JPH0922018A - Method for assembling liquid crystal display element and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To entirely obviate the occurrence of positional deviation of a second transparent substrate relative to a first transparent substrate by executing the pressurization of the first and second transparent substrates assembled and arranged to face each other after registration under the air pressure given a pressure difference from the inside of a sealing material. SOLUTION: The lower transparent substrate 21 is placed on a lower transparent substrate stage 3 and the upper transparent substrate 22 on an upper transparent substrate stage 4 within a bell-jar 2. The pressurization of the respective lower and upper transparent substrates 21, 22 assembled and arranged to face each other after the registration is executed under the air pressure given the pressure difference from the inside of the sealing material 23. The pressures applied on the lower and upper transparent substrates 21, 22 are, therefore, made uniform perpendicularly to these transparent substrates 21, 22. The pressurization in the state of having no deviation of the upper transparent substrate 22 relative to the lower transparent substrate 21 is thereby resulted. As a result, the registration accuracy is eventually retained as it is even after the such pressurization stage is executed after the accurate registration is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of assembling a liquid crystal display device and an apparatus therefor, and more particularly to a method of assembling a liquid crystal display device for arranging processed upper and lower transparent substrates so as to face each other via a sealing material. Regarding the device.

[0002]

2. Description of the Related Art A liquid crystal display device comprises transparent substrates which are arranged to face each other with a liquid crystal interposed therebetween.

In this case, for example, the pixel electrodes arranged in a matrix on the liquid crystal side surface of one transparent substrate,
A signal line for supplying a video signal to each of the pixel electrodes is formed, and a common electrode for generating an electric field between the pixel electrode and the common electrode is formed on the liquid crystal side surface of the other transparent substrate. Etc. are formed.

The liquid crystal interposed between the transparent substrates is sealed by a sealing material formed between the transparent substrates to surround the display area.

Conventionally, when manufacturing a liquid crystal display device having such a structure, among the transparent substrates on which electrodes and the like have been formed, a sealing material is partially opened on one of the transparent substrates and a liquid crystal sealing port is formed. Is formed by coating so that the other transparent substrate is aligned with the transparent substrate thus configured with the sealing material interposed therebetween. Then, pressure is applied to each transparent substrate, and the distance between them is set to a predetermined dimension.

After that, after the sealing material is solidified, liquid crystal is filled through the liquid crystal filling port, and after the filling is completed, the liquid crystal filling port is sealed.

[0007]

However, although the liquid crystal display element assembled in this way is aligned in advance, the upper transparent substrate is misaligned with respect to the lower transparent substrate. Was pointed out.

Therefore, as a result of pursuing this cause, since the alignment of each transparent substrate is performed in the atmosphere, a large amount of air remains in the region surrounded by the sealing material, and when pressure is applied in this state. It was found that the pressure in the region was increased and a force for shifting the transparent substrate was generated.

Further, it has been found that the non-uniformity of pressure due to mechanical strain or the like is one of the causes because the pressurization is also performed by mechanical pressure.

The present invention has been made under such circumstances, and an object thereof is a method of assembling a liquid crystal display element that does not cause the second transparent substrate to be misaligned with respect to the first transparent substrate. To provide a device.

It is another object of the present invention to provide a method and apparatus for assembling a liquid crystal display element, which can perform the alignment and the assembly of the first and second transparent substrates in substantially the same process.

[0012]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, a first transparent substrate and a second transparent substrate in which an uncured sealing material is formed so as to enclose the liquid crystal so as to enclose the liquid crystal, and a spacer agent is dispersed in the display region. In the method of assembling the liquid crystal display element, the method includes a step of pressing after aligning and assembling after facing each other, and applying the pressure to the facing facing arrangement of the second transparent substrate with respect to the first transparent substrate by a predetermined pressure. After the step of performing in an atmosphere and the assembly of the second transparent substrate with respect to the first transparent substrate so as to face each other, the predetermined pressure atmosphere is changed to a pressure atmosphere higher than the predetermined pressure atmosphere so that the pressure difference between the inside and the inside of the sealing material is It is characterized in that it is carried out in the step of providing.

[0014]

According to the method of assembling the liquid crystal display element having the above-described structure, the pressure applied to the first and second transparent substrates, which are arranged to face each other after the alignment after the assembly, is performed between the seal material and the seal member. It is performed by the atmospheric pressure that makes a difference.

Therefore, the pressure applied to each of the first and second transparent substrates is vertical and uniform with respect to the transparent substrate.

This means that the second transparent substrate is pressed with no displacement relative to the first transparent substrate.

Therefore, even after such a pressurizing step after performing the accurate alignment, the alignment accuracy is preserved as it is.

Further, since the first and second transparent substrates are aligned with each other and assembled at the time before and after the time when the pressure is changed, respectively,
It becomes possible to perform them in almost the same process.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method of assembling a liquid crystal display device and an apparatus therefor according to the present invention will be described below with reference to the drawings.

First, FIG. 2 is an explanatory view showing members to be assembled according to the present invention. FIG. 1A is a plan view of a lower transparent substrate 21 which is a constituent member of a liquid crystal display element.
Further, FIG. 3B shows a plan view of the upper transparent substrate 22.

The lower transparent substrate 21 is arranged such that the upper transparent substrate 22 faces it (the position of the upper transparent substrate 22 relative to the lower transparent substrate 21 thus facing is shown in the figure). A sealing material 23 for sealing the liquid crystal interposed between the upper transparent substrate 22 and the upper transparent substrate 22 is applied and formed so as to surround the portion to be the display region DP.

An opening is provided in a part of the sealing material 23, and this opening constitutes an enclosing port 23A for filling the liquid crystal in a later step.

Further, another sealing material 24 connected to the sealing material 23 is applied and formed on the surface of the lower transparent substrate 21 so as to surround the sealing port 23. Seal material 2
An opening 24A is provided in a part of No. 4, and this opening 24A is closed when a predetermined gap is formed.
Further, each of the sealing materials 23 and 24 is made of an adhesive made of a material that is sufficiently softened at several tens of degrees Celsius.

Here, the reason for forming the sealing material 24 and selecting the materials for the respective sealing materials 23, 24 will become clear in the following description.

Although not shown, the lower transparent substrate 21 has scanning signals extending in the x direction and juxtaposed in the y direction in the display area DP on the surface on which the liquid crystal is positioned. A line, and extending in the y direction and x
Video signal lines arranged in parallel in the direction are formed so as to be insulated from the scanning signal lines.

Each area surrounded by each of these signal lines constitutes a pixel area, and each of these pixel areas constitutes a display surface arranged in a matrix.

Further, to each pixel region, a thin film transistor TFT which is turned on by the supply of the scanning signal (voltage) of the scanning signal line, and a video signal from the video signal line is supplied through the turned on thin film transistor TFT. Pixel electrodes and the like are provided. This pixel electrode is formed by a transparent electrode made of ITO, for example.

The signal lines extend beyond the area where the sealing material 23 is formed to the periphery of the lower transparent substrate 21 to form the external terminals 25. Therefore, the upper transparent substrate 21 is formed so as to extend outward from the lower transparent substrate 21 (indicated by a chain line in FIG. 2A) in the region where the external terminals 25 are formed. .

Although not shown in the figure, minute glass fibers or resin beads are scattered in the display area DP of the lower transparent substrate 21. This is because when the upper transparent substrates 22 are arranged to face each other in a later step, the gap between the substrates is maintained at a predetermined value by the diameter of the glass fiber or the resin beads.

On the other hand, in the display area DP on the surface of the upper transparent substrate 22 facing the lower transparent substrate 21, a common electrode or the like is formed, which is not shown. The common electrode is formed by a transparent electrode made of ITO, for example. This is because it is possible to change the light transmittance of the liquid crystal so as to be arranged between the common electrode and the pixel electrode of the lower transparent substrate 21 by an electric field applied between them.

Along with the common electrode, red, blue, and green color filters are formed in, for example, three pixels adjacent to and facing each pixel region of the lower transparent substrate 21.

From this, in assembling the lower transparent substrate 21 and the upper transparent substrate 22 in the subsequent process, the alignment of them becomes important. This is because a predetermined color filter must be accurately arranged to face one pixel electrode.

For this reason, the lower transparent substrate 21 and the upper transparent substrate 22 are provided with the alignment marks 28 and 29, respectively. The alignment marks 28 on the lower transparent substrate 21 are formed on the outer side of the sealing material 23, and it is sufficient that at least two alignment marks 28 are provided, but in this embodiment, four alignment marks 28 are provided to achieve perfect alignment. It has become a thing.

These alignment marks 28 and 29 are arranged on the lower transparent substrate 21 and the upper transparent substrate 22 facing each other.
If the corresponding ones are superposed on each other when observed in a plane, the transparent substrates 21 and 22 are provided so as to be opposed to each other without any positional deviation.

FIG. 1 is a sectional view showing an embodiment of a liquid crystal display element assembling apparatus according to the present invention.

First, there is a base 1, on which a bell jar 2 made of a transparent material is arranged.

Inside the bell jar 2, there are arranged, for example, a lower transparent substrate arrangement table 3 on which the lower transparent substrate 21 is arranged and an upper transparent substrate arrangement table 4 on which the upper transparent substrate 22 is arranged.

The lower transparent substrate arranging table 3 is arranged in a plane (xy plane in the figure) parallel to the surface of the base 1, and the shaft 5 extending through the base 1 in the z direction in the figure. It is being fixed via the support material 6. The shaft body 5 can be moved in the axial direction (+ z direction or −z direction) by a drive mechanism (not shown) built in the base 1. As a result, the lower transparent substrate placement table 3 is + z in the figure as needed.
Direction or −z direction.

Further, the lower substrate placement table 3 is provided with a frame 6A formed integrally with the support member 6, for example, and the lower transparent substrate 21 is placed on the frame 6A. . The lower transparent substrate 21 is placed on the frame 6A by a vacuum chuck mechanism (not shown). As a result, the lower transparent substrate 21 is substantially fixed to the frame 6A. Will be placed in.

The frame 6A can hold the lower transparent substrate 21 only in the peripheral portion thereof, and the central portion excluding the peripheral portion is provided with a through hole. Further, a rubber material 6B is provided so as to cover the surface of the frame 6A opposite to the lower transparent substrate 21 side on which the frame 6A is mounted. The function of this rubber material 6B will become clear in the later description.

Although the upper transparent substrate placement table 4 is restricted from moving in the z direction in the figure by a member not shown, it can be moved in a certain range by the xy stage 7 with respect to the xy plane in the figure. It is like this.

The upper transparent substrate placement table 4 is provided with a frame 8A fixed to the xy stage 7, and the upper transparent substrate 22 is placed in the frame 8A. The arrangement of the upper transparent substrate 22 with respect to the frame 8A is performed by a vacuum chuck mechanism (not shown). As a result, the upper transparent substrate 22 is mounted on the frame 8A in a substantially fixed state. Will be done.

The frame 8A can hold the upper transparent substrate 22 only in the peripheral portion thereof, and the central portion excluding the peripheral portion is provided with a through hole. Further, a rubber material 8B is provided so as to cover the surface of the frame 8A opposite to the upper transparent substrate 22 side. The function of the rubber material 8B will be clarified in the later description together with the rubber material 6B.

Further, the inside of the bell jar 2 can be decompressed and brought into the atmospheric condition if necessary. Therefore, the base 1 has an exhaust pipe 11 for exhausting and an air supply pipe 12 for supplying air. It is provided.

On the other hand, an image recognition device (not shown) is arranged outside the bell jar 2, and the image recognition sensor section 9 thereof is
The alignment mark 28 of the upper transparent substrate 21 and the alignment mark 29 of the lower transparent substrate 22 are arranged at a position where they can be recognized.

Here, through holes 10 are formed in the rubber material 8B and the frame 8A of the upper transparent substrate placement table 4 so as not to interfere with the recognition of the alignment marks 28 and 29 of the image recognition sensor section 9. There is.

FIG. 3 is a diagram showing a process for assembling the lower transparent substrate 21 and the lower transparent substrate 22 using the assembling apparatus. Hereinafter, the description will be divided into Step 1 and Step 2.

Step 1. ((A) in the figure ) As shown in the figure, the lower transparent substrate 21 is placed on the lower transparent substrate placement table 3, and the upper transparent substrate 22 is placed on the upper transparent substrate placement table 4. In this case, the lower transparent substrate 21 can be fixed to the lower transparent substrate arrangement table 3 and the upper transparent substrate 22 can be fixed to the upper transparent substrate arrangement table 4 by a vacuum chuck mechanism (not shown).

In this case, the inside of the bell jar 2 is maintained in the atmospheric state, and the lower transparent substrate arrangement table 3 and the upper transparent substrate arrangement table 4 are arranged at a sufficient distance.

After that, the lower transparent substrate placement table 3 is moved in the z direction in the drawing to move it.
Is brought close to the upper transparent substrate placement table 4.

By driving the xy stage 7, the upper transparent substrate placement table 4 is freely moved on the xy plane. This is because the upper transparent substrate 22 is aligned with the lower transparent substrate 21.

The alignment in this case is performed by the lower transparent substrate 21.
The degree of overlap between the alignment mark 28 and the alignment mark 29 on the upper transparent substrate 22 is recognized by the recognition of the image recognition sensor unit 9 through the through hole 10 provided in the upper transparent substrate placement table 3. ing.

In this specification, the arrangement of the lower transparent substrate 21 and the upper transparent substrate 22 in such aligned state, that is, the state in which the sealing material 23 is not yet in contact with the upper transparent substrate 22. This arrangement is referred to as the alignment facing arrangement.

Step 2. ((B) in the figure) After the alignment is performed in this way, the inside of the bell jar 2 is decompressed (100 to 150 Tor by exhaust through the exhaust pipe 11).
r) do.

Further, the lower transparent substrate placement table 3 is shown as + z in the figure.
By moving in the direction, the lower transparent substrate 21 comes into contact with the upper transparent substrate 22 via the sealing material 23 while maintaining the alignment. In this case, as described above, since the glass fibers or the resin beads 30 are scattered in the region within the sealing material 23, the distance between the upper transparent substrate 22 and the lower transparent substrate 21 is the glass fibers or the resin beads. It is set according to the diameter of 30.

Since the sealing material 23 is formed in the pattern shown in FIG. 2 (a), the internal area thereof is sealed while being depressurized.

In this case, the lower transparent substrate arranging table 3 and the upper transparent substrate arranging table 4 are provided with rubber materials 6B and 8B, respectively, which are in close contact with each other, whereby the transparent substrates 21 and 22 are separated from each other. The arranged space is the rubber material 6B,
It is designed to be an independent space shielded from the space outside 8B.

In this specification, the arrangement of the lower transparent substrate 21 and the upper transparent substrate 22 thus assembled, that is, the sealing material 23 is the upper transparent substrate 2
The arrangement in the state of being in contact with 2 is referred to as an assembled opposing arrangement.

After that, the inside of the bell jar 2 is returned to the atmosphere by the air supply through the air supply pipe 12. As a result, a uniform pressure is applied to the periphery of the upper transparent substrate 22 and the lower transparent substrate 21 through the rubber materials 6B and 8B over the entire area, and the sealing material 23 is sufficiently softened at a temperature of several tens of degrees Celsius. Come to do. The opening 24A of the sealing material 24 is blocked by the sealing material extending.

That is, by doing this,
After the alignment, the pressure is applied to the lower and upper transparent substrates 21 and 22 that are opposed to each other in the assembling operation by the atmospheric pressure that causes a pressure difference between the transparent substrates 21 and 22.

Therefore, the pressure applied to the transparent substrates 21 and 22 on the lower side and the upper side is the same.
It is perpendicular to and uniform.

This means that the upper transparent substrate 22 is pressed against the lower transparent substrate 21 without any displacement.

Therefore, even after such a pressurizing step after performing the accurate alignment, the alignment accuracy is preserved as it is.

After that, the assembly of the upper transparent substrate 22 and the lower transparent substrate 21 taken out from the bell jar 2 cuts the area where the sealing material 24 is formed, as shown in FIG. By carrying out (along the dotted line), the sealing port 23A which is the opening of the sealing material 23 is exposed. At this time, the display area surrounded by the sealing material 23 is filled with the atmosphere. As a result, the liquid crystal display element at the stage immediately before filling the liquid crystal is manufactured.

In the above-described embodiment, the rubber material 6 is provided on each of the lower transparent substrate placement table 3 and the upper transparent substrate placement table 4.
Although B and 8B are provided, it goes without saying that they are not necessarily required if the sealing material 23 on the transparent substrate is formed as shown in FIG.

If the lower transparent substrate placement table 3 and the upper transparent substrate placement table 4 are provided with the rubber materials 6B and 8B, respectively, the sealing material 23 on the transparent substrate is not necessarily formed as shown in FIG. Needless to say, it is not necessary.

In any case, when the inside of the bell jar 2 is returned to the atmosphere, the inside of the region surrounded by the sealing material 23 can be kept in a reduced pressure state.

Further, in the above-mentioned embodiment, the bell jar 2 is used.
Although the inside is returned to the atmosphere from the depressurized state, it is not necessarily limited to this. In short, the same effect can be obtained if the atmospheric pressure in the bell jar 2 can be changed from small to large.

[0069]

As is apparent from the above description,
According to the method and apparatus for assembling the liquid crystal display element according to the present invention, the assembly can be performed without causing any positional misalignment of the second transparent substrate with respect to the first transparent substrate.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an apparatus for assembling a liquid crystal display device according to the present invention.

FIG. 2 is a plan view showing a configuration of a lower transparent substrate and an upper transparent substrate which are targets of a method of assembling a liquid crystal display device according to the present invention.

FIG. 3 is a process drawing showing an embodiment of a method of assembling a liquid crystal display device according to the present invention.

FIG. 4 is an explanatory view showing a process after assembling the liquid crystal display device according to the present invention.

[Explanation of symbols]

2 ... Bell jar, 3 ... Lower transparent substrate placement table, 4 ... Upper transparent substrate placement table, 7 ... xy stage, 11 ... Exhaust pipe, 12 ... Air supply pipe, 21 ... Lower transparent Substrate, 22 ...
... upper transparent substrate, 23 ... sealing material.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Koichi Okamoto 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Devices Division

Claims (5)

[Claims] 1. A first transparent substrate and a second uncured sealing material that surrounds a display area so that liquid crystal is sealed therein, and a spacer agent is dispersed in the display area.
In a method of assembling a liquid crystal display device, which includes a step of assembling and facing each other after aligning with a transparent substrate, and applying pressure, wherein the pressing is performed by aligning the second transparent substrate with the facing opposite to the first transparent substrate. In a predetermined pressure atmosphere, and
After the second transparent substrate is assembled and opposed to the transparent substrate, a pressure difference is created between the predetermined pressure atmosphere and the inside of the seal material by setting the pressure atmosphere higher than the predetermined pressure atmosphere. A method for assembling a characteristic liquid crystal display device. 2. The method for assembling a liquid crystal display device according to claim 1, wherein the predetermined pressure atmosphere is a reduced pressure atmosphere and the pressure atmosphere higher than the predetermined pressure is an air atmosphere. 3. The second transparent substrate is formed on a transparent substrate, in which a sealing material formed in the second transparent substrate has an opening formed in a part thereof and is formed so as to surround the opening and is cut off in a later step. The method for assembling a liquid crystal display device according to claim 1, wherein the sealed sealing material is formed. 4. A first transparent substrate and a second uncured sealing material that surrounds a display area so that liquid crystal is enclosed and in which a spacer agent is dispersed in the display area.
A bell jar for accommodating the transparent substrate, a means for aligning and assembling the second transparent substrate with respect to the first transparent substrate and for assembling and opposing, and a bell jar before and after the assembling and opposing arrangement of the second transparent substrate with respect to the first transparent substrate. An apparatus for assembling a liquid crystal display device, comprising: a means for returning the inside from a reduced pressure to the atmosphere. 5. The apparatus for assembling a liquid crystal display device according to claim 4, wherein an xy stage for aligning the second transparent substrate with the first transparent substrate is provided in the bell jar.