JP2002014364A - Liquid crystal display element and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display element with high reliability which can prevent a transparent electrode from being broken by a crack as much as possible, and a method for manufacturing the same. SOLUTION: In the liquid crystal display element constituted so that a liquid crystal layer 5 is held between translucent resin substrates 1 and 2, and transparent electrodes 3 and 4 consisting of ITO are formed on the facing surface of each substrates 1 and 2, when X-ray diffraction peak strength of the surface (2, 2, 2) of the ITO is set to H1 and the X-ray diffraction peak strength of the surface (2, 2, 2) at the time of crystallizing the ITO completely is set to H2, crystallinity C1 of the ITO is in the area expressed by the formula of C1=H1/H2<0.6. Besides, all the production processes of the liquid crystal display element are performed under such a temperature condition that the ITO is maintained in an amorphous state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly, to a liquid crystal display device having a liquid crystal layer sandwiched between two light-transmitting resin substrates and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal display element in which a liquid crystal layer is sandwiched between two light-transmitting resin substrates, a transparent substrate made of ITO (Indium Tin Oxide) is formed on the substrate. Electrodes are formed to drive the liquid crystal one pixel at a time.

[0003] By the way, when an ITO thin film is crystallized, flexibility is insufficient, and when an ITO electrode is formed on a flexible film substrate to manufacture a liquid crystal cell,
If the step of bending the substrate is present, there is a problem that cracks occur in the ITO electrode and the production yield decreases. In addition, in a liquid crystal display element that can be used like a paper even after manufacturing, the IT
There is a problem that the O electrode is disconnected and a display failure occurs.

Japanese Patent Application Laid-Open No. Hei 8-21399 describes that in a liquid crystal display element, when ITO is crystallized, flexibility is insufficient, so that amorphous ITO is preferable. However, this publication does not disclose any measures for preventing crystallization of ITO in the manufacturing process of the liquid crystal display element.

Accordingly, an object of the present invention is to provide a highly reliable liquid crystal display element capable of preventing disconnection of a transparent electrode due to a crack as much as possible and a method of manufacturing the same.

[0006]

In order to achieve the above object, a liquid crystal display device according to the present invention has a liquid crystal layer sandwiched between two light-transmitting resin substrates. In a liquid crystal display device in which a transparent electrode made of ITO is formed on at least one surface, the crystallinity C
1 indicates that the X-ray diffraction peak intensity of the (2, 2, 2) plane of ITO is H1, and (2, 2, 2) when the ITO is completely crystallized.
2) Assuming that the X-ray diffraction peak intensity of the surface is H2,
It is characterized by being within the range represented by. C1 = H1 / H2 <0.6 (Equation 1)

Further, in the manufacturing method according to the present invention, a liquid crystal layer is sandwiched between two light-transmitting resin substrates, and a transparent electrode made of ITO is formed on at least one surface of the two substrates. In the method of manufacturing a liquid crystal display element described above, all the manufacturing steps are performed under a temperature condition for maintaining the ITO in an amorphous state.

In the manufacturing method according to the present invention, it is preferable that the temperature of the manufacturing process is maintained so that the above-mentioned formula 1 is satisfied when a liquid crystal display element having a liquid crystal layer sandwiched between the resin substrates is completed. Further, during the manufacturing process, the method may include at least one of a step of bonding the two resin substrates while applying heat and pressure or a step of thermocompression bonding a circuit pattern for external connection to the extraction electrode portion of the transparent electrode. Good. Then, the crystallinity C2 of the ITO immediately before the step of bonding the two resin substrates or the step of thermocompression bonding the circuit pattern for external connection is determined by the value of ( Assuming that the X-ray diffraction peak intensity of the (2, 2, 2) plane is H3, the intensity is preferably in the range represented by the following expression 2. C2 = H3 / H2 <0.4 (Equation 2)

Further, it is preferable that all the manufacturing steps are performed at a temperature lower than the crystallization start temperature of the ITO.

In the liquid crystal display device and the method of manufacturing the same according to the present invention, ITO used as a material of a transparent electrode
Is formed on the substrate surface by using, for example, sputtering. By adjusting the film forming conditions such as sputtering, an almost amorphous ITO film can be obtained. Crystallization of ITO reduces flexibility and cracks easily.
More preferably, ITO is in an amorphous state. However, when ITO is annealed at a high temperature for a long time, it easily crystallizes. If the ITO is crystallized at the time of completion of the liquid crystal cell, the ITO is easily cracked by an external force received during use after commercialization.

In order to obtain a highly reliable liquid crystal display element which is less likely to crack during use, the degree of progress of crystallization at the time of completion of the liquid crystal display element becomes a problem. The degree of crystallization of ITO can be evaluated by the X-ray diffraction peak intensity on the (2, 2, 2) plane. At the time of completion of the liquid crystal display element, (2, 2,
The X-ray diffraction peak intensity of the (2), (2), (2) plane when the crystal was completely crystallized by applying annealing at a sufficiently high temperature to the ITO for a sufficiently long time was changed to H1.
As 2, the crystallinity C1 is defined as C1 = H1 / H2,
By controlling the value in the range of C1 <0.6, a highly reliable liquid crystal display element free from cracks can be obtained.

On the other hand, most of the cracks generated during the manufacture of the liquid crystal display element are caused by the process of bending the resin substrate,
Occurs because a force acts on O. In particular, cracks are likely to occur in a process in which heat and pressure are simultaneously applied to ITO. Such a process (hereinafter, referred to as a heating / pressing process)
Among them, the step of bonding two resin substrates sandwiching the liquid crystal layer and the step of thermocompression bonding the circuit pattern for the external connection terminal are steps particularly likely to cause cracks in ITO. In order to prevent the generation of cracks in these heating / pressing steps, the degree of progress of ITO crystallization immediately before these heating / pressing steps becomes a problem. The crystallinity C2 at the stage immediately before the heating / pressing step is defined as C2 = H3 /, where the X-ray diffraction peak intensity of the (2,2,2) plane at the stage immediately before the heating / pressing step is H3. By defining it as H2 and controlling it in the range of C2 <0.4, it is possible to prevent cracks from occurring in the heating / pressing step.

The degree of crystallization after the annealing of amorphous ITO is determined by the annealing temperature and the annealing time. The higher the annealing temperature and the longer the annealing time, the more the crystallization proceeds. However, the relationship between the annealing temperature and the crystallization progress rate is not a linear relationship. When annealing is performed at a temperature exceeding a certain temperature, crystallization rapidly progresses as the annealing time increases, and at a temperature lower than that, crystallization hardly progresses even if the annealing time is increased.

Therefore, within the normal annealing time range (several hours or less), the anneal temperature at which the crystallization of ITO hardly progresses is set as the crystallization start temperature Ts. Assuming that the X-ray diffraction peak intensity of the (2, 2, 2) plane after annealing the amorphous ITO for 1 hour is H4, H4 / H2 = 1/5 (H2 is ITO (Intensity of the X-ray diffraction peak when crystallized is completely crystallized). By performing annealing added for various purposes during the manufacturing process at a temperature equal to or lower than the crystallization start temperature Ts, it is possible to prevent the progress of crystallization of ITO during the manufacturing process and prevent cracks from occurring during the manufacturing process. As a result, it is possible to prevent the occurrence of cracks during use after completion of the display element.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display device and a method for manufacturing the same according to the present invention will be described with reference to the accompanying drawings.

(Liquid Crystal Display Device, See FIG. 1) FIG. 1 shows a sectional structure of a liquid crystal display device according to one embodiment of the present invention.

In FIG. 1, reference numerals 1 and 2 denote two opposing light-transmitting resin substrates. Examples of such resin substrates 1 and 2 include polycarbonate, polyether sulfone, and polyethylene terephthalate, and any thin and flexible film can be used.

On the surfaces of the resin substrates 1 and 2, transparent electrodes 3 and 4 are disposed so as to face each other. The present embodiment has a simple matrix electrode structure in which a plurality of strip-shaped transparent electrodes 3 and 4 face each other so as to be orthogonal to each other. Note that the present invention can be used for not only a simple matrix but also an active matrix electrode structure (for example, a pixel electrode, a TFT-type source electrode, a MIM-type counter electrode, and the like). ITO is used as a transparent electrode material.

A liquid crystal layer 5 is sandwiched between two resin substrates 1 and 2. As a typical liquid crystal material used for a liquid crystal display device having the configuration shown in FIG. 1, for example, a polymer dispersed liquid crystal, a cholesteric nematic phase transition liquid crystal, a liquid crystal that selectively reflects light in a visible wavelength range (cholesteric liquid crystal,
A chiral nematic liquid crystal obtained by adding a chiral material to a nematic liquid crystal). In the latter case, a substrate 2 that absorbs light (such as a black substrate or a substrate painted black) may be used as the substrate 2 on the side opposite to the observation side.

Of course, if necessary, a member such as a polarizing plate, a light reflecting layer, and a color filter may be provided in addition to the structure shown in FIG. 1 to provide a twisted nematic liquid crystal, a super twisted nematic liquid crystal, and a smectic phase at room temperature. A ferroelectric liquid crystal or an antiferroelectric liquid crystal showing the following can be used.

A seal wall 6 for sealing liquid crystal is provided outside the display area on the outer periphery of the resin substrates 1 and 2. As the sealing material, for example, a thermosetting resin or the like can be used.

In order to keep the liquid crystal layer 5 at a predetermined thickness, a spacer 7 and a resin structure 8 are arranged. Spacer 7
And the resin structure 8 may be both used, or only one of them may be used. The spacer 7 may be mixed in the resin structure 8. As the material of the spacer 7, finely divided glass fiber, inorganic material such as ball-shaped silicate glass and alumina powder, or organic synthetic spherical particles such as divinylbenzene-based cross-linked polymer and polystyrene-based cross-linked polymer are used. It is possible. If a resin-coated spacer is used, the spacer 7 can be fixed on the substrates 1 and 2 by a heat treatment.

As the resin structure 8, various resin materials can be used, and an organic material which does not cause a chemical reaction with a liquid crystal material to be used and has a suitable elasticity is preferably used. Examples of such materials include polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polymethacrylic resin, polyacrylate resin, polystyrene resin, polyamide resin, polyethylene resin, polyurethane resin, polypropylene resin, fluorine resin Resin,
Polyacrylonitrile resin, polyvinyl ether resin,
There are a polyvinyl ketone resin, a polyether resin, a polycarbonate resin, a chlorinated polyether resin, a polyvinyl pyrrolidone resin, and a saturated polyester resin, and a plurality of these may be used in combination.

The resin structure 8 can be made of not only a thermoplastic resin but also a thermosetting resin, a photo-setting resin or the like.

Further, insulating films 9a and 9b are provided on the substrates 1 and 2, respectively, in order to prevent short-circuiting of the electrodes 3 and 4. As a material of the insulating films 9a and 9b, an inorganic material such as silicon oxide, an organic material such as a polyimide resin or an epoxy resin, or the like can be used.

Further, alignment control films 10a and 10b for controlling the molecular alignment direction of the liquid crystal may be provided on the insulating films 9a and 9b, respectively. Such an orientation control film 10a,
A typical example of the material 10b is a polyimide resin.

(Manufacturing method, see FIGS. 2 and 3) The liquid crystal display device can be manufactured as follows.

First, as shown in FIGS. 2A and 2B,
A transparent electrode material made of ITO is formed on the washed and dried substrates 1 and 2 by an EB (electron beam) evaporation method, a sputtering method, a CVD method, or the like. For patterning the transparent electrode, a photolithography method may be used, or a laser etching method may be used.

Then, as shown in FIGS. 2C and 2D, insulating films 9a and 9b and orientation control films 10a and 10b are applied on the electrode surfaces of both substrates 1 and 2. For these coatings, a spin coating method, a bar coating method, a roll coating method, or the like can be used. After coating, the coating material is annealed to evaporate the solvent. If necessary, the alignment control films 10a and 10b (for example, polyimide resin) may be subjected to an alignment treatment.

Next, on the substrate 2, FIG.
As shown in (B ′), spacers 7 are scattered to form seal walls 6 around the substrate 2. By providing the seal wall 6, the liquid crystal material can be reliably sealed between the substrates 1 and 2, and the substrates 1 and 2 can be supported in a wide area together with the resin structure 8, so that the gap between the substrates can be reduced. It can be kept uniform over the entire display element.

In FIG. 2 and FIG. 3 described later,
Although the seal wall 6 is disposed on the orientation control film 10, the position at which the seal wall 6 is provided may be appropriately determined in consideration of the adhesiveness to the surface on which the seal wall 6 is provided, and the like, as shown in FIG. May be provided directly on the substrate 2 and the electrode 4, or may be provided on the insulating film 9.

For dispersing the spacers, a method of disposing them on a substrate by a method such as a dry dispersing method, a wet dispersing method, dipping, or air adhesion can be adopted. Note that spacers may be sprayed on the substrate on which the resin structure is manufactured, or the spacer may be included at the same time when the resin structure is manufactured. When a resin-coated spacer is used as the spacer, it is preferable to apply annealing after spraying to fix the spacer on the substrate.

The spacer 7 'may be included in the seal wall 6. The size of the spacer 7 'included in the seal wall 6 can be substantially the same as the size of the spacer 7 scattered in the display area.

On the other hand, on the substrate 1, as shown in FIG. 2E, resin materials 8 'are arranged in a predetermined arrangement by a printing method using a screen plate or a metal mask, a dispenser or an ink jet method. Then, the resin material 8 ′ is cured to form the resin structure 8. As the resin material 8 ′, the above-described thermoplastic resin, thermosetting resin, photocurable resin, electron beam curable resin, or the like can be used, and the resin is softened at a temperature equal to or lower than the softening temperature of the substrate 1 after being cured. I just need.

In the manufacturing method shown in FIG. 2, since the seal wall 6 is provided on a substrate different from the resin structure 8, it is easy to change the forming method and the material of the seal wall 6 and the resin structure 8. become. For example, a fine resin structure 8 is formed in the display area using a screen plate or a metal mask, and a dispenser is used to form the seal wall 6 outside the display area. Can be suppressed. Further, as the resin structure 8 in the display area, a resin which emphasizes fineness and adhesiveness is selected, and as the seal wall 6, high airtightness is provided so that impurities do not enter the liquid crystal layer from the outside, and long-term reliability is obtained. Can be selected. Of course, both can be provided on the same substrate.

When the seal wall 6 is made of the same resin material as the resin structure 8 and the seal wall 6 and the resin structure 8 are formed on the same substrate by the same method, the steps can be simplified. Furthermore, by simultaneously forming the seal wall 6 and the resin structure 8, the production process can be minimized.

After the substrate before bonding is thus prepared, the substrate 2 is placed on a heat-producible flat substrate such as a hot plate 30 capable of vacuum suction as shown in FIG.
The substrate 2 is heated. By heating the substrate 2, the viscosity of the high-viscosity liquid crystal material can be reduced, so that when the two substrates are overlapped, entrapment of air bubbles between the substrates can be reduced.

If the sealing wall 6 is set in a semi-cured state before the two substrates are bonded, the two substrates can be bonded more reliably. For example, when a thermosetting resin material is used as the material of the seal wall 6, the seal wall 6 can be brought into a semi-cured state by heating with the hot plate 30.

Next, the substrate 1 on which the resin structure 8 is formed
And the substrate 2 on which the spacer 7 and the seal wall 6 are arranged.

FIG. 3 shows how the two substrates are bonded together. In bonding the two substrates, at least one of the substrates 1 and 2 is heated to soften the resin material 8 '. Then, as shown in FIG. 3A, the liquid crystal material 5 'is dropped on the end of the substrate 1 fixed on the hot plate 30, and the substrate 2 is dropped on the end where the liquid crystal material 5' is dropped. Overlap the ends of. Then, the substrate 2 is bent so as to lift the end on the opposite side of the substrate 2, and the liquid crystal material 5 ′ is superposed while being spread while pressing the substrate 2 against the substrate 1 with a pressing member. As the pressing member for pressing the substrate 2, a heat generating roller is preferably used. FIG. 3A shows an example in which the substrate 2 is pressed by the pressing roller 51 and the pressing and heating roller 52.

The substrate 1 is placed on a hot plate 30 which has been heated to a predetermined temperature, with the surface on which the alignment film 10a is formed facing up, and a liquid crystal material 5 'is applied to the edge of the substrate 1. Drip. The liquid crystal material 5 'may be dropped in an amount equal to or greater than the volume surrounded by the seal wall 6 and the substrates 1 and 2.

The seal wall 6 is preferably kept in a semi-cured state until the substrates 1 and 2 are overlaid. The semi-cured state can suppress the elution of the sealing resin component into the liquid crystal material 5 '. Note that, as in the present manufacturing method, when a seal wall is provided on a substrate different from the substrate provided with the resin structure and the two substrates are bonded to each other, heating of the seal wall after semi-curing may be performed only during pressurization. It is possible to suppress a decrease in the adhesive force due to excessive curing of the seal wall.

After bonding, as shown in FIG. 3B, the substrates 1 and 2 are sandwiched between a pair of flat substrates 75 via a silicon sheet 76, a load is applied, and the temperature is maintained at an appropriate temperature and time. After a lapse of time sufficient to complete the bonding, the bonded substrates are cooled, and the flat substrate 75 is removed to form a liquid crystal display element. It is preferable that the cooling is performed gradually while applying a load.

In addition to the above-described manufacturing method of filling the liquid crystal material while bonding the two substrates, the liquid crystal material may be vacuum-injected from the opening provided in the seal wall 6 after the substrates 1 and 2 are bonded. Can also be produced.

A driver circuit for driving a display element by connecting an external connection circuit pattern such as a flexible circuit board to the electrode take-out portion provided around the obtained liquid crystal display element by thermocompression bonding using a heat seal or the like. Connect with

As described above, in manufacturing a liquid crystal display element,
Annealing is applied for various purposes. For example, annealing for evaporating the solvent after applying the insulating film or the orientation control film, annealing for fixing the bead spacer to the substrate, and the like are included. A hot plate or an oven can be used for these annealings. When using a hot plate, batch processing cannot be performed and single-wafer processing is performed.
The substrate can be heated to a high temperature in a short time. When an oven is used, batch processing is possible although heating takes time.

(Examples and Comparative Examples) Hereinafter, examples and comparative examples of the liquid crystal display device manufactured by the present inventors will be described.

Example 1 On a surface of two polyethersulfone resin substrates, ITO was sputtered to a thickness of 1000 Å. The obtained ITO
XRD (X-ray diffractometer) to check the crystal state of the film
As a result, no X-ray diffraction peak was observed, indicating that the film was in an amorphous state.

The ITO film was patterned by photolithography to form a transparent electrode pattern.

Next, an insulating film and an orientation control film were applied. The annealing of the insulating film and the annealing of the orientation control film are 140
C. for 1 hour each.

FIG. 4 shows the relationship between the annealing temperature and the XRD measurement result when annealing for 1 hour is performed. FIG. 5 shows the relationship between the annealing time at 140 ° C. and the XRD measurement results. From FIG. 4, it can be seen that the crystallization of ITO progresses rapidly when annealed at a temperature exceeding a certain temperature. Also, from FIG.
When annealing is performed at a temperature lower than that temperature, crystallization is very slow, and it may be determined that crystallization hardly progresses within a practical annealing time for manufacturing a liquid crystal display element. According to FIG. 4, the crystallization start temperature Ts of this ITO film is about 140 ° C. The numerical value of the crystallization start temperature Ts varies depending on the ITO film formation conditions.

Further, a resin-coated spacer was sprayed on one of the substrates, and was fixed by annealing at 140 ° C. for 1.5 hours. A seal wall for sealing a liquid crystal material was formed on the same substrate outside the display region by a screen printing method. On the other substrate, a plurality of resin structures were formed in a column shape by screen printing using a thermoplastic resin. Thereafter, the two substrates were bonded together to seal the liquid crystal material.

A driver circuit is connected to the obtained liquid crystal cell.
The flexible substrate using heat sealing.
Continued. Head pressure 20kgf /
cm ^TwoAt a head temperature of 140 ° C.

In order to examine the crystallization state at each stage of the above-described liquid crystal display element manufacturing process, the crystallization state of ITO was determined by XRD on a substrate annealed under the same thermal conditions as in the above-described liquid crystal display element manufacturing. Table 1 below shows the results of the examination. It is understood from FIGS. 4 and 5 that the annealing treatment for 10 minutes or less or 100 ° C. or less can be ignored because the effect of promoting ITO crystallization is sufficiently small. Therefore, only for annealing at a temperature of 140 ° C. or higher, XRD measurement was performed after annealing.

[0055]

[Table 1]

As is evident from Table 1, the X-ray diffraction peak intensity is at most 62.68 cps, indicating that a high non-crystallized state is maintained. As is clear from FIG. 4, the X-ray diffraction peak intensity is about 3 in a completely crystallized state.
Since it is 50 cps, in the case of Table 1, it is about 0.17 or less in terms of crystallinity.

FIG. 6 is a graph showing the relationship between the crystallinity of ITO and the crack generation rate. Crystallinity C on the horizontal axis
Indicate that the X-ray diffraction peak intensity when annealed at various temperatures for 1 hour is H1, and the X-ray diffraction intensity when the ITO is completely crystallized.
Assuming that the line diffraction peak intensity is H2, the ratio of H1 to H2 was calculated. The crack generation rate on the vertical axis is the number of cracks generated per 1 mm ² when wound around a rod having a diameter of 4 mm. FIG. 6 shows that the occurrence of cracks in ITO is more likely to occur as the crystallinity C increases. In order to prevent generation of cracks, ITO having a crystallinity C of 0.6 or less is desirable.

Such a crystalline state can be achieved by performing the annealing at a temperature lower than the crystallization start temperature Ts.
Cracks in ITO can be prevented during the manufacturing process or during use of the completed display element.

Under the above manufacturing conditions, the crystallinity C2 immediately before the heat seal thermocompression bonding was 0.18, and the crystallinity C1 at the time of panel completion was 0.17. The reason why C1 is slightly smaller than C2 is probably due to a measurement error.

No disconnection due to cracks in the ITO of the completed liquid crystal display element was observed. When a force of 10 kg was applied to the obtained liquid crystal display device as an external pressure of 1 cm ² , no crack was generated.

Example 2 Annealing of the insulating film and annealing of the orientation control film were each performed at 120 ° C. for 1 hour, and spacer heat treatment was performed at 120 ° C. for 1.5 hours. Other manufacturing conditions are the same as in the first embodiment. The crystallinity C2 immediately before the heat seal thermocompression bonding was 0.07. The crystallinity C1 at the time of completion of the liquid crystal display element was 0.07.

No disconnection due to cracks in the ITO of the completed liquid crystal display element was observed. When a force of 10 kg was applied to the obtained liquid crystal display device as an external pressure of 1 cm ² , no crack was generated.

Example 3 An insulating film annealing and an orientation control film annealing were performed at 150 ° C. for 1 hour and a spacer heat treatment was performed at 150 ° C. for 1.5 hours. Other manufacturing conditions are the same as in the first embodiment. The crystallinity C2 immediately before the heat seal thermocompression bonding was 0.4. The crystallinity C1 after the completion of the liquid crystal display element was 0.4.

No disconnection due to cracks in the ITO of the completed liquid crystal display element was observed. When a force of 10 kg was applied to the obtained liquid crystal display device as an external pressure of 1 cm ² , no crack was generated.

(Comparative Example 1) Annealing of the insulating film and annealing of the orientation control film were each performed at 160 ° C. for 1 hour, and spacer heat treatment was performed at 160 ° C. for 1.5 hours. Other manufacturing conditions are the same as in the first embodiment. The crystallinity C2 at the stage immediately before the heat seal thermocompression bonding was 0.95. The crystallinity C1 after the completion of the liquid crystal display element was 0.95.

In the completed liquid crystal display element, a large number of cracks occurred in the ITO of the display portion and the heat seal thermocompression bonding portion, so that many pixels did not operate normally.

(Annealing Conditions and Generation of Cracks) As described above, the present inventor examined the correlation between the annealing conditions of ITO and the crystallization and generation of cracks. Further, by controlling the crystallinity of the ITO to a predetermined value or less after the completion of the device, it was possible to prevent the occurrence of cracks in the ITO film during production and during use after production. Furthermore, it was confirmed that by annealing at a temperature lower than the crystallization start temperature, a liquid crystal display element can be manufactured without substantially crystallizing the ITO film.

Due to these functions and effects, there is no disconnection of the transparent electrode due to cracks, so that the production yield is high, and even during use, a display defect due to disconnection of the transparent electrode due to generation of cracks due to external pressure is generated. , And a highly reliable liquid crystal display element free of defects was obtained.

(Other Embodiments) The liquid crystal display device and the method of manufacturing the same according to the present invention are not limited to the above embodiments, but can be variously modified within the scope of the invention.

For example, in addition to a single liquid crystal cell configuration,
A liquid crystal display element capable of full-color display may be formed by laminating liquid crystal layers performing selective reflection of red, green, and blue, for example.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is an explanatory view showing a manufacturing process of the liquid crystal display element.

FIG. 3 is an explanatory view showing a manufacturing process of the liquid crystal display element.

FIG. 4 is a graph showing a relationship between an annealing temperature and an XRD measurement result.

FIG. 5 is a graph showing a relationship between an annealing time at a predetermined temperature and an XRD measurement result.

FIG. 6 is a graph showing the relationship between the crystallinity of ITO and the crack generation rate.

[Explanation of symbols]

 1, 2, resin substrate 3, 4, transparent electrode 5, liquid crystal layer 8, resin structure

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/1341 G02F 1/1341 5G307 G09F 9/30 339 G09F 9/30 339Z H01B 5/14 H01B 5/14 A (72) Inventor Masakazu Okada 2-313 Azuchicho, Chuo-ku, Osaka City, Osaka Prefecture F-term in Osaka International Building Minolta Co., Ltd. 2H088 EA02 FA04 FA09 FA16 FA17 FA24 GA02 HA02 JA05 KA02 MA16 MA17 2H089 LA07 LA08 LA09 LA20 MA01X MA04X NA09 NA22 NA25 NA43 NA45 NA48 NA55 NA56 NA58 NA60 QA02 QA11 QA12 QA13 QA14 RA05 TA02 2H090 HB08Y HC05 HC15 HD14 JB03 JC11 JC17 KA05 LA01 MA04 MB10 2H092 GA05 HA04 KB23 NA25 NA04 NA23 NA04 NA23 NA25 NA28 FB12 5G307 FA02 FB01 FC03

Claims (8)

[Claims] 1. A liquid crystal display device in which a liquid crystal layer is sandwiched between two light-transmitting resin substrates, and a transparent electrode made of ITO is formed on at least one surface of the two substrates. The crystallinity C1 of the ITO is (2, 2, 2) of the ITO.
H1 is the X-ray diffraction peak intensity of the surface, and H2 is the X-ray diffraction peak intensity of the (2,2,2) plane when the ITO is completely crystallized. C1 = H1 / H2 <0.6 (Equation 1) 2. The liquid crystal display device according to claim 1, further comprising a resin structure for keeping the thickness of the liquid crystal layer at a predetermined value between the two resin substrates. 3. Production of a liquid crystal display device in which a liquid crystal layer is sandwiched between two light-transmitting resin substrates, and a transparent electrode made of ITO is formed on at least one surface of the two substrates. A method of manufacturing a liquid crystal display element, wherein all the manufacturing steps are performed under a temperature condition that keeps the ITO in an amorphous state. 4. The method according to claim 1, wherein the temperature of the manufacturing process is maintained at the time of completion of the liquid crystal display device in which the liquid crystal layer is sandwiched between the resin substrates so as to satisfy the expression (1).
The manufacturing method of the liquid crystal display element described in. 5. The method according to claim 3, further comprising the step of bending the resin substrate during the manufacturing process. 6. The manufacturing process includes at least one of a step of bonding the two resin substrates while applying heat and pressure, and a step of thermocompression bonding an external connection circuit pattern to an extraction electrode portion of the transparent electrode. 6. The method for manufacturing a liquid crystal display device according to claim 3, wherein 7. The degree of crystallinity C2 of the ITO immediately before the step of bonding the two resin substrates or the step of thermocompression bonding the circuit pattern for external connection may be different from the crystallinity C2 of the ITO immediately before the step. Assuming that the X-ray diffraction peak intensity of the (2,2,2) plane of ITO is H3, the intensity is in the range represented by the following expression 2, C2 = H3 / H2 <0.4 (expression 2) The method for manufacturing a liquid crystal display device according to claim 6. 8. The liquid crystal display device according to claim 3, wherein all the manufacturing steps are performed at a temperature lower than the crystallization start temperature of the ITO. Production method.