JP3701948B2 - Liquid crystal display device manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a liquid crystal display device using columnar spacers (projections) for keeping a gap for liquid crystal injection constant.
[0002]
[Prior art]
As shown in FIG. 9, the liquid crystal display device produces an image by changing the amount of light 5 from the backlight light source by controlling the alignment state of liquid crystal molecules with a thin film transistor (TFT) 1. When using liquid crystal LC as an optical shutter, the accuracy of the thickness (gap) of the liquid crystal layer affects display characteristics such as light transmittance, contrast ratio, and response speed, so it is important to keep this uniform. . In general, bead-shaped fine particles called spacers 4 are used as the method. The spacer 4 is made of spherical silica or divinylbenzene polymer.
[0003]
First, the spacer dispersion step and the subsequent liquid crystal injection step will be described below.
[0004]
An alignment film is formed on the TFT substrate 2 on which the TFT 1 and the electrode wiring are formed, and this is rubbed (rubbing the surface of the alignment film with a cloth). After that, the spacers 4 are dispersed on the TFT substrate 1 and the color filter substrate 3 is overlapped and joined with a predetermined gap. In order to disperse a predetermined number of bead-shaped spacers 4 uniformly over the entire substrate, for example, a dry spraying method has been put into practical use.
[0005]
Note that the periphery of the two substrates is sealed with a sealing agent except for the injection port for injecting liquid crystal. Thereafter, the substrate is carried into a vacuum chamber. In the vacuum chamber, when the pressure in the substrate becomes equal to or lower than a predetermined pressure by the pressure reducing operation, the liquid crystal injection port is immersed in the liquid crystal layer and the vacuum chamber is returned to the atmospheric pressure. Then, the liquid crystal is filled in the gap by the pressure difference between the atmospheric pressure and the substrate internal pressure (reduced pressure).
[0006]
However, many technical problems have been pointed out in the spacer dispersion method, such as deterioration of gap uniformity due to spacer aggregation, increase in tact due to the spacer dispersion process, and light leakage due to alignment unevenness in the vicinity of the spacer.
[0007]
In particular, in a birefringence mode liquid crystal display device typified by a transverse electric field method, since the setting specifications of the gap are strict (design value ± 0.1 μm), spacer dispersion unevenness (such as lump unevenness) is displayed in the horizontal electric field method display. The quality is greatly reduced. Even if the spacers can be evenly dispersed, the spacer diameters vary (average value ± 0.2 μm), and the variation of the spacers itself cannot be neglected.
[0008]
In order to solve the above problem, a columnar spacer method has been proposed in which a film (for example, a color filter layer) formed on a glass substrate is left by etching to form a protrusion on the glass substrate. Since selective arrangement is possible, there is no dispersion unevenness of the columnar spacers, and since a precise film formation process is used, the uniformity of the spacer height that defines the gap is excellent. Furthermore, since the columnar spacer can be selectively formed in the light shielding region, the influence of the alignment unevenness can be avoided. For example, Japanese Laid-Open Patent Publication No. 10-186379 discloses that a protrusion is separately made of a light shielding film, and Japanese Laid-Open Patent Publication No. 10-268356 discloses that a separate protrusion is made of a color filter film. Has been. Further, JP-A-9-73088 and JP-A-10-48636 disclose the use of columnar spacers for the purpose of reducing mechanical damage to columnar spacers caused by alignment film rubbing cloth and improving rubbing unevenness in the vicinity of the spacers. Optimization of shape and arrangement method is introduced.
[0009]
[Problems to be solved by the invention]
However, when the columnar spacer technology is put into practical use, a new technical problem of considering the use environment temperature has been found. Hereinafter, the problem will be described with reference to the drawings.
[0010]
(1) Display unevenness due to thermal expansion of liquid crystal (see FIG. 10)
After the vacuum injection, the liquid crystal LC has a negative pressure (P ₁ Is maintained at atmospheric pressure or lower), and as shown in FIG. ₁ The columnar spacer 6 receives the compression pressure p from the substrates 2 and 3 and the columnar spacer 6 is elastically deformed (elastic compression amount F). However, since the liquid crystal LC is heated by the radiant heat from the light source and the drive circuit, the liquid crystal LC is thermally expanded and its internal pressure P ₁ Will increase. As a result, as shown in FIG. ₁ P above atmospheric pressure ₂ If it becomes, the columnar spacer 6 will peel from the glass substrate 3 supported by it, and the substrate support effect by the columnar spacer 6 will be lose | eliminated. As a result, the effect of the spacer that applies a uniform pressure to the substrate is lost, and display unevenness accompanying the deterioration of the uniformity of the gap is induced.
[0011]
Although the value of the thermal expansion depends on the liquid crystal material, for example, the thermal expansion coefficient α = 7.46 × 10 ^-Four In the / K liquid crystal, if the temperature rises by 20 ° C. from room temperature (about 20 ° C.), assuming that the initial gap g is 5 μm, the value of thermal expansion is estimated to be about 0.075 μm.
[0012]
(2) Bubble generation by liquid crystal negative pressure (see Fig. 11)
Due to the force balance condition, the internal pressure P of the liquid crystal LC ₁ The columnar spacer 6 pushes up the glass substrate 3 with a reaction force f1 corresponding to the pressure difference corresponding to the atmospheric pressure (see FIG. 11A). If the liquid crystal LC thermally contracts due to a decrease in the temperature of the liquid crystal LC, the amount of elastic contraction of the columnar spacer 6 increases following this. As the elastic shrinkage increases, the reaction force f2 of the columnar spacer 6 also increases. At the same time, the atmospheric pressure and the internal pressure P of the liquid crystal LC are maintained in order to maintain a balance with the reaction force f2. _Three The differential pressure increases. As a result, the internal pressure of the liquid crystal decreases, the negative pressure of the liquid crystal LC is promoted, and bubbles are generated by the liquid crystal vaporization.
[0013]
An object of the present invention is to provide a method for manufacturing a liquid crystal display device that can solve the above-described problems and prevent generation of display unevenness due to thermal expansion of liquid crystal and generation of bubbles due to thermal contraction.
[0014]
[Means for Solving the Problems]
The manufacturing method of the liquid crystal display device of the present invention is to make a protrusion by etching a film formed on a substrate,
A sealant is applied in an annular shape around the substrate except for the liquid crystal injection port,
The area occupancy of the protrusions with respect to the region surrounded by the sealant is 0.0001 or more and 0.0029 or less,
Overlaying another substrate on the substrate via the protrusion and the sealant,
After that, liquid crystal is injected into the area surrounded by the sealing agent from the liquid crystal injection port. Then, a sealant is applied to the liquid crystal injection port with an interval of 30 minutes or more and 60 minutes or less without heating or pressurization from the completion of liquid crystal injection. It is characterized by that.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
First, the structure of the liquid crystal display device and the thin film transistor will be described. After that, the relationship between the area occupancy rate of the columnar spacer and the use environment temperature will be described.
[0016]
(1) Basic configuration of liquid crystal display device
FIG. 1 is a diagram illustrating a configuration of a liquid crystal display device. FIG. 2 is a diagram illustrating a state in which the liquid crystal contact surface is placed on the color filter substrate on which the columnar spacers are formed, and is an enlarged view of a region IV in FIG.
[0017]
The TFT substrate 11 and the color filter substrate 12 are arranged to face each other with a predetermined gap (not shown), and the gap is filled with liquid crystal LC. A scanning signal wiring 13 and a video signal wiring 14 are formed on the TFT substrate 11 so as to cross each other. In order to control the pixel region V surrounded by the wirings 13 and 14 by switching, a TFT 15 is provided in the vicinity of the intersection of the wirings. The color filter substrate 12 is formed with striped red, green, and blue colored layers 16, 17, and 18 and a black matrix layer 19 that partitions them. The columnar spacer 23 is disposed on the blue colored layer 16.
[0018]
The periphery of the TFT substrate 11 is prevented from leaking liquid crystal by a sealing agent 21 formed in an annular shape (excluding the injection port 20). The liquid crystal filling region surrounded by the sealant 21 is a region that is directly subjected to pressure action due to thermal expansion and contraction of the liquid crystal. A peripheral light shielding layer 22 is formed in an annular shape so as to cover the sealing agent 21 and extend into the liquid crystal filling region. As a result, a display area surrounded by the peripheral light shielding layer 22 is formed. As a material of the sealing agent 21, an epoxy resin is mainly used. As a material of the black matrix layer 19, a metal such as chromium, nickel, or aluminum or a black resin is used. In the case of the metal black matrix layer, the thickness is set to 0.05 to 0.5 μm. In the case of the resin black matrix layer, the thickness is set to 0.5 to 3 μm in order to ensure light shielding. As the material of the colored layer, an acrylic resin in which a pigment is dispersed is used. Although the thickness of the colored layer varies depending on the color characteristics, it is preferably 0.5 to 2.5 μm.
[0019]
According to the enlarged view of the color filter substrate side and the sectional view taken along the line VI-VI in FIG. 4 (FIGS. 2 and 4), the black matrix layer 19 and the colored layer CF are laminated on the color filter substrate 12. A columnar spacer 23 is provided on these layers via an overcoat film (protective film) OC. Photosensitive resin such as acrylic resin is used as the material of the columnar spacer 23. The columnar spacers 23 are formed by a predetermined thickness (gap), and then etched (patterned) by a photolithography method. Even if alignment unevenness due to the columnar spacers 23 (alignment processing failure of the alignment film) occurs, the columnar spacers 23 and the vicinity thereof are covered with the black matrix layer 19, so that problems of display unevenness such as light leakage can be avoided. The overcoat layer OC is made of a transparent organic insulating film such as an acrylic resin. The thickness is desirably 0.5 to 3.0 μm.
[0020]
(2) Basic structure of TFT
FIG. 3 is a configuration diagram of one pixel of a liquid crystal display device called a horizontal electric field method, and is an enlarged view of a region V in FIG. The drain electrode 24 connected to the TFT 15 has a comb shape. The common electrode 25 formed in the same layer as the drain electrode 24 also has a comb shape. If the TFT 15 is conductive, a signal propagating through the video signal wiring 26 is applied to the drain electrode 24, and a voltage difference between the drain electrode 24 and the common electrode 25 generates an electric field parallel to the TFT substrate 11. . This electric field changes the alignment state of the liquid crystal molecules to control the luminance of one pixel. The common electrode 25 is connected to the common signal wiring 27. The common signal wiring 27 extends to the substrate end in parallel with the scanning signal wiring 13, and the common signal wiring 27 is also electrically connected to a common electrode of each pixel arranged in the wiring direction. An angle θ1 in the figure indicates a rubbing direction angle of the alignment film formed on the TFT substrate 11 (an angle with respect to the video signal wiring), and θ1 = 15 °. In a liquid crystal having positive dielectric anisotropy, the rubbing direction angle is generally set to 0 ° to 30 ° with respect to the video signal wiring 26, and the alignment film rubbing direction on the TFT substrate and the color filter substrate It is set equal to the alignment film rubbing direction.
[0021]
(3) Area occupation ratio of columnar spacers
FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. 2 and shows the cross-sectional shape of the columnar spacer 23.
[0022]
Since the columnar spacer 23 is formed by a photolithography method, the cross section has a trapezoidal shape. Therefore, in the present specification, a value obtained by dividing the volume of the columnar spacer 23 by the height h is used as a conversion area. The area occupation ratio of the columnar spacers 23 is a numerical value obtained by dividing the substrate area value of the liquid crystal filled region surrounded by the sealant and the sum of the converted area values of all the columnar spacers included in the region.
[0023]
When one columnar spacer having the same shape is arranged for each pixel, the value of the area occupancy may be a value obtained by dividing the converted area value of one columnar spacer by the area value of one pixel. it can.
[0024]
If the area occupancy is too large, the columnar spacer 23 cannot secure a sufficient amount of compressive deformation. Therefore, if the liquid crystal thermally expands due to the temperature rise of the liquid crystal display device, the substrate supported by the columnar spacer 23 is separated from the columnar spacer 23. If the columnar spacer 23 cannot support the substrate, uniform pressure is not applied to the substrate, and display unevenness occurs. On the other hand, if the area occupancy is too large, the reaction force against the substrate on the columnar spacer 23 side due to the thermal contraction of the liquid crystal increases, thereby promoting the decrease in the liquid crystal internal pressure and causing the problem of bubble generation. As a result of the experiment, the upper limit of the area occupation ratio of the columnar spacer 23 is 0.003, preferably 0.002, and more preferably 0.0015 (see Examples 1, 2, 3, and 4).
[0025]
On the other hand, if the value of the area occupancy is too small, the columnar spacer 23 is compressed and broken by the atmospheric pressure (98000 Pa) applied to the liquid crystal display device at the time of liquid crystal injection. The compressive fracture strength of a photosensitive resin such as an acrylic resin used for the columnar spacer 23 is 9.8 × 10. ⁷ ~ 9.8 × 10 ⁸ It is generally considered to be about Pa. Since the value obtained by dividing the atmospheric pressure (98000 Pa) by the compressive fracture strength is 0.001 to 0.0001, the lower limit value of the area occupation ratio of the columnar spacer 23 is 0.0001. In consideration of design variations of the columnar spacers 23 and the usage status of the liquid crystal display device (influence of external pressure, etc.), the lower limit is preferably about 0.0005.
[0026]
Embodiment 2
The feature of this embodiment is that the problem caused by the use environment temperature of the columnar spacer is improved by the pressure sealing treatment of the liquid crystal display device. The outline of the pressure sealing process and the effect of the pressure sealing process will be described below.
[0027]
Around the TFT substrate or color filter substrate, a thermosetting sealant (XN31A manufactured by Mitsui Toatsu Chemical Co., Ltd.) is annularly formed except for the liquid crystal injection port (the portion that becomes the injection port by overlapping the substrate) for injecting liquid crystal. Apply with a dispenser device. After that, the TFT substrate and the color filter substrate are overlaid and heated to about 200 ° C., and are thermally cured at 60000 Pa for 1 hour. In addition, Macrorod PF-41 (Nippon Electric Glass Co., Ltd.) was mixed with this sealing agent at a ratio of about 2 wt%.
[0028]
Next, the substrate is carried into a vacuum chamber. In the vacuum chamber, when the pressure in the substrate becomes equal to or lower than a predetermined pressure by the decompression operation, the liquid crystal injection port is immersed in the liquid crystal to return the vacuum chamber to atmospheric pressure. Liquid crystal is injected into the gap by the pressure difference between the atmospheric pressure and the substrate internal pressure (negative pressure). At this time, a pressure corresponding to approximately atmospheric pressure is applied to the columnar spacers, whereby the columnar spacers are compressed and deformed. When the liquid crystal injection is completed, the liquid crystal at the liquid crystal injection port is wiped off. Due to the surface tension of the liquid crystal, the internal pressure is maintained at a negative pressure for a predetermined time, and gradually approaches atmospheric pressure.
[0029]
When a certain period of time has elapsed after the completion of liquid crystal injection, the liquid crystal injection port of the liquid crystal display device is sealed with a sealant simultaneously with the pressure treatment (this is called pressure sealing treatment). This pressure sealing process contributes to the prevention of bubble mixing and the improvement of gap uniformity, and has the following important effects.
[0030]
FIG. 5 shows the relationship between the elapsed time from the completion of liquid crystal injection to the sealing of the injection port and the liquid crystal internal pressure. In FIG. 5, the horizontal axis represents the elapsed time after completion of the injection, the vertical axis represents the liquid crystal internal pressure, and corresponds to the gap value between the substrates. As shown in FIG. 5, when the liquid crystal injection is completed (S ₁ With the passage of time from the point), the internal pressure of the liquid crystal approaches the atmospheric pressure, and the elastic compression amount of the columnar spacers decreases with this (that is, the gap value increases). If the injection port is sealed, the gap is completely closed, and the internal pressure of the liquid crystal does not change thereafter. FIG. 5 illustrates a display unevenness generation region A and a bubble generation region B, and a display stable region C sandwiched between these regions.
[0031]
The display unevenness generation region A refers to a region that induces display unevenness defects when the liquid crystal temperature is 50 ° C. or higher, and the bubble generation region B refers to a region that induces bubble defects when the liquid crystal temperature is −20 ° C. or less.
[0032]
Time t from completion of injection ₂ When it has elapsed, the moving point S ₂ It is thought that the internal pressure of the liquid crystal changes. Moving point S ₂ Is located in the display unevenness generation region A. If the liquid crystal injection port is sealed under this pressure state, display unevenness may occur during the high temperature test. In order to avoid this, the entire surface of the liquid crystal panel substrate is applied with a predetermined pressure together with sealing the inlet (this causes the columnar spacers to be recompressed). By this pressure sealing, the internal pressure of the liquid crystal is changed to the moving point S. _Three (Display stable area). In other words, the pressure sealing treatment can control the internal pressure of the liquid crystal, and can improve the occurrence of defects at high and low temperatures of the liquid crystal.
[0033]
Therefore, if the columnar spacer is compressed by changing the internal pressure of the liquid crystal by pressure sealing, the substrate and the columnar spacer can be made difficult to peel even if the liquid crystal is thermally expanded when the temperature of the liquid crystal rises. However, this pressure sealing, on the other hand, promotes the generation of bubbles (increase in the reaction force of the columnar spacers), so the upper limit of the applied pressure is 40000 Pa, preferably 20000 Pa (see Examples 5, 6 and 7). ). The lower limit of the applied pressure is desirably 1000 Pa in order to ensure a constant pressurizing effect. In addition, this pressurization time needs at least about 5 minutes.
[0034]
It should be noted that a predetermined time t from the completion of liquid crystal injection _Three If the time has elapsed, the internal pressure of the liquid crystal will be ₁ More moving point S _Three It is thought that it moves to the vicinity. Therefore, after the injection is completed, the time t _Three If a sealant is applied after a certain amount of time has passed, the pressurizing process is not necessary (see Examples 8, 9, 10, and 11).
[0035]
Embodiment 3
The feature of this embodiment is that two types of spacers having different heights are arranged. As shown in FIG. 6A, a height difference L is provided between the first columnar spacer 23A and the second columnar spacer 23B. Next, when the glass substrate 3 receives the compression pressure Po and the compression amount α of the columnar spacer 23B is L or less, only the reaction force f1 of the second columnar spacer 23B acts on the substrate (FIG. 6B). . Therefore, the reaction force f1 of the columnar spacer 23B can be smaller than the reaction force (the sum of f1 and f2) when the columnar spacer 23 having the same height is used (FIG. 6C). As a result, under the conditions of the area occupation ratio of the same columnar spacer and the compression force of the same columnar spacer, the amount of compressive deformation of the columnar spacer becomes larger when the height of the columnar spacer is different than when the height is made equal. it can. That is, the amount of compression of the columnar spacer can be increased by varying the height of the columnar spacer. As a result of the experiment, it was found that when the two types of columnar spacers were formed at the same ratio, the difference in height between them was preferably about 0.05 μm or more (see Examples 12 and 13).
[0036]
【Example】
Hereinafter, the parameters and experimental results (visual evaluation) related to the first embodiment are shown in Examples 1 to 4, the parameters and experimental results related to the second embodiment are shown in Examples 5 to 11, and the parameters related to the third embodiment. The experimental results are summarized in Examples 12 and 13.
[0037]
Example 1 (see FIG. 7)
The converted area value of the columnar spacer 23 is 1.1 × 10. ^-Four mm ² It is.
The arrangement pitch of the columnar spacers 23 is 264 μm (horizontal direction H) × 264 μm (vertical direction V).
The horizontal direction H refers to the direction of the scanning signal wiring, and the vertical direction V refers to the direction of the video signal wiring.
The area occupancy is 0.0016.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
The time from completion of liquid crystal injection to sealing of the injection port is 60 minutes.
As a result, it was excellent in the characteristics of the high temperature test (50 ° C. operation test) and the low temperature test (−20 ° C. operation test) by visual evaluation of the panel, and display unevenness and bubbles were not observed.
[0038]
Example 2
The converted area value of the columnar spacer is 1.1 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 176 μm (horizontal direction) × 264 μm (vertical direction).
The area occupancy is 0.0024.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
The time from completion of liquid crystal injection to sealing of the injection port is 60 minutes.
As a result, display unevenness was hardly observed in the high temperature test by visual evaluation of the panel.
[0039]
Example 3
The converted area value of the columnar spacer is 1.1 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 88 μm (horizontal direction) × 264 μm (vertical direction).
The area occupancy is 0.0048.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
The time from completion of liquid crystal injection to sealing of the injection port is 60 minutes.
As a result, slight display unevenness was observed in the high temperature test by visual evaluation of the panel.
[0040]
Example 4
The converted area value of the columnar spacer is 1.1 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 80 μm (horizontal direction) × 264 μm (vertical direction).
The area occupancy is 0.0059.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
The time from completion of liquid crystal injection to sealing of the injection port is 60 minutes.
As a result, display unevenness was noticeably observed in the high temperature test by visual evaluation of the panel, and bubbles were also generated in the low temperature test.
[0041]
Example 5
The converted area value of the columnar spacer is 1.1 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 240 μm (horizontal direction) × 240 μm (vertical direction).
The area occupancy is 0.0019.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
The time from completion of liquid crystal injection to sealing of the injection port is 120 minutes.
As a result, display unevenness was observed in the high temperature test by visual evaluation of the panel.
[0042]
Example 6
The converted area value of the columnar spacer is 1.1 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 240 μm (horizontal direction) × 240 μm (vertical direction).
The area occupancy is 0.0019.
The pressurizing condition when applying the sealant is 20000 Pa.
The time from completion of liquid crystal injection to sealing of the injection port is 120 minutes.
As a result, display unevenness and bubbles were not observed in the panel visual evaluation.
[0043]
Example 7
The converted area value of the columnar spacer is 1.1 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 240 μm (horizontal direction) × 240 μm (vertical direction).
The area occupancy is 0.0019.
The pressurizing condition when applying the sealant is 49000 Pa.
The time from completion of liquid crystal injection to sealing of the injection port is 120 minutes.
As a result, bubbles were observed in the low-temperature test by visual evaluation of the panel.
[0044]
Example 8
The converted area value of the columnar spacer is 0.8 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 240 μm (horizontal direction) × 240 μm (vertical direction).
The area occupancy is 0.0014.
The time from completion of liquid crystal injection to sealing of the injection port is 0 minute.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
As a result, bubbles were generated in the low temperature test by visual evaluation of the panel.
[0045]
Example 9
The converted area value of the columnar spacer is 0.8 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 240 μm (horizontal direction) × 240 μm (vertical direction).
The area occupancy is 0.0014.
The time from completion of liquid crystal injection to sealing of the injection port is 30 minutes.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
As a result, display unevenness and bubbles were not observed in the visual evaluation of the panel.
[0046]
Example 10
The converted area value of the columnar spacer is 0.8 × 10 ^-Four mm ² It is.
Arrangement pitch of columnar spacers: 240 μm (horizontal direction) × 240 μm (vertical direction).
The area occupancy is 0.0014.
The time from completion of liquid crystal injection to sealing of the injection port is 60 minutes.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
As a result, in the panel visual evaluation, display unevenness and bubbles were not observed.
[0047]
Example 11
The converted area value of the columnar spacer is 0.8 × 10 ^-Four mm ² It is.
The arrangement pitch of the columnar spacers is 240 μm (horizontal direction) × 240 μm (vertical direction).
The area occupancy is 0.0014.
The time from completion of liquid crystal injection to sealing of the injection port is 120 minutes.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
As a result, display unevenness was observed in the high temperature test by visual evaluation of the panel.
[0048]
Example 12 (see FIG. 8)
The converted area value of the columnar spacer 23A is 2.0 × 10. ^-Four mm ² It is.
The arrangement pitch of the columnar spacers 23A is 240 μm (horizontal direction H) × 240 μm (vertical direction V).
The height of the columnar spacer 23A is 3.4 μm.
The converted area value of the columnar spacer 23B is 0.5 × 10. ^-Four mm ² It is.
The arrangement pitch of the columnar spacers 23B is 240 μm (horizontal direction) × 240 μm (vertical direction).
The height of the columnar spacer 23B is 3.6 μm.
The area occupancy is 0.0029.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
The time from completion of liquid crystal injection to sealing of the injection port is 60 minutes.
As a result, display unevenness and bubbles were not observed in the panel visual evaluation.
[0049]
Note that both of the two types of columnar spacers 23A and 23B may be disposed in the overlapping portion of the black matrix and the colored layer on the color filter substrate (for example, different types of columnar spacers on the blue layer and the red layer, respectively). The first columnar spacers 23A are disposed in the overlapping portion of the black matrix and the colored layer on the color filter substrate, and the second columnar spacers 23B are disposed in the region on the TFT substrate side facing the overlapping portion. good.
[0050]
Example 13
The converted area value of the columnar spacer A is 2.0 × 10. ^-Four mm ² It is.
The arrangement pitch of the columnar spacers A is 240 μm (horizontal direction) × 240 μm (vertical direction).
The height of the columnar spacer A is 3.4 μm.
The converted area value of the columnar spacer B is 0.5 × 10. ^-Four mm ² It is.
The arrangement pitch of the columnar spacers B is 240 μm (horizontal direction) × 240 μm (vertical direction).
The height of the columnar spacer B is 3.4 μm.
The area occupancy is 0.0029.
The pressurizing condition at the time of applying the sealant is not a pressure sealing process.
The time from completion of liquid crystal injection to sealing of the injection port is 60 minutes.
As a result, slight display unevenness was observed in the high temperature test by visual evaluation of the panel.
[0051]
【The invention's effect】
As described above, according to the manufacturing method of the present invention, since the area occupation ratio of the columnar spacers is set to an optimum value, a liquid crystal display device that has no display unevenness when used at a high temperature and does not generate bubbles when used at a low temperature is obtained. Can do.
[0052]
In addition, when the height of the columnar spacers is made different, the amount of compression of the columnar spacers can be further ensured, and there can be obtained a liquid crystal display device that has no display unevenness when used at high temperatures and does not generate bubbles when used at low temperatures.
[0053]
Further, when the pressure sealing treatment is performed, a liquid crystal display device capable of suppressing display unevenness during high temperature use can be obtained.
[0054]
Further, when the injection port of the liquid crystal display device is sealed with a sealant at a predetermined time interval from the liquid crystal injection, a liquid crystal display device free from bubbles during low temperature use without display unevenness when used at high temperature is obtained. Can do.
[Brief description of the drawings]
FIG. 1 is a partially cutaway plan view showing a configuration of a liquid crystal display device.
2 is a diagram illustrating a color filter substrate on which columnar spacers are formed with a liquid crystal contact surface on top, and is an enlarged view of a region IV in FIG.
FIG. 3 is a configuration diagram for one pixel of a liquid crystal display device called a horizontal electric field method, and is an enlarged view of a region V in FIG. 1;
4 is a cross-sectional view taken along line VI-VI in FIG.
FIG. 5 is a diagram for explaining a relationship between an elapsed time from liquid crystal injection completion time to injection port sealing and liquid crystal internal pressure.
FIG. 6 is a diagram illustrating an operation for changing the height of a columnar spacer.
FIG. 7 is a diagram illustrating the arrangement of columnar spacers according to the first embodiment.
FIG. 8 is a view for explaining columnar spacer arrangement of Example 12.
FIG. 9 is a plan view illustrating a configuration of a conventional bead-shaped spacer.
FIG. 10 is a diagram for explaining a problem caused by thermal expansion of liquid crystal.
FIG. 11 is a diagram for explaining a problem caused by thermal compression of liquid crystal.
[Explanation of symbols]
11 TFT substrate
12 Color filter substrate
13 Scanning signal wiring
14, 26 Video signal wiring
15 TFT
16, 17, 18 Colored layer
19 Black matrix layer
20 inlet
21 Sealant
22 Surrounding light shielding layer
23 Columnar spacer
24 Drain electrode
25 Common electrode
27 Common signal wiring

Claims (2)

Etching the film formed on the substrate to create a protrusion,
A sealant is applied in an annular shape around the substrate except for the liquid crystal injection port,
The area occupancy ratio of the protrusions with respect to the region surrounded by the sealant is 0.0014 or more and 0.0024 or less,
Overlaying another substrate on the substrate via the protrusion and the sealant,
After that, the liquid crystal is injected into the region surrounded by the sealing agent from the liquid crystal injection port ,
A manufacturing method of a liquid crystal display device, characterized in that a sealing agent is applied to the liquid crystal injection port at an interval of 30 minutes or more and 60 minutes or less without heating or pressurizing after completion of liquid crystal injection. . Preparation of liquid crystal display device according to claim 1 Symbol placement difference in height of the projection portion is 0.05μm or more.

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