JP4203027B2 - 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 method for manufacturing a liquid crystal display device in which liquid crystal is sealed between two substrates using a dropping injection method.

  Among liquid crystal display devices, active matrix color liquid crystal display devices using thin film transistors (TFTs) as switching elements are attracting attention as a mainstream of flat panel displays, and manufacturing methods capable of mass production with high quality are required.

  The manufacturing process of the liquid crystal display device is roughly divided into an array process for forming a wiring pattern, a switching element (such as an active matrix type) such as a thin film transistor (TFT) on a glass substrate, an alignment process, a spacer arrangement, and a counter A cell process for encapsulating liquid crystal between glass substrates, and a module process for mounting a driver IC and mounting a backlight.

  Among these, in the spacer arrangement process performed in the cell process, a method of dispersing a large number of beads-like spherical particles on the substrate surface and a method of forming columnar spacers on one or both of the opposing glass substrates instead of the spherical particles Either of these is used. The spacer formed by these methods is used to keep the cell gap (cell thickness) between the opposing glass substrates constant.

  In the liquid crystal injection process, the array substrate on which the TFT is formed and the counter substrate on which the color filter (CF) or the like is formed are bonded to each other through the sealant, and then the sealant is cured, A method (vacuum injection method) is used in which the liquid crystal and the substrate are placed in a vacuum chamber, the injection port opened in the sealing agent is immersed in the liquid crystal, and then the pressure in the chamber is returned to atmospheric pressure so that the liquid crystal is sealed between the substrates. .

  On the other hand, in recent years, for example, a prescribed amount of liquid crystal is dropped on the substrate surface in the frame of the main seal formed in a frame shape around the array substrate, and the liquid crystal is sealed by bonding the array substrate and the counter substrate in a vacuum. The injection method has attracted attention. Compared with the vacuum injection method that has been widely used in the manufacture of conventional liquid crystal display panels, this dripping injection method can significantly reduce the amount of liquid crystal material used first, and secondly shorten the liquid crystal injection time. From the above, application in the liquid crystal display panel manufacturing process is strongly desired because it has the possibility of reducing the cost of manufacturing the liquid crystal display panel and improving the mass productivity.

  In the dropping injection method, a predetermined amount of liquid crystal is dropped onto a substrate using a liquid crystal dropping injection device (dispenser). However, there is a problem that the amount of liquid crystal sealed between the two substrates to be bonded is excessive or insufficient due to the dropping accuracy of the dispenser and the variation in the cell gap. If the amount of liquid crystal sealed is insufficient, so-called bubbles are formed. Further, when the amount of sealed liquid crystal is large, display unevenness occurs. Any panel that has these bubbles or display irregularities is a defective product.

  In the method of securing the cell gap with the columnar spacers, resin pillars having a height of several microns are formed on the substrates, and thus the pillar height (film thickness) is likely to vary between the substrates. If the support height variation between the substrates is large, if the liquid crystal dropping amount set for a certain substrate is applied as it is to another substrate, the amount of liquid crystal is too large or too small. Even in a multi-planar substrate in which a plurality of liquid crystal display panels are formed from a single glass substrate, there is a possibility that variations in the column height occur between the display panel formation regions. For this reason, the optimal liquid crystal dropping amount in the multi-faced glass substrate may be different for each display panel forming region.

  In addition, in the method of securing the cell gap by bead dispersion, spherical particles having almost the same size are used, but the optimum liquid crystal sealed between two substrates to be bonded depending on the number of beads dispersed (dispersion density). Since the amount is different, the amount of dropped liquid crystal may be excessive or insufficient as described above.

  An object of the present invention is to provide a method for manufacturing a liquid crystal display device capable of dropping liquid crystal with an optimum dropping amount for each substrate in a dropping injection method.

  In the method of manufacturing a liquid crystal display device in which liquid crystal is injected by dropping liquid crystal on a substrate and bringing the liquid crystal dropping surface side of the substrate to face the counter substrate and returning from bonding to atmospheric pressure in a vacuum, An optimal liquid crystal amount sealed between two substrates to be bonded is predicted based on a state of a substrate on which liquid crystal is dropped, and the dropped liquid crystal amount is controlled based on the predicted value. This is achieved by the manufacturing method.

  In the method for manufacturing a liquid crystal display device according to the present invention, the optimum amount of liquid crystal is predicted by measuring a height of a columnar spacer provided to determine a cell thickness between the two substrates. To do.

  In the method for manufacturing a liquid crystal display device according to the present invention, the optimum amount of liquid crystal is predicted by measuring a distribution density of spherical particles dispersed to determine a cell thickness between the two substrates. To do.

  In the method for manufacturing a liquid crystal display device according to the present invention, the optimum amount of liquid crystal is predicted for each panel formation region in a multi-sided substrate.

  In the method for manufacturing a liquid crystal display device of the present invention, the optimum amount of liquid crystal is predicted in parallel with a step of forming a main seal on one of the two substrates.

  In the method for manufacturing a liquid crystal display device according to the present invention, the optimum amount of liquid crystal is predicted on a substrate stage on which the liquid crystal is dropped.

  According to the present invention, in the method for manufacturing a liquid crystal display device using the dropping injection method, the column height of the columnar spacer can be measured, and the optimum amount of liquid crystal can be dropped based on the measured value. Moreover, when spraying spherical particles, the spraying density can be measured and the optimum amount of liquid crystal can be dropped based on the measured density. Therefore, according to the present invention, an optimal liquid crystal amount can be dropped for each liquid crystal display panel, so-called bubbles due to insufficient liquid crystal amount and display unevenness due to excessive liquid crystal amount can be eliminated, and stable mass production becomes possible.

  As described above, according to the present invention, an optimal amount of liquid crystal can be dropped for each liquid crystal display panel, so that gap defects due to so-called bubbles and excessive liquid crystals can be eliminated, and stable mass production becomes possible. Therefore, according to the present invention, defects due to the dropping injection process can be reduced, and a yield equivalent to the current vacuum injection process can be achieved. In addition, the cost can be reduced by simplifying the process by applying the dropping injection method.

  A method of manufacturing a liquid crystal display device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a configuration example of a CF substrate used in the method of manufacturing a liquid crystal display device according to the present embodiment, and shows a CF substrate used in an MVA (Multi-domain Vertical Alignment) liquid crystal display device. This CF substrate is an example of a spacerless CF provided with a column that also serves as a spacer by further overlapping a protruding structure when forming a black matrix (BM) by resin superposition.

  In FIG. 1A, the shaded portions are portions where color resins R, G, and B are formed and function as color filters. The other portions function as a black matrix BM by overlapping color resins. Protrusions 20 and 20c are formed thereon. FIG. 1B is a cross-sectional view taken along the line A-A ′ of FIG. As shown in FIG. 1B, the color resins R, G, and B are formed on the glass substrate 22, but the color matrix of two colors is overlapped between the pixels in the horizontal direction to form the black matrix BM. FIG. 1C is a cross-sectional view taken along the line B-B ′ of FIG. In the portion excluding the lattice point, two colors of resin are superimposed to form a black matrix BM. However, at the lattice point, three colors of color resin are superimposed, and furthermore, a protrusion 20c that is a part of the protrusion 20 is overlapped. The portion functions as a columnar spacer (post).

  Next, a schematic configuration of the flanger pump type dispenser used in the method of manufacturing the liquid crystal display device according to the present embodiment will be described with reference to FIG. In FIG. 2, the dispenser 30 has a hollow cylindrical housing 32 and is used with the central axis of the cylindrical shape substantially in the vertical direction. An elongated rod-like piston 34 is supported in the housing 32 so as to be movable in the vertical direction along a cylindrical central axis. The tip of the piston 34 can move inside the nozzle 36 provided at the vertically lower end of the housing 32. From the opening in the side wall near the nozzle 36 of the housing 32, the liquid crystal in the liquid crystal storage container 38 can flow into the nozzle 36 along the arrow shown in the figure via the supply pipe 40. The liquid crystal that has reached the inside of the nozzle 36 is dripped from the nozzle 36 depending on the amount of movement of the tip of the piston 34 at the nozzle 36 and is not discharged from the nozzle 36 due to the surface tension of the liquid crystal itself unless it receives external force. It is like that.

  Two air inlets 42 and 44 provided in the vertical direction are attached to the side wall of the air chamber in the housing 32. A partition wall 46 that separates the air chamber into two is fixed to the piston 34. The partition wall 46 can slide on the air chamber wall between the air inlets 42 and 44 together with the piston 34. Accordingly, when the air flows into the air chamber from the air inlet 42, the partition wall 46 receives pressure downward and moves downward. When the air flows into the air chamber from the air inlet 44, the partition wall 46 receives pressure upward and moves upward. Move to. Thereby, the piston 34 can be moved by a predetermined amount in the vertical direction.

  The air inlets 42 and 44 are connected to a pump controller 48. The pump controller 48 sucks air and feeds air into one of the air inlets 42 and 44 at a predetermined timing.

  The dispenser 30 configured as described above drops 5 mg of liquid crystal 50 per shot. The liquid crystal dripping amount per shot can be adjusted by controlling the vertical movement amount of the piston 34 using a micro gauge 52 fixed to the piston 34 protruding above the housing 32. It is like that.

  Next, an outline of the dropping injection method used in the method of manufacturing the liquid crystal display device according to the embodiment of the present invention will be described with reference to FIG. First, as shown in FIG. 3A, for example, liquid crystal 62 is dropped from a dispenser 30 (not shown) onto a plurality of locations on the substrate surface of the array substrate 60 on which switching elements such as TFTs are formed. Next, a common substrate or color filter is formed in the display area, and a CF substrate 66 that is a counter substrate coated with a UV sealant 64 that is cured by ultraviolet (UV) irradiation is provided around the display area. To be attached to the array substrate 60. This step is performed in a vacuum. Next, when the bonded substrate is returned to the atmosphere, as shown in FIG. 3B, the liquid crystal 62 between the bonded array substrate 60 and the CF substrate 66 is diffused by atmospheric pressure. Next, as shown in FIG. 3C, the UV light 72 is irradiated to the sealant 64 while moving the UV light source 70 in the moving direction 68 along the application region (main seal) of the sealant 64, and the sealant 64. Is cured. As a result, a liquid crystal display panel is obtained in which the cell gap (cell thickness) between the array substrate 60 and the CF substrate 66 is secured by the plurality of columns 20c shown in FIG.

  Here, the relationship between the cell thickness and the optimum dripping amount is as shown in FIG. 4, for example. FIG. 4 shows a liquid crystal display panel having a frame portion diagonal length of 15 inches and a cell thickness of 5 μm. In the subsequent drawings, the liquid crystal display panel will be described as an example. FIG. 4 shows the range of the optimum drop amount and the excess or deficiency of the liquid crystal amount by taking the drop amount (mg) of the liquid crystal on the horizontal axis, and shows that 250 mg shown in the middle of the figure is the optimum drop amount. Yes. The drop amount margin (optimum drop amount range) 200 in the liquid crystal display panel is ± 2.0% of the optimum drop amount, and is in the range of 245 mg to 255 mg. In the range 202 where the dripping amount is 245 mg or less, the amount of liquid crystal is insufficient, so-called bubbles are generated, resulting in a defective panel. In addition, in the range 204 where the dripping amount exceeds 255 mg, excess liquid crystal is pushed to the surrounding frame portion, causing display unevenness due to an increase in the cell thickness of the frame portion, resulting in a defective panel.

  FIG. 5 shows the relationship between the column height of the column spacer of the liquid crystal display panel and the optimum amount of liquid crystal. In FIG. 5, the horizontal axis represents the column height (μm), and the vertical axis represents the optimum amount of liquid crystal (mg). As shown in FIG. 5, when the column height varies within a range of ± 0.2 μm centering on 5 μm, the optimum liquid crystal amount varies within a range of ± 10 mg centering on 250 mg.

  As can be seen from the comparison with FIG. 4, in the case of a 15-inch panel, when the cell thickness is 5 μm, the optimum drop amount range is obtained when the column height is within the range of 5 ± 0.1 μm. Actually, the variation in the height of the support is within ± 0.1 μm within the same lot. However, in the case of different lots depending on the film forming conditions, a variation of ± 0.2 μm may occur. In addition, in the case of multi-chamfering in which a plurality of panels are formed from a single glass substrate, the column spacers formed in each panel formation region on the glass substrate have a column height difference of ± 0.1 μm between the panel formation regions. Can be.

  The range of the optimum dripping amount with respect to the difference in the column height is as shown in FIG. 6, for example. The horizontal axis of FIG. 6 represents the dripping amount (mg). In FIG. 6, the optimum dropping range 210 when the column height is 5 μm is 245 mg to 255 mg. This is the same as the optimum drop amount range 200 shown in FIG. On the other hand, the optimum dripping range 212 when the column height is 4.9 μm is 240 to 250 mg. Moreover, the optimal dripping range 214 when the column height is 5.1 μm is 250 to 260 mg.

  Assuming that the drop amount of the liquid crystal is set for a column height of 5 μm, if the column column height on which the liquid crystal is actually dropped is 4.9 μm or 5.1 μm as shown in FIG. Such a problem arises. That is, when a liquid crystal in a range (indicated by the arrow 216) exceeding the maximum allowable drop amount of 250 mg is dropped onto the substrate in the optimum drop range 212, a liquid crystal excess occurs. Alternatively, when a liquid crystal in a range smaller than the minimum allowable drop amount of 250 mg (indicated by an arrow 218) is dropped onto the substrate in the optimum drop range 214, a shortage of liquid crystal occurs.

  Thus, a defect occurs when the dripping amount differs by 2.0% or more with respect to the column height. In other words, if the column height differs by 0.1 μm, a 2% deviation occurs for a cell thickness of 5 μm. If the liquid crystal drop amount is fixed assuming that the cell thickness is 5 μm, there is no margin to absorb the variation in the column height of each substrate, and the liquid crystal drop amount is caused by other factors such as a dispenser. If it fluctuates, panel failure will occur.

  Therefore, in this embodiment, in the dropping injection process described with reference to FIG. 3, the column height of the columnar spacer is measured in advance, and the liquid crystal dropping amount can be controlled based on the measured value.

  FIG. 7 illustrates a method for measuring strut height. FIG. 7 shows a case of two chamfering in which two liquid crystal display panels 82 are manufactured from one glass substrate 80. For example, two CF substrates 82 on which columnar spacers are formed are A surface and B surface as shown in the figure, and each of the A surface and B surface has a plurality of points (in the example shown, five places from 1 to 5). The column height is measured with a laser displacement meter 84 to obtain an average value. The CF substrate surface has already been subjected to a predetermined alignment process.

  Next, a heat combined type UV sealant is applied to the TFT substrate side after the alignment treatment. Next, the amount of liquid crystal dropped on the TFT substrate side is controlled based on the column height on the CF substrate side measured in advance by the method shown in FIG.

  For liquid crystal dropping, two dispensers are prepared as shown in FIG. One dispenser 90 is the same as that described in FIG. 2, and is adjusted to drop 5 mg of liquid crystal per shot. The other dispenser 92 has the same structure as the dispenser 90, but is adjusted so as to drop 2 mg of liquid crystal per shot by adjusting the micro gauge 52.

  As shown in FIG. 8, the glass substrate 94 on which the TFT substrate is formed also has a two-chamfered configuration in which two TFT substrates 96 are obtained, like the glass substrate 80 for CF substrate formation (see FIG. 7). . In the region 82 where each TFT substrate is formed, a main seal 98 is formed by a UV sealant applied in a frame shape on the outer periphery.

  First, on the surface on which the TFT substrate 96 is formed within the frame of the UV sealant 98, a dispenser 90 adjusted to 5 mg per shot is used, and the column height of columnar spacers arranged on the CF substrate side measured in advance is averaged. Based on this, a predetermined amount of liquid crystal 100 is dropped. For example, in the case of dimension measurement (sampling) of the finished CF substrate, the case where the A surface has an average column height of 5 μm and the B surface has an average of 5.1 μm is described as an example.

  On the surface on which the TFT substrate facing the A surface is formed, 50 shots of 5 mg of 1 mg of liquid crystal are dropped by the dispenser 90 as a standard. For example, the column height of the columnar spacer is measured for each substrate or by sampling at a predetermined interval, and one shot increase or one shot decrease is controlled with a variation of 0.1 μm.

  On the surface on which the TFT substrate facing the B surface is formed, 51 shots of 1 mg of 5 mg of liquid crystal are dropped as a standard by the dispenser 90. For example, the column height of the columnar spacer is measured for each substrate or by sampling at a predetermined interval, and one shot increase or one shot decrease is controlled with a variation of 0.1 μm.

  Since the dispenser 90 has a variation of ± 1% in terms of the drop amount, in order to drop within the drop amount margin, the drop amount is controlled near the center of the optimum dropping range for each column height described in FIG. Otherwise, defects may occur. In addition, there is a case where a drip amount setting value for one shot is large and a problem occurs in fine adjustment. In such a case, the liquid crystal 101 for adjustment is dropped and finely adjusted with a dispenser 92 having a small drop amount.

  Next, the glass substrates whose drop amounts are controlled in this way are bonded together in a vacuum as described with reference to FIG. Since the inside of the surface is kept in vacuum when the atmosphere is released, the gap formation is completed with the differential pressure. Thereafter, the sealant 98 is irradiated with UV light for primary curing, and then thermally cured in an oven. Two liquid crystal display panels are obtained by scribing and cutting a predetermined position on each surface of the two glass substrates bonded together.

  In addition, since the number of shots of the dispenser is as large as 50 times, there is a possibility that the total dropping amount of liquid crystal to be dropped varies. Therefore, (1) the liquid crystal corresponding to the required total weight or total volume is quantified in advance, and then the total liquid crystal is dropped, or (2) the panel is placed on the weigh scale and the liquid crystal is dropped while being dispensed with a dispenser. A method of monitoring the amount of change in weight and determining the amount of dripping may be included.

Next, a configuration example of an inline process apparatus used in the method of manufacturing the liquid crystal display device according to the present embodiment will be described with reference to FIGS. FIG. 9 shows an apparatus configuration in the case where the column height measurement and the seal drawing are performed in parallel.
In FIG. 9, both the CF substrate and the TFT substrate have been subjected to the alignment process, carried into cleaning machines 1250 and 122, and cleaned. The cleaned CF substrate is transported to the column height measuring device 124. The cleaned TFT substrate is conveyed to the seal drawing device 126.

  The column height measuring device 124 includes a laser displacement meter, for example. The column heights at a plurality of points of the columnar spacer formed on the CF substrate are measured, and the average value is given to the liquid crystal dropping device 128 as a column height measurement result. On the other hand, the seal drawing device 126 has the same structure and function as the dispenser shown in FIG. 2, and draws a UV sealant in a frame shape on the outer periphery of the TFT substrate to form a main seal. The TFT substrate on which the main seal is formed is conveyed to the liquid crystal dropping device 128.

  The liquid crystal dropping device 128 has the dispenser shown in FIG. 2, and drops a predetermined amount of liquid crystal based on the measurement result of the column height on the CF substrate into the main seal of the TFT substrate. Next, the CF substrate and the TFT substrate are conveyed to the vacuum bonding apparatus 130 and bonded together while maintaining a predetermined cell gap. After undergoing the curing process by the UV curing apparatus 132, the CF substrate and the TFT substrate are conveyed to the downstream apparatus.

  Next, another configuration example of the inline process apparatus used in the method of manufacturing the liquid crystal display device according to the present embodiment will be described with reference to FIG. FIG. 10 shows an apparatus configuration when the column height measurement and the seal drawing are performed almost simultaneously on the same substrate. In FIG. 10, the cleaned CF substrate is carried into the column height measurement and seal drawing device 125, and the column height measurement and the seal drawing are performed almost simultaneously. Since the seal drawing is performed while monitoring the undulation of the substrate surface with a laser displacement meter, the laser displacement meter is also used for measuring the column height. Therefore, the cleaned TFT substrate is inserted into the liquid crystal dropping device 128 as it is without drawing a seal. In this case, seal drawing is performed on the CF substrate. According to the configuration of FIG. 10, since the seal drawing device on the TFT substrate side can be omitted, the installation space of the device can be reduced.

  Next, still another configuration example of the inline process apparatus used in the method of manufacturing the liquid crystal display device according to the present embodiment will be described with reference to FIG. FIG. 11 shows an apparatus configuration when the column height measurement and the liquid crystal dropping are performed almost simultaneously. In FIG. 11, the cleaned CF substrate is conveyed to a column height measurement and liquid crystal dropping device 129. Further, the TFT substrate on which the seal drawing is performed by the seal drawing device 126 is also carried into the column height measurement and liquid crystal dropping device 129.

  In the column height measurement and liquid crystal dropping device 129, in addition to the dispenser, a small laser displacement meter for measuring the column height is incorporated in an XY stage for liquid crystal dropping. Therefore, the column height measurement and liquid crystal dropping device 129 drops a predetermined amount of liquid crystal on the CF substrate or TFT substrate based on the column height measurement value of the columnar spacer on the CF substrate. Also with the configuration of FIG. 11, the installation space of the apparatus can be reduced.

  In the liquid crystal display panel manufactured through the above process, the amount of liquid crystal is determined in accordance with the height of the column. Therefore, so-called air bubbles due to the shortage of liquid crystal and gap defects due to excessive liquidity do not occur at all, so that extremely stable display quality can be maintained. Further, mixing CF substrates with different production dates and causing them to flow in the process conventionally means the occurrence of a defect. However, according to the present embodiment, not only the limitation is eliminated, but also within the same lot. Therefore, it is possible to absorb all the fluctuations in the optimum drop amount and the fluctuations in the optimum drop amount in the multi-chamfer glass substrate surface.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the above embodiment, the columnar spacer is provided on the CF substrate side, but the present invention is not limited thereto, and may be provided on the TFT substrate side, or may be provided on both the CF substrate and the TFT substrate.

  Further, the example in which the cell thickness is secured by the columnar spacer has been described, but the present invention is not limited to this, and the present invention can be similarly applied to a method of securing the cell thickness by dispersing beads on one substrate. In the case of bead spraying, it is possible to feed back the spraying density of beads, which has been measured for other purposes, to the drop amount control, and drop a predetermined amount of liquid crystal based on the spray density as in the above embodiment. The effect of can be obtained.

It is a figure which shows the structural example of CF substrate used with the manufacturing method of the liquid crystal display device by one embodiment of this invention. It is explanatory drawing of the dispenser used with the manufacturing method of the liquid crystal display device by one embodiment of this invention. It is explanatory drawing of the dripping injection method used with the manufacturing method of the liquid crystal display device by one embodiment of this invention. It is explanatory drawing of the range of the optimal dripping amount, and the excess and deficiency of the amount of liquid crystals. It is a relationship figure of support | pillar height and the optimal amount of liquid crystals. It is explanatory drawing of the range of the optimal dripping amount with respect to various support | pillar height. It is explanatory drawing of height measurement. It is explanatory drawing of the dripping amount control in the dripping injection method used with the manufacturing method of the liquid crystal display device by one embodiment of this invention. It is a figure which shows the structural example of the in-line process apparatus used with the manufacturing method of the liquid crystal display device by one embodiment of this invention. It is a figure which shows the other structural example of the in-line process apparatus used with the manufacturing method of the liquid crystal display device by one embodiment of this invention. It is a figure which shows the further another structural example of the in-line process apparatus used with the manufacturing method of the liquid crystal display device by one embodiment of this invention.

Explanation of symbols

20 Protrusion 20c Protrusion (support)
30 Dispenser 32 Housing 34 Piston 36 Nozzle 38 Liquid crystal container 40 Supply pipes 42, 44 Air inlet 46 Partition 48 Pump controller 50 Liquid crystal 52 Micro gauge 60 Array substrate (TFT substrate)
62 Liquid crystal 64 UV sealant 66 CF substrate 68 Movement direction 70 UV light source 72 UV light 80 Glass substrate 82 Substrate surface to be a panel (CF substrate) 84 Laser displacement meter 90, 92 Dispenser 94 Glass substrate 96 Substrate surface 98 to be a TFT substrate UV sealant 100, 101 Liquid crystal 120, 122 Washing machine 124 Post height measurement device 125 Post height measurement and seal drawing device 126 Seal drawing device 128 Liquid crystal dropping device 129 Post height measurement and liquid crystal dropping device 130 Vacuum bonding device 132 UV curing device

Claims (1)

In a manufacturing method of a liquid crystal display device in which liquid crystal is injected by dropping liquid crystal onto a substrate, bringing the liquid crystal dropping surface side of the substrate to face a counter substrate and bonding the substrate in a vacuum, and then returning to atmospheric pressure.
Measure the distribution density of the spherical particles dispersed on one of the two substrates ,
A method of manufacturing a liquid crystal display device, wherein an optimum amount of liquid crystal is dropped based on the measured value of the spray density .

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