JP2001083533A - Production of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce required duration necessary for pouring a liquid crystal composition into a liquid crystal cell and sealing. SOLUTION: In this manufacturing method of a liquid crystal display device, the liquid crystal cell L, which is constituted of an array substrate 100 and a counter substrate 200 which are stuck together by a sealant 106 applied except a liquid crystal pouring port 107, is formed. Then the liquid crystal composition 300 is poured into the liquid crystal cell L from the liquid crystal pouring port 107 and then the liquid crystal pouring port 107 is sealed. In this case, in each process, at the time of increasing pressure in the liquid crystal cell L, that is, at the time of pressurizing, the liquid crystal cell L is heated and at the time of reducing pressure in the liquid crystal cell L, that is, at the time of evacuating, the liquid crystal cell L is cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a method for injecting a liquid crystal composition into a liquid crystal cell and a method for sealing the liquid crystal composition.

[0002]

2. Description of the Related Art A liquid crystal display device comprises a liquid crystal cell formed by bonding a pair of glass substrates opposed to each other at a predetermined interval with a sealing material, and a liquid crystal composition sealed in the liquid crystal cell. And The liquid crystal composition is sealed in the liquid crystal cell through an opening formed in the sealing material, that is, a liquid crystal injection port.

That is, the liquid crystal cell is placed in a vacuum chamber together with a container containing a liquid crystal composition. The vacuum chamber is evacuated for several hours, and the liquid crystal injection port provided in the liquid crystal cell is immersed in the liquid crystal composition while the pressure inside the liquid crystal cell is reduced. When the inside of the tank is released to the atmospheric pressure, the liquid crystal composition is injected into the liquid crystal cell. The liquid crystal cell into which the liquid crystal composition has been injected is set in a jig every few sheets with a spacer interposed between the cells.

When a plurality of liquid crystal cells are pressurized at a predetermined pressure by the jig, a liquid crystal composition excessively injected into the liquid crystal cell is discharged from a liquid crystal injection port. When the liquid crystal composition is discharged until the liquid crystal composition in the liquid crystal cell reaches a predetermined amount, a sealing material is applied to the liquid crystal injection port. In the liquid crystal cell, the sealing material is sucked into the cell by releasing the pressurized state by the jig and slightly reducing the pressure. Then, the sealing material is cured.

[0005]

When excess liquid crystal composition in a liquid crystal cell is discharged from a liquid crystal injection port by pressurizing the liquid crystal cell, a liquid crystal composition having a relatively high viscosity is discharged from the liquid crystal injection port. However, there is a problem that the required time is long.

Further, if the liquid crystal cell is excessively pressurized in order to shorten the liquid crystal composition discharge time, spacers in the liquid crystal cell may be damaged, and the cell gap may not be properly maintained. Is high.

Further, in the step of sucking the sealing material into the liquid crystal cell by reducing the pressure, if the viscosity of the liquid crystal composition is relatively high, the time required for suction is long in order to obtain a predetermined amount of suction. There is also the problem of becoming.

The present invention has been made in view of the above-mentioned problems, and has as its object to reduce the time required for injecting and sealing a liquid crystal composition into a liquid crystal cell. An object of the present invention is to provide a method for manufacturing a display device.

[0009]

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: A step of bonding the other substrate to form a liquid crystal cell, a step of injecting a liquid crystal composition from a liquid crystal injection port into the liquid crystal cell, and a step of disposing a sealing material in the liquid crystal injection port and sealing the liquid crystal cell, In the method for manufacturing a liquid crystal display device having
In the filling step, the liquid crystal cell is heated, and the liquid crystal composition is discharged from the liquid crystal filling port.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a liquid crystal display device according to the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an example of a liquid crystal display panel of a liquid crystal display device manufactured by the manufacturing method of the present invention.

FIG. 2 schematically shows a circuit configuration of a liquid crystal display device manufactured by the manufacturing method of the present invention.

As shown in FIGS. 1 and 2, the liquid crystal display panel 10 includes an array substrate 100 as a first substrate, an opposing substrate 200 as a second substrate opposed to the array substrate 100, and an array substrate. 100 and a liquid crystal composition 300 disposed between the opposing substrate 200. In such a liquid crystal display panel 10, a display area 102 for displaying an image includes an array substrate 100 and a counter substrate 20.
And a peripheral area 104 having various wiring patterns and a driving circuit formed in a region surrounded by a sealing material 106 for pasting with 0.
Are formed in a region outside the sealing material 106. The sealing material 106 is used for filling the liquid crystal composition 300 between the array substrate 100 and the counter substrate 200.
It is applied except for 07.

The display area 102 of the array substrate 100 is
As shown in FIG. 2, mxn pixel electrodes 151 arranged in a matrix on a transparent insulating substrate, for example, a glass substrate having a thickness of 0.7 mm, are formed along the row direction of the pixel electrodes 151. M scanning lines Y1 to Ym, n signal lines X1 to Xn formed along the column direction of these pixel electrodes 151, and scanning lines Y1 to Ym and signal lines corresponding to mxn pixel electrodes 151. Mxn thin film transistors, ie, pixel TFTs 121, arranged as switching elements near the intersections of X1 to Xn,
The scanning line driving circuit 18 for driving Ym, these signal lines X1
To Xn.

The scanning lines Y and the signal lines X are made of a low-resistance material such as aluminum or a molybdenum-tungsten alloy. The pixel electrode 151 is made of a transparent conductive material, for example, indium-tin-oxide or I
It is formed by TO.

The TFT 121 is constituted by, for example, a top gate type polycrystalline silicon thin film transistor having a portion protruding from the scanning line Y as a gate electrode and a polycrystalline silicon thin film as an active layer. The source region of the semiconductor layer is
A source electrode electrically connected to the pixel electrode 151 is in contact, and a drain region of the semiconductor layer is in contact with a drain electrode forming a part of a signal line.

The surface of the pixel electrode 151 is
And is covered with an alignment film for aligning the liquid crystal composition 300 interposed between them.

Each of the TFTs 121 has a potential of the signal lines X1 to Xn driven by the signal line driving circuit 19 when the corresponding scanning line is driven by the scanning line driving circuit 18 and the pixel electrode 151 of the corresponding row is selected. Is applied to the pixel electrodes 151 in the corresponding rows.

The scanning line driving circuit 18 provided in the peripheral area 104Y sequentially supplies a scanning voltage to the scanning lines Y1 to Ym in a horizontal scanning cycle, and the signal line driving circuit 19 provided in the peripheral area 104X controls each horizontal scanning line. In the scanning cycle, the pixel signal voltage is supplied to the signal lines X1 to Xn.

The scanning line driving circuit 18 and the signal line driving circuit 19 are constituted by complementary circuits composed of an n-channel thin film transistor and a p-channel thin film transistor. These thin film transistors are top gate thin film transistors using a polycrystalline semiconductor thin film such as a polycrystalline silicon thin film, that is, a non-single-crystal semiconductor thin film as an active layer.

The display area 10 of the array substrate 100
2 and non-pixel portions in the peripheral area 104 (X, Y),
That is, wiring patterns such as signal lines X and scanning lines Y, T
The array substrate 10 is placed on the FT 121, the peripheral frame, and the like.
A spacer (not shown) for forming a gap of about 5 μm between the first substrate 0 and the counter substrate 200 is provided.
A gap between the array substrate 100 and the counter substrate 200 is set. As the spacer, a spherical spacer may be scattered and arranged, or may be formed integrally with the substrate.

The display area 102 of the opposing substrate 200 is made of a transparent conductive member that forms a potential difference between the pixel electrode 151 and a transparent insulating substrate, for example, a glass substrate having a thickness of 0.7 mm. Counter electrode 20 formed of, for example, indium-tin-oxide or ITO.
4 and an alignment film for aligning the liquid crystal composition 300 interposed between the liquid crystal composition 300 and the array substrate 100.

The counter electrode 204 includes a plurality of pixel electrodes 151.
Are set to the reference potential. An electrode transfer material, that is, a silver paste as a transfer, disposed around the substrate is provided to supply a voltage from the array substrate 100 to the counter substrate 200, and the counter electrode 204 is connected to the counter electrode drive connected via the transfer. Driven by the circuit 20.

A liquid crystal capacitor CL is formed by the liquid crystal layer 300 sandwiched between the pixel electrode 151 and the counter electrode 204. The array substrate 100 includes a pair of electrodes for forming an auxiliary capacitance CS in parallel with the liquid crystal capacitance CL. That is, the storage capacitor CS is formed by a potential difference formed between the storage capacitor electrode 61 having the same potential as the pixel electrode 151 and the storage capacitor line 52 set to a predetermined potential.

On the front and back surfaces of the liquid crystal display panel 10, that is, on the outer surfaces of the array substrate 100 and the opposing substrate 200, a polarization plane whose polarization plane is selected according to the display mode of the liquid crystal display device, the twist angle of the liquid crystal composition and the like. Boards are provided as needed.

Next, a method of manufacturing the liquid crystal display panel 10 applied to the liquid crystal display will be described. FIGS. 3A to 3E show the liquid crystal panel shown in FIG.
It is sectional drawing at the time of cutting | disconnection by the -A 'line.

First, as shown in FIG. 3A, a liquid crystal cell L composed of an array substrate 100 and a counter substrate 200 bonded by a sealing material 106 is formed.

That is, the scanning lines Y and the signal lines X, and the scanning lines Y and the signal lines X are arranged in a matrix on the glass substrate.
Thin film transistor 121 arranged near the intersection with
An array substrate 100 including a pixel electrode 151 and the like electrically connected to the thin film transistor 121 is prepared. Further, a counter substrate 200 having a counter electrode 204 and the like disposed on the glass substrate is prepared. And the array substrate 1
00 and an alignment film are formed on the surface of the counter substrate 200.

The liquid crystal injection port 10 surrounds the display area 106 of the array substrate 100 or the counter substrate 200.
Except for 7, the sealing material 106 is applied. Then, the array substrate 100 and the counter substrate 200 are bonded together with the alignment films facing inward, and the sealant 106 is cured. This allows
A liquid crystal cell L is formed.

Subsequently, as shown in FIG. 3B, a liquid crystal composition 300 is injected into the liquid crystal cell L through a liquid crystal injection port.

That is, as shown in FIG. 4, a plurality of, for example, twenty-five, liquid crystal cells L are stacked in a holding mechanism 4 provided in a vacuum chamber 401 of a liquid crystal injecting device 400.
02. In the vacuum chamber 401,
A liquid crystal boat 403 having the liquid crystal composition 300 subjected to the defoaming treatment is arranged. The vacuum chamber 401 includes an exhaust valve 404
Evacuated for about 5 hours. As a result, the inside of each liquid crystal cell L is evacuated from the liquid crystal injection port, and the pressure inside the cells is reduced.

Then, the lower base mechanism 405 is raised, and each liquid crystal cell L held by the holding mechanism 402 is moved.
Is a liquid crystal composition 300 filled in a liquid crystal boat 403.
Dip for about 4 hours. At this time, by gradually returning the pressure in the vacuum chamber 401 to the atmospheric pressure, the liquid crystal cell L
Due to the pressure difference from the inside and the capillary phenomenon, the liquid crystal composition 300
Is injected into the liquid crystal cell L.

When the liquid crystal composition 300 is injected into the liquid crystal cell L in this manner, the liquid crystal composition 300 is slightly injected into the liquid crystal cell L as shown in FIG.

Subsequently, as shown in FIG. 3C, the liquid crystal cell L into which the liquid crystal composition 300 has been injected is heated while maintaining the pressure, and the excessively injected liquid crystal composition 300 is discharged. .

That is, as shown in FIG. 5, the liquid crystal cells L into which the liquid crystal composition 300 has been injected are stacked with a plurality of cells interposed therebetween with a spacer therebetween.
Is held under pressure by the holding mechanism 502. At this time,
The liquid crystal cell L is pressurized at 150 kgf. Further, each liquid crystal cell L held by the holding mechanism 502 is heated from the periphery thereof by a heating device 504 such as a heater at a predetermined temperature for a predetermined time.

The liquid crystal composition 30 injected into the liquid crystal cell L
In the case of 0, when heated, its viscosity decreases and its volume expands. By controlling the pressure and the heating temperature, the amount discharged from the liquid crystal inlet 107 can be controlled. As described above, by heating the liquid crystal cell L held under pressure, the time required for discharging the excessively injected liquid crystal composition 300 can be shortened. The processing time can be reduced to about half.

Subsequently, as shown in FIG. 3D, a sealing material 108 is applied to the liquid crystal injection port 107 with the amount of the liquid crystal composition 300 in the liquid crystal cell L being a predetermined amount. Here, the predetermined amount is the amount of the liquid crystal composition 300 corresponding to the volume in the liquid crystal cell L in a state where the gap between the array substrate 100 and the counter substrate 200 in the liquid crystal cell L is properly maintained at room temperature. It is.

That is, as shown in FIG. 5, a liquid crystal cell L having a predetermined amount of the liquid crystal composition 300 is heated by a heating device 504.
In a state where the sealing member 108 is pressed and held by the holding mechanism 502 while being heated by the above, a sealing material 108 made of an ultraviolet curable resin is applied to the liquid crystal inlet 107 by a dispenser (not shown). The applied sealing material 108 is arranged on the end face of the liquid crystal cell L.

Subsequently, as shown in FIG. 3E, the liquid crystal cell L is cooled, the sealing material 108 is sucked into the liquid crystal cell L, and the sealing material is cured.

That is, as shown in FIG. 5, the pressure of the liquid crystal cell L coated with the sealing material 108 is reduced while being held by the holding mechanism 502. At this time,
For example, the liquid crystal cell L has a weight of 150 kgf to 100 kgf.
The pressure is reduced to a degree. Further, each liquid crystal cell L held by the holding mechanism 503 is cooled from its periphery by a cooling device 506 such as an air blow at a predetermined temperature for a predetermined time.

The liquid crystal composition 30 injected into the liquid crystal cell L
In the liquid crystal cell L, the sealing material 108 disposed on the end face of the liquid crystal cell L is sucked into the liquid crystal cell L when cooled.

As described above, by cooling the held liquid crystal cell L in addition to the pressure reduction of the liquid crystal cell L, the pressure in the liquid crystal cell L becomes a negative pressure as compared with the time of pressurization.
8 can be sucked into the liquid crystal cell L, and the array substrate 100 and the opposing substrate 200 in the liquid crystal cell L can be sucked.
Can be properly maintained. For this reason, it is possible to reduce the time required for sucking the sealing material 108 and adjusting the gap in the liquid crystal cell L to an appropriate value, and the processing time is reduced to about half as compared with the case where only the pressure is reduced. It is possible to do.

The sealing material sucked into the liquid crystal cell L is cured by being irradiated with ultraviolet rays.

Through the steps described above, the liquid crystal display panel 10 in which the liquid crystal composition 300 is sealed in the liquid crystal cell L is manufactured.

As described above, according to the method of manufacturing the liquid crystal display device, the liquid crystal cell L including the array substrate 100 and the counter substrate 200 bonded together by the sealing material 106 applied except for the liquid crystal injection port 107 is provided. Is formed in the liquid crystal cell L through the liquid crystal injection port 107.
In the method of manufacturing a liquid crystal display device in which the liquid crystal composition 300 is injected and the liquid crystal injection port 107 is sealed, when the extra liquid crystal composition 300 is discharged, the liquid crystal cell L is heated while the liquid crystal cell L is heated. When sucking, the pressure is reduced and the liquid crystal cell L is cooled.

When the liquid crystal composition 300 is excessively injected into the liquid crystal cell L, the liquid crystal composition 30 is adjusted to an appropriate amount.
It is necessary to discharge 0. At this time, by heating the liquid crystal cell L while applying pressure, the volume of the liquid crystal composition 300 expands, and the viscosity of the liquid crystal composition decreases. The time required for discharging can be reduced.

In the case where the liquid crystal composition 300 in the liquid crystal cell L is sealed with an appropriate amount of the liquid crystal injection port by a sealing material, the liquid crystal cell L is cooled while reducing the pressure. Since the volume of the liquid crystal composition 300 shrinks, the sealing material can be quickly sucked into the liquid crystal cell L as compared with the case where only the pressure is reduced, and the time required for processing can be reduced. Becomes

In this embodiment, heating and pressurizing, and
Although the cooling and the pressure reduction are combined, only the volume change of the liquid crystal composition by the temperature control may be used. That is, it is possible to perform only temperature control such as heating when discharging an excess liquid crystal composition and cooling when suctioning the sealing material, and in this case, the manufacturing apparatus can be further simplified.

[0049]

As described above, according to the present invention, there is provided a method of manufacturing a liquid crystal display device capable of shortening the time required for injecting and sealing a liquid crystal composition into a liquid crystal cell. can do.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an example of a liquid crystal display panel manufactured by a method of manufacturing a liquid crystal display device of the present invention.

FIG. 2 is a diagram schematically showing a configuration of a liquid crystal display device manufactured by a method of manufacturing a liquid crystal display device of the present invention.

FIGS. 3A to 3E are views for explaining a method for manufacturing a liquid crystal display device of the present invention.

FIG. 4 is a diagram schematically showing a configuration of a liquid crystal injection device applied to a method of manufacturing a liquid crystal display device of the present invention.

FIG. 5 is a diagram schematically showing a configuration of a liquid crystal sealing device applied to the method for manufacturing a liquid crystal display device of the present invention.

[Explanation of symbols]

 Reference Signs List 10: liquid crystal display panel 100: array substrate 106: sealing material 107: liquid crystal injection port 108: sealing material 200: counter substrate 300: liquid crystal composition 400: liquid crystal injection device 500: liquid crystal sealing device

Claims (3)

[Claims] 1. A step of forming a liquid crystal cell by bonding one substrate to another substrate with a sealing material applied except for a liquid crystal injection port, and injecting a liquid crystal composition into the liquid crystal cell from the liquid crystal injection port. In a method for manufacturing a liquid crystal display device, comprising the steps of: disposing a sealing material in a liquid crystal injection port to seal the liquid crystal display; and in the injection step, heating the liquid crystal cell and discharging the liquid crystal composition from the liquid crystal injection port. A method of manufacturing a liquid crystal display device. 2. A step of forming a liquid crystal cell by bonding one substrate to the other substrate with a sealing material applied except for a liquid crystal injection port, and injecting a liquid crystal composition into the liquid crystal cell from the liquid crystal injection port. In a method for manufacturing a liquid crystal display device, comprising: a step of disposing a sealing agent in a liquid crystal injection port to seal the liquid crystal display; And cooling the liquid crystal cell and sucking the sealing material into the liquid crystal cell. 3. A step of forming a liquid crystal cell by bonding one substrate to another substrate with a sealing material applied except for a liquid crystal injection port, and injecting a liquid crystal composition into the liquid crystal cell from the liquid crystal injection port. Heating the liquid crystal cell into which the liquid crystal composition has been injected while maintaining the pressure, and discharging the liquid crystal composition until the liquid crystal composition in the liquid crystal cell reaches a predetermined amount; and sealing the liquid crystal injection port. A method for manufacturing a liquid crystal display device, comprising: a step of sealing with a material; a step of cooling the liquid crystal cell to suck the sealing material into the liquid crystal cell; and a step of curing the sealing material.