JP2842981B2 - Manufacturing method of liquid crystal display device - Google Patents

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 in which a polarizing plate is adhered to a liquid crystal panel formed by sandwiching liquid crystal between a pair of glass substrates.

[0002]

2. Description of the Related Art In a manufacturing process of a liquid crystal display device, a transparent electrode, an alignment film and the like are generally formed on a pair of glass substrates, and after alignment treatment is performed, a sealing material is printed. A glass substrate is attached with the surfaces on which the transparent electrodes are formed facing each other. Then, after performing a dividing process for terminal connection and formation of a liquid crystal injection port, liquid crystal is injected between the bonded glass substrates and sealed.

[0003] Next, a polarizing plate is adhered to the surfaces of the two glass substrates, respectively. In the attaching step of the polarizing plate, static electricity is generated. This static electricity is accumulated in the liquid crystal panel through the external circuit connection terminal exposed from the facing glass substrate by the terminal-out process in the dividing step, so that the accumulated portion becomes uneven in contrast and degrades display quality. Was causing it.

[0004] For this reason, it is necessary to effectively suppress the generation of static electricity, and in the sticking step of the polarizing plate, the static electricity is removed by performing a blow or humidification, etc. However, such a static elimination process alone cannot provide a sufficient effect, and still causes contrast unevenness due to accumulation of static electricity. So, conventionally,
In addition to static elimination, measures are taken to equalize the potentials of all electrodes of the external circuit connection terminals so that the generated static electricity does not affect display quality.

More specifically, patterning is performed so that the terminals of the external circuit connection terminals on the side of the substrate are connected to each other so that the terminals can be connected to each other. The part has been cut off.

In this way, even if static electricity is generated when the polarizing plate is attached, all the electrodes of the external circuit connection terminals are maintained at the same potential, thereby preventing the contrast unevenness of the liquid crystal display device. In addition, the display quality can be prevented from deteriorating.

However, in the above-mentioned method, there is a restriction due to the size of the original substrate also in forming the continuous terminal portion. Further, since the terminal portion is cut off later, glass chips are generated, so that the post-process is performed. There is a disadvantage that foreign matter is easily mixed in by the cutting powder. Furthermore, since a cutting operation or the like is required, there is a problem that workability is low.

In order to solve such a problem, a method has been proposed in which a conductive tape such as a copper foil is adhered to the entire surface of the terminal for connecting an external circuit, and after the polarizing plate is adhered, the conductive tape is peeled off. ing.

[0009]

However, in the above-described method of attaching a conductive tape such as a copper foil, it is possible to solve the problem of the restriction due to the size of the original substrate and the problem of foreign matter in glass chips. However, on the other hand, a problem has arisen that leakage between terminals is likely to occur due to residue of the conductive tape remaining after peeling or an adhesive substance.In addition, since it is an operation of attaching a conductive tape such as a thin copper foil, Workability is still low and workability has not been improved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to improve the operability and eliminate the risk of terminal-to-terminal leakage and to reduce the risk of inter-terminal leakage by connecting all the electrodes of the external circuit connection terminals. An object of the present invention is to propose a method of manufacturing a liquid crystal display device that can maintain a same potential and obtain a liquid crystal display device with high display quality without contrast unevenness.

[0011]

According to a first aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising the steps of: providing a polarizing plate on a pair of substrates opposed to each other with a liquid crystal interposed therebetween; Before attaching, on the plurality of external circuit connection terminals formed on the substrate, apply conductive silicon rubber over the entire direction orthogonal to each terminal, after attaching the polarizing plate,
The conductive silicon rubber is peeled off.

According to a second aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, comprising the steps of: The conductive silicon rubber is applied to a region on an external circuit connection terminal corresponding to the vicinity of an end of a counter substrate provided opposite to the terminal.

According to a third aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device according to the first or second aspect, further comprising: The conductive silicon rubber is applied so that the upper surface of the conductive silicon rubber is reached.

[0014]

According to the method of the first aspect, prior to the attachment of the polarizing plate to the substrate, the conductive silicon rubber is applied to the external circuit connection terminals over the entire direction orthogonal to each terminal. As a result, all the electrodes of the external circuit connection terminals are maintained at the same potential, and no uneven charging occurs due to static electricity generated when the polarizing plate is attached. As a result, contrast unevenness of the display unit due to static electricity does not occur. In this case, it is possible to maintain all the electrodes of the external circuit connection terminals at the same potential by a simpler work than applying a conductive tape such as a conventional thin copper foil, in which conductive silicon rubber is applied. As a result, workability can be improved. Furthermore, even if a residue or the like is generated when the conductive silicon rubber is peeled off, there is no possibility that the terminal leak occurs due to the residue in consideration of the resistivity of the conductive silicon rubber, and the terminal leakage occurs. Can also be avoided.

As a result, all the electrodes of the external circuit connection terminals are maintained at the same potential with good workability and without the risk of inter-terminal leakage, and the display quality of the liquid crystal display device is free from contrast unevenness. A high liquid crystal display device can be obtained.

Further, according to the method of the second aspect, the area on the external circuit connection terminal corresponding to the vicinity of the end of the counter substrate is
Since the conductive silicon rubber is applied, even if the conductive silicon rubber remains, the reliability of connection between the external circuit connection terminal and the drive circuit connected thereto is not reduced, and the external A liquid crystal display device with high connection reliability between a circuit connection terminal and a driving circuit or the like can be obtained.

According to the third aspect of the present invention, since the conductive silicon rubber is applied so that the upper surface reaches the extended portion of the opposing substrate, the opposing substrate can be extended even after the conductive silicon rubber is peeled off. As a result, the conductive silicon rubber remains in the portion, whereby a moisture proof effect is imparted to the joint between the substrates, and a highly reliable liquid crystal display device having excellent moisture proof properties can be obtained.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

In the liquid crystal display device manufactured by the method of manufacturing a liquid crystal display device according to the present embodiment, TAB (Tape Automated Bonding) and FPC (F
lexible Priented Circuit) is connected.

The liquid crystal panel 2 is, as shown in FIG.
A pair of glass substrates 1a and 1 on which transparent electrodes 3.3 as scanning electrodes and signal electrodes and alignment films 4.4 are formed, respectively.
b are arranged to face each other, and a spacer 7 and a liquid crystal 6 are sandwiched between these substrates 1a and 1b.

The manufacturing process of the liquid crystal panel 2 will be described with reference to the flowchart of FIG.

First, a pair of glass substrates 1a and 1b
Transparent electrodes 3.3 made of TO (Indium Tin Oxide) or the like are respectively formed (P1), and an alignment film 4.4 made of polyimide, polyvinyl alcohol or the like is formed thereon (P1).
2). Then, after the orientation treatment is performed (P3), the sealing material 5 is printed on the glass substrate (P4), the spacers 7 are scattered, and the pair of glass substrates 1a and 1b are bonded (P5).

Next, the bonded glass substrates 1a and 1
After b is divided into a predetermined shape (P6), terminals are formed, a liquid crystal injection port is formed, and the like, and then the liquid crystal 6 is injected and sealed between the glass substrates 1a and 1b. (P
7) (see FIG. 2).

Subsequently, the polarizing plates 8.8 are adhered to the glass substrates 1a and 1b. In the attaching process of the polarizing plates 8.8, static electricity is generated. 8
Prior to the bonding step, the external circuit connection terminals 3a exposed from the ends of the glass substrates 1a and 1b by the above-mentioned dividing process.
The conductive silicon rubber 9 is applied by a dispenser (not shown) over the entire direction orthogonal to the terminals (P8). The application of the conductive silicon rubber 9 makes the potentials of all the electrodes of the external circuit connection terminals 3a formed on the glass substrate 1b equal.

The conductive silicone rubber 9 is applied with a width of 0.5 mmφ in consideration of the releasability, and the application position is
As shown in FIGS. 1 and 3, the vicinity of the end of the glass substrate 1a, that is, the vicinity of the extension 1a 'of the glass substrate 1a, so as not to overlap with the connection portion with the drive circuit in the external circuit connection terminal 3a to be performed later. Area and the upper surface thereof is the extension 1
a '.

The conductive silicon rubber 9 is obtained by mixing conductive particles 9b into a silicon rubber 9a. The conductive silicon rubber 9 has good releasability and is connected to a drive circuit. A low-molecular component that causes a decrease in reliability is used. For example, KE34 (conductive particles; carbon) manufactured by Shin-Etsu Silicone Co., Ltd. is used. Further, as the conductive particles 9a, carbon or the like is suitable. In addition, metal filler such as Ni or Cu, or plastic beads coated with metal may be used. In this embodiment, the conductive particles 9b having a diameter of several μm or more are used so as to be larger than the gap between the glass substrates 1a and 1b. The appropriate amount of the conductive particles 9b added is such that the volume resistivity is 10 ³ to 10 ⁶ Ωcm.

Thereafter, as shown in FIG. 4, polarizing plates 8.8 are adhered to the respective surfaces of the glass substrates 1a and 1b opposite to the surfaces on which the transparent electrodes 3.3 are formed. (P9). At this time, near the end of the glass substrate 1a of the external circuit connection terminal 3a formed on the glass substrate 1b,
As described above, the conductive silicon rubber 9 is applied,
Since the potentials of all the electrodes of the external circuit connection terminal 3a are equal, it is possible to prevent the static electricity generated in the step of attaching the polarizing plates 8.8 from being partially accumulated in the liquid crystal panel.

Thereafter, the conductive silicon rubber 9 applied to the external circuit connection terminals 3a of the glass substrate 1b is peeled off (P10). As described above, in the present embodiment, the conductive silicon rubber 9 is applied so that the upper surface of the conductive silicon rubber 9 reaches the extension 1a '. After this, the conductive silicon rubber 9 remains at the joint between the glass substrates 1a and 1b, and a moisture-proof effect is imparted to the joint between the glass substrates 1a and 1b. In particular, in the present embodiment, since the conductive particles 9b having a diameter larger than the gap between the glass substrates 1a and 1b are used, the conductive particles 9b penetrate into the cell gap of the extension 1a '. Thus, only the silicon rubber 9a remains after the conductive silicon rubber 9 is peeled off (see FIG. 4). In addition, even if the diameter of the conductive particles 9b is small and even if the conductive particles 9b penetrate into the gap of the extension 1a ', the resistance between the terminals in the residue after the peeling of the conductive silicon rubber 9 becomes 1
If 0 ⁷ Ω or more, because it does not leak, not much of a problem.

In this way, the liquid crystal panel 2 in which the liquid crystal 6 is sandwiched between the pair of glass substrates 1a and 1b on which the transparent electrodes 3 are formed through the respective steps P1 to P10.
Is completed.

Thereafter, a drive circuit (not shown) is connected to the electrode surface of the external circuit connection terminal 3a of the liquid crystal panel 2 manufactured as described above via an anisotropic conductive film or the like, and other mounting is performed. Thus, a liquid crystal display device is completed. As described above, in the present embodiment, the conductive silicon rubber 9 is provided on the glass substrate 1a which does not overlap with the connection portion of the drive circuit.
Since the conductive silicon rubber 9 is applied to the vicinity of the end, even if the conductive silicon rubber 9 remains in the peeling step of the conductive silicon rubber 9 in P10, the connection reliability between the drive circuit and the external circuit connection terminal 3a is reduced. There is no danger that the properties will decrease.

In the above description, referring to FIGS. 1 and 3, the step of applying the conductive silicon rubber 9 to the external circuit connecting terminals 3a formed on the glass substrate 1b and connecting the driving circuit. However, for the external circuit connection terminal (not shown) formed on the other glass substrate 1a constituting the liquid crystal panel 2, the processing such as the application of the conductive silicon rubber 9 and the connection of the drive circuit is also performed. This is performed similarly to the above glass substrate 1b. Further, the step of peeling the conductive silicon rubber 9 can be performed after the drive circuit is attached to the external circuit connection terminal 3a.

As described above, in the manufacturing method of the liquid crystal display device of this embodiment, the conductive silicon rubber 9 is connected to the external circuit connecting terminals 3a of the liquid crystal panel 2 prior to the step of attaching the polarizing plates 8 and 8. Is applied, all the electrodes of the external circuit connection terminals 3a are maintained at the same potential, and no charging unevenness due to static electricity generated at the time of attaching the polarizing plate occurs. As a result, contrast unevenness of the display unit due to static electricity does not occur. . In this case, all the electrodes of the external circuit connection terminals 3a are maintained at the same potential by a simpler work than applying a conductive tape, such as a conventional thin copper foil, in which the conductive silicon rubber 9 is applied. Therefore, workability can be improved. Furthermore, even if a residue or the like occurs when the conductive silicon rubber 9 is peeled off, in consideration of the resistivity of the conductive silicon rubber 9, no leakage occurs between the terminals due to the residue. The risk of leaks can be avoided. As a result of these,
With good workability, all electrodes of external circuit connection terminals are kept at the same potential without having the risk of terminal leakage,
It is possible to obtain a liquid crystal display device with high display quality without contrast unevenness.

In this embodiment, the glass substrate 1
Since the conductive silicon rubber 9 is applied to the region on the external circuit connection terminal 3a corresponding to the vicinity of the end of the terminal a, even if the conductive silicon rubber 9 remains, the external circuit connection terminal The reliability of the connection between the drive circuit 3a and the driving circuit is not reduced, thereby making it possible to obtain a liquid crystal display device with high connection reliability between the driving circuit and the external circuit connection terminal.

Further, since the conductive silicon rubber 9 is applied so that the upper surface reaches the extended portion 1a 'of the glass substrate 1a, the glass substrate 1 can be removed even after the conductive silicon rubber 9 is peeled off.
a silicone rubber 9a in the cell gap of the extension 1a '
Is left, and the silicon substrate 9a
1b is provided with a moisture-proof effect, whereby a highly reliable liquid crystal display device having excellent moisture-proof properties can be obtained.

[0035]

According to the method for manufacturing a liquid crystal display device according to the first aspect of the present invention, as described above, before attaching a polarizing plate to a pair of substrates provided to face each other with a liquid crystal therebetween, Conductive silicone rubber is applied over a plurality of external circuit connection terminals formed on the substrate over the entire direction orthogonal to each terminal, and after the polarizer is attached, the conductive silicone rubber is peeled off.

Therefore, a liquid crystal display device of high display quality without unevenness in contrast can be maintained with good workability, without fear of inter-terminal leakage, and maintaining all electrodes of the external circuit connection terminals at the same potential. This has the effect that it can be obtained.

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 of the present invention, wherein the method comprises: The conductive silicon rubber is applied to a region on an external circuit connection terminal corresponding to the vicinity of an end of the counter substrate provided.

Therefore, in addition to the effect of the above-mentioned claim 1, there is an effect that a liquid crystal display device with high connection reliability between the external circuit connection terminal and the drive circuit or the like can be obtained. As described above, in the method for manufacturing a liquid crystal display device, the method for manufacturing a liquid crystal display device according to claim 1 or 2, wherein the conductive silicon rubber is disposed such that the upper surface of the conductive silicon rubber reaches the extension of the counter substrate. This is to apply a conductive silicone rubber.

Therefore, in addition to the effects of claim 1 or claim 2, an effect is obtained that a highly reliable liquid crystal display device having excellent moisture proofing properties can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a liquid crystal panel in which conductive silicon rubber is applied to external circuit connection terminals on a glass substrate in a method for manufacturing a liquid crystal display device according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the liquid crystal panel before conductive silicon rubber is applied.

FIG. 3 is a cross-sectional view of the liquid crystal panel shown in FIG.

FIG. 4 is a cross-sectional view of the liquid crystal panel after the conductive silicon rubber has been peeled off.

FIG. 5 is a flowchart showing a manufacturing process of the liquid crystal panel.

[Explanation of symbols]

 1a ・ 1b Glass substrate (substrate) 2 Liquid crystal panel 3a Terminal for external circuit connection 6 Liquid crystal 8 Polarizer 9 Conductive silicon rubber 9a Silicon rubber 9b Conductive particles

Claims (3)

(57) [Claims] 1. Prior to attaching a polarizing plate to a pair of substrates provided opposite to each other with a liquid crystal interposed therebetween, a plurality of terminals for connecting external circuits formed on the substrate are orthogonal to each terminal. A method for manufacturing a liquid crystal display device, comprising: applying conductive silicon rubber over the entire direction in which the conductive silicon rubber is applied, and peeling the conductive silicon rubber after attaching the polarizing plate. 2. The conductive silicon rubber is applied to a region on an external circuit connection terminal corresponding to the vicinity of an end of a counter substrate provided opposite to a substrate on which the external circuit connection terminal is formed. 2. The method for manufacturing a liquid crystal display device according to claim 1, wherein: 3. The liquid crystal display device according to claim 1, wherein the conductive silicon rubber is applied so that the upper surface of the conductive silicon rubber reaches the extension of the counter substrate. Method.