JP4180342B2 - Manufacturing method of liquid crystal panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal panel configured by enclosing a liquid crystal between a pair of substrates. Le In particular, a liquid crystal panel that maintains a constant distance between a pair of substrates by columnar spacers. Le It relates to a manufacturing method.
[0002]
[Prior art]
The liquid crystal panel is advantageous in that it is thin and lightweight and consumes less power, and is used in displays such as calculators, home appliances, and OA (Office Automation) devices. The liquid crystal panel is also used as a spatial light modulator in an input device of an optical information processing system and a computer generated hologram.
[0003]
A liquid crystal panel used for a display of an OA device usually has a structure in which liquid crystal is sealed between a pair of substrates. A TFT (Thin Film Transistor) and a pixel electrode are formed for each pixel on one substrate, and a common electrode common to each pixel is formed on the other substrate. Hereinafter, the substrate on which the pixel electrode and the TFT are provided is referred to as a TFT substrate, and the substrate disposed to face the TFT substrate is referred to as a counter substrate.
[0004]
The distance (cell gap) between the TFT substrate and the counter substrate is usually maintained constant by spherical beads made of resin or ceramic. The beads are dispersed on one of the TFT substrate and the counter substrate when the TFT substrate and the counter substrate are bonded with a sealant.
[0005]
However, in the method of dispersing beads on the substrate, the beads are not necessarily distributed uniformly over the entire substrate. If the beads are not evenly distributed over the entire substrate, in-plane variation of the cell gap occurs, causing a reduction in display quality. Further, since the liquid crystal molecules have a property of being aligned along the surface of the bead, if the bead exists in the pixel region, an alignment abnormality occurs and the display quality is deteriorated.
[0006]
Therefore, it has been proposed to form a columnar spacer between pixel regions (for example, a portion where a data bus line and a gate bus line intersect) using a photoresist (for example, JP-A-8-220546). No., JP-A-2001-83517, and JP-A-2001-201750).
[0007]
[Patent Document 1]
JP-A-8-220546
[Patent Document 2]
JP 2001-83517 A
[Patent Document 3]
JP 2001-201750 A
[Patent Document 4]
JP-A-8-110524
[0008]
[Problems to be solved by the invention]
However, the present inventors consider that the conventional liquid crystal panel using columnar spacers has the following problems.
[0009]
That is, in the conventional method of forming columnar spacers using a photoresist, the columnar spacers are bonded to one substrate, but not bonded to the other substrate. Therefore, as shown in FIG. 7, assuming that the spacer 51 is bonded to the counter substrate 50 and the spacer 51 is not bonded to the TFT substrate 60, the external pressure is applied to the point A between the spacers 51. The cell gap around the point A varies greatly, causing interference fringes, variations in color tone, variations in drive voltage characteristics, and the like.
[0010]
In JP-A-8-110524, spacers coated with a thermoplastic resin are dispersed on one substrate, and when the two substrates are bonded, the spacers are joined to both substrates by the thermoplastic resin. Is described. However, in this method, the spacer cannot be arranged at a desired position.
[0011]
From the above, an object of the present invention is to provide a liquid crystal panel that avoids large fluctuations in the substrate gap (cell gap) with respect to external pressure, and avoids the generation of interference fringes, variations in color tone, and variations in drive voltage characteristics. Le It is to provide a manufacturing method.
[0012]
[Means for Solving the Problems]
The above-described problems include a step of preparing a first substrate and a second substrate, a step of applying a positive photosensitive resin on the first substrate to form a photosensitive resin film, and the photosensitive resin. An exposure / development step of exposing and developing the film to form a spacer; a step of heat-treating the spacer into a semi-cured state; a rubbing step of rubbing the first substrate; A re-exposure step for re-exposing a spacer, and the first substrate and the second substrate are bonded by a sealing agent and the spacer, and are surrounded by the sealing agent, the first substrate, and the second substrate. Liquid crystal sealing process for sealing the liquid crystal in the space In the above order This is solved by a method for manufacturing a liquid crystal panel.
[0016]
In the present invention, the positive photosensitive resin is used to form the spacer. Thereafter, when the spacer is re-exposed, the photosensitive resin constituting the spacer is photodecomposed, the spacer is softened, and the adhesiveness is improved. When the first substrate and the second substrate are overlapped in this state, the spacer and the first and second substrates are bonded. Thereafter, for example, heat treatment is performed to cure the spacer.
[0017]
Thus, in the present invention, the spacer is formed using the positive photosensitive resin, and then the first substrate and the second substrate are overlapped after the re-exposure, so that the spacer and the first and second substrates are overlapped. Can be firmly joined. Thereby, even if an external pressure is applied, a significant change in the cell gap is avoided, and the occurrence of interference fringes, variations in color tone, and variations in drive voltage characteristics are avoided.
[0018]
When the rubbing process is performed on the alignment film provided on the first substrate, the spacer needs to be heat-treated before the rubbing process so as to be in a semi-cured state. As a result, the spacer can be prevented from being scraped during the rubbing process, and the cell gap can be maintained at a desired value. Also in this case, when the spacer is re-exposed, the photosensitive resin constituting the spacer is photodecomposed and the adhesiveness can be recovered.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0020]
(LCD panel)
FIG. 1 is a plan view showing one pixel of a liquid crystal panel according to an embodiment of the present invention, and FIG. Note that the present embodiment describes an example in which the present invention is applied to a transmissive liquid crystal display panel.
[0021]
As shown in FIG. 2, the liquid crystal display panel of the present embodiment includes a TFT substrate 10 and a counter substrate 20 that are arranged to face each other, and a liquid crystal sealed between the TFT substrate 10 and the counter substrate 20. 30. A polarizing plate is disposed below the TFT substrate 10 and above the counter substrate 20. A light source (backlight) is disposed below the TFT substrate 10.
[0022]
As shown in FIGS. 1 and 2, the TFT substrate 10 includes a glass substrate 11, a gate bus line 12, a data bus line 14, a TFT 15 and a pixel electrode 18 formed on the glass substrate 11. The gate bus line 12 extends in the horizontal direction, and the data bus line 14 extends in the vertical direction. A region partitioned by the gate bus line 12 and the data bus line 14 is a pixel region. One pixel electrode 18 and one TFT 15 are formed in each pixel region.
[0023]
In this embodiment, as shown in FIG. 1, a part of the gate bus line 12 serves as a gate electrode of the TFT 15, and a source electrode 15 s and a drain electrode of the TFT 15 are provided on both sides of the channel protective film 16 in the width direction, respectively. 15d is arranged. The source electrode 15 s is electrically connected to the pixel electrode 18 through a contact hole 17 a formed in the insulating film 17, and the drain electrode 15 d is electrically connected to the data bus line 14. An alignment film 19 made of polyimide or the like is formed on the pixel electrode 18. The surface of the alignment film 19 is subjected to a rubbing process for determining the alignment direction of liquid crystal molecules when no electric field is applied.
[0024]
On the other hand, the counter substrate 20 includes a glass substrate 21 and a black matrix 22, an insulating film 23, and a common electrode 24 formed on one surface side (lower side in FIG. 2) of the glass substrate 21. The black matrix 22 is formed so as to cover the area between the pixels and the TFT formation area. The insulating film 23 is formed on the lower side of the glass substrate 21 so as to cover the black matrix 22. A common electrode 24 is formed under the insulating film 23, and an alignment film 25 made of polyimide or the like is formed under the common electrode 24. The surface of the alignment film 25 is also rubbed to determine the alignment direction of the liquid crystal molecules when no electric field is applied.
[0025]
The TFT substrate 10 and the counter substrate 20 are arranged so that the surfaces on which the alignment films 19 and 25 are formed are opposed to each other, and constitute a liquid crystal panel together with the liquid crystal 30 sealed between them.
[0026]
The distance between the TFT substrate 10 and the counter substrate 20 is maintained constant by a columnar spacer 26 provided on a portion where the gate bus line 12 and the data bus line 13 intersect. This columnar spacer 26 is formed of a positive photoresist and is bonded to both the TFT substrate 10 and the counter substrate 20.
[0027]
In the liquid crystal panel configured as described above, when an image is displayed, a scanning signal is sequentially supplied from a driving circuit (not shown) to the gate bus lines 12 arranged in the vertical direction and displayed on the data bus line 14. Supply the signal. The TFT 15 connected to the gate bus line 12 supplied with the scanning signal is turned on, and a display signal is written to the pixel electrode 18 via the TFT 15. As a result, an electric field corresponding to the display signal is generated between the pixel electrode 18 and the common electrode 24 to change the direction of the liquid crystal molecules, and as a result, the amount of light transmitted through the pixel changes. A desired image can be displayed on the liquid crystal panel by controlling the amount of transmitted light for each pixel.
[0028]
(Liquid crystal panel manufacturing method)
Hereinafter, the manufacturing method of the liquid crystal panel of the embodiment of the present invention will be described.
[0029]
First, the TFT substrate 10 and the counter substrate 20 as shown in FIGS. 1 and 2 are manufactured.
[0030]
A method for manufacturing the TFT substrate 10 will be briefly described. First, a first metal film is formed on the glass substrate 11 by PVD (Physical Vapor Deposition), and the first metal film is patterned by photolithography to form gate bus lines 12. Thereafter, a gate insulating film 13 is formed on the entire upper surface of the glass substrate 11, and a first silicon film serving as an operation layer of the TFT 15 and a SiN film serving as a channel protective film 16 are formed thereon. Thereafter, the SiN film is patterned by photolithography to form a channel protective film 16 in a predetermined region above the gate bus line 12.
[0031]
Next, a second silicon film in which an impurity serving as an ohmic contact layer is introduced at a high concentration is formed on the entire upper surface of the glass substrate 11, and then a second metal film is formed on the second silicon film. To do. Then, the second metal film, the second silicon film, and the first silicon film are patterned by photolithography to determine the shape of the silicon film serving as the operation layer of the TFT 15, the data bus line 14, the source electrode 15s and the drain electrode 15d are formed.
[0032]
Next, an insulating film 17 is formed on the entire upper surface of the glass substrate 11, and a contact hole 17 a is formed at a predetermined position of the insulating film 17. Thereafter, a film made of a transparent conductor such as ITO (Indium-Tin Oxide) is formed on the entire upper surface of the glass substrate 11. Then, the pixel electrode 18 electrically connected to the source electrode 15s of the TFT 15 through the contact hole 17a is formed by patterning this transparent conductor film. Thereafter, an alignment film 19 made of polyimide is formed on the entire upper surface of the glass substrate 11. In this way, the TFT substrate 10 is completed.
[0033]
Hereinafter, a method for manufacturing the counter substrate 20 will be briefly described. First, a metal film such as Cr is formed on the glass substrate 21, and the black matrix 22 is formed by patterning the metal film. Thereafter, an insulating film 23 is formed on the glass substrate 21. In the case of forming a color liquid crystal display panel, the insulating film 23 is formed of red (R), green (G), and blue (B) resin, and any one of red, green, and blue is used for each pixel. A color insulating film 23 is disposed.
[0034]
Next, a common electrode 24 is formed on the insulating film 23 using a transparent conductor such as ITO. Thereafter, an alignment film 25 made of polyimide is formed on the common electrode 24. In this way, the counter substrate 20 is completed.
[0035]
Next, a columnar spacer 26 is formed on one side of the TFT substrate 10 and the counter substrate 20. In the present embodiment, the spacer 26 is formed on the counter substrate 20 side.
[0036]
That is, as shown in FIG. 3A, a positive photoresist is applied on the counter substrate 20 to a thickness of about 2 μm by spin coating to form a resist film 35. Pre-bake for 1 minute at a temperature of ° C.
[0037]
Next, after exposing the resist film 35 to ultraviolet rays through an exposure mask provided with a predetermined pattern, a development process is performed to form columnar spacers 26 as shown in FIG. Thereafter, the surface of the counter substrate 20 is washed with pure water and then dried.
[0038]
The spacer 26 has a cylindrical shape with a diameter of 10 μm, for example. The spacer 26 is formed at a position corresponding to the intersection between the gate bus line 12 and the data bus line 14. For example, the horizontal and vertical pitches of the spacers 26 are both 100 μm.
[0039]
Next, heat treatment is performed at a temperature of 120 ° C. for 10 minutes, so that the resist constituting the spacer 26 is in a semi-cured state. Thereafter, the alignment film 25 is rubbed. A general rubbing process is performed by rubbing the surface of the alignment film in one direction with a roller wound with a cloth such as nylon.
[0040]
At this time, if the resist constituting the spacer 26 is not subjected to heat treatment, the hardness of the resist is low, so that the spacer 26 is scraped during the rubbing process and a desired cell gap cannot be maintained. However, in the present embodiment, the resist constituting the spacer 26 is made into a semi-cured state by heat treatment, so that the spacer 26 is prevented from being scraped by the rubbing process.
[0041]
Thereafter, the spacer 26 is re-exposed and the resist constituting the spacer 26 is photolyzed. Thereby, the spacer 26 is softened and the adhesiveness is improved.
[0042]
Next, as shown in FIG. 4, a sealing agent 36 made of a thermosetting resin is applied on the counter substrate 20 so as to surround the display area. However, the sealing agent 36 is not applied to a portion that becomes a liquid crystal injection port for injecting liquid crystal between the substrates.
[0043]
After that, as shown in FIG. 3C, the TFT substrate 10 and the counter substrate 20 are aligned and superposed, and heat-treated at the curing temperature of the sealant 36 while applying pressure in the heat treatment apparatus. 36 is cured. As a result, the spacer 26 is once softened while being pressurized and then cured, and is firmly bonded to the TFT substrate 10 and the counter substrate 20. The sealing agent 36 needs to be cured at a temperature at which the effect of the rubbing treatment applied to the alignment films 19 and 25 is not lost. Hereinafter, a structure (panel before liquid crystal sealing) formed by bonding the TFT substrate 10 and the counter substrate 20 is referred to as an empty panel.
[0044]
Next, liquid crystal 30 is injected between the TFT substrate 10 and the counter substrate 20 by vacuum injection. That is, a container containing liquid crystal and an empty panel are placed in a vacuum chamber, and the vacuum chamber is evacuated to a vacuum state. Thereafter, the liquid crystal inlet of the empty panel is placed in the liquid crystal, and the inside of the vacuum chamber is returned to atmospheric pressure. Then, the liquid crystal enters the empty panel due to the difference between the pressure in the internal space of the empty panel and the atmospheric pressure, and the liquid crystal is filled in the internal space of the panel. Thereafter, a panel filled with liquid crystal is sandwiched between two flat plates to push out excess liquid crystal, and the liquid crystal injection port is sealed with a sealing resin. In this way, the liquid crystal panel according to the present embodiment is completed.
[0045]
The photoresist film to be the spacer 26 is preferably formed from a polysilane resist. The polysilane resist is softened by exposure and silanol is formed. Since this silanol exhibits strong adhesion to the alignment films 19 and 25 made of polyimide, the spacer 26 can be firmly bonded to the TFT substrate 10 and the counter substrate 20.
[0046]
Moreover, it is preferable that an aryl group is introduced into the polysilane resist. When an aryl group is introduced into the polysilane resist, developability with an aqueous alkali solution is improved, exposure time is shortened and resolution is expected to be improved. The reason why the developability of the polysilane resist is improved by the annealing group is not clear, but is considered as follows.
[0047]
That is, when a polysilane resist is exposed, silanol is generated in the resist. This silanol is soluble in an alkaline aqueous solution. However, when an aryl group is introduced into the side chain of the polysilane, the silanol produced reacts with each other compared to the case where an alkyl group is introduced into the side chain. It becomes difficult and stable without crosslinking. Thereby, it comes to show the strong solubility with respect to aqueous alkali solution, and developability improves.
[0048]
However, in the present invention, the spacer 26 may be formed of a positive photoresist having a property of being softened by exposure, and the material of the spacer 26 is not limited to polysilane resist according to the present embodiment.
[0049]
In the present embodiment, since the alignment film is rubbed after the spacer 26 is in a semi-cured state, the spacer 26 is hardly scraped off during the rubbing process. For this reason, the cell gap of a liquid crystal display panel can be made into a desired value.
[0050]
In the present embodiment, since the spacer 26 is bonded to both the TFT substrate 10 and the counter substrate 20, resistance to external pressure (stress resistance) is high. For example, as shown in FIG. 5, even if an external pressure is applied to the portion between the spacers, the substrate 30 does not move away from the spacers 26, and a large variation in the cell gap is avoided. Thereby, generation of interference fringes, variations in color tone, and variations in drive voltage characteristics are avoided.
[0051]
The present invention relates to a twisted nematic (TN) liquid crystal, a super twisted nematic (STN) liquid crystal, a nematic cholesteric phase transition liquid crystal, a polymer dispersed liquid crystal, a ferroelectric liquid crystal, an antiferroelectric liquid crystal, and a twisted grain boundary liquid crystal. In addition, the present invention can be applied to a liquid crystal panel using a smectic A phase liquid crystal or the like exhibiting an electroclinic effect.
[0052]
In the above-described embodiment, the case where the present invention is applied to a transmissive liquid crystal panel has been described. However, the scope of the present invention is not limited to the transmissive liquid crystal panel. The present invention can be applied to a reflective liquid crystal panel and a spatial light modulator other than a transmissive liquid crystal panel.
[0053]
Hereinafter, the results of examining the display quality when the liquid crystal panel according to the example of the present invention is actually manufactured and the external pressure is applied will be described in comparison with the comparative example.
[0054]
(Example 1)
Two glass substrates having a length of 200 mm, a width of 100 mm, and a thickness of 1.1 mm were prepared. And the ITO film | membrane was formed on one surface of these glass substrates, respectively, and it was set as the transparent electrode.
[0055]
Next, using a spin coater, a polyimide solution having a concentration of 3 wt% is applied on the transparent electrode at a rotational speed of 2000 rpm to form a polyimide film, and then the polyimide film is baked at a temperature of 200 ° C. for 30 minutes. An alignment film was obtained.
[0056]
A positive polysilane resist was applied to one of the two glass substrates on which the transparent electrode and the alignment film were formed in this manner using a spin coater to form a resist film having a thickness of 2.0 μm.
[0057]
Next, the glass substrate was placed on a hot plate, and the resist film was pre-baked at a temperature of 100 ° C. for 1 minute. Then, 800 mJ / cm is applied to the resist film through an exposure mask provided with a predetermined pattern. ² After being exposed to ultraviolet rays (UV) with an energy of 1, development processing was performed with an alkali developer (TMAH 2.38%) to form cylindrical spacers having a diameter of 10 μm arranged in a horizontal direction and a vertical direction at a pitch of 100 μm. . Thereafter, the surface of the glass substrate was washed with pure water, and then dried by heating on a hot plate at a temperature of 130 ° C. for 1 minute.
[0058]
Next, both glass substrates were rubbed. Thereafter, an epoxy resin was used as a sealing agent, and the sealing agent was applied on one glass substrate by a printing method. At this time, the sealing agent was applied in a frame shape along the edge of the glass substrate except for a portion serving as a liquid crystal injection port. In addition, the epoxy resin used as the sealing agent is cured at a temperature of 150 ° C. for 1 hour.
[0059]
Next, 100mJ / cm on the spacer ² UV light was re-exposed with the energy of and the resist constituting the spacer was photolyzed.
[0060]
It has been previously confirmed that when the polysilane resin used for the resist under the above conditions is re-exposed, the average molecular weight is reduced by about 30%. Further, as a result of IR (infrared) spectroscopic measurement, it has been confirmed that silanol increases in the resist after re-exposure.
[0061]
Next, after bonding this pair of glass substrates so that the transparent electrodes face each other, they were put in a vacuum bag. And it heated for 1 hour at the temperature of 150 degreeC, and the epoxy resin which is a sealing agent was hardened. By this heating, the spacer was once softened and bonded to the substrate, and then cured while bonded to the substrate.
[0062]
A ferroelectric liquid crystal is injected by a vacuum injection method between a pair of substrates (empty panels) bonded by a sealant and a spacer in this way, and the liquid crystal injection port is sealed to produce a ferroelectric liquid crystal display panel. did.
[0063]
Polarizing plates were arranged above and below the liquid crystal display panel, respectively. The polarizing plate was arranged so that the polarization axes were orthogonal (cross Nichols).
[0064]
Then, the center of the liquid crystal display panel was pushed with a pen load of 100 g with a pen tip having a tip diameter of 0.8 mm. However, there was no change in display color around the pen tip, and stress resistance was recognized against external forces that reduce the cell gap.
[0065]
Moreover, although the center part of the liquid crystal display panel was supported and a load of 300 g was applied to both ends, no change in display color was observed over the entire screen.
[0066]
(Example 2)
A positive type novolac resist is used as a resist, and the exposure energy of ultraviolet rays at the time of spacer formation is 50 mJ / cm. ² , UV energy at the time of re-exposure is 30mJ / cm ² A liquid crystal display panel was produced under the same conditions as in Example 1 except for the above.
[0067]
As a result of testing this liquid crystal display panel in the same manner as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance as in Example 1.
[0068]
(Example 3)
A liquid crystal display panel was produced under the same conditions as in Example 1 except that a photoresist in which a phenyl group was introduced as an aryl group into the side chain of polysilane was used as a positive photoresist serving as a spacer.
[0069]
As a result of testing this liquid crystal display panel by the same method as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance characteristics as in Example 1.
[0070]
Example 4
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that twisted nematic liquid crystal was used as the liquid crystal sealed between the substrates and the cell gap was 6 μm.
[0071]
As a result of testing this liquid crystal display panel by the same method as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance characteristics as in Example 1.
[0072]
(Example 5)
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that a super twisted nematic liquid crystal was used as the liquid crystal to be sealed between the substrates, and the cell gap was 6 μm.
[0073]
As a result of testing this liquid crystal display panel by the same method as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance characteristics as in Example 1.
[0074]
(Example 6)
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that nematic cholesteric phase transition type liquid crystal was used as the liquid crystal sealed between the substrates, and the cell gap was changed to 6 μm.
[0075]
As a result of testing this liquid crystal display panel by the same method as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance characteristics as in Example 1.
[0076]
(Example 7)
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that antiferroelectric liquid crystal was used as the liquid crystal sealed between the substrates.
[0077]
As a result of testing this liquid crystal display panel by the same method as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance characteristics as in Example 1.
[0078]
(Example 8)
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that twist grain boundary liquid crystal was used as the liquid crystal sealed between the substrates and the cell gap was changed to 6 μm.
[0079]
As a result of testing this liquid crystal display panel by the same method as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance characteristics as in Example 1.
[0080]
Example 9
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that smectic A-phase liquid crystal was used as the liquid crystal sealed between the substrates and the cell gap was 6 μm.
[0081]
As a result of testing this liquid crystal display panel by the same method as in Example 1, it was confirmed that the liquid crystal display panel had good stress resistance characteristics as in Example 1.
[0082]
(Example 10)
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that the liquid crystal was injected between the substrates by the dropping injection method. That is, as shown in FIG. 6, the sealing agent 36 was applied on the TFT substrate 20 on which the spacers were formed so as to surround the display area. Thereafter, the ferroelectric liquid crystal 30 was dropped on the TFT substrate 20 by a dispenser. In this case, the dropping amount of the liquid crystal 30 was determined according to the size of the panel and the cell gap, and was dropped after being dispersed on the TFT substrate 20. Thereafter, a counter substrate (not shown) was superimposed on the TFT substrate 20, and the sealing agent 36 was cured by heating.
[0083]
The liquid crystal display panel thus manufactured was tested in the same manner as in Example 1. As a result, it was confirmed that the liquid crystal display panel had good stress resistance as in Example 1. In Example 10, since the liquid crystal was sealed between the substrates by the dropping injection method, it was possible to significantly reduce the time required for manufacturing compared to Example 1.
[0084]
(Comparative Example 1)
A liquid crystal display panel was produced under the same conditions as in Example 1 except that the spacer after the rubbing treatment was not re-exposed.
[0085]
This liquid crystal display panel was tested in the same manner as in Example 1. As a result, when the center of the panel was pushed with a pen load of 100 g with a pen tip having a tip diameter of 0.8 mm, a display defect in which a change in display color was observed around the pen tip occurred. From this, it was found that the spacer and one substrate were not joined.
[0086]
(Comparative Example 2)
A liquid crystal display panel was manufactured under the same conditions as in Example 1 except that a negative polysilane resist was used instead of the positive polysilane resist.
[0087]
This liquid crystal display panel was tested in the same manner as in Example 1. As a result, when the center of the panel was pushed with a pen load of 100 g with a pen tip having a tip diameter of 0.8 mm, a display defect in which a change in display color was observed around the pen tip occurred. From this, it was found that the spacer and one substrate were not joined.
[0088]
(Supplementary Note 1) A pair of substrates disposed opposite to each other, a plurality of spacers formed of a positive photosensitive resin, bonded to both of the pair of substrates, and maintaining a constant interval between the pair of substrates; A liquid crystal panel comprising: a liquid crystal sealed between the pair of substrates.
[0089]
(Supplementary note 2) The liquid crystal panel according to supplementary note 1, wherein an alignment film subjected to a rubbing process is formed on each of the pair of substrates.
[0090]
(Supplementary note 3) The liquid crystal panel according to supplementary note 1, wherein the spacers are arranged at regular intervals.
[0091]
(Supplementary Note 4) The liquid crystal is a twisted nematic liquid crystal, a super twisted nematic liquid crystal, a nematic cholesteric phase transition liquid crystal, a polymer dispersed liquid crystal, a ferroelectric liquid crystal, an antiferroelectric liquid crystal, a twist grain boundary liquid crystal, or a smectic A. The liquid crystal panel according to appendix 1, wherein the liquid crystal panel is any one selected from the group consisting of phase liquid crystals.
[0092]
(Additional remark 5) The process of preparing a 1st board | substrate and a 2nd board | substrate, The process of apply | coating positive type photosensitive resin on the said 1st board | substrate, and forming the photosensitive resin film | membrane, The said photosensitive resin film | membrane The first substrate and the second substrate are joined by an exposure / development process in which a spacer is formed by performing exposure and development processes on the substrate, a re-exposure process in which the spacer is re-exposed, and a sealant and the spacer. And a liquid crystal sealing step of sealing a liquid crystal in a space surrounded by the sealing agent, the first substrate, and the second substrate.
[0093]
(Supplementary note 6) The method for manufacturing a liquid crystal panel according to supplementary note 5, further comprising a rubbing step of performing a rubbing process on the first substrate between the exposure / development step and the re-exposure step.
[0094]
(Supplementary note 7) The method of manufacturing a liquid crystal panel according to supplementary note 6, further comprising a step of heat-treating the spacer to make a semi-cured state between the exposure / development step and the rubbing step.
[0095]
(Additional remark 8) The manufacturing method of the liquid crystal panel of Additional remark 5 characterized by using a polysilane resist as positive photosensitive resin.
[0096]
(Supplementary note 9) The method for producing a liquid crystal panel according to supplementary note 8, wherein the polysilane resist contains an aryl group.
[0097]
(Additional remark 10) The said polysilane resist produces | generates silanol by the said re-exposure, The manufacturing method of the liquid crystal panel of Additional remark 8 characterized by the above-mentioned.
[0098]
(Additional remark 11) The said liquid-crystal enclosure process is implemented by the vacuum injection method, The manufacturing method of the liquid crystal panel of Additional remark 5 characterized by the above-mentioned.
[0099]
(Additional remark 12) The said liquid-crystal enclosure process is implemented by the dropping injection method, The manufacturing method of the liquid crystal panel of Additional remark 5 characterized by the above-mentioned.
[0100]
(Supplementary note 13) The method for manufacturing a liquid crystal panel according to supplementary note 5, wherein, in the liquid crystal sealing step, the spacer is joined to the second substrate in a heated and softened state.
[0101]
(Additional remark 14) The manufacturing method of the liquid crystal panel of Additional remark 5 characterized by using the thermosetting resin hardened | cured at temperature higher than the curing temperature of the said photosensitive resin as said sealing agent.
[0102]
(Supplementary Note 15) As the liquid crystal, twisted nematic liquid crystal, super twisted nematic liquid crystal, nematic cholesteric phase transition liquid crystal, polymer dispersed liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, twist grain boundary liquid crystal, and smectic A 6. The method for manufacturing a liquid crystal panel according to appendix 5, wherein any one selected from the group consisting of phase liquid crystals is used.
[0103]
【The invention's effect】
As described above, according to the liquid crystal panel of the present invention, since the spacer is bonded to both of the pair of substrates, the substrate and the spacer are not separated even when an external pressure is applied to the liquid crystal panel. A significant change in (substrate spacing) is avoided. Thereby, generation of interference fringes, variations in color tone, and variations in drive voltage characteristics are avoided.
[0104]
In addition, according to the method for manufacturing a liquid crystal panel of the present invention, the first substrate and the second substrate are overlaid after the spacer is formed using the positive photosensitive resin and then re-exposed. The first and second substrates can be firmly bonded. Thereby, even if an external pressure is applied, a significant change in the cell gap is avoided, and the occurrence of interference fringes, variations in color tone, and variations in drive voltage characteristics are avoided.
[Brief description of the drawings]
FIG. 1 is a plan view showing one pixel of a liquid crystal panel according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line II of FIG.
3A to 3C are cross-sectional views showing a method of manufacturing a liquid crystal panel according to an embodiment of the present invention in the order of steps.
FIG. 4 is a plan view showing a sealing agent applied on a substrate.
FIG. 5 is a schematic diagram showing a change in cell gap when an external pressure is applied to the liquid crystal panel according to the embodiment of the present invention.
FIG. 6 is a schematic diagram showing a dropping injection method.
FIG. 7 is a schematic diagram showing a change in cell gap when an external pressure is applied to a conventional liquid crystal panel.
[Explanation of symbols]
10, 60 ... TFT substrate,
11, 21 ... Glass substrate,
13: Gate insulating film,
12 ... Gate bus line,
14: Data bus line,
15 ... TFT,
15d ... drain electrode,
15s ... source electrode,
16 ... Channel protective film,
17, 23 ... Insulating film
17a ... contact hole,
18 ... pixel electrode,
19, 25 ... alignment film,
20, 50 ... counter substrate,
22 ... Black matrix,
24 ... Common electrode,
26, 51 ... spacers,
30 ... Liquid crystal,
35 ... resist film,
36 ... Sealing agent.

Claims (2)

Preparing a first substrate and a second substrate;
Applying a positive photosensitive resin on the first substrate to form a photosensitive resin film;
An exposure / development process in which the photosensitive resin film is exposed and developed to form spacers;
Heat treating the spacer to a semi-cured state;
A rubbing step of performing a rubbing process on the first substrate;
A re-exposure step of re-exposing the spacer;
Liquid crystal encapsulation that joins the first substrate and the second substrate by a sealant and the spacer and encloses liquid crystal in a space surrounded by the sealant, the first substrate, and the second substrate. Process and
Are performed in the above-described order .   2. The method of manufacturing a liquid crystal panel according to claim 1, wherein a polysilane resist is used as the positive photosensitive resin.

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