next, a second sealant 22 is applied to the gap between the substrates 1a and 1b from the outer periphery of the sealant layer 21 of the liquid crystal display panel 6 (see FIG. 1) to the edges of the transparent substrates 1a and 1b. Solidify (step J). This second sealant 2
As the material 2, an ultraviolet (UV) curable epoxy resin, a thermosetting epoxy resin, or the like is used and is applied by a transfer method or the like. In this case, application at about 20 to 70 ° C. is preferable because the viscosity of the resin decreases and the resin immediately flows into the gap. The solidification depends on the sealing agent used, but when a UV curable resin is applied, for example, it is irradiated with UV to be cured.

Then, a liquid crystal material is injected into the gap between the two transparent substrates 1a and 1b, and the injection port 3 is sealed with a sealant 5 (see FIG. 1) (step K).

After that, a polarizing plate (not shown) is attached to the surface of each of the transparent substrates 1a and 1b (step L), and post-processes such as visual inspection and assembly are performed (step M) to obtain a liquid crystal display element. .

[0027]

According to the present invention, the seal portions of the two transparent substrates are formed in two steps, and the second seal agent is adhered after cutting the substrates, so that the seal portions are on the edge side of the substrate. On the other hand, the dead space is reduced with respect to the entire area of the liquid crystal display panel, and the effective display area can be increased. Therefore, the liquid crystal display element that can display the same size can be downsized, and the requirements for light, thin, short, and small electronic devices can be satisfied.

Further, when used in a large-sized liquid crystal display device such as a destination display at a station or an airport, a display on the street, etc., the liquid crystal display panels are arranged vertically and horizontally. The dead space of the seam can be reduced, and continuous display can be obtained without a feeling of strangeness.

Further, according to the present invention, since the gap between the substrates at the edge of the transparent substrate is filled with the second sealant, the liquid crystal material does not enter the outer periphery of the sealant layer when the liquid crystal material is injected. Therefore, the yield of the liquid crystal material can be improved without providing a stopper or the like, and the number of steps for wiping the extra liquid crystal material is not required, which greatly contributes to the cost reduction.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a liquid crystal display panel manufactured by an embodiment of a method for manufacturing a liquid crystal display element of the present invention.

FIG. 2 is a diagram schematically showing an example in which a liquid crystal display panel is made of a large transparent original plate.

FIG. 3 is a process drawing for explaining an example of a method for manufacturing a liquid crystal display element of the present invention.

[Explanation of symbols]

 1a, 1b Transparent substrate 2 Seal part 4 Liquid crystal layer 6 Liquid crystal display panel 21 Sealing agent layer 22 Second sealing agent

Claims (2)

[Claims] 1. An original plate made of two light-transmissive base materials on which at least one electrode pattern for a liquid crystal display element is formed, is provided around at least one of the patterns of the two original plates. A method for producing a liquid crystal display element by bonding the two sealing plates with the sealing agent layer while maintaining a constant gap therebetween, and then cutting the two original plates at the outer periphery of the sealing agent layer. 2 between the edge of the transparent substrate formed by the cutting and the sealant layer
A method for manufacturing a liquid crystal display element, which comprises injecting a second sealant into a gap between transparent substrates to solidify the second sealant. 2. The seal portion formed by the seal agent layer and the second seal agent is 1. from the edge of the transparent substrate.
The method for producing a liquid crystal display element according to claim 1, wherein the sealing agent layer is provided so as to be in a range of 5 mm or less.