JP3976544B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly to a liquid crystal display device in which two substrates are bonded using a substrate on which columnar spacers having different heights are formed and a manufacturing method thereof.
[0002]
[Prior art]
In recent years, it is well known that a liquid crystal display device is used for a display device of a portable personal computer or a mobile phone.
[0003]
Of these liquid crystal display devices, the active matrix liquid crystal display device has a display characteristic capable of preventing crosstalk, and is well known.
[0004]
In particular, a liquid crystal display device using a TFT (Thin Film Transistor) as a switching element has a high TFT driving capability, and thus is well known to exhibit excellent display characteristics comparable to a CRT (Cathode-Ray Tube). is there.
[0005]
Such a conventional liquid crystal display device is disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-201750.
[0006]
In general, a liquid crystal display device has a structure in which liquid crystal is sealed between two transparent substrates. A common electrode, a color filter, an alignment film, and the like are formed on one surface of two surfaces (facing surfaces) facing each other of the transparent substrate, and a TFT, a pixel electrode, and the like are formed on the other surface. An alignment film or the like is formed.
[0007]
Furthermore, a polarizing plate is affixed to the opposite surface of each transparent substrate. For example, in the case of a TN (Twisted Nenatic) type liquid crystal display device, these two polarizing plates are arranged so that the polarizing axes of the polarizing plates are orthogonal to each other, and according to this, light is transmitted without applying an electric field. In a state where an electric field is applied, a light shielding mode, that is, a normally white mode is set. Further, when the polarization axes of the two polarizing plates are parallel, the normally black mode is set.
[0008]
Hereinafter, a substrate on which TFTs, pixel electrodes, and the like are formed is referred to as a drive element substrate, and a substrate on which common electrodes, color filters, and the like are formed is referred to as a counter substrate.
[0009]
As shown in FIG. 9, in the conventional liquid crystal display device, a columnar spacer 1 is formed between a pair of glass substrates, that is, between a counter substrate 3a and a driving element substrate 3b, and the counter substrate 3a is formed by these columnar spacers 1. And the driving element substrate 3b are maintained in a predetermined gap.
[0010]
The conventional liquid crystal display device has a structure using the drive element substrate 3b in which the heights of the columnar spacers 1 are uniformly aligned so that the final gap is uniformly formed.
[0011]
[Problems to be solved by the invention]
However, in the case of this structure, the liquid crystal display device of the prior art increases the number of columnar spacers 1 or the area of each columnar spacer 1 in order to make the final gap uniform so that the contact between the counter substrate 3a and the driving element substrate 3b is increased. The area will increase.
[0012]
As a result, there is a problem in that the frictional resistance when the two substrates are bonded increases and the alignment operation becomes difficult.
[0013]
Conversely, by reducing the area of the columnar spacer 1 to facilitate the alignment operation, it becomes difficult to obtain a uniform gap.
[0014]
In addition, even if the contact area of the columnar spacer 1 is such that the alignment operation can be performed, the time required for the alignment operation and the number of times of the alignment operation are much longer than those of the product that does not use the columnar spacer 1, and the tact time of the bonding process is reduced. There's a problem.
[0015]
Accordingly, an object of the present invention is to provide a liquid crystal display device capable of forming a more uniform gap than the current state and a manufacturing method thereof, as well as solving the above-described problems.
[0016]
[Means for Solving the Problems]
The liquid crystal display device of the present invention includes a pair of driving element substrates and a counter substrate, a driving element pattern formed on the driving element substrate, a CF pattern formed on the counter substrate, the driving element substrate, A first columnar spacer having a height necessary for forming a target gap value when the counter substrate is bonded, and a second columnar spacer having a height higher than that of the first columnar spacer; And a sealant that bonds and fixes the two drive element substrates and the counter substrate with a uniform gap, and the drive element substrate on which the first and second columnar spacers are formed; While performing the alignment operation on the counter substrate, when the two substrates are bonded to the target gap by pressing, the counter substrate and the second columnar spacer are in contact with each other, Alignment so that the frictional resistance of the contact surface between the two columnar spacers and the counter substrate is at least ½ or less of the frictional resistance of the contact surface between each of the first and second columnar spacers and the counter substrate. After the alignment operation was completed, the second columnar spacer was crushed by further pressing, and finally the two substrates were brought close to the height of the first columnar spacer to form the target gap. It is a configuration.
[0017]
Furthermore, in the liquid crystal display device of the present invention, the contact area between the second columnar spacer and the counter substrate is set to be ½ or less of the contact area between the first columnar spacer and the counter substrate.
[0018]
Furthermore, the second columnar spacer of the liquid crystal display device of the present invention is formed to be higher by about 0.1 to 0.5 μm than the first columnar spacer.
[0019]
In the method of manufacturing a liquid crystal display device according to the present invention, the counter substrate is stopped when the counter substrate comes into contact with the second columnar spacer, and the counter electrode is opposed to the driving element substrate so as not to contact the first columnar spacer. A substrate stacking process for stacking substrates, an alignment process for performing an alignment operation by moving the counter substrate with respect to the drive element substrate in order to align the positions of the CF pattern and the drive element pattern, and the alignment operation are completed. Thereafter, by pressing, the counter substrate is brought close to the drive element substrate to a position where it contacts the first columnar spacer while crushing the second columnar spacer to form a target gap. It is the structure which has a process.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail below with reference to the drawings.
[0021]
The present invention relates to a structure of a liquid crystal display device in which a target gap is formed by bonding two substrates using a substrate in which columnar spacers 1 having two or more different heights are formed on one or both substrates. Related to manufacturing method.
[0022]
FIG. 1 is a plan view showing components of the liquid crystal display device according to the first embodiment of the present invention. 2 is a cross-sectional view taken along the line AA ′ of the liquid crystal display device according to the first embodiment of the present invention shown in FIG.
[0023]
Referring to FIG. 1, FIG. 2, and FIG. 3, the liquid crystal display device according to the first embodiment of the present invention is formed on a pair of drive element substrate 3b and counter substrate 3a, and on this drive element substrate 3b. Drive element pattern 3ba, CF pattern 3aa formed on the counter substrate 3a, and columnar spacer (low) which is a height necessary to form a target gap value when bonded to the counter substrate 3a 1b, a columnar spacer (high) 1a which is about 0.1 to 0.5 μm higher than the columnar spacer (low) 1b, and the two substrates of the drive element substrate 3b and the counter substrate 3a are bonded and fixed with a uniform gap. Sealing material 2 to be provided.
[0024]
FIG. 1B shows the enlarged portion 11 in the arrangement state of the columnar spacers 1. The columnar spacers 1 are arranged in the X-axis direction and the Y-axis direction.
[0025]
As shown in FIG. 4, the columnar spacer 1 is formed using a resin-based material on the pattern avoiding the opening 4 of the driving element pattern 3ba (the CF pattern 3aa and the driving element pattern 3ba are omitted). ing).
[0026]
The columnar spacer 1 has a columnar spacer (low) 1b which is a height necessary for forming a target gap value when bonded to the counter substrate 3a, and about 0.1 to 0.5 μm higher than that. The columnar spacer (high) 1a has a two-stage height of a high columnar spacer (high) 1a, and the ratio of the columnar spacer (high) 1a is about 1/2 to 1/4 of the entire columnar spacer 1. Further, after the alignment process (not shown) and the counter substrate 3a are bonded to the drive element substrate 3b on which the columnar spacers 1 are formed, a sealing material 2 for fixing is applied.
[0027]
Further, the alignment process is also performed on the counter substrate 3a side. After the counter substrate 3a is bonded to the driving element substrate 3b while being pressed, the sealing material 1 is cured to obtain the structure of the liquid crystal display device (see FIGS. 1 and 2).
[0028]
Next, a manufacturing process of the liquid crystal display device according to the first embodiment of the present invention will be described.
[0029]
As shown in FIGS. 6, 7 and 8, in the bonding process of the liquid crystal display device according to the embodiment of the present invention, the driving element substrate 3b on which the columnar spacer 1 is formed and the counter substrate 3a are aligned. The purpose is to apply two substrates to the target gap by pressing.
[0030]
At this time, by using the substrate on which the columnar spacers 1 of different heights are formed as shown in the figure, the alignment operation is performed when the counter substrate 3a and the columnar spacer (high) 1a are in contact with each other. The target gap is formed by bringing the two substrates closer to the position of the columnar spacer (low) 1b while squeezing the columnar spacer (high) 1a by applying a press.
[0031]
According to this structure, a more uniform gap can be obtained while the alignment operation is easy.
[0032]
Next, with reference to FIG. 5, the manufacturing method of the liquid crystal display device of the 1st Embodiment of this invention is demonstrated.
[0033]
In step S52, the columnar spacer 1 is formed on the drive element substrate 3b on which the drive element pattern 3ba of the liquid crystal display device according to the first embodiment of the present invention is formed, and then alignment treatment is performed (step S53), and the seal The material 2 is applied (step S54).
[0034]
The counter substrate 3a is also subjected to orientation treatment (step S56), and after being bonded to the drive element substrate 3b in the bonding step (step S57), the sealing material 2 is cured (step S58).
[0035]
Referring to FIGS. 6, 7 and 8 again, the operation flow of the bonding process of the liquid crystal display device according to the first embodiment of the present invention will be described.
[0036]
First, the counter substrate 3a is overlaid on the drive element substrate 3b. At this time, the counter substrate 3a is stopped when it contacts the columnar spacer (high) 1a so as not to contact the columnar spacer (low) 1b (see FIG. 6).
[0037]
Therefore, the contact area between the counter substrate 3a and the columnar spacer 1 at this stage can be suppressed to 1/2 to 1/4 of the area finally contacting.
[0038]
Next, in order to align the positions of the CF pattern 3aa and the drive element pattern 3ba in the liquid crystal display device according to the first embodiment of the present invention, the alignment operation is performed by moving the counter substrate 3a with respect to the drive element substrate 3b. Perform (see FIG. 7).
[0039]
Next, after the alignment operation of the liquid crystal display device according to the first embodiment of the present invention is completed, the counter substrate is moved to a position in contact with the columnar spacer 1b while pressing the column spacer (high) 1a by applying a press. 3a is brought close to the drive element substrate 3b to form a target gap (see FIG. 8).
[0040]
Next, a liquid crystal display device according to a second embodiment of the present invention will be described.
[0041]
The liquid crystal display device according to the second embodiment of the present invention is not limited to the two stages of the liquid crystal display device according to the first embodiment of the present invention as the stage of the columnar spacer height, but includes multiple stages. .
[0042]
And the liquid crystal display device of the 2nd Embodiment of this invention does not limit the ratio of the columnar spacer (high) which occupies for the columnar spacer 1, It is the structure which forms the columnar spacer of different height.
[0043]
Next, in the liquid crystal display device according to the third embodiment of the present invention, the height of the columnar spacer itself is changed as a method of changing the height of the columnar spacer of the liquid crystal display device according to the third embodiment of the present invention. The height of the columnar spacer is changed by forming columnar spacers having the same height at different heights on the substrate.
[0044]
Further, in the columnar spacer of the liquid crystal display device according to the fourth embodiment of the present invention, the columnar spacer (high) 1a is formed on one substrate, the columnar spacer (low) 1b is formed on the other substrate, and The structure is formed on the counter substrate side.
[0045]
This structure can also be applied to a process of bonding substrates onto which liquid crystal is dropped. In this case, by forming the columnar spacer (high) higher than the dropped liquid crystal material, not only the frictional resistance due to the columnar spacer but also the resistance due to the surface tension of the liquid crystal material can be reduced. The alignment operation of the dropping and bonding process is also greatly facilitated.
[0046]
【The invention's effect】
As described above, according to the present invention, first, there is an improvement in gap uniformity when the final gap is formed.
[0047]
The reason for this is that when the columnar spacers 1 are used, the frictional resistance of the columnar spacers 1 that are in contact during the alignment operation in the bonding process is very large, so the number of columnar spacers 1 can be reduced, You are forced to reduce the area.
[0048]
Therefore, it is difficult to form columnar spacers 1 that are necessary and sufficient to keep the gap uniform. According to the present invention, the area of the columnar spacer 1 that is in contact during the alignment operation can be reduced to about ½ to ¼, and the frictional resistance can be greatly reduced. On the other hand, the area of the columnar spacer 1 that is in contact with the final gap can be increased by 2 to 4 times, and the uniformity of the gap is dramatically improved.
[0049]
As a second effect, the tact time of the bonding process can be increased. As described above, since the frictional resistance by the columnar spacer 1 during the alignment operation is small, the counter substrate 3a can be easily moved, and the time required for the alignment operation and the number of alignment operations can be reduced. The tact time in the bonding process is shortened.
[Brief description of the drawings]
FIG. 1 is a plan configuration diagram of a liquid crystal display device according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along line AA ′ of the liquid crystal display device according to the first embodiment of the present invention.
FIG. 3 is a perspective view of the liquid crystal display device according to the first embodiment of the present invention.
FIG. 4 is another perspective view of the liquid crystal display device according to the first embodiment of the present invention.
FIG. 5 is a flowchart showing manufacturing steps of the liquid crystal display device according to the first embodiment of the present invention.
FIG. 6 is a diagram showing a manufacturing process of the liquid crystal display device according to the first embodiment of the present invention;
FIG. 7 is a diagram showing another manufacturing process of the liquid crystal display device according to the first embodiment of the present invention;
FIG. 8 is a diagram showing still another manufacturing process of the liquid crystal display device according to the first embodiment of the present invention.
FIG. 9 is a configuration diagram of a conventional liquid crystal display device.
[Explanation of symbols]
1 Columnar spacer 1a Columnar spacer (high)
1b Columnar spacer (low)
2 sealing material 3 substrate 3a counter substrate 3b drive element substrate 3aa CF pattern 3ba drive element pattern 4 opening 11 enlarged portion S51 to S58

Claims (6)

When a pair of drive element substrate and counter substrate, a drive element pattern formed on the drive element substrate, a CF pattern formed on the counter substrate, and the drive element substrate and the counter substrate are bonded together A first columnar spacer having a height necessary for forming a target gap value; a second columnar spacer having a height higher than that of the first columnar spacer; the driving element substrate; A sealing material for bonding and fixing two substrates of a counter substrate with a uniform gap;
While performing the alignment operation between the driving element substrate on which the first and second columnar spacers are formed and the counter substrate, the two substrates are bonded to the target gap by pressing, When the second columnar spacer comes into contact, the frictional resistance of the contact surface between the second columnar spacer and the counter substrate is a contact between each of the first and second columnar spacers and the counter substrate. The alignment operation is performed so that the frictional resistance of the surface is at least ½ or less, and after the alignment operation is completed, the second columnar spacer is crushed by pressing further, and finally the height of the first columnar spacer is increased. A liquid crystal display device characterized in that two substrates are brought close to each other to form a target gap. The liquid crystal display device according to claim 1, wherein a contact area between the second columnar spacer and the counter substrate is ½ or less of a contact area between the first columnar spacer and the counter substrate. The liquid crystal display device according to claim 1, wherein the second columnar spacer is about 0.1 to 0.5 μm higher than the first columnar spacer. 4. The liquid crystal display device according to claim 1, further comprising a third columnar spacer having a height different from that of the first columnar spacer and the second columnar spacer. 4. The liquid crystal display device according to claim 1, wherein the second columnar spacer is formed on the drive element substrate, and the first columnar spacer is formed on the counter substrate. A method of manufacturing a liquid crystal display device applied to the liquid crystal display device according to claim 1,
A substrate stacking step of stopping the counter substrate in contact with the second columnar spacer and stacking the counter substrate on the driving element substrate so as not to contact the first columnar spacer;
An alignment step of performing an alignment operation by moving the counter substrate with respect to the drive element substrate in order to align the positions of the CF pattern and the drive element pattern;
After the alignment operation is completed, by pressing, the counter substrate is brought close to the driving element substrate to a position where it contacts the first columnar spacer while crushing the second columnar spacer, and a target gap is obtained. A method for manufacturing a liquid crystal display device, comprising: a gap forming step of forming a gap.

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