JP4902176B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

  The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a liquid crystal display device manufactured by a liquid crystal dropping bonding method.

  A liquid crystal display device is manufactured by, for example, manufacturing a cell by bonding a thin film transistor (TFT) array substrate and a color filter substrate, and encapsulating a liquid crystal material inside the cell.

  As a method for enclosing the liquid crystal material in the cell, a vacuum injection method has been well known. For example, Patent Document 1 discloses a technique for injecting a liquid crystal material into a plurality of cells at once.

  Here, in a general vacuum injection method, the space (inside the cell) sandwiched between two substrates (the TFT array substrate and the color filter substrate) having a liquid crystal injection port is evacuated, and the liquid crystal injection port is liquid crystal. After contacting the material, the liquid crystal material is injected into the cell by returning the atmosphere to atmospheric pressure.

Specifically, first, the TFT array substrate and the color filter substrate are bonded together by a seal portion formed in an open pattern frame shape having a liquid crystal injection port, and then an unnecessary portion of each substrate is divided to obtain a liquid crystal injection port. A cell is exposed. Next, the manufactured cell is attached to the injection cassette so that the liquid crystal injection port faces downward. The cassette with the cells attached and the liquid crystal dish containing the liquid crystal material are accommodated in the vacuum chamber, and the inside of the chamber is vacuum degassed to about 1.0 × 10 ⁻³ Pa. After bringing the material into contact with the liquid crystal inlet of the cell, the liquid crystal material is injected into the cell by returning the inside of the chamber to atmospheric pressure. Furthermore, a liquid crystal material is sealed by applying a sealing resin to the liquid crystal inlet and curing the resin. In this way, the liquid crystal material is injected into the cell.

  When a liquid crystal material is injected into a small cell, first, as shown in FIG. 7, a TFT array substrate 105 and a counter substrate 106 each having a plurality of structural units (cell formation portions a to i) are disposed. Are bonded together to form a substrate 109a. Next, as shown in FIG. 8, the substrate 109a is divided into strips so that, for example, the liquid crystal inlets of the three structural units of the cell forming portions a, b, and c are arranged on one side, A substrate 109b is produced. Furthermore, the side of the strip substrate 109b where the liquid crystal injection ports are arranged is immersed in a liquid crystal material, and the liquid crystal material is simultaneously injected into each cell of the strip substrate 109b, thereby simplifying and ensuring the handling of the cells during the injection. I have to. Then, as shown in FIG. 9, the strip substrate 109b is divided into each cell, and the liquid crystal display device (cell) 109c is manufactured.

  However, the injection of the liquid crystal material by the vacuum injection method as described above has a problem that the injection time becomes longer as the liquid crystal display device becomes larger.

Therefore, in recent years, liquid crystal material is injected by a liquid crystal dropping bonding method instead of the vacuum injection method. In this liquid crystal dropping bonding method, before the TFT array substrate and the color filter substrate are bonded together, a liquid crystal material is dropped on the surface of one substrate, and the TFT array substrate and the color filter substrate are formed in a closed pattern frame shape. In this method, the liquid crystal material is spread in the cell gap by bonding through the seal portion (see, for example, Patent Documents 2, 3, and 4). According to this liquid crystal dropping and bonding method, the injection time can be shortened compared to the above-described vacuum injection method, the loss of the liquid crystal material can be reduced, and steps such as sealing the liquid crystal injection port can be omitted. Can do.
JP-A-11-147612 Japanese Patent No. 3084975 JP-A-3-246514 JP-A-5-281562

  By the way, the glass substrate constituting the TFT array substrate and the color filter substrate tends to increase in size in recent years. Since a plurality of structural units each serving as a cell are formed on the enlarged glass substrate (mother substrate), the bonded mother substrate (TFT array substrate and color filter substrate) is divided into structural units. Therefore, a plurality of cells are often manufactured simultaneously at the same time.

  However, in the conventional liquid crystal dropping and laminating method, the liquid crystal material is dropped on each constituent unit in one mother substrate, so if there is a problem such as disconnection in the seal portion of a certain constituent unit However, the liquid crystal material is dropped on the defective structural unit in the same manner as other structural units having no defective. If this happens, not only will defective cells be produced, but liquid crystal material will leak around the defective cells, and when it will be divided into structural units later, the liquid crystal material will adhere to the production equipment. There is also a risk of reducing the efficiency.

  The present invention has been made in view of such points, and the object of the present invention is to reduce the production efficiency due to defective cells when a plurality of liquid crystal display devices are manufactured collectively by the liquid crystal dropping bonding method. It is to suppress.

  In order to achieve the above object, according to the present invention, a liquid crystal material is dropped on each cell forming portion other than a defective cell forming portion on a substrate in which a plurality of cell forming portions each serving as a cell are arranged in a matrix. It is what you do.

  Specifically, in the method for manufacturing a liquid crystal display device according to the present invention, a pair of substrates in which a plurality of cell forming portions each serving as a cell are arranged in a matrix is manufactured, and each of the above-described substrates is formed on one of the pair of substrates. A substrate manufacturing process for forming a frame-shaped seal portion for enclosing a liquid crystal material for each cell forming portion, and in each of the manufactured substrates, a defective cell forming portion is detected and one of the pair of substrates is detected. A liquid crystal dropping step of dropping the liquid crystal material on each of the other cell forming portions excluding the detected defective cell forming portion, and a substrate for bonding the substrate on which the liquid crystal material is dropped and the other of the pair of substrates A bonding step and a dividing step of dividing the bonded pair of substrates for each cell forming portion, and in the liquid crystal dropping step, a mother substrate constituting at least one of the pair of substrates Goods data, failure film formation in each cell forming unit, or and detecting a cell forming part of the defect by patterning defects in each cell forming portion.

  According to the above method, in the liquid crystal dropping step, delivery data of a mother substrate constituting at least one of a pair of substrates (for example, delivery data of a glass substrate or a color filter substrate) in each substrate produced in the substrate production step. Detecting a defective cell formation portion by a film formation failure in each cell formation portion or a patterning failure in each cell formation portion, and one of a pair of substrates in which a plurality of cell formation portions are arranged in a matrix Since the liquid crystal material is dropped on each of the other cell forming portions except the detected defective cell forming portion, the liquid crystal material is not dropped on the defective cell forming portion. Therefore, after that, a defective cell is not produced as it is through the substrate bonding step and the dividing step, so that a reduction in production efficiency is suppressed. Therefore, when a plurality of liquid crystal display devices (cells) are manufactured collectively by the liquid crystal dropping bonding method, a decrease in production efficiency due to defective cells is suppressed.

  After the pair of bonded substrates are sandwiched between a pair of polarizing plates, an inspection process may be provided in which light is transmitted through each of the cell forming portions and the quality of each of the cell forming portions is determined.

According to the above method, since the liquid crystal material is not encapsulated in the cell composed of the defective cell formation portion, the light transmission behavior is different from the cell composed of the normal cell formation portion encapsulated with the liquid crystal material. Therefore, it is possible to easily determine the quality of the cell composed of each cell forming portion by transmitting light to each cell forming portion through the polarizing plate .

  According to the present invention, the liquid crystal material is dropped on each of the other cell forming portions except for the defective cell forming portion on the substrate in which a plurality of cell forming portions each serving as a cell are arranged in a matrix. When a plurality of liquid crystal display devices (cells) are manufactured collectively by the alignment method, it is possible to suppress a decrease in production efficiency due to defective cells.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment.

Embodiment 1 of the Invention
1 to 5 show Embodiment 1 of a method for manufacturing a liquid crystal display device and a liquid crystal dropping device according to the present invention.

  First, a liquid crystal dropping apparatus will be described with reference to FIGS. Here, FIG. 1 is a schematic cross-sectional view of the liquid crystal dropping device 20, and FIG. 2 is a schematic cross-sectional view of the syringe 10 constituting the liquid crystal dropping device 20.

  As shown in FIG. 1, the liquid crystal dropping device 20 includes a stage 2 on which a substrate 6 to be treated is adsorbed and fixed, a base 1 on which the stage 2 is placed, and a syringe installed above the stage 2. 10 (liquid crystal dropping unit), a frame 3 for fixing the syringe 10 to the base unit 1, and a dropping control unit 7 for controlling operations of the stage 2 and the syringe 10.

  The stage 2 is provided with a linear guide or the like so that the surface of the stage 2 can be slid in the horizontal direction (XY direction) while the surface of the substrate 6 is attracted to the surface by an electrostatic chuck or the like.

  As shown in FIG. 2, the syringe 10 has a discharge port on the bottom surface, a container part 11 filled with a liquid crystal material 15 inside, and attached from the top surface of the container part 11 to the inside, and a needle at the lower end. An air cylinder 13 having a valve 14 and a pressurizing valve 12 attached to the upper surface of the container part 11 are provided. Here, the needle valve 14 is configured to fit into the discharge port of the container portion 11. When discharging the liquid crystal material 15, a certain pressure is applied to the inside of the container portion 11 by the pressurizing valve 12, and the needle valve 14 is moved up and down by the air cylinder 13. The liquid crystal material 15 is discharged (dropped) one by one.

  Next, a manufacturing system 50 using the liquid crystal dropping device 20 having the above configuration will be described with reference to FIG.

  The manufacturing system 50 includes a delivery data input unit 31, a TFT array substrate manufacturing device 32, a TFT array substrate inspection device 33, an alignment film forming device 34, a seal portion forming device 35, a seal portion inspection device 36, A liquid crystal dropping device 20, a bonding device 37, a seal portion curing device (not shown), a cutting device 38, a polarizing plate attaching device (not shown), a lighting inspection device 39, a delivery data input unit 31, And a production line host computer 40 that is connected to each of the devices 20 and 32 to 39 and manages the entire system.

  Next, a method of manufacturing a liquid crystal display device (cell) using the manufacturing system 50 having the above configuration will be described with reference to the flowchart of FIG.

  First, in St 11, delivery data including a substrate ID number and positional information of a defective part on the delivered glass substrate is taken into the production line host computer 40 via the delivery data input unit 31.

  In subsequent St12, a plurality of cell forming portions each serving as a cell are arranged in a matrix form on the delivered glass substrate by the TFT array substrate manufacturing apparatus 32 using a known method. A substrate is produced. Here, in each cell formation part of the TFT array substrate, for example, a plurality of pixel electrodes provided in a matrix, a thin film transistor (TFT) provided for each pixel electrode, and a space between the pixel electrodes are mutually parallel. And a plurality of source lines that cross each gate line and extend between the pixel electrodes in parallel with each other.

  In subsequent St13, the TFT array substrate inspection apparatus 33 performs an appearance inspection, an electro-optical inspection, and the like on the manufactured TFT array substrate. Here, the appearance inspection is to optically inspect the wiring pattern with a CCD camera or the like, and the electro-optical inspection is to install a modulator (electro-optical element) so as to face the TFT array substrate. A wiring pattern is electro-optically inspected by applying a voltage between the TFT array substrate and the modulator and making light incident and capturing a change in luminance of the light with a CCD camera or the like. Then, inspection data including position information of a defective portion due to a defect such as disconnection of the wiring pattern is taken into the production line host computer 40.

  In subsequent St14, the surface of the TFT array substrate is washed, polyimide resin is printed by the alignment film forming device 34, and then baked and rubbed in one direction with a rotating cloth to form an alignment film. To do.

  Further, in order to regulate the cell gap, for example, spacers made of plastic beads or the like are dispersed on the TFT array substrate. In addition, when using the board | substrate in which the photo spacer was formed as a color filter (CF) board | substrate mentioned later, the process of spraying the said spacer becomes unnecessary.

  In St21, the delivery data including the substrate ID number and the location information of the defective part on the delivered color filter (CF) substrate is taken into the host computer 40 via the delivery data input unit 31. Here, each cell forming portion of the color filter substrate is a substrate in which, for example, an R / G / B colored layer, a common electrode, and the like are sequentially laminated.

  In subsequent St22, the surface of the color filter substrate is washed, and polyimide resin is printed by the alignment film forming device 34, and then baked and rubbed in one direction with a rotating cloth to form an alignment film. To do.

  In subsequent St23, a seal portion forming device 35 forms a frame-shaped seal portion for each cell forming portion of the color filter substrate on which the alignment film is formed. Specifically, for example, the inside of a syringe provided with a nozzle having a minute hole of 0.15 mm or more and 0.45 mm or less is filled with a sealing material, and the distance between the color filter substrate and the nozzle tip is maintained at about 30 μm. Then, by discharging the filled sealing material from the nozzle, the color filter substrate or the nozzle is moved to draw the sealing material into a closed pattern of a frame shape (rectangular shape) with a single stroke. , Forming a seal part. Further, the seal portion is made of, for example, a combined resin of UV curing and heat curing.

  In subsequent St24, the seal portion inspection device 36 inspects the seal portion formed on the color filter substrate for disconnection. In the disconnection inspection of the seal portion, the disconnection is detected by passing the color filter substrate on which the seal portion is formed under the illumination device and the inspection camera and reading and processing the image at that time. Then, the inspection data including the position information of the disconnection of the seal portion is registered in the production line host computer 40. Here, an epi-illumination device using a light source such as a halogen lamp or a line illumination device of about 25 W is used as the illumination device, and a CCD camera or line sensor having a focal length capable of recognizing a height of 50 μm is used as the inspection camera. Is used. Moreover, the seal | sticker part test | inspection apparatus 36 is comprised so that it may be judged that the seal | sticker part is disconnected, for example, when the part which the one end and other end of a seal | sticker part overlap is lost.

  In subsequent St25, as shown in FIGS. 1, 2, and 5, the cell forming portions a and b of the color filter substrate (the substrate to be processed) 6 on which the seal portion 4 is formed by the liquid crystal dropping device 20 are provided. , C, d, e, g, h and i, the liquid crystal material 15 is dropped from the syringe 10. Specifically, based on the position information (for example, the position information on the disconnection of the seal portion) of the defective portion taken into the production line host computer 40, the dropping control unit 7 controls each cell forming unit on the color filter substrate 6. a to i, cell forming portions a, b, c, d, e, g, h and i in which the seal portion 4 is normally formed and the liquid crystal material should be dropped, and a liquid crystal material having a disconnection in the seal portion 4 The liquid crystal material 15 is dropped only on the cell forming portions a, b, c, d, e, g, h, and i by appropriately operating the stage 2 and the syringe 10 by dividing into cell forming portions f that should not be dropped. .

  In subsequent St31, the bonding device 37 bonds the TFT array substrate on which the alignment film is formed in St14 and the color filter substrate on which the liquid crystal material is dropped in St25 under vacuum. Specifically, the TFT array substrate and the color filter substrate 6 are accommodated in the processing chamber constituting the bonding apparatus 37, the inside of the processing chamber is evacuated, and then the TFT array substrate and the color filter substrate 6 are filled. And paste together. Thereafter, nitrogen gas or the like is supplied to the inside of the processing chamber, and the inside of the processing chamber is restored to atmospheric pressure. At this time, the bonded substrate is released to the atmosphere, so that the surfaces of both the TFT array substrate and the color filter substrate are pressed by atmospheric pressure, and the seal portion 4 is crushed to a predetermined thickness. And the color filter substrate have a predetermined distance.

  Further, the seal portion of the bonded substrate is cured by a seal portion curing device including a UV irradiation device and a thermal baking device. Specifically, the seal portion 4 is temporarily cured by irradiation with UV light from a UV irradiation device, and then the temporarily cured seal portion 4 is finally cured by heating with a thermal baking device.

  In subsequent St32, the bonded substrate on which the seal portion 4 has been cured is cut into cells by the cutting device 38 for each cell.

  Then, a polarizing plate is affixed on both the front and back surfaces of each divided cell by a polarizing plate affixing device.

  In St33 to be performed lastly, the lighting inspection device 39 performs a lighting inspection on the cell to which the polarizing plate is attached. Specifically, for example, a gate inspection signal with a bias voltage of −5 V, a period of 16.7 msec, a pulse width of 50 μsec and a pulse voltage of +10 V is input to each gate line on the TFT array substrate constituting the cell, and all TFTs are connected. Turn on. Further, a source inspection signal having a potential of ± 2 V whose polarity is inverted every 16.7 msec is inputted to each source line on the TFT array substrate, and a charge corresponding to ± 2 V is written to the pixel electrode via each TFT. . At the same time, a common electrode inspection signal having a direct current potential of -1 V is input to the common electrode on the color filter substrate constituting the cell. At this time, a voltage is applied to the liquid crystal capacitance formed between the pixel electrode and the common electrode, and a normal pixel is turned on. Further, since the liquid crystal material 15 is not sealed in the cell (cell forming portion f) in which the seal portion 4 is disconnected, each normal cell forming portion a, b, c, d, e in which the liquid crystal material 15 is sealed. , G, h, and i have different light transmission behavior and do not light up and invert. Therefore, the quality of each cell can be easily determined by transmitting light to each cell via the polarizing plate. Therefore, a defective cell (cell formation part f) can be easily found in the lighting inspection.

  The liquid crystal display device (cell) 9 is manufactured as described above. As shown in FIG. 6, the liquid crystal display device 9 includes a TFT array substrate 5 and a color filter substrate 6 that are arranged to face each other, and a seal portion 4 that is provided in a frame shape between the substrates 5 and 6. And a liquid crystal layer made of a liquid crystal material 15 provided inside the seal portion 4 between both the substrates 5 and 6, and a polarizing plate 8 is attached to each surface of the TFT array substrate 5 and the color filter substrate 6. Yes.

  As described above, according to the manufacturing method of this embodiment, in the liquid crystal dropping process, in the color filter substrate 6 in which the seal part 4 is formed in the color filter substrate manufacturing process (seal drawing process), the seal part 4 is disconnected. The generated defective cell forming portion f is detected, and each of the other cell forming portions a, b, c, d, e, g excluding the detected defective cell forming portion f is detected with respect to the color filter substrate 6. Since the liquid crystal material 15 is dropped on h, i, the liquid crystal material 15 is not dropped on the defective cell forming portion f. Therefore, a defective cell (cell forming portion f) is not produced as it is, and the liquid crystal material 14 does not leak from the disconnected portion of the seal portion 4, and the leakage of the liquid crystal material 15 in the peripheral portion is suppressed. Therefore, a decrease in production efficiency can be suppressed. Therefore, when a plurality of liquid crystal display devices (cells) are manufactured collectively by the liquid crystal dropping bonding method, the production efficiency due to defective cells can be reduced.

  When the liquid crystal material is injected into the plurality of strip-shaped cells shown in FIGS. 7 to 9 by the vacuum injection method, the liquid crystal material is not selectively injected into a specific cell f having a defect in the strip substrate 109b. It is technically difficult to do so.

<< Other Embodiments >>
In the first embodiment, the disconnection generated in the seal portion 4 is detected as a defect in the cell formation portion, and the liquid crystal material is dropped on each cell formation portion other than the cell formation portion where the disconnection is detected. Although the present invention has been exemplified, the present invention detects defects such as film formation defects and patterning defects in each cell forming part in the manufacturing process, or detects defects such as foreign matter contamination and resist defects in the delivered mother board. Or the dropping of the liquid crystal material may be controlled.

  In each of the above embodiments, an active matrix drive type liquid crystal display device has been exemplified. However, the present invention can also be applied to a passive matrix drive type liquid crystal display device.

  As described above, the present invention can suppress a decrease in production efficiency due to defective cells when a plurality of liquid crystal display devices are manufactured collectively by the liquid crystal dropping bonding method. Useful for.

1 is a schematic cross-sectional view of a liquid crystal dropping device 20 according to Embodiment 1. FIG. 3 is a schematic cross-sectional view of a syringe 10 that constitutes the liquid crystal dropping device 20. FIG. 1 is a block diagram showing a manufacturing system 50 according to Embodiment 1. FIG. 4 is a flowchart showing a process flow in the method for manufacturing the liquid crystal display device according to the first embodiment. It is a perspective view of the color filter substrate 6 after dropping the liquid crystal material 15. 2 is a schematic cross-sectional view of a liquid crystal display device 9 according to Embodiment 1. FIG. It is a perspective view of the conventional 109a. It is a perspective view of the conventional strip board | substrate 109b. It is a perspective view of the conventional cell 109c.

a, b, c, d, e, f, g, h, i Cell forming portion 5 TFT array substrate 6 Color filter substrate (substrate to be processed)
7 Dropping control unit 8 Polarizing plate 9 Liquid crystal display device (cell)
10 Syringe (liquid crystal dropping part)
11 Syringe body 15 Liquid crystal material 20 Liquid crystal dropping device

Claims (2)

A pair of substrates in which a plurality of cell forming portions each serving as a cell are arranged in a matrix are formed, and a frame shape for enclosing a liquid crystal material in each of the cell forming portions on one of the pair of substrates. A substrate manufacturing process for forming a seal portion;
In each of the manufactured substrates, a defective cell formation portion is detected, and the liquid crystal material is dropped on each of the other cell formation portions except for the detected defective cell formation portion on one of the pair of substrates. A liquid crystal dropping step;
A substrate bonding step of bonding the substrate on which the liquid crystal material is dropped and the other of the pair of substrates;
A dividing step of dividing the bonded pair of substrates for each cell forming part,
In the liquid crystal dropping step, the defective cell formation portion is detected by delivery data of a mother substrate constituting at least one of the pair of substrates, a film formation failure in each cell formation portion, or a patterning failure in each cell formation portion. A method for manufacturing a liquid crystal display device. In the manufacturing method of the liquid crystal display device described in Claim 1,
A liquid crystal, comprising: an inspection step in which light is transmitted through each cell forming portion and the quality of each cell forming portion is determined after the pair of bonded substrates are sandwiched between a pair of polarizing plates. Manufacturing method of display device.

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