JP2002107740A - Method and apparatus for manufacturing liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that cell thickness is fluctuated due to excess or deficiency of liquid crystal dripping and defectively stuck state is caused such as mounting of a liquid crystal on a sealing, etc., in conventional liquid crystal dripping methods. SOLUTION: An amount of the dripped liquid crystal is measured. When the amount of dripping is inappropriate, sticking operation is not carried out and the liquid crystal is recovered. Also, because no sealing is formed on the substrate to which the liquid crystal is to be dripped, the liquid crystal and the substrate are easily regenerated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a liquid crystal display panel, and more particularly, to a method in which a liquid crystal is dropped on one of substrates before the two substrates constituting the liquid crystal display panel are bonded to each other. The present invention relates to a liquid crystal dropping method for bonding two substrates and a manufacturing apparatus therefor.

[0002]

2. Description of the Related Art In a liquid crystal display panel, a liquid crystal cell is formed by applying a sealing resin to the periphery of opposing inner surfaces of two glass substrates having transparent electrodes on the surface and bonding them with a gap therebetween. Further, a liquid crystal is sealed inside the seal forming the gap.

As a method of enclosing liquid crystal in a liquid crystal cell,
Conventionally, a vacuum injection method has been used, in which a liquid crystal cell is held in a vacuum in a vacuum bell jar, air in the liquid crystal cell is eliminated, and an injection port provided in a part of a seal of the liquid crystal cell is filled with liquid crystal. After returning the inside of the bell jar to normal pressure while immersed in the container in which is stored, the liquid crystal is allowed to permeate the liquid crystal cell by atmospheric pressure, and then the liquid crystal is sealed in the liquid crystal cell by sealing the injection port with resin. .

In addition, in the liquid crystal injection method, since the injection time becomes longer as the size of the liquid crystal cell becomes larger, first, as shown in FIG.
A method has been proposed in which a curable resin 4 is applied to a peripheral portion, a liquid crystal 5 is dropped on the inside of a seal by a dispenser, the liquid crystal is filled with the liquid crystal, and two substrates are bonded to each other. Such a liquid crystal sealing method is hereinafter referred to as a “liquid crystal dropping method”. This liquid crystal dropping method is described in, for example, JP-A-63-179323.

[0005]

In the liquid crystal dropping method, however, the distance between cells (cell thickness) is determined by the amount of liquid crystal dropped inside the seal. However, defects such as variations in cell thickness, residual bubbles due to an insufficient amount of liquid crystal, and protrusion of liquid crystal outside the seal due to excess amount of liquid crystal, etc., have occurred. When these defects are reproduced, it is difficult to collect the liquid crystal and the substrate because the sealant is formed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a liquid crystal display which can be easily reproduced and has excellent productivity even when the liquid crystal is out of an appropriate amount and becomes defective in the liquid crystal dropping method. A method and apparatus for manufacturing a panel are provided.

[0007]

According to a first aspect of the present invention, there is provided a method of manufacturing a liquid crystal display panel, comprising: measuring an amount of a liquid crystal dropped, and when the amount of the dropped liquid crystal deviates from a reference value, It is characterized by collecting.

According to the present invention, when the amount of the dropped liquid crystal deviates from the reference value, by collecting the dropped liquid crystal, it is possible to eliminate a defect due to excess or deficiency of the liquid crystal.

According to a second aspect of the present invention, in the method of manufacturing a liquid crystal display panel according to the first aspect, the formation of the seal is performed on the substrate after the liquid crystal is dropped. .

According to the present invention, since no seal is formed on the substrate when the liquid crystal is dropped, if the amount of the dropped liquid crystal deviates from the reference value, only the liquid crystal is collected without mixing the seal into the liquid crystal. can do.

According to a third aspect of the present invention, in the method for manufacturing a liquid crystal display panel according to the first aspect, the formation of the seal is performed on a substrate facing the substrate on which the liquid crystal is dropped. Features.

According to the present invention, since no seal is formed on the substrate when the liquid crystal is dropped, if the amount of the dropped liquid crystal deviates from the reference value, only the liquid crystal is collected without mixing the seal into the liquid crystal. can do.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display panel according to the first aspect, wherein the collected liquid crystal is reused.

According to the present invention, since the collected liquid crystal is reused, expensive liquid crystal is not wasted, so that the manufacturing cost can be reduced.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display panel according to the first aspect, wherein the substrate from which the liquid crystal is collected is reused.

According to the present invention, by reusing the substrate from which the liquid crystal has been collected, the substrate on which electrodes, TFTs, etc. are formed is not wasted, so that the manufacturing cost can be reduced.

According to a sixth aspect of the present invention, in the method of manufacturing a liquid crystal display panel according to the first aspect, the amount of the dropped liquid crystal is measured to be insufficient. In this case, the liquid crystal is not immediately collected, but after the insufficient amount is added and dropped, the liquid crystal drop amount is measured again.

According to the present invention, the dropping amount of the liquid crystal can be made closer to the reference value by measuring the dropping amount of the liquid crystal again after adding the insufficient amount and dropping.

According to a seventh aspect of the present invention, there is provided an apparatus for manufacturing a liquid crystal display panel, comprising: a dropping unit for dropping a required amount of liquid crystal on a substrate on which a seal is not formed; A measuring means for measuring, a judging means for comparing the drop amount of the liquid crystal measured by the measuring means with a reference value to judge pass / fail, and collecting and re-collecting the liquid crystal dropped when the judging means judges no. It is characterized by comprising a liquid crystal collecting means to be used, and a substrate collecting means to collect and reuse the substrate after collecting the liquid crystal by the liquid crystal collecting means.

According to the present invention, it is possible to provide an apparatus for manufacturing a liquid crystal display panel which is capable of easily reproducing a defective cell thickness and has excellent productivity.

[0021]

Embodiments of the present invention will be described below.

(Embodiment 1) FIG. 1 shows a flowchart of a method for manufacturing a liquid crystal panel according to the present invention.

The pre-treatment step (S11) is a step including cleaning and orientation treatment of the substrate on which the transparent electrode is formed, and pre-treats the substrate used for bonding.

Next, a required amount of liquid crystal is dropped on one of the substrates using a dispenser (S12). The drop amount of the liquid crystal is determined by the substrate size and the distance between the substrates, and the density is 1.0%.
In the case of a liquid crystal of 7 g / cm ³ , for example, the substrate size is 308
When the size is mm × 231 mm and the interval is 4.5 μm, the drop amount is 342 mg.

After the liquid crystal is dropped, the actual drop amount is measured (S13). As a means of measuring the amount of liquid crystal dripping,
(1) An image determination method for measuring the drop area and planar shape of a liquid crystal dropping substrate using a CCD area sensor or a CCD sign sensor. (2) The weight of a liquid crystal dropping syringe is measured, before and after dropping. Weight comparison method,
(3) Volume determination method for measuring the drop area and three-dimensional shape of the liquid crystal dropping substrate using a scanning laser displacement meter, (4)
The liquid crystal dropping amount is confirmed by measurement using a combination of (1) to (3).

Then, the drop amount is compared with the reference value (S1).
4) As a result, if it is an allowable amount, the spacer is sprayed (S1
7) and the other substrate on which the seal has been formed (S18) is sent to a bonding step and bonded at a predetermined interval. At the time of bonding, the substrate on which the liquid crystal is dropped is placed down, and the substrate with the spacers is brought to the upper side.The dispersed spacers adhere to the substrate by electrostatic force, van der Waals force, moisture adsorption force, etc. So they don't fall. It is also possible to use a spacer having a fixing agent to fix the substrate to the substrate in advance, or to use a substrate with ribs provided with irregularities on the substrate using a resin or the like.

When the drop amount is out of the reference value, the dropped liquid crystal is collected (S15) and the substrate is collected (S16) and reused. The liquid crystal can be collected by (1) a method of collecting the liquid crystal by suctioning with a suction nozzle, (2) a collecting method of inclining the substrate and pouring the liquid into a collecting port provided below, and (3) collecting and collecting the liquid crystal by an air knife. A collection method of flowing into a collection port provided on the outside, (4) a combination of (2) and (3),
(5) Collection is performed by a method of collecting liquid crystal by using an air knife and sucking the liquid crystal with a suction nozzle, and (6) a method of rotating the substrate and scattering it to a collection port provided on the outer periphery of the substrate by centrifugal force to collect the liquid crystal.

When collecting the liquid crystal, it is preferable that no seal is formed. If the seal is formed, it is difficult to reuse the collected liquid crystal because the sealant is mixed. Further, cleaning for regenerating the substrate becomes difficult. Therefore, it is preferable that the seal be formed on the substrate after the liquid crystal is dropped or on the substrate facing the substrate on which the liquid crystal is dropped. If the height of the seal is set to be about two to three times the cell thickness after the completion of the liquid crystal display panel, a seal is formed on the substrate side opposite to the substrate on which the liquid crystal is dropped. Also, it is possible to prevent the liquid crystal from sticking out of the seal at the time of bonding.

As described above, the amount of the dropped liquid crystal is measured,
By collecting the liquid crystal when it is below the standard value,
Since only a liquid crystal having an appropriate amount of dropped liquid crystal is used in the bonding step, a defective cell thickness can be prevented. Also,
By forming the seal on the substrate after the liquid crystal is dropped or on the substrate facing the substrate on which the liquid crystal is dropped, it becomes easy to collect the dropped liquid crystal and the substrate, and the collected liquid crystal and the substrate are recycled. Utilization can reduce manufacturing costs.

(Embodiment 2) FIG. 2 shows another flowchart of a method of manufacturing a liquid crystal panel according to the present invention.

The description of the same steps as in the first embodiment is omitted. The difference is that the liquid crystal drop amount is inspected, and if the drop amount is smaller than the reference value (S24), the process returns to the liquid crystal drop (S22) without collecting the liquid crystal and performs the drop again. In this method of dropping liquid crystal again, the dropping condition of the dispenser is adjusted according to the shortage of the dropping amount, and the liquid is dropped.
For example, the amount of drop can be adjusted by adjusting the drop time of the dispenser.

When the amount of dripping is too large than the reference value (S2
5) Since it is difficult to remove only the excess, the reuse is performed by collecting the liquid crystal (S26) and collecting the substrate (S27).

As described above, when the drop amount of the liquid crystal is small, the shortage is re-dropped without immediately collecting the liquid crystal, so that the probability that the drop amount becomes the reference value increases, and the yield can be increased. .

[0034]

As described above, the method and apparatus for manufacturing a liquid crystal display panel according to the present invention measure the amount of liquid crystal dropped and collect the liquid crystal when the amount of liquid crystal is out of the reference value, thereby obtaining the cell thickness. This has the effect of preventing defects.

The formation of the seal is performed on the substrate after the liquid crystal has been dropped, or on the substrate facing the substrate on which the liquid crystal has been dropped, so that the dropped liquid crystal and the substrate can be easily collected. .

Further, there is an effect that the manufacturing cost can be reduced by reusing the collected liquid crystal and substrate.

When the amount of the liquid crystal dropped is small, the shortage of the liquid crystal is not immediately collected and the insufficient amount is dropped again, so that the probability that the amount of the liquid drop becomes a reference value increases, and the effect of increasing the yield is obtained. Play.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a method for manufacturing a liquid crystal panel according to the present invention.

FIG. 2 is a flowchart illustrating a method of manufacturing another liquid crystal panel according to the present invention.

3A and 3B show a conventional method for manufacturing a liquid crystal panel, in which FIG. 3A is a schematic perspective view, and FIG. 3B is a schematic sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent electrode 2, 3 Substrate 4 Seal 5 Liquid crystal

Claims (7)

[Claims] 1. A liquid crystal drop bonding method in which a liquid crystal is dropped on one substrate before bonding two substrates constituting a liquid crystal display panel and the two substrates are bonded under reduced pressure. A method for manufacturing a liquid crystal display panel, comprising: measuring an amount of dropped liquid crystal; and collecting the dropped liquid crystal when the amount of dropped liquid crystal deviates from a reference value. 2. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the formation of the seal is performed on the substrate after the liquid crystal is dropped. 3. The method for manufacturing a liquid crystal display panel according to claim 1, wherein the formation of the seal is performed on a substrate facing the substrate on which the liquid crystal is dropped. 4. The method according to claim 1, wherein the collected liquid crystal is reused. 5. The method according to claim 1, wherein the substrate from which the liquid crystal is collected is reused. 6. As a result of measuring the amount of the dropped liquid crystal, when the amount of the dropped liquid crystal is insufficient, the liquid crystal is not immediately collected, but after the insufficient amount is added and dropped, the liquid crystal is dropped again. 2. The method according to claim 1, wherein the amount is measured. 7. A dropping means for dropping a required amount of liquid crystal on a substrate on which a seal is not formed, a measuring means for measuring an amount of liquid crystal dropped by the dropping means, and a liquid crystal measured by the measuring means. Judgment means for comparing the dropping amount with a reference value to determine pass / fail, a liquid crystal collection means for collecting and reusing the liquid crystal dropped when the judgment means judges no, and a liquid crystal being collected by the liquid crystal collection means. An apparatus for manufacturing a liquid crystal display panel, comprising: a substrate collecting means for collecting and reusing a collected substrate.