JP2001166320A - Manufacturing method of liquid crystal display element - Google Patents

Abstract

(57) [Problem] To provide a method of manufacturing a liquid crystal display element with good productivity, which does not cause defects caused by remaining bubbles, liquid crystal leakage, and uneven cell gap. SOLUTION: A liquid crystal layer 3 is applied to one substrate 1 in a film shape having the same thickness as the liquid crystal layer at the time of completion of encapsulation, and has the same shape as the outer shape of the liquid crystal layer at the time of completion of encapsulation. After the sealing material 4 is provided on the other substrate 2 in a frame shape larger than the outer shape of the layer 3 and the two substrates 1 and 2 are overlapped under reduced pressure,
The thickness of the liquid crystal layer 3 serving as the cell gap 12 is measured by the cell thickness meter 11.
The liquid crystal display element 6 is manufactured by expanding the sealing material 4 and sealing the liquid crystal by pressing while measuring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for manufacturing a liquid crystal display element used for a notebook personal computer, a display and the like.

[0002]

2. Description of the Related Art FIG. 8 is a schematic sectional view showing the structure of a liquid crystal display element 6. The liquid crystal display element 6 has a pair of substrates 1 and 2 facing each other, the two substrates 1 and 2 are bonded together by a sealant 4, and the area between the two substrates 1 and 2 is indicated by oblique lines. Liquid crystal 3 is enclosed. Distance between substrates 1 and 2 in which liquid crystal is sealed (hereinafter referred to as cell gap)
Is maintained by a large number of spacers 5 distributed between the substrates 1 and 2. The two substrates 1 and 2 are provided with a TFT element, a transparent electrode, a color filter, an alignment film, and the like (not shown).

As a method of filling liquid crystal between substrates of a liquid crystal display element, there is a method called a conventional vacuum injection method.
FIG. 9 is a schematic diagram for explaining a conventional vacuum injection method. In the vacuum injection method, first, spacers are sprayed on one or the other substrate in advance, and the two substrates are sealed with a frame-shaped sealing material 22.
Paste together. At this time, the sealing material 22 is provided with an opening serving as a liquid crystal injection port 23. afterwards,
The sealing material 22 is cured to manufacture the empty cell 21 in which the liquid crystal 24 is not sealed.

Next, an empty cell 21 and a liquid crystal 24 indicated by oblique lines are shown.
Is placed in the vacuum chamber 20. The inside of the vacuum chamber 20 is evacuated, the inside of the empty cell 21 is evacuated, and the liquid crystal 24 is defoamed. After sufficiently evacuating, the inlet 23 of the empty cell 21 is immersed in the liquid crystal 24, and the inside of the vacuum chamber 20 is returned to the atmospheric pressure. Then, empty cell 2
The liquid crystal 24 permeates into the cell 21 from the injection port 23 due to the pressure difference between the inside and outside. After the liquid crystal 24 is filled in the cell 21, the cell 21 is taken out, the injection port 23 is sealed with, for example, an ultraviolet curing resin, and the injection of the liquid crystal 24 is completed.

In the vacuum injection method, after the inside of the empty cell 21 is evacuated, the liquid crystal 24 is brought into contact with the injection port 23, and the outside of the empty cell 21 is returned to the atmospheric pressure. The injection is performed by the pressure difference. However, it is impossible to make the inside of the empty cell 21 completely at 0 atm, that is, a state in which no gas molecules are present, by exhausting only from the inlet 23, and there is no gas molecule adsorbed on the inner surface of the empty cell 21. I do. For this reason, the liquid crystal 24 is
As the gas is injected into the cell 1, the pressure in the cell 21 increases, and the pressure difference between the inside and outside of the cell 21 eventually disappears, and bubbles at atmospheric pressure remain in the cell 21.

In particular, in recent monitor liquid crystal display devices having a diagonal size of 15 inches or more, the volume of gas remaining in the injected liquid crystal is large, which may adversely affect the display of the liquid crystal display device. ing. Further, the cell gap between the two substrates is on the order of μm, and the thickness tends to be further reduced. It takes a very long time to evacuate an empty cell having such a narrow cell gap by exhausting only from the inlet. Similarly, it takes time to fill the liquid crystal into the empty cell, and in the above-mentioned 15-inch diagonal liquid crystal display element, it takes about 10 hours from the start of the exhaustion of the empty cell to the completion of the liquid crystal encapsulation. I need.

As another method of manufacturing a liquid crystal display element, a method in which a liquid crystal is supplied to a substrate in advance, and then two substrates are bonded and the liquid crystal is sealed is disclosed in Japanese Patent Application Laid-Open No. 63-109413 and Japanese Patent Publication No. 8-20627. No. 6,086,045.

FIG. 10 is a process chart for explaining the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 63-109413.
First, in FIG. 10A, the sealing material 4
And a spacer 5 are provided.

In FIG. 10B, under a reduced pressure, a required amount of liquid crystal 3 is applied to the whole area on one substrate 2 inside sealing material 4.
Is dripped uniformly. In FIG. 10C, the other substrate 1 is overlapped with the sealing material 4 under reduced pressure.
In FIG. 10D, the sealing material 4 is cured, and the enclosing of the liquid crystal 3 is completed.

FIG. 11 is a process chart for explaining the manufacturing method disclosed in Japanese Patent Publication No. Hei 8-20627. FIG.
In FIG. 1A, a predetermined amount of liquid crystal 3 is placed inside a sealing material 4 provided on one substrate 2. At this time, the liquid crystal 3 is supplied so as to be smaller than the outer shape of the liquid crystal layer at the time of completion of the encapsulation and thicker than the sealing material 4.

In FIG. 11B, the other substrate 1 and the one substrate 2 are overlapped. At this time, the other substrate 1 is in contact with the liquid crystal 3, but there is a gap between the substrate 1 and the sealing material 4.

In FIG. 11 (c), the two substrates 1 and 2 are weighted under reduced pressure to spread the liquid crystal 3, and the other substrate 1 and the sealing material 4 are brought into contact with each other and bonded.

In the liquid crystal sealing method shown in FIGS. 10 and 11, since the liquid crystal 3 is evacuated before the one substrate 2 and the other substrate 1 on which the liquid crystal 3 is dropped are bonded to each other, the liquid crystal 3 is evacuated compared to the above-described vacuum injection method. The time for evacuating the cell surrounded by the two substrates 1 and 2 and the sealing material 4 is greatly reduced. Further, in the liquid crystal sealing method, since the liquid crystal 3 is supplied onto the substrate 2, the liquid crystal display element can be manufactured in a short time without injecting the liquid crystal which requires a long time in the vacuum injection method.

Further, by making the volume of the supply amount of the liquid crystal 3 equal to the volume of the space in the cell surrounded by the two substrates 1 and 2 and the sealing material 4, the cell is filled with the liquid crystal 3; It is possible to prevent a space from being formed in the cell. Further, since the pressure is reduced in a state where the inner surface of the cell is open, gas molecules adsorbed on the inner surface are also effectively removed. Therefore, it is difficult for gas to remain in the liquid crystal 3 after being filled.

[0015]

In the method shown in FIGS. 10 and 11, the liquid crystal 3 is supplied to the substrate 2 in advance, and then the two substrates 1 and 2 are bonded together to enclose the liquid crystal 3.
The amount and distribution of the liquid crystal 3 supplied on the substrate 2 is very important. If the amount of the liquid crystal 3 is larger than the space in the cell determined by the prescribed cell gap and the sealing material 4, the liquid crystal 3 spreads by laminating and swirls the sealing material 4 to cause liquid crystal leakage. There is a problem that it becomes thicker.

Conversely, if the amount of the liquid crystal 3 is small, a reduced pressure space is left between the sealing material 4 and the liquid crystal 3, and air enters from the outside under atmospheric pressure and bubbles remain in the liquid crystal 3. There is a problem that the cell gap becomes thinner than a predetermined value.

Further, if the distribution of the liquid crystal 3 is not uniform, it causes display unevenness. The non-uniform distribution of the liquid crystal 3
When an attempt is made to correct the pressure by pressing the substrates 1 and 2, the liquid crystal 3 flows, and if this flow is strong, the spacers 5 that maintain the cell gap flow, and the cell gap is not kept uniform, resulting in poor production. turn into. In addition,
Variations in the cell gap and movement of the spacers 5 due to the flow of the liquid crystal 3 cause a decrease in the display quality of the liquid crystal display element 6 even if it does not cause a defect in production.

According to the method disclosed in JP-A-63-109413 shown in FIG. 10, an amount of the liquid crystal 3 corresponding to the space in the cell surrounded by the two substrates 1 and 2 and the sealing material 4.
Is uniformly dropped on the entire area of the substrate 2 inside the sealing material 4. However, it is difficult to uniformly supply the liquid crystal 3 to the vicinity of the inside of the uncured sealing material 4. In particular, when the two substrates are brought into close contact with each other by pushing and spreading the sealing material 4 formed to be thicker than the cell gap, it is more difficult to apply the liquid crystal 3 to the vicinity of the inside of the sealing material 4.

Further, FIG.
According to the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-157, the liquid crystal 3 is provided to be smaller than the inner shape of the sealing material 4, so that if an appropriate amount of the liquid crystal 3 is supplied to one of the substrates 2, the liquid crystal 3 is spread out and the sealing material 4 is spread. 4 can be prevented, and the liquid crystal 3 can be prevented from penetrating between the sealing material 4 and the other substrate 1 and hindering the close contact.

However, in this method, since the liquid crystal 3 is smaller than the inner shape of the sealing material 4 and is provided slightly thicker than the sealing material 4 so as to prevent the liquid crystal 3 from spreading too fast, the two substrates 1 , 2 are superimposed, and the liquid crystal 3
Must be spread out, which may cause the spacer 5 to move.

Further, the liquid crystal 3 is brought into contact with the other substrate 1,
Thereafter, the pressure is reduced, so that when the other substrate 1 comes into contact with the liquid crystal 3, a gas at atmospheric pressure exists between the sealing material 4 and the liquid crystal 3. Slight intervening gas molecules may remain. When bonding, the liquid crystal 3 is placed between the sealing material 4 and the other substrate 1.
In order for the liquid crystal 3 to be spread out to reach the sealing material 4, the sealing material 4 and the other
Need to be in contact with Therefore, in this method, gas molecules tend to remain in the cell.

Further, the liquid crystal 3 is supplied by a method of dropping as an aggregate of minute points, a screen method, and a blade method. However, when the liquid crystal 3 is dropped as an aggregate of minute points, one droplet needs to be made very small in order not to cause the movement of the spacer 5 due to the flow of the liquid crystal 3, and an enormous number of points are dropped. There is a problem that it takes time to do so.

In the application by the screen method and the blade method, when the liquid crystal 3 is applied to the inside of the sealing material 4, the uncured sealing material 4 becomes an obstacle, and the liquid crystal 3 is applied to the vicinity of the inside of the sealing material 4. Can not do it. In particular, when the two substrates are brought into close contact with each other by pushing and spreading the sealing material 4 formed to be thicker than the cell gap, it is more difficult to apply the liquid crystal 3 to the vicinity of the inside of the sealing material 4.

In the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 60-75817, the liquid crystal is applied by an offset printing method. However, as in the above-described screen method and blade method, it is difficult to apply the liquid crystal around the inside of the sealing material. In addition, there is a problem that the substrate is easily damaged.

The present invention does not cause defects caused by residual bubbles, variation in liquid crystal supply amount, liquid crystal leakage, liquid crystal flow, variation in cell gap, and uneven cell gap.
Production method of liquid crystal display element with good productivity, and bubbles,
An object of the present invention is to provide a liquid crystal display device having high display quality without liquid crystal leakage and uneven cell gap.

[0026]

According to the present invention, a frame-like sealing material is interposed between a pair of substrates arranged at a predetermined interval, and a liquid crystal is filled in a space surrounded by the sealing material and the two substrates. In a method of manufacturing a liquid crystal display element manufactured by encapsulating a layer, a liquid crystal layer is applied to one substrate in a film shape having the same thickness as the liquid crystal layer when encapsulation is completed, and in the same shape as the outer shape of the liquid crystal layer when encapsulation is completed. Then, the sealing material is provided on one or the other substrate in a frame shape larger than the liquid crystal layer and larger than the outer shape of the liquid crystal layer, and the two substrates are overlapped and pressed under reduced pressure, and the sealing material is expanded. This is a method for manufacturing a liquid crystal display element, characterized by sealing liquid crystal.

According to the present invention, the liquid crystal is applied in the shape at the time of completion of the encapsulation, and the liquid crystal is not spread when the two substrates are bonded, so that the flow of the liquid crystal and the unevenness of the film thickness do not occur. In addition, the sealing material is provided thicker than the liquid crystal layer thickness at the time of completion of the encapsulation, is pressed to a prescribed cell gap, is expanded until it reaches the liquid crystal layer, and a reduced pressure space between the liquid crystal and the sealing material is formed. Since it is filled, no air bubbles remain in the liquid crystal layer at the time of completion of the encapsulation.

Further, since the liquid crystal is applied before the substrates are bonded, the liquid crystal display element can be manufactured in a short time, and the productivity is good.

Further, according to the present invention, a liquid crystal is sucked out by capillary action by a slit member having a slit, and the liquid crystal sucked up to the opening of the slit member and one of the substrates are brought into contact with each other. Move
The liquid crystal layer is applied to the substrate in the form of a film having the same thickness as the thickness of the liquid crystal layer when the encapsulation is completed, and in the same shape as the outer shape of the liquid crystal layer when the encapsulation is completed.

According to the present invention, the liquid crystal layer can be uniformly applied to the vicinity of the inside of the sealing material with the same thickness as the liquid crystal layer at the time of completion of the encapsulation.

Further, according to the present invention, when a rectangular liquid crystal layer is applied to a substrate, the length of the opening of the slit member is set to the length of one side of the rectangle of the liquid crystal layer. Contact the substrate, relatively move the slit member and the substrate by the length of the other side of the liquid crystal rectangle,
A liquid crystal layer is applied to a substrate.

According to the present invention, the liquid crystal can be applied in the same shape as the liquid crystal layer at the time of completion of the rectangular encapsulation. Further, in this manufacturing method, a plurality of rectangular liquid crystal layers can be easily coated on the same substrate by performing the above-described coating operation using a plurality of slit members or by repeatedly performing the above-described coating operation. The device can be manufactured at one time.

Further, according to the present invention, when two substrates are bonded together under reduced pressure, the two substrates are superposed and pressed while measuring the thickness of the liquid crystal layer. The sealing material is cured at the time when the thickness of the sealing material is reached.

According to the present invention, insufficient pressurization and overpressing during bonding can be prevented, and variations in the cell gap can be prevented.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device used for a notebook computer, a display, and the like has a pair of substrates facing each other, each substrate is bonded by a sealing material, and liquid crystal is sealed between the substrates. Have been. The distance (cell gap) between the substrates in which the liquid crystal is sealed is maintained by a number of spacers distributed between the substrates. In addition, a TFT element, a color filter, an alignment film, a transparent electrode, and the like are formed on each substrate.

FIG. 1 is a process chart showing a method for manufacturing a liquid crystal display element 6 according to an embodiment of the present invention.

In FIG. 1 (a), first, a film having the same thickness as the prescribed liquid crystal layer thickness at the time of encapsulation completion and having the same shape as the outer shape of the liquid crystal layer at the time of encapsulation completion, for example, 5 μm, is formed on one substrate 1. The liquid crystal layer 3 is applied to a rectangular film having a thickness by using a liquid crystal that has been subjected to a depressurizing process by reducing the pressure in advance.

Further, spacers 5 are dispersed on the other substrate 2 to provide a sealing material 4. The sealing material 4 is made of a UV-curable resin and is 0.4 mm wide and thicker than the liquid crystal layer 3 by a dispenser. In this embodiment, the sealing material 4 is a line having a thickness of 25 μm and is larger than the outer shape of the applied liquid crystal layer 3. Draw in a rectangular frame shape with an interval of 0.5 mm on each side between the outer shape of the layer 3 and the inner shape of the sealing material 4. Since the sealing material 4 is provided on the other substrate 2, it does not hinder the application of the liquid crystal layer 3.

In FIG. 1B, each of the substrates 1 and 2 is placed such that the surface of the first substrate 1 on which the liquid crystal layer 3 is applied and the surface of the other substrate 2 on which the sealing material 4 and the spacer 5 are provided face each other. 12. It is held in the vacuum chamber 10, and the inside of the vacuum chamber 10 is 13.
The pressure is reduced to 3 Pa. At this time, gas molecules dissolved in the liquid crystal during application and gas molecules adsorbed on the surfaces of the substrates 1 and 2 are removed by reducing the pressure.

In FIG. 1C, one substrate 1 and the other substrate 2
Are brought close to each other until the distance becomes 0.5 mm, and then the substrates 2 and 3 are relatively moved in the horizontal direction to perform alignment. At this time, the sealing material 4 and the one substrate 1
There is a gap between them, and the sealing material 4 does not come into contact with the liquid crystal 3 or shift due to the alignment.

In FIG. 1D, while measuring the cell gap 12 in the portion where the liquid crystal exists by the cell thickness gauge 11, pressure is applied while maintaining the parallel state of the two substrates 1 and 2 and gradually. Pressing and squeezing the sealing material 4 together. At this time, the sealing material 4 has a thickness of 25 μm to 5 μm.
The line width is expanded from 0.4 mm to 2 mm.
The inner side of the sealing material 4 before being crushed is provided with an interval of 0.5 mm from the outer shape of the liquid crystal layer 3.
And the space between the sealing material 4 and the sealing material 4 are filled.

At this time, when the sealing material 4 spread inside reaches the liquid crystal layer 3, the sealing material 4 spreads outside, so that air bubbles enter into the liquid crystal layer 3 within the range of this spreading. That is, the flushing of the sealing material 4 does not occur.
Therefore, it is possible to absorb a variation in the amount of liquid crystal and a slight displacement between the sealing material 4 and the liquid crystal layer 3 due to the alignment of the substrates 1 and 2.

The liquid crystal layer 3 is applied in the same thickness and shape as the liquid crystal layer at the time of completion of the encapsulation. If it is not pressed, it will not adhere to the entire surface of the other substrate 2.

In a conventional vacuum injection method in which a liquid crystal is injected after manufacturing an empty cell, there is no liquid crystal at the time of bonding the empty cells, and an air layer of several μm cannot be measured with high accuracy. In addition, in this method, the cell gap is controlled by empirically changing the injection time instead of measuring the cell thickness at the time of liquid crystal injection. Therefore, the variation of the empty cell becomes the variation of the cell gap.

In this embodiment, since the thickness of the liquid crystal layer 3 serving as the cell gap 12 is gradually increased while actually being measured by the cell thickness gauge 11, it is possible to prevent over-pressing and under-pressing. In addition, variations in cell gap can be eliminated. As the cell thickness gauge 11, a device for measuring retardation due to optical interference, which is used for measuring a cell gap after injection by a conventional vacuum injection method, is applied.

In FIG. 1E, when the liquid crystal layer 3 has a specified thickness, the sealing material 4 is cured by irradiating ultraviolet rays.
At this time, the ultraviolet rays are irradiated only from the back surface of the substrate to the sealing material 4 by the light guide path 13, but not to the liquid crystal layer 3. After that, the pressure in the vacuum chamber 10 is released to return to the atmospheric pressure, and the bonded substrate is taken out to complete the liquid crystal encapsulation.

In many cases, the ultraviolet curing resin used for the sealing material 4 is not completely cured by short-time ultraviolet irradiation. Therefore, the substrate bonded by the above procedure is put into a UV furnace, and the liquid crystal layer 3 is masked. Then, the sealing material 4 is completely cured by irradiating ultraviolet rays for several minutes to several tens of minutes.

Further, by heating the room temperature by about 10 ° C. to 50 ° C., the curing of the sealing material 4 is promoted. However, if the heating is performed excessively, these problems do not occur because the positions of the two substrates 1 and 2 may be shifted due to thermal expansion, or the sealing material 4 may be peeled off due to the warpage of the substrates 1 and 2. It is necessary to heat in the range.

As described above, in the manufacturing method shown in FIG.
A liquid crystal display device free from uneven cell gap, liquid crystal leakage and air bubbles can be produced in a short time.

In this embodiment, the sealing material 4 and the liquid crystal layer 3 are provided on separate substrates, but may be provided on the same substrate. As a procedure to provide on the same substrate,
On the other hand, after the sealing material 4 is provided on the substrate 2 in a frame shape, the sealing material 4
The liquid crystal layer 3 is applied in a predetermined shape on the inside of the substrate, and thereafter, bonding is performed according to the procedure of the above embodiment. After applying the liquid crystal in a predetermined shape, the sealing material 4 is dispensed with a dispenser.
May be provided in a frame shape.

In the method in which the sealing material 4 and the liquid crystal layer 3 are provided on the same substrate, the distance between the sealing material 4 and the liquid crystal layer 3 does not change due to the alignment of the two substrates 1 and 2. Therefore, the distance can be controlled by the accuracy of the application position between the sealing material 4 and the liquid crystal layer 3, and the allowable range for the variation in the amount of liquid crystal is further increased.

Next, a method of applying the liquid crystal layer 3 will be described. FIG. 2 is a perspective view schematically showing the slit member 30, and FIG.
FIG. The liquid crystal layer 3 is applied by an application nozzle 42 having the slit member 30.

The slit member 30 has a triangular prism shape and has a slit 31 formed from the base to the vertex of the triangle.
Are formed over the entire length in the longitudinal direction. Coating nozzle 42
Has a slit member 30 and a container 38 filled with liquid crystal indicated by oblique lines. When the bottom of the slit member 30 is attached to and held in a liquid crystal reservoir 33 as shown in FIG. 3, the liquid crystal is slit by capillary action. It is sucked up to the opening 34 of the member 30.

When the rectangular liquid crystal layer 3 is applied, if the length 32 of the opening 34 of the slit 31 is equal to the length of one side of the rectangular liquid crystal layer 3, the liquid crystal sucked up to the opening 34 and the substrate 1 And the substrate 1 and the application nozzle 42 are relatively moved by the length of the other side of the rectangle of the liquid crystal layer 3, whereby the rectangular liquid crystal layer 3 can be applied to the substrate 1.

Next, a procedure for applying the liquid crystal layer 3 will be described. FIG. 4 is a process chart showing a method of applying the liquid crystal layer 3 by the application nozzle 42. In FIG. 4A, the substrate 1 is vacuum-adsorbed on the downward horizontal surface of the surface plate 40 with the surface to be coated with the liquid crystal facing down, and the application nozzle 42 is connected to the opening 34 of the slit 31 and the length 32 of the opening 31. The substrate 1 is held horizontally at an interval in the height direction so that one side of the substrate, which has been determined, becomes parallel.

In FIG. 4B, the application nozzle 42 is horizontally moved at a constant speed in a direction perpendicular to the application nozzle 42.

In FIG. 4C, the application nozzle 42 arrives at the position where the application of the liquid crystal layer 3 is started.
The liquid crystal sucked up to the opening 34 of the slit 31 and the substrate 1
Is applied to the substrate 1 together with the platen 40 so that
Approach 2.

In FIG. 4D, the application nozzle 42 is continuously moved at a constant speed in the horizontal direction while maintaining the contact state between the liquid crystal and the substrate 1.

In FIG. 4E, when the application nozzle 42 reaches the position where the application of the liquid crystal layer 3 is completed, the substrate 1 is raised together with the platen 40 so that the substrate 1 is separated from the liquid crystal.

Thus, the liquid crystal layer 3 can be applied to the substrate 1 in the same rectangular film shape as when the encapsulation is completed.

The thickness of the liquid crystal layer 3 is determined by the height 36 from the liquid surface of the liquid crystal reservoir 33 to the opening 34 and the distance 3 between the slits 31.
5, the height 37 of the slit member 30, the distance between the opening 34 of the slit member 30 and the substrate 1, the surface tension of the liquid crystal on the substrate 1, the viscosity of the liquid crystal, and the moving speed of the application nozzle 42.

The physical shape 35, 37 of the slit 31
Is constant depending on the design. The surface tension and viscosity of the liquid crystal are as follows if the material of the liquid crystal and the substrate 1 are constant.
The temperature can be controlled by keeping the temperature at the time of application constant.

Therefore, the opening 34 of the slit member 30
Between the liquid crystal reservoir 33 and the opening 34
By controlling the height 36 and the moving speed of the coating nozzle 42, the coating start position and the coating end position can be controlled, and the coating area and the coating amount can be managed. 3 can be applied.

Further, in the coating method using the coating nozzle 42, a mask or the like is not required, and the liquid crystal is only in contact with the substrate. Therefore, when the sealing material 4 and the liquid crystal layer 3 are provided on the same substrate, It can be applied to near the inside of the material 4. For this reason, as described above, the liquid crystal layer 3 can be accurately applied at an interval of 0.5 mm from the inside of the sealing material 4.

In this embodiment, the coating nozzle 42 is moved horizontally and the substrate 1 is moved up and down. However, the substrate 1 is moved horizontally and the coating nozzle 42 is moved up and down, or one of them is moved. Only one may be moved horizontally and vertically.
Further, if the liquid crystal layer 3 is uniformly applied with a predetermined thickness, the substrate 1 or the application nozzle 42 may be moved in the horizontal direction after the liquid crystal contacts the substrate 1.

As a method of applying the liquid sucked up to the opening of the slit member by capillary action to the substrate, a method of applying a lacquer or a color filter of a liquid crystal display element is disclosed in JP-A-6-343908 and This is disclosed in JP-A-8-224528.

Next, a method for manufacturing a plurality of liquid crystal display elements from one set of substrates will be described. FIG. 5 is a plan view showing the substrate 1 on which two rectangular liquid crystal layers 3 are applied. FIG. 6 is a process chart showing a method of applying two rectangular liquid crystal layers 3 by one application nozzle 42. In FIGS. 5 and 6, the liquid crystal is indicated by oblique lines.

In FIG. 6A, the substrate 1 is vacuum-sucked on a downward horizontal surface of the surface plate 40 so that the surface on which the liquid crystal is applied faces downward. Further, the application nozzle 42 is horizontally held with a gap in the height direction with respect to the substrate 1 such that the opening of the slit and one side of the substrate 1 having the determined length are parallel.

In FIG. 6B, the substrate 1 together with the platen 40 is
The slit is moved horizontally at a constant speed in a direction perpendicular to the length direction of the slit.

In FIG. 6C, the timing at which the application nozzle 42 reaches the first liquid crystal application start position is adjusted.
The application nozzle 42 is brought close to the substrate 1 such that the liquid crystal sucked up to the opening of the slit is in contact with the substrate 1.

In FIG. 6D, the timing of moving the substrate 1 together with the platen 40 to the first coating end position while maintaining the contact state between the liquid crystal and the substrate 1 and reaching the coating end position To lower the application nozzle 42,
The contact state between the liquid crystal and the substrate 1 is cut off. By doing so, the first liquid crystal layer 3 is applied.

In FIG. 6E, at the timing when the application nozzle 42 reaches the second liquid crystal application start position,
The application nozzle 42 is brought close to the substrate 1 such that the liquid crystal sucked up to the opening of the slit is in contact with the substrate 1.

In FIG. 6 (f), while maintaining the contact state between the liquid crystal and the substrate 1, the substrate 1 is moved together with the surface plate 40 horizontally to the second coating end position, and the timing of reaching the coating end position is reached. To lower the application nozzle 42,
The contact state between the liquid crystal and the substrate 1 is cut off. By doing so, the second liquid crystal layer 3 is applied. As described above, in the method shown in FIG. 6, two rectangular liquid crystal layers 3 as shown in FIG.

FIG. 7 is a schematic diagram for explaining a coating method using a coating device 43 in which two coating nozzles 42 are arranged in series. The coating device 43 moves the coating device 43 to the coating end position in the direction of the arrow shown in FIG. 7 while bringing the liquid crystal sucked up to the openings of the two coating nozzles 42 and the substrate 1 into contact with each other. The contact state between the liquid crystal and the substrate 1 is cut off according to the arrival timing. In this way, the coating device 43 can apply two rectangular liquid crystal layers 3 to the substrate 1 as shown in FIG.

Further, by combining the method shown in FIG. 6 and the method shown in FIG. 7, m coating nozzles are arranged in one row, and the coating operation is repeated n times, whereby m × n pieces of nozzles are formed on one substrate. A rectangular liquid crystal layer can be applied.

A substrate on which a plurality of liquid crystal layers are applied by the above procedure and a substrate on which a sealing material having a corresponding shape is provided are bonded by the procedure described with reference to FIG. 1 to divide each liquid crystal display element. A plurality of liquid crystal display elements can be manufactured from one set of substrates. This method can efficiently manufacture a plurality of liquid crystal display elements in a short time and is suitable for mass production.

In the manufacturing method of the present invention, the recent 15
Even a monitor liquid crystal display element of inches or more can be manufactured in a short time without leaving bubbles in the liquid crystal layer.

[0078]

As described above, according to the present invention, the liquid crystal is applied in the shape at the time of completion of the encapsulation, and the liquid crystal is not spread when the two substrates are bonded. No unevenness occurs. Further, since the sealing material is expanded to fill the reduced pressure space between the liquid crystal and the sealing material, no air bubbles remain in the liquid crystal layer at the time of completion of the sealing.

Further, since the liquid crystal is applied before bonding the substrates, the liquid crystal display device can be manufactured in a short time, and the productivity of the liquid crystal display device is improved.

Further, according to the present invention, the liquid crystal is applied with the same thickness and shape as the liquid crystal layer at the time of the encapsulation completion by the slit member for sucking the liquid crystal by the capillary phenomenon. The display element can be manufactured in a short time.

Further, according to the present invention, a plurality of slit members having the length of the opening equal to one side of the rectangular liquid crystal layer at the time of completion of the encapsulation are formed on the substrate by the length of the other side of the rectangular liquid crystal layer. The liquid crystal can be applied in the same shape as the liquid crystal layer at the completion of the encapsulation by relatively moving the liquid crystal. Also,
By performing the above-described coating operation using a plurality of slit members or by repeating the coating operation, a plurality of rectangular liquid crystal layers can be easily coated on the same substrate, and a plurality of liquid crystal display elements can be manufactured at a time. be able to. For this reason,
A liquid crystal display device free from uneven cell gap, liquid crystal leakage and air bubbles can be efficiently produced in a short time.

Further, according to the present invention, since the pressure is applied while measuring the thickness of the liquid crystal layer, the thickness of the liquid crystal layer can be accurately controlled, and the variation in the cell gap can be prevented.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for manufacturing a liquid crystal display element according to an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing a slit member 30.

FIG. 3 is a sectional view schematically showing a coating nozzle having a slit member.

FIG. 4 is a process chart showing a method of applying the liquid crystal layer 3 by an application nozzle 42.

FIG. 5 is a plan view showing the substrate 1 on which two rectangular liquid crystal layers 3 are applied.

FIG. 6 is a process chart showing a method of applying two rectangular liquid crystal layers 3 by one application nozzle 42;

FIG. 7 is a schematic diagram for explaining a coating method using a coating device 43 in which two coating nozzles 42 are arranged in series.

FIG. 8 is a sectional view showing a configuration of the liquid crystal display element 6.

FIG. 9 is a schematic diagram for explaining a conventional vacuum injection method.

FIG. 10 is a process chart for explaining a manufacturing method disclosed in Japanese Patent Application Laid-Open No. 63-109413.

FIG. 11 is a process chart for explaining a manufacturing method disclosed in Japanese Patent Publication No. Hei 8-20627.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 One substrate 2 The other substrate 3 Liquid crystal layer 4 Sealing material 5 Spacer 6 Liquid crystal display element 10 Vacuum chamber 11 Cell thickness gauge 12 Cell gap 13 Light guide path 30 Slit member 31 Slit 32 Opening length 33 Liquid crystal reservoir 34 Opening 35 Slit spacing 40 Surface plate 42 Application nozzle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toru Kira 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 2H089 LA49 MA07Y NA09 NA22 NA42 NA49 QA12 QA14 SA01 TA09 4D075 AC02 AC84 AC86 AC95 BB05Y BB56Z CA47 DA06 DC19 DC22 EA05 4F042 AA06 BA06 BA08 CB03 CB10

Claims (4)

[Claims] 1. A manufacturing method in which a frame-shaped sealing material is interposed between a pair of substrates arranged at a predetermined interval, and a liquid crystal layer is sealed in a space surrounded by the sealing material and the two substrates. In the method of manufacturing a liquid crystal display element, the liquid crystal layer is applied to one substrate in a film shape having the same thickness as the liquid crystal layer at the time of completion of the encapsulation, and in the same shape as the outer shape of the liquid crystal layer at the time of the completion of the encapsulation,
In a frame shape that is thicker than the liquid crystal layer and larger than the outer shape of the liquid crystal layer,
A seal material is provided on one or the other substrate, the two substrates are overlapped and pressed under reduced pressure, and the seal material is expanded.
A method for manufacturing a liquid crystal display element, wherein liquid crystal is sealed. 2. A liquid crystal is sucked out by capillary action by a slit member having a slit, and the liquid crystal sucked up to the opening of the slit member and one substrate are brought into contact with each other.
The liquid crystal layer is applied to the substrate by moving the substrate and the slit member relatively to form a film with the same thickness as the liquid crystal layer when encapsulation is completed, and the same shape as the liquid crystal layer when encapsulation is completed. The method for manufacturing a liquid crystal display element according to claim 1. 3. When applying a rectangular liquid crystal layer to a substrate, the length of the opening of the slit member is set to the length of one side of the rectangle of the liquid crystal layer. 3. The method for manufacturing a liquid crystal display element according to claim 2, wherein the liquid crystal layer is applied to the substrate by bringing the slit member and the substrate relatively into contact with each other by the length of another side of the rectangular shape of the liquid crystal. 4. When bonding two substrates under reduced pressure, the two substrates are superimposed and pressed while measuring the thickness of the liquid crystal layer, and the thickness of the liquid crystal layer is reduced to a predetermined thickness. Wherein the sealing material is cured at the time when
4. The method for manufacturing a liquid crystal display device according to any one of items 3.