WO2006097993A1

WO2006097993A1 - Liquid crystal display device and method for manufacturing liquid crystal display device

Info

Publication number: WO2006097993A1
Application number: PCT/JP2005/004466
Authority: WO
Inventors: Shinji Tadaki; Yoshinori Kiyota; Toshiaki Yoshihara; Hironori Shiroto; Tetsuya Makino; Keiichi Betsui
Original assignee: Fujitsu Limited
Priority date: 2005-03-14
Filing date: 2005-03-14
Publication date: 2006-09-21
Also published as: CN101142516B; JPWO2006097993A1; CN101142516A

Abstract

Two types of spacers [a first type spacer (10) and a second type spacer (11)] having different materials and different physical properties are provided between glass substrates (5 and 7) for securing a cell gap being uniform in-plain. The first type spacer (10) has a glass transition temperature (approximately 150˚C) higher than that (approximately 100˚C) of the second spacer (11). The first type spacer (10) has a linear expansion coefficient of 100 ppm or more and a compressive elasticity of 100 MPa or more. The second type spacer (11) has a linear expansion coefficient of 200 ppm or more and a compressive elasticity of 100 MPa or more. The glass substrates (5 and 7) are combined at a temperature lower than the glass transition temperature of the first type spacer (10), and a liquid crystalline material is injected at a temperature higher than the glass transition temperature of the second type spacer.

Description

Liquid crystal display device and method of manufacturing liquid crystal display device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display device that performs image display by controlling light transmittance of a liquid crystal material by applying a voltage, and a method for manufacturing a liquid crystal display device, and in particular, maintains a gap between opposing substrates. The present invention relates to a liquid crystal display device that defines the characteristics of a spacer for the purpose and a method for manufacturing the liquid crystal display device.

Background art

In recent years, liquid crystal display devices are widely used in various devices because of their low power consumption and portability. On the other hand, disadvantages include low response speed and poor color reproducibility due to the use of color filters. As a technique for solving these drawbacks, a liquid crystal display device using a strong dielectric liquid crystal has been developed.

[0003] Ferroelectric liquid crystal panels using chiral smetatic C phase (Sc * phase) are being researched as devices that can realize high-speed response and high-definition display. However, since the S c * phase has a layer structure, there is a drawback in that the orientation state is easily destroyed by an external force. For this reason, columnar or spherical spacers are provided so as to maintain a gap (cell gap) between the substrates (see, for example, Patent Document 1).

Patent Document 1: JP 2000-89232 A

Disclosure of the invention

Problems to be solved by the invention

[0004] The uniform orientation state of the Sc * phase is the isotropic phase (Iso phase), one-strength irrnematic phase (N * phase), one-stral irrus metatic C phase (Sc * phase) In this case, it is obtained by applying a DC voltage during the phase transition from the N * phase to the Sc * phase. Due to the volume shrinkage during this phase transition and the difference in linear expansion coefficient between the Sc * phase and the panel components (especially spacers), stress may be applied to the liquid crystal and alignment defects may occur.

[0005] When the spacer is used! /, When the spacer is used, it is possible to maintain a certain amount of voids in the direction in which the cell gap is reduced by increasing the density or area of the spacer. , The cell gap cannot be controlled in the expanding direction. In addition, there is a problem that the strength of the spacer is partially reduced due to uneven film thickness of the spacer. Therefore, Patent Document 1 describes a method capable of controlling a cell gap in an expanding direction using a spacer having adhesiveness, and performing highly precise cell gap control.

[0006] However, when an adhesive spacer is used, the volume of liquid crystal sealed in the cell gap is determined when the liquid crystal is injected. The difference from the space maintained by the pacer Stress the liquid crystal. In particular, when adhesive spacers are provided at high density, defects such as voids occur due to differences in the linear expansion coefficient and compression elasticity between the display area and the seal portion, and the display characteristics are remarkably increased. to degrade.

[0007] Further, in the liquid crystal panel in which the two substrates are bonded to each other by a peripheral sealing material and a thermosetting adhesive and the ferroelectric liquid crystal is sealed, the area of the spacer provided in the display area Is increased, cracks from the seal part or alignment defects due to stress invade the display area during the cooling process after the alignment process due to differences in the linear expansion coefficient and compression modulus between the display area and the seal part. Cause image quality degradation. In addition, this alignment defect may disappear with time, but it easily occurs due to a temperature change and deteriorates the display quality.

[0008] The present invention has been made in view of such circumstances, and has a plurality of types having specific physical properties (linear expansion coefficient, compression elastic modulus, and glass transition temperature) that can favorably follow the temperature change of liquid crystal. An object of the present invention is to provide a liquid crystal display device capable of reducing alignment stress by reducing the stress generated in the liquid crystal by using the spacer.

[0009] Another object of the present invention is to satisfactorily follow the change in the shape of the spacer with the change in the temperature of the liquid crystal by defining the glass transition temperatures of the plurality of types of spacers according to the temperature in the manufacturing process. Another object of the present invention is to provide a method of manufacturing a liquid crystal display device that can reduce stress generated in liquid crystal and suppress alignment defects.

Means for solving the problem

In the liquid crystal display device according to the present invention, a liquid crystal material is sealed in a gap between opposed substrates, and a plurality of types of spacers are provided to maintain the gap between the substrates. In the apparatus, the plurality of types of spacers have a linear expansion coefficient of lOOppm or more and a pressure. A first type spacer having a compressive modulus of lOOMPa or higher and a second type spacer having a linear expansion coefficient of 200 ppm or higher and a compressive modulus of lOOMPa or higher. The glass transition temperature of the spacer is higher than the glass transition temperature of the second type spacer.

In the liquid crystal display device of the present invention, the first type spacer having a high glass transition temperature is used for maintaining a gap (cell gap) between the substrates, and the glass transition temperature is low. A seed spacer is used to bond the substrates. These type 1 spacers (linear expansion coefficient: lOOppm or more, compression modulus: lOOMPa or more) and type 2 spacers (linear expansion coefficient: 20 Oppm or more, compression modulus: lOOMPa or more) are liquid crystal materials. Because it is made of a material close to the physical properties (linear expansion coefficient, compression modulus), it is easy to follow the temperature change of the liquid crystal material. Therefore, stress on the liquid crystal material is reduced and alignment defects are less likely to occur.

The liquid crystal display device according to the present invention is characterized in that the first type spacer has a linear expansion coefficient of 300 ppm or more.

The liquid crystal display device according to the present invention is characterized in that the first type spacer has a compressive elastic modulus of 500 MPa or more.

In the liquid crystal display device according to the present invention, the second type spacer has a linear expansion coefficient of 300 ppm or more.

In the liquid crystal display device according to the present invention, the second type spacer has a compressive elastic modulus of 500 MPa or more.

[0016] It is preferable that the first type spacer has a linear expansion coefficient of 300 ppm or more and a compressive elastic modulus of 500 MPa or more. Also, the second type spacer has a linear expansion coefficient. Is preferably 30 Oppm or more, and its compression modulus is 500 MPa or more. By having such physical properties, the physical properties (linear expansion coefficient, compressive elastic modulus) of the liquid crystal material become closer, so the stress on the liquid crystal material is further reduced and alignment defects are less likely to occur.

The liquid crystal display device according to the present invention is characterized in that the first-type spacer and the second-type spacer are stacked.

In the liquid crystal display device of the present invention, the first-type spacer and the second-type spacer are laminated. Therefore, the area occupied by the spacer is reduced and the effective display area is widened.

[0019] A method for manufacturing a liquid crystal display device according to the present invention includes a plurality of types of spacers including a first type spacer and a second type spacer having a glass transition temperature lower than that of the first type spacer. A method of manufacturing a liquid crystal display device in which a plurality of substrates are bonded together with a liquid crystal material injected into a gap between the substrates, and the temperature at which the substrates are bonded is set to the first type spacer. The glass transition temperature is lower than the glass transition temperature of the second type spacer, and the temperature at which the liquid crystal material is injected is higher than the glass transition temperature of the second type spacer.

[0020] In the method of manufacturing a liquid crystal display device of the present invention, the temperature at which the substrates are bonded is set lower than the glass transition temperature of the first type spacer having a high glass transition temperature. Therefore, since the substrates are supported by the first type spacer when the substrates are bonded, the cell structure is not crushed and a predetermined gap is maintained between the opposing substrates. Also, the temperature at which the liquid crystal material is injected is set higher than the glass transition temperature of the type 2 spacer having a low glass transition temperature. In general, the linear expansion coefficient above the glass transition temperature is larger than the linear expansion coefficient below the glass transition temperature, so the cell gap is large until a phase transition occurs after the liquid crystal material is injected. It changes in. Therefore, the type 2 spacer with the glass transition temperature lower than the temperature at the time of injection follows the transition of the large linear expansion coefficient of the liquid crystal material. Therefore

, The stress on the liquid crystal is reduced and alignment defects are less likely to occur.

[0021] The method for manufacturing a liquid crystal display device according to the present invention is characterized in that a glass transition temperature of the second type spacer is not more than a phase transition temperature of the liquid crystal material.

[0022] In the method for producing a liquid crystal display device of the present invention, the second type spacer whose glass transition temperature is lower than or equal to the phase transition temperature of the liquid crystal material is the same as that of the liquid crystal material. It becomes easier to follow the temperature change.

[0023] In the method for manufacturing a liquid crystal display device according to the present invention, the first type spacer has a linear expansion coefficient of lOOppm or more and a compression elastic modulus of lOOMPa or more, and the second type spacer is It is characterized by a linear expansion coefficient of 200 ppm or more and a compressive elastic modulus of lOOMPa or more.

[0024] In the method for manufacturing a liquid crystal display device of the present invention, the linear expansion coefficient and the compressive elastic modulus of the first type spacer are set to lOOppm or more and lOOMPa or more so as to approach the physical properties of the liquid crystal material. The linear expansion coefficient and compression modulus of the type 2 spacer shall be 200 ppm or more and lOOMPa or more.

[0025] The method for manufacturing a liquid crystal display device according to the present invention is characterized in that the second type spacer exhibits adhesiveness after the substrates are bonded together.

In the method for manufacturing a liquid crystal display device of the present invention, since the second type spacer exhibits adhesiveness after the substrates are bonded together, it is possible to control the cell gap in the expanding direction. The invention's effect

[0027] In the liquid crystal display device of the present invention, the first-type spacer and the first-type spacers having different glass transition temperatures.

The physical properties (linear expansion coefficient, compressive modulus) of the two types of spacers are made easy to follow the temperature changes of the liquid crystal material, so stress on the liquid crystal material can be reduced and orientation defects can be reduced. Occurrence can be suppressed.

In the method for manufacturing a liquid crystal display device of the present invention, the temperature at which the substrates are bonded is set lower than the glass transition temperature of the first type spacer, and the temperature at which the liquid crystal material is injected is set to the first temperature.

Since the glass transition temperature is higher than the glass transition temperature of the type 2 spacer, the predetermined cell gap can be maintained at the time of bonding, and the type 2 spacer can easily follow the temperature change of the liquid crystal material. Thus, the stress on the liquid crystal can be reduced and the occurrence of alignment defects can be suppressed. In addition, when the glass transition temperature of the type 2 spacer is set to be equal to or lower than the phase transition temperature of the liquid crystal material, good follow-up to the temperature change of the liquid crystal material can be performed even in the vicinity of the phase transition. In addition, since the type 2 spacer exhibits adhesiveness after the substrates are bonded together, it is possible to control the cell gap in the expanding direction.

In the present invention, even if the area occupied by the spacer is increased, the stress on the liquid crystal material can be reduced and the occurrence of alignment defects can be suppressed, so that the display image quality does not deteriorate. Therefore, the area occupied by the spacer can be increased as compared with the case where a conventional spacer is used, and a large panel strength and excellent display quality can be realized.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a liquid crystal panel of a liquid crystal display device according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a cell state when substrates are bonded together in the method for manufacturing a liquid crystal display device of the present invention. FIG. 3 is a schematic cross-sectional view showing a cell state at the time of liquid crystal injection in the method for manufacturing a liquid crystal display device of the present invention.

FIG. 4 is a cross-sectional view showing a liquid crystal panel of another example of the liquid crystal display device according to the present invention. Explanation of symbols

[0031] 1 LCD panel

4 pixel electrodes

5 Glass substrate

6 Common electrode

7 Glass substrate

10 Type 1 spacer

11 Type 2 spacer

12 Liquid crystal layer

BEST MODE FOR CARRYING OUT THE INVENTION

[0032] The present invention will be specifically described with reference to the drawings illustrating embodiments thereof. The present invention is not limited to the following embodiment.

FIG. 1 is a cross-sectional view showing a liquid crystal panel 1 of a liquid crystal display device according to the present invention. As shown in FIG. 1, the liquid crystal panel 1 includes a flat electrode layer 2 and pixel electrodes 4 arranged in a matrix via contact holes 3 and TFTs connected to the pixel electrodes 4 (not shown). A glass substrate 5 having a flat common electrode 6 and a glass substrate 7 having a flat common electrode 6. An alignment film 8 and an alignment film 9 are provided on the pixel electrode 4 and the common electrode 6, respectively.

[0034] In order to maintain a uniform in-plane void (cell gap) between glass substrates 5 and 7, two types of spacers with different materials and physical properties, type 1 spacer 10 and type 2 spacer Support 11 is provided. The glass transition temperature of the first type spacer 10 (about 150 ° C) is higher than the glass transition temperature of the second type spacer 11 (about 100 ° C). Further, the linear expansion coefficient of the first type spacer 10 is lOOppm or more, more preferably 300ppm or more, and the compression modulus of the first type spacer 10 is lOOMPa or more, more preferably 500MPa or more. is there. On the other hand, the linear expansion coefficient of the type 2 spacer 11 is 200 ppm or more, more preferably 300 ppm or more, and the compression modulus of the type 2 spacer 11 is lOOMPa or more, more preferably 500 MPa or more. . These spacers 10 and 11 and a seal (not shown) form a gap having a predetermined length between the glass substrates 5 and 7, and a ferroelectric liquid crystal is sealed in the gap to form a liquid crystal layer. 12 is formed. Further, a polarizing plate 13 and a polarizing plate 14 are provided on the outer surfaces of the glass substrate 5 and the glass substrate 7, respectively.

Next, a method for manufacturing such a liquid crystal display device will be described. A flat resin layer 2 is provided on one glass substrate 5 having TFTs, contact holes 3 are formed, ITO is formed, and pixel electrodes 4 are formed by patterning. Next, the first type spacer 10 is formed, and the alignment film 8 is provided. A common electrode 6 is formed by depositing ITO on the other glass substrate 7, and an alignment film 9 is provided. Further, the second type spacer 11 is formed on the glass substrate 5. After the glass substrates 5 and 7 are rubbed, a seal is formed on the glass substrate 7 and the glass substrates 5 and 7 are bonded together.

[0037] The temperature at which this bonding is performed (about 135 ° C) is set lower than the glass transition temperature of the first type spacer 10. Therefore, even if an external force is applied as shown in FIG. 2, the first-type spacer 10 functions as a stopper due to its rigidity, so that the cell structure is maintained and a predetermined length of cell gap is maintained. Thus, the first type spacer 10 having a high glass transition temperature functions to maintain a cell gap at the time of bonding.

[0038] The liquid crystal material, such as the inlet, is heated and pressurized and injected into the empty panel thus manufactured, and after the injection is completed, it is cooled to room temperature and the inlet is sealed. After warming up to the phase transition temperature, orientation treatment is performed by applying a direct current voltage, and then cooled to room temperature again.

The temperature at which this liquid crystal material is injected (about 110 ° C.) is set higher than the glass transition temperature of the second type spacer 11. Therefore, as shown in FIG. 3, when the liquid crystal material is injected, the cell gap having a predetermined length is maintained by the second type spacer 11 having a large linear expansion coefficient. In addition, the glass transition temperature of the type 2 spacer 11 is lower than the phase transition temperature of the liquid crystal material. Therefore, in the cooling process after the injection, the type 2 spacer 11 does not exceed the glass transition temperature until the liquid crystal material undergoes a phase transition, and therefore changes with a large linear expansion coefficient. As a result, the stress on the liquid crystal material is reduced.

[0040] The glass transition temperature is low. The type 2 spacer 11 exhibits adhesiveness after bonding the substrates, and adheres the glass substrates 5 and 7 to control not only the reduction of the cell gap but also the expansion. . FIG. 4 is a cross-sectional view showing a liquid crystal panel 1 of another example of the liquid crystal display device according to the present invention. In FIG. 4, the same parts as those in FIG. In the example shown in FIG. 4, the first type spacer 10 and the second type spacer 11 are stacked. Of course, this example also achieves the same effect as the above-described example. In addition, since the area occupied by the spacer can be reduced, the effective display area can be expanded.

Next, regarding specific examples and comparative examples of the present invention, the manufacturing process and the characteristics of the manufactured liquid crystal display device will be described. Examples 1 and 2 correspond to the configuration example shown in FIG. 1, and Example 3 corresponds to the configuration example shown in FIG.

[0043] (Example 1)

A flat resin layer 2 having a thickness of 2.5 m was provided on one glass substrate 5 having a TFT, and after forming a contact hole 3, ITO was formed and a pixel electrode 4 was formed by patterning. Next, a first type spacer 10 having a linear expansion coefficient of 335 ppm, a compression modulus of 590 MPa, and a glass transition temperature of 150 ° C. is formed with an area ratio of 5% and a height of 1.8 m. Film Formation An alignment film 8 was formed by Z firing. A common electrode 6 was formed by depositing ITO on the other glass substrate 7, and an alignment film 9 was also formed by polyimide film Z firing.

[0044] Furthermore, the second-type spacer 11 is made of a glass substrate with an area ratio of 5% using an acrylic resist having a linear expansion coefficient after curing of 249 ppm, a compression modulus of 339 MPa, and a glass transition temperature of 108 ° C. After forming to 5 and pre-curing at 100 ° C for 10 minutes, it was rubbed. In addition, after the glass substrate 7 was rubbed, a seal was formed, and the glass substrates 5 and 7 were bonded together so that the rubbing directions were parallel. This was sealed in a vacuum pack and fired at 135 ° C for 90 minutes to produce an empty panel.

[0045] Monostable ferroelectric liquid crystal was heated in a chiral nematic state (110 ° C) and injected into the produced empty panel under pressure, and after injection was completed, it was cooled to room temperature and the injection port was sealed. . This panel was heated to a chiral nematic state, and an orientation treatment was performed by applying a DC voltage of 12 V between the cells before and after the N *-Sc * transition temperature. From this state, it was gradually cooled to room temperature.

In this liquid crystal panel, alignment defects did not occur in the liquid crystal layer direction immediately after the alignment treatment.

In addition, even when the temperature changed, alignment defects did not occur. [0047] As a result of applying a load to this liquid crystal panel using a push-pull gauge and applying a load resistance test to a rectangular area with a side of lcm, the orientation was not applied for the first time when a load of 21.6 X 10 ⁴ Pa was applied. A defect occurred and the black state was destroyed.

[0048] (Example 2)

A flat resin layer 2 having a thickness of 2.5 m was provided on one glass substrate 5 having a TFT, and after forming a contact hole 3, ITO was formed and a pixel electrode 4 was formed by patterning. Next, a first type spacer 10 having a linear expansion coefficient of 529 ppm, a compressive elastic modulus of 58 MPa, and a glass transition temperature of 150 ° C. is formed with an area ratio of 5% and a height of 1. Further, a polyimide film is formed. An alignment film 8 was formed by Z firing. A common electrode 6 was formed by depositing ITO on the other glass substrate 7, and an alignment film 9 was also formed by polyimide film Z firing.

[0049] Further, the second-spacer 11 is made of a glass substrate with an area ratio of 5% by an acrylic resist having a linear expansion coefficient after curing of 330 ppm, a compression modulus of 310 MPa, and a glass transition temperature of 108 ° C. After forming to 5 and pre-curing at 100 ° C for 10 minutes, it was rubbed. In addition, after the glass substrate 7 was rubbed, a seal was formed, and the glass substrates 5 and 7 were bonded together so that the rubbing directions were parallel. This was sealed in a vacuum pack and fired at 135 ° C for 90 minutes to produce an empty panel.

[0050] A monostable ferroelectric liquid crystal was heated in a chiral nematic state (110 ° C) and injected under pressure into the produced empty panel. After the injection was completed, it was cooled to room temperature and the injection port was sealed. . This panel was heated to a chiral nematic state, and an orientation treatment was performed by applying a DC voltage of 12 V between the cells before and after the N *-Sc * transition temperature. From this state, it was gradually cooled to room temperature.

In addition, even when the temperature changed, alignment defects did not occur.

[0052] As a result of applying a load to a rectangular area of 1 cm on a side using a push-pull gauge and applying a load resistance test to this liquid crystal panel, the alignment was not applied for the first time when a load of 25.5 X 10 ⁴ Pa was applied. A defect occurred and the black state was destroyed.

[0053] (Example 3)

A flat resin layer 2 with a thickness of 2.5 m is provided on one glass substrate 5 with TFT, After forming the tato hole 3, ITO was deposited and the pixel electrode 4 was formed by patterning. Next, a first type spacer 10 having a linear expansion coefficient of 335 ppm, a compression elastic modulus of 590 MPa, and a glass transition temperature of 150 ° C. is formed with an area ratio of 10% and a height of 1. Further, a polyimide film is formed. An alignment film 8 was formed by Z firing. A common electrode 6 was formed by depositing ITO on the other glass substrate 7, and an alignment film 9 was also formed by polyimide film Z firing.

[0054] Furthermore, the second type spacer 11 has already been formed of an acrylic resist having a linear expansion coefficient after curing of 249 ppm, a compression modulus of 339 MPa, and a glass transition temperature force S of 108 ° C. It was formed on a type 1 spacer 10 at an area ratio of 2%, pre-cured at 100 ° C. for 10 minutes, and then subjected to a rubbing treatment. Further, after the glass substrate 7 was rubbed, a seal was formed, and the glass substrates 5 and 7 were bonded together so that the rubbing directions were parallel. This was sealed in a vacuum pack and baked at 135 ° C for 90 minutes to produce an empty panel.

[0055] Monostable ferroelectric liquid crystal was heated in a chiral nematic state (110 ° C) and injected into the produced empty panel under pressure, and after the injection was completed, it was cooled to room temperature and the injection port was sealed. . This panel was heated to a chiral nematic state, and an orientation treatment was performed by applying a DC voltage of 12 V between the cells before and after the N *-Sc * transition temperature. From this state, it was gradually cooled to room temperature.

In this liquid crystal panel, alignment defects were not generated in the liquid crystal layer direction immediately after the alignment treatment.

[0057] Using a push-pull gauge, a load was applied to this liquid crystal panel in a rectangular area of 1 cm on a side, and as a result of a load-bearing test, it was the first orientation when a load of 21.6 X 10 ⁴ Pa was applied. A defect occurred and the black state was destroyed.

[0058] (Comparative Example 1)

A flat resin layer 2 having a thickness of 2.5 m was provided on one glass substrate 5 having TFTs, and after forming a contact hole 3, ITO was formed and a pixel electrode 4 was formed by patterning. Next, a spacer having a linear expansion coefficient of 63 ppm, a compressive modulus of 934 MPa, and a glass transition temperature of 200 ° C. (corresponding to the first type spacer 10 of the present invention) is obtained with an area ratio of 5% and a height of 1 The film was formed with a thickness of 8 μm, and a polyimide film was formed. ITO film is formed on the other glass substrate 7 to form the common electrode 6, and polyimide film is also formed by Z firing. An alignment film 9 was formed.

Both glass substrates 5 and 7 were rubbed with a rayon puff. Furthermore, adhesive beads (corresponding to type 2 spacer 11 of the present invention) having an average particle diameter of about 4 μm and a linear expansion coefficient of 61 ppm, a compression modulus of 256 MPa, and a glass transition temperature of 100 ° C. It was sprayed on the glass substrate 5 in the density of about 100 ZMM ^2. Further, a seal was formed on the glass substrate 7 and the glass substrates 5 and 7 were bonded together so that the rubbing directions were parallel. This was enclosed in a vacuum pack and baked at 135 ° C for 90 minutes to produce an empty panel.

[0060] A monostable ferroelectric liquid crystal was heated in a chiral nematic state (110 ° C) and injected under pressure into the produced empty panel, and after the injection was completed, it was cooled to room temperature and the injection port was sealed. . This panel was heated to a chiral nematic state, and an orientation treatment was performed by applying a DC voltage of 12 V between the cells before and after the N *-Sc * transition temperature. From this state, it was gradually cooled to room temperature.

In this liquid crystal panel, alignment defects occurred in the liquid crystal layer direction immediately after the alignment treatment.

[0062] (Comparative Example 2)

A flat resin layer 2 having a thickness of 2.5 m is provided on one glass substrate 5 having a TFT, a contact hole 3 is formed, an ITO film is formed, and a pixel electrode 4 is formed by patterning. Further, an alignment film 8 was formed by film formation Z baking of polyimide. ITO was formed on the other glass substrate 7 to form the common electrode 6, and the alignment film 9 was formed by the same film formation Z firing of polyimide. Both glass substrates 5 and 7 were rubbed with a rayon puff.

[0063] Silica beads with a particle size of 1. 8 / zm (corresponding to type 1 spacer 10), an average particle size of 61ppm linear compression coefficient, 256MPa compressive modulus, 100 ° C glass transition temperature About 4 μm adhesive beads (corresponding to the second type spacer 11) were sprayed on the glass substrate 5 with a density of about 100 Zmm ² each. Further, a seal was formed on the glass substrate 7, and the glass substrates 5 and 7 were bonded together so that the rubbing directions were parallel. This was sealed in a vacuum pack and baked at 135 ° C for 90 minutes to produce an empty panel.

[0064] A monostable ferroelectric liquid crystal was heated in a chiral nematic state (110 ° C) and injected under pressure into the produced empty panel. After the injection was completed, it was cooled to room temperature and the injection port was sealed. . This panel is heated to a chiral nematic state, and before and after the N *-Sc * transition temperature, Orientation treatment was performed by applying a DC voltage of 12V between the cells. From this state, it was gradually cooled to room temperature.

In addition, even when the temperature changed, alignment defects did not occur. As a result of applying a load resistance test to this liquid crystal panel using a push-pull gauge and applying a load to a rectangular area of 1 cm on one side, an alignment defect occurred when a load of 9.8 X 10 ⁴ Pa was applied. State destroyed

In Comparative Example 2, when the density of the adhesive beads was 100 Zmm ² or more, alignment defects were generated after the alignment treatment, and the amount of alignment defects generated increased due to temperature change. This is because the linear expansion coefficient of the adhesive beads is small.

[0067] (Comparative Example 3)

A flat resin layer 2 having a thickness of 2.5 m was provided on one glass substrate 5 having TFTs, and after forming a contact hole 3, ITO was formed and a pixel electrode 4 was formed by patterning. Next, a spacer with a linear expansion coefficient of 335ppm, a compression modulus of 590MPa, and a glass transition temperature of 150 ° C (corresponding to type 1 spacer 10) is formed with an area ratio of 5% and a height of 1. Further, an alignment film 8 was formed by polyimide film Z firing. A common electrode 6 was formed by depositing ITO on the other glass substrate 7, and an alignment film 9 was also formed by polyimide film Z firing. Both glass substrates 5 and 7 were rubbed with a rayon puff.

[0068] About 100 adhesive beads (corresponding to type 2 spacer 11) with a linear expansion coefficient of 61 ppm, a compression modulus of 256 MPa, and a glass transition temperature of 100 ° C and an average particle size of about 4 μm It was sprayed on the glass substrate ⁵ at a density of ZMM ^2. In addition, a seal was formed on the glass substrate ⁷ and the glass substrates 5 and 7 were bonded together so that the rubbing directions were parallel. This was sealed in a vacuum pack and baked at 135 ° C for 90 minutes to produce an empty panel.

[0069] A monostable ferroelectric liquid crystal was heated to a chiral nematic state (110 ° C) and injected into the produced empty panel under pressure. After the injection was completed, the injection port was sealed by cooling to room temperature. . This panel was heated to a chiral nematic state, and an orientation treatment was performed by applying a DC voltage of 12 V between the cells before and after the N *-Sc * transition temperature. From this state, it was gradually cooled to room temperature. In this liquid crystal panel, alignment defects did not occur in the liquid crystal layer direction immediately after the alignment treatment. In addition, even when the temperature changed, alignment defects did not occur. As a result of applying a load resistance test to this liquid crystal panel using a push-pull gauge and applying a load to a rectangular area of 1 cm on a side, an alignment defect was generated when a load of 15.7 X 10 ⁴ Pa was applied. State destroyed

[0071] As described above, in Comparative Example 1, alignment defects occurred immediately after the alignment treatment. Further, in Comparative Examples 2 and 3, although no alignment defects occurred immediately after the alignment treatment, 9.8 X 10 ⁴ Pa (Comparative Example 2) and 15.7 X 10 ⁴ Pa (Comparative Example 3) Loading force is not obtained and load bearing characteristics are not good. The target value of load resistance in a general liquid crystal display device is 19.6 X 10 ⁴ Pa, and neither of Comparative Examples 2 and 3 has achieved this target value.

[0072] In contrast, in Examples 1 to 3, there is of course no orientation defect immediately after the orientation treatment, and in Examples 1 and 3, 21.6 X 10 ⁴ Pa resistance resistance. The load was obtained and the above target value was achieved. In Example 2, an even greater load resistance of 25.5 X 10 ⁴ Pa was realized.

Claims

The scope of the claims

[1] In a liquid crystal display device in which a liquid crystal material is sealed in a gap between opposing substrates and a plurality of types of spacers are provided to maintain the gap between the substrates, the plurality of types of spacers are provided. The first type spacer with a linear expansion coefficient of lOOppm or more and a compression modulus of lOOMPa or more, and the second type spacer with a linear expansion coefficient of 200ppm or more and a compression modulus of elasticity of lOOMPa or more. And a glass transition temperature of the first type spacer is higher than a glass transition temperature of the second type spacer.

2. The liquid crystal display device according to claim 1, wherein the first type spacer has a linear expansion coefficient of 300 ppm or more.

[3] The compression elastic modulus of the first type spacer is 500 MPa or more.

The liquid crystal display device according to 1.

4. The liquid crystal display device according to claim 1, wherein the second type spacer has a linear expansion coefficient of 300 ppm or more.

5. The liquid crystal display device according to claim 1, wherein the compression modulus of the second type spacer is 500 MPa or more.

6. The liquid crystal display device according to any one of claims 1 to 5, wherein the first type spacer and the second type spacer are laminated.

[7] A plurality of substrates including a first type spacer and a second type spacer having a glass transition temperature lower than that of the first type spacer are bonded together, A method of manufacturing a liquid crystal display device, in which a liquid crystal material is injected into a gap between the substrates, wherein the temperature at the time of bonding the substrates is lower than the glass transition temperature of the first type spacer, and the liquid crystal material A method for manufacturing a liquid crystal display device, characterized in that a temperature at the time of injecting is higher than a glass transition temperature of the second type spacer.

8. The method for producing a liquid crystal display device according to claim 7, wherein the glass transition temperature of the second type spacer is not more than the phase transition temperature of the liquid crystal material.

[9] The first type spacer has a linear expansion coefficient of lOOppm or more and a compressive modulus of 100 MPa or more, and the second type spacer has a linear expansion coefficient of 200 ppm or more and is compressed. 9. A liquid crystal display device according to claim 7 or 8, wherein the liquid crystal display device has an efficiency ratio of lOOMPa or more. Manufacturing method.

10. The method for manufacturing a liquid crystal display device according to claim 7, wherein the second type spacer exhibits adhesiveness after the substrates are bonded together.