JP2002287148A - Method for manufacturing liquid crystal device, liquid crystal device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid crystal device wherein contaminants and impurities remaining in the inner part of a liquid crystal can be reduced to the utmost, an alignment defect is eliminated and the reduction of the life of the liquid crystal can be prevented. SOLUTION: When the liquid crystal device provide with a liquid crystal layer 41 interposed between substrates 10 and 20 and alignment layers 11 and 21 formed on the surfaces on the liquid crystal layer side of the substrates is manufactured, at least one substrate is constituted of a light transmitting material, and the alignment layers are constituted of an obliquely deposited film consisting of an inorganic material. A sealing material 30 is constituted of a UV curing type sealing material and the entire surfaces of the substrates are irradiated with UV to cure the sealing material and burn off the organic contaminants on the surfaces of the alignment layers, simultaneously when or after the sealing material is disposed between the substrates to stick the both substrates to each other and before the liquid crystal is injected between the substrates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal device, and a liquid crystal device and an electronic device obtained by the method.
In particular, the present invention relates to a technique in which an obliquely deposited film is selected as an alignment film and the entire surface is irradiated with ultraviolet light.

[0002]

2. Description of the Related Art Various electronic devices such as a notebook personal computer, a portable game machine, and an electronic organizer often use a liquid crystal display device with low power consumption as a display unit. In particular, in recent years, demand for a liquid crystal display device capable of performing color display has been increasing with the frequent use of display contents. In general, a liquid crystal device is configured such that a pair of substrates disposed opposite to each other are bonded together with a predetermined cell gap therebetween via a sealing material, and the region surrounded by the sealing material is mainly aligned with electrodes and wirings for driving a liquid crystal. A film is formed, and liquid crystal is sealed in a region surrounded by a sealant between the substrates. The liquid crystal sealed between the substrates as described above is usually filled between the substrates in a vacuum atmosphere through a sealing hole formed in a part of the sealing material, and the sealing hole is closed with the sealing material after vacuum filling. Is sealed between the substrates.

An alignment film is provided for aligning liquid crystal molecules in a predetermined direction. An organic resin film having molecular alignment such as polyimide is provided on the liquid crystal layer side of each substrate so as to be in contact with the liquid crystal. The surface of the organic resin film is subjected to a treatment such as rubbing with a rubbing roll to impart a desired orientation, and is used for practical use. Next, as the sealing material, a sealing agent made of a thermosetting resin or an ultraviolet curing resin is applied to the substrate surface in a ring shape, and then heated after application,
The sealant is cured by irradiation with ultraviolet rays to form a seal material.

FIG. 9 is an explanatory view showing one step in the case of manufacturing a liquid crystal panel using an ultraviolet-curing type sealant in order to manufacture this type of liquid crystal device. In FIG. 9, a glass substrate 100 which is disposed to face with an appropriate cell gap,
UV curable uncured sealant layer 1 on the periphery of 101
02, one substrate 100 and the other substrate 101
A liquid crystal cell 105 is formed by forming alignment films 103 and 104 on the inner surface side of the liquid crystal cell. The liquid crystal panel 105 shown in FIG.
Indicates a state before liquid crystal is injected, and the substrates 100, 10
No liquid crystal is injected between the two.

In order to cure the uncured sealant layer 102 of the liquid crystal cell 105 in the state shown in FIG. 9, a shield plate 1 large enough to cover the inside of the sealant layer 102 is required.
06 on the upper substrate 100, and the shielding plate 106
Irradiates ultraviolet light (UV light) from above through the shielding plate 1
06 existing in the area not covered by the sealant layer 102
Is cured to form a sealing material, and after the curing of the sealing material, a liquid crystal injection step is performed. The reason why the inside of the sealant layer 102 is shielded by the shield plate 106 in this step is to prevent the alignment film made of an organic polymer material from being damaged by ultraviolet irradiation (UV irradiation).

[0006]

However, the structure of this type of liquid crystal device has been increasingly complicated year by year due to demands for color display, high definition, high aperture ratio, and the like. And fine wiring and the like have been miniaturized, fine impurities and contaminants accompanying the film forming process when forming various electrodes and wiring formed on the substrate have passed through the cleaning process on the substrate surface. Even a small amount remains. In particular, when the rubbing treatment for rubbing the surface of the alignment film is performed, contaminants and impurities accompanying the rubbing treatment tend to remain on the surface of the alignment film. However, since liquid crystal panels are not clearly established at present, liquid crystal panels are generally completed while leaving a small amount of contaminants and impurities.

[0007] Such a small amount of contaminants and impurities are usually unlikely to adversely affect the display of the liquid crystal device,
If ions remain due to contaminants in the liquid crystal while driving the liquid crystal for a long time, the specific resistance of the liquid crystal layer itself decreases, and a weak current flows through the liquid crystal during driving, There is a problem that extra power consumption is required or an alignment defect is likely to be caused due to this, and there is a possibility that the life of the liquid crystal may be shortened. In addition, there is a fear of display failure such as flicker or burn-in.

The present invention has been made in view of the above-mentioned problems, and it is possible to minimize the amount of contaminants and impurities remaining in the liquid crystal by effectively utilizing ultraviolet rays.
An object is to provide a method for manufacturing a liquid crystal device which can eliminate alignment defects and shorten the life of liquid crystal. Another object of the present invention is to provide such an excellent liquid crystal device and an electronic apparatus provided with such a liquid crystal device.

[0009]

According to the present invention, there is provided a liquid crystal display device comprising: a pair of substrates; a liquid crystal layer sandwiched between the substrates by a sealing material formed between the substrates; When manufacturing a liquid crystal device comprising an alignment film formed on the surface of the liquid crystal layer side, the alignment film is composed of an obliquely deposited film made of an inorganic material, and the sealing material is made of an ultraviolet curable resin. And simultaneously arranging a sealant between the substrates and bonding both substrates, or after bonding both substrates and before injecting liquid crystal between the substrates, applying ultraviolet light to the substrates. The sealing material is cured by irradiating the entire surface, and at the same time, contaminant organic substances on the surface of the alignment film are burned.

Since the entire surface of the substrate is irradiated with ultraviolet light, the entire surface of the alignment film formed on the substrate is irradiated with ultraviolet light, and organic impurities and contamination remaining on the alignment film in the previous process are removed. The object can be incinerated by ultraviolet irradiation. Prior to the step of curing the sealant of the liquid crystal panel, each substrate is subjected to various film forming steps including various wiring steps and electrode forming steps, and further to an alignment film forming step. Even if a cleaning process is performed in these steps, trace impurities and contaminants are present on the surface of the alignment film. Among these trace impurities and contaminants, organic substances can be burned out by irradiation with ultraviolet rays when the sealant is cured with ultraviolet rays. Therefore, the amount of impurities and contaminants present in the liquid crystal after the injection of the liquid crystal can be reduced, and the rate of decrease in the specific resistance of the liquid crystal after the injection between the substrates is reduced. As a result, the alignment defect of the liquid crystal is reduced and the life of the liquid crystal is shortened. It is possible to provide a liquid crystal device without any problem.

Next, the present invention is characterized in that the oblique deposition is performed from a direction inclined by 70 to 85 degrees from the normal line of the substrate. By obliquely vapor-depositing at an angle in this range from the substrate normal, an alignment film having an alignment property capable of reliably exhibiting a pretilt angle with respect to the liquid crystal can be obtained. The present invention uses a substrate provided with an electrode for driving a liquid crystal as the substrate,
The rate at which the specific resistance of the liquid crystal layer measured after injecting the liquid crystal between the substrates is lower than the specific resistance of the liquid crystal before the injection between the substrates is 1/10 or less. If the specific resistance decreases at such a rate, the decrease in the specific resistance of the liquid crystal can be suppressed to a state that does not adversely affect the liquid crystal display. Further, if the specific resistance is reduced to such a degree, there is no substantial adverse effect on the display of the liquid crystal, the liquid crystal is not deteriorated even when used for a long period, and the driving power of the liquid crystal is less likely to be increased.

[0012] A liquid crystal device according to the present invention is obtained by any one of the above-described manufacturing methods. With these liquid crystal devices, it is possible to provide a liquid crystal device which does not have alignment defects due to impurities or residues, has high specific resistance, and can realize uniform liquid crystal alignment. An electronic apparatus according to another aspect of the invention includes the liquid crystal device described above as a display unit.
With these electronic devices, it is possible to provide an electronic device including, as a display means, a liquid crystal device which does not have alignment defects due to impurities or residues, has high specific resistance, and can realize uniform liquid crystal alignment.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment in which the present invention is applied to a passive matrix type liquid crystal display device will be described with reference to the drawings, but the present invention is limited to the following embodiments. is not. What is to be manufactured in the present embodiment is a simple matrix type liquid crystal display device A whose sectional structure is shown in FIG. 1 and whose planar structure is shown in FIG. However, in this embodiment, although it is mounted on an actual liquid crystal display device such as a polarizing plate or a retardation plate, description and display of element parts unnecessary for the description of the present invention are omitted. The dimensions and the numbers of the respective components do not reflect the substance, and the dimensions and the numbers are appropriately adjusted for easy illustration and explanation. In the following description, the driving method of the liquid crystal is a passive matrix method for convenience of explanation, but it goes without saying that an active matrix method may be used as in other embodiments described later.

The liquid crystal display device A of this embodiment basically includes a pair of glass substrates, that is, a first substrate 10 and a second substrate 20, which are opposed to each other with a predetermined cell gap, and a pair of the substrates. A sealing material 30 sandwiched between the peripheral portions between the sealing material 30 and formed in a frame shape in a plan view, and a liquid crystal layer 41 filled in a region 40 surrounded by the substrates 10 and 20 and the sealing material 30 are filled. It is provided. On the inner surface side (liquid crystal side) of the first substrate 10, an ITO (Indium)
A large number of striped first electrodes 12 made of a transparent conductive material such as Tin Oxide (indium tin oxide) are formed. One end of each first electrode 12 extends on the substrate outside the sealing material 30 to form a connection end,
On the electrode 12, an alignment film 11 made of an obliquely deposited film is formed.

On the other hand, on the inner surface of the second substrate 20, R (red), G (green), B
Color filters 23 arranged in the order of (blue), a plurality of striped second electrodes 22 made of a transparent conductive material such as ITO formed at positions intersecting the first electrodes 12 with a cell gap therebetween, An alignment film 21 made of a vapor-deposited film is formed. In addition, one end of the second electrode 22 extends on the substrate outside the sealing material 30 and is a connection terminal. In the region 40 between the substrates, spacers 42 for keeping the cell gap constant against external pressure are dispersed. In the liquid crystal display device A of the present embodiment, a retardation plate and a polarizing plate are actually provided on the substrate 10, but illustration and description are omitted.

The liquid crystal display device A having the above structure is manufactured through the steps shown in FIGS. 3A to 3D. First, as shown in FIG.
And then, as shown in FIG. 3B, the first substrate 1
A first electrode 12 is formed on the lower surface (surface on the liquid crystal side) of the first electrode 12 by a photolithography technique.
1 is formed by an oblique evaporation method. The first electrode 12 is formed so as to extend on a substrate outside a sealing material formed later so that one terminal is a connection terminal. Also, the second
On the substrate 20, an alignment film 21 is formed on the second electrode 22 by an oblique deposition method.

Here, the oblique deposition method will be described below. The oblique deposition method is known as a method capable of forming an inorganic alignment film such as silicon oxide (SiO) on a substrate. This is a technique in which vapor deposition particles generated from the vapor deposition source are obliquely deposited on a substrate to form a thin film made of inclined columnar crystals. Specifically, the inorganic material is deposited from a direction inclined at about 70 to 85 degrees with respect to the substrate normal, in other words, from a direction inclined at about 5 to 20 degrees from the substrate surface, This is a method of growing columnar crystals arranged at a predetermined angle.

FIG. 4 shows the relationship between the alignment film having a columnar crystal structure formed by the oblique deposition method and the alignment state of the liquid crystal molecules. On the first substrate 10 side, columnar crystals 45 are formed in parallel on the electrode 12 at a predetermined angle. Θ _{1 in the} figure
Is the deposition angle with respect to the substrate surface (for example,
20 degrees, that is, 70 to 85 degrees with respect to the substrate normal. ), And θ _p indicates the angle of the columnar crystal 45 from the substrate surface. In the case of the inorganic alignment film formed by oblique deposition of SiO, the deposition angle is generally 0 to 25 with respect to the substrate normal.
Until ゜, the pretilt cannot be given to the liquid crystal molecules 41a. In other words, a columnar crystal cannot be generated, and becomes a crystal of random orientation or parallel orientation.

On the other hand, when the deposition angle is 70 ° with respect to the substrate normal (20 ° with respect to the substrate surface), it is approximately 15 °.
A pretilt of ２０20 degrees can be imparted to the liquid crystal molecules 41a, and a pretilt of approximately 20 to 25 ° is applied to the liquid crystal molecules 41a when the deposition angle is 75 ° with respect to the substrate normal (15 ° with respect to the substrate surface). When the deposition angle is 80 ° relative to the substrate normal (10 ° relative to the substrate surface), a pretilt of approximately 20 to 30 ° can be applied to the liquid crystal molecules 41a. At 5 ° to the line (85 ° to the substrate surface), a pretilt of approximately 27 to 37 ° can be given to the liquid crystal molecules 41a. In addition, a value of about 1 ° to 6 ° can be easily obtained as the pretilt angle by performing two-stage vapor deposition by combining two kinds of vapor deposition angles that can provide different pretilt angles in the oblique vapor deposition method. As described above, in the obliquely deposited film, the pretilt angle (1 to 6 °) in a relatively low range to the high pretilt angle (1
5 to 30 °), so that various pretilt angles can be handled. Since the alignment films 11 and 21 formed by the oblique deposition method are not organic alignment films such as polyimide, they have high light resistance to ultraviolet light and excellent heat resistance.

Next, as shown in FIG. 3C, the ultraviolet-curable resin ink is drawn using a coating device such as a dispenser, and the uncured sealing material 301 is drawn in a frame shape.
Next, separately from the first substrate 10, a color filter 23 is formed on one surface of the second substrate 20, though not described in detail, and a second electrode 22 is formed thereon. Second electrode 22
Is the first substrate 10 such that one terminal is a connection terminal.
It extends over the substrate outside the sealing material 301 formed thereon. Subsequently, an alignment film 21 is also formed on the second electrode 22 by the same oblique deposition method as the above oblique deposition method. Further, spacers 42 are scattered on the alignment film 21. In a panel having a diagonal size of 1 inch (2.54 cm) or less, the spacers 42 are often not sprayed.

Then, as shown in FIG. 3D, the first substrate 10 and the second substrate 20 are respectively aligned with the alignment films 11 and 21.
Are bonded in a vacuum atmosphere so that the first substrate 1 faces inward, alignment is performed to correct the displacement between the first substrate 10 and the second substrate 20, and then the first substrate 1 is returned to the atmospheric pressure.
0 and the second substrate 20 are uniformly pressed, and a liquid crystal panel having a uniform cell gap is obtained. Thereafter, by irradiating the entire surface of the first substrate 10 from the first substrate 10 side, in other words, the entire surface of the liquid crystal panel with ultraviolet rays (UV light), the uncured sealing material 301 is cured to inject liquid crystal as the sealing material 30. Complete the previous panel. Here, the aforementioned sealing material 30
When the ultraviolet irradiation and the heating are used together during the curing, the curing of the sealing material 301 is further promoted, and the curing is achieved in a shorter time. Here, when irradiating ultraviolet rays (UV light),
For the purpose of completely curing the uncured sealing material 301 and for the purpose of sufficiently burning organic substances and residues on the alignment films 11 and 21 with ultraviolet light, the amount of ultraviolet light applied to the surface of the first substrate 10 is set to 1000 to 1000. It is preferable to be in the range of about 10,000 mJ / cm ² .

The liquid crystal panel completed as described above includes:
Liquid crystal is injected from a sealing material injection port (not shown) by a conventional method such as a vacuum injection method, and the liquid crystal display panel is completed by closing the injection port with the sealing material.

In the liquid crystal display panel having the above-described structure, the inorganic alignment films 11 and 21 are formed by oblique vapor deposition. There is no danger of the 11, 11 being damaged. When irradiating with ultraviolet light, the ultraviolet light is applied to the alignment film 1.
Since the entire surface of each of the alignment films 1 and 21 is irradiated,
Organic impurities and residues remaining on the surface portions of 1, 21 can be reliably removed by burning.

Here, the organic impurities and residues existing on the surface portions of the alignment films 11 and 21 are referred to as the alignment films 11 and 2.
1 or in a process prior to the process of forming the alignment films 11 and 21 or in the process of forming the alignment films 11 and 2
1 means various kinds of trace amounts of organic foreign matter remaining on the alignment films 11 and 21 in a transporting step, a bonding step, and the like after the formation of 1. If liquid crystal is injected while these organic impurities and residues remain, these organic impurities and residues will be mixed into the liquid crystal. These organic impurities and residues do not adversely affect the display of the liquid crystal display device if the amount is small, but may have a bad influence on the display if the amount is large, and regardless of the amount,
It causes unnecessary ions to be generated in the liquid crystal, causes a weak current to flow while driving the liquid crystal itself for a long period of use, and causes a wasteful improvement in the driving power of the liquid crystal. May shorten the life of the device. At this point, the ultraviolet light is applied to the alignment films 11, 2
If the entire surface of the substrate 1 is irradiated, a trace amount of organic impurities or residues existing on the alignment films 11 and 21 can be efficiently removed by burning. It is not possible to completely remove trace amounts of organic impurities and residues by irradiating ultraviolet rays, but by burning them, the trace amounts of impurities and residues are further reduced, so that adverse effects on the liquid crystal hardly occur. Can be reliably performed.

From the viewpoint of removing organic impurities and residues by ultraviolet rays, in a liquid crystal panel provided with a conventional polyimide resin alignment film, there is a possibility that the alignment film itself may be damaged when irradiated with ultraviolet rays. Therefore, the resin-based alignment film cannot be directly irradiated with ultraviolet rays. Therefore,
In a liquid crystal panel using a resin-based alignment film, the alignment film is conventionally covered with a shielding plate, and only the sealing material is irradiated with ultraviolet rays to cure the sealing material. Impurities and residues attached to the alignment film cannot be removed. In this regard, in this embodiment, an orientation film of an inorganic oblique deposition film that is not easily damaged by ultraviolet light is applied,
Irradiation with ultraviolet rays can burn off impurities or residues on the alignment film without risk of damaging the alignment film.

Normally, the liquid crystal used in the liquid crystal display device is about 10 ¹³ Ω · cm, for example, 10 ¹⁵ Ω · cm before injection.
It has a specific resistance in the range of 10 ¹² Ω · cm. However, when this liquid crystal is injected into the liquid crystal panel, and after the injection, a current is applied to the electrodes of the liquid crystal panel and the specific resistance of the liquid crystal layer is measured, the specific resistance decreases. The rate of this reduction is preferably 1/10 or less so that, for example, a liquid crystal having a specific resistance of 10 ¹³ Ω · cm has a specific resistance of about 10 ¹² Ω · cm. Reduction rate exceeding 1/10, for example, specific resistance is 1/1
If the rate of decrease is as large as 00, the specific resistance tends to be 1/1000, and the current tends to flow into the liquid crystal being driven, power is easily wasted, and there is a possibility that the display may become uneven. 1/10 or less, for example, 1/1 to 1/1
If the rate of decrease is in the range of 0, the liquid crystal does not deteriorate even after long-term use, current does not flow through the liquid crystal during driving, display unevenness does not occur, and alignment failure does not occur. .

In the above embodiment, the manufacturing method in the case of a passive matrix structure has been described as a driving method of the liquid crystal panel. However, the driving method of the liquid crystal panel may of course be an active matrix method. Therefore, a method for manufacturing an active matrix type liquid crystal display device will be described below. FIG.
An example of an active matrix transmission type liquid crystal display device using an FD element as a switching element will be described. FIG. 5 (A)
FIG. 5 is a schematic perspective view showing the overall configuration of the liquid crystal display device, and FIG. 5B is an enlarged view of one pixel in FIG. 5A.
As shown in FIG. 5A, the liquid crystal display device 60 of this example has two substrates, that is, an element substrate 61 (first substrate) on which a TFD element is formed and a counter substrate 62 (second substrate).
Are arranged facing each other, and a sealing material 6
3 is arranged, and a liquid crystal layer (not shown) is sandwiched in a region surrounded by a seal material 63 between the substrates. In the liquid crystal display device 60 of this example, similarly to the liquid crystal panel of the previous embodiment, a sealing material 63 is interposed between the substrates 61 and 62 so that the liquid crystal is sealed inside the sealing material 63 and the substrate 6 is also sealed.
An alignment film is formed on the surface in contact with the liquid crystal of Nos. 1 and 62 by an oblique vapor deposition method equivalent to that of the previous embodiment. However, the alignment film is not shown in FIG. The circuit portion is mainly shown.

A large number of data lines 64 are provided on the liquid crystal layer side of the element-side substrate 61 shown in FIG. 5, and a large number of pixel electrodes 65 are connected to each data line 64 via a TFD element 66. The pixel electrodes 65 are arranged in a matrix in plan view. On the other hand, on the inner surface side of the opposing substrate 62, a number of strip-shaped scanning lines 67 are formed in a direction crossing the data lines 64. The TFD element 66 shown in FIG.
As shown in (B), the first conductive film 68, an insulating film 69 formed on the surface of the first conductive film 68, and a second conductive film 70 formed on the surface of the insulating film 69. It is configured. Then, the first conductive film 68 of the TFD element 66 is connected to the data line 64, and the second conductive film 70 is connected to the pixel electrode 65.
It is connected to the.

The present invention can also be applied to an active matrix type liquid crystal display device 60 using the above-mentioned TFD element as a switching element. Irradiation with ultraviolet rays (ultraviolet light) may be used to cure the sealing material. In the liquid crystal display device 60 of this example, the same effect as in the case of the liquid crystal display device A can be obtained. That is, after the substrates 61 and 62 are bonded and before the liquid crystal is injected, the uncured sealing material is cured by irradiation with ultraviolet rays to form the sealing material 63. Since there is no danger of being irradiated and when irradiating the ultraviolet rays, the ultraviolet rays are applied to the entire surface of the alignment film, so that organic impurities and residues remaining on the surface portion of the alignment film can be burned. Here, as the irradiation conditions of the ultraviolet rays, the same conditions as those in the above embodiment can be adopted.

FIG. 6 shows an example of an active matrix type liquid crystal display device using a TFT element as a switching element. FIG. 6A is a perspective view showing the entire structure of the liquid crystal display device of this example. FIG. 6B is an enlarged view of one pixel in FIG. Liquid crystal display device 80 of this example
Has almost the same configuration as the previous example, which is a liquid crystal display device using a TFD element, as shown in FIG.
That is, the element substrate on which the TFT element is formed (first substrate)
A substrate (substrate) 74 and an opposing substrate (second substrate) 75 are arranged to face each other, and a sealing material 73 is arranged between these substrates in a frame shape.
A liquid crystal layer (not shown) is sealed in a region surrounded by the seal member 73 between the substrates. On the liquid crystal side surface of the element substrate 74, a large number of source lines 76 (data lines) and a large number of gate lines 77 (scanning lines) are provided in a grid pattern so as to intersect each other. A TFT element 78 is formed near the intersection of each source line 76 and each gate line 77,
The pixel electrodes 79 are connected via the T elements 78, and the many pixel electrodes 79 are arranged in a matrix in plan view. On the other hand, a common electrode 85 made of a transparent conductive material such as ITO is formed on the surface of the counter substrate 75 on the liquid crystal layer side corresponding to the display area.

As shown in FIG. 6B, the TFT element 78 includes a gate electrode 81 extending from the gate line 77, an insulating film (not shown) covering the gate electrode 81, and a semiconductor layer formed on the insulating film. 82, a source electrode 83 extending from a source line 76 connected to a source region in the semiconductor layer 82, and a drain electrode 84 connected to a drain region in the semiconductor layer 82. The drain electrode 84 of the TFT element 78 is connected to the pixel electrode 79.

The present invention can be applied to an active matrix type liquid crystal display device 80 using the above-described TFT element as a switching element, and the entire surface is cured when the sealing material is cured as in the previous embodiment. The sealing material may be cured by irradiating ultraviolet rays. That is, when the uncured sealing material is cured by ultraviolet irradiation to form the sealing material 73 after the substrates 74 and 75 are bonded and before the liquid crystal is injected, the alignment film due to oblique deposition may be damaged. Since there is no danger of being irradiated and when irradiating ultraviolet rays, ultraviolet rays are radiated to the entire surface of the alignment film, so that organic impurities and residues remaining on the surface portion of the alignment film can be burned. Here, as the irradiation conditions of the ultraviolet rays, the same conditions as those in the above embodiment can be adopted.

(Embodiment of Electronic Apparatus) Next, a specific example of an electronic apparatus provided with any one of the liquid crystal display devices A, 60 and 80 will be described. FIG. 7A is a perspective view illustrating an example of a mobile phone. In FIG. 7A, reference numeral 5
Reference numeral 00 denotes a mobile phone main body, and reference numeral 501 denotes a liquid crystal display unit (display means) using any one of the liquid crystal display devices A, 60, and 80. FIG. 7B shows a word processor,
FIG. 1 is a perspective view showing an example of a portable information processing device such as a personal computer. 7B, reference numeral 600 denotes an information processing device, reference numeral 601 denotes an input unit such as a keyboard, and reference numeral 60 denotes an input unit.
Reference numeral 3 denotes an information processing apparatus main body, and reference numeral 602 denotes a liquid crystal display unit (display means) using any one of the liquid crystal display devices A, 60, and 80. FIG. 7C is a perspective view illustrating an example of a wristwatch-type electronic device. In FIG. 7C, reference numeral 700 denotes a watch main body, and reference numeral 701 denotes a liquid crystal display unit (display means) using any one of the liquid crystal display devices A, 60, and 80. Each of the electronic devices shown in FIGS. 7A to 7C includes the liquid crystal panels A, 60, and 8 described above.
0 is provided with a liquid crystal display portion using any one of the above, so that there is no defective alignment due to impurities or residues, a high specific resistance is provided, and an electronic device having a liquid crystal display device capable of realizing uniform liquid crystal alignment is provided. Features that can be.

FIG. 8 shows an example in which a liquid crystal device according to the present invention is applied to a projection type electronic apparatus. FIG. 8 is a schematic diagram showing an example of a three-panel projection type liquid crystal display device.
In the figure, reference numeral 510 is a light source, 513 and 514 are dichroic mirrors, 515, 516 and 517 are reflection mirrors,
18, 519 and 520 are relay lenses, 522 and 52
3, 524 denotes a liquid crystal light valve (liquid crystal device), 525 denotes a cross dichroic prism, and 526 denotes a projection lens system.

The light source 510 includes a lamp 511 such as a metal halide and a reflector 512 for reflecting light from the lamp 511.
It is composed of The dichroic mirror 513 that reflects blue light and green light transmits red light out of white light from the light source 510 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 517 and is incident on the liquid crystal light valve 522 for red light.

On the other hand, among the color lights reflected by the dichroic mirror 513, the green light is reflected by the dichroic mirror 514 that reflects green light, and is incident on the liquid crystal light valve 523 for green. On the other hand, the blue light also passes through the second dichroic mirror 514. For the blue light, in order to compensate for the difference in the optical path length from the green light and the red light, a light guiding means 521 including a relay lens system including an entrance lens 518, a relay lens 519, and an exit lens 520.
, Through which blue light is incident on the blue light liquid crystal light valve 524.

The three color lights modulated by the respective light valves enter the cross dichroic prism 525. This prism has four right angle prisms bonded together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface. The three color lights are combined by these dielectric multilayer films to form light representing a color image. The synthesized light is projected on a screen 527 by a projection lens system 526, which is a projection optical system, and an image is enlarged and displayed.

Here, the liquid crystal light valves 522, 52
3, 524, there is a tendency that the interval between pixels is extremely short due to the demand for higher definition, and based on this tendency, the electric field of an adjacent pixel electrode is reduced to the electric field of an adjacent pixel. There is a possibility that the influence will be exerted. In such a case, it is considered effective to increase the pretilt of the liquid crystal, and the orientation film formed by the oblique deposition method is more advantageous than the polyimide alignment film because the pretilt angle can be increased as described above. . Based on such a background, the liquid crystal device provided with the orientation film formed by the oblique deposition method according to the present invention is effective also in the projection type liquid crystal display device. Other effects are the same as those of the previous embodiment.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A transparent substrate of ITO and a first substrate using an obliquely deposited SiO film having a thickness of 500.degree.
Acrylic UV cured as a sealant, with a 4.5 μm cell gap between a transparent electrode of O and a second substrate using a 500 ° thick SiO obliquely deposited film formed at a deposition angle of 85 ° as an alignment film. A panel sample was obtained by bonding using a mold resin. The entire surface of the panel sample was irradiated with ultraviolet rays using a 4 KW water-cooled metal halide lamp to cure the sealant. The ultraviolet intensity on the surface of the panel sample was 80 mW / cm ² (365 nm). Further, the temperature of the glass substrate during ultraviolet irradiation was controlled to be about 50 ° C. The curing condition of the sealing agent was 1500 mJ /
cm ² . For the panel thus obtained, 1
Inject a liquid crystal material having a specific resistance of 0 ¹³ (Ωcm)
After the injection, the electrodes of the liquid crystal panel were energized to measure the specific resistance of the liquid crystal layer. The specific resistance was about 10 ¹² (Ω · cm). Although a slight decrease in specific resistance is observed in this example, the rate of decrease in specific resistance is smaller than in any of Comparative Examples 1 to 5 shown below, and there is no orientation defect due to impurities or residues, and a high specific resistance is obtained. The effect of the method of the present invention that resistance can be obtained was confirmed.

[Comparative Example 1] The oblique deposition film was omitted for each of the above glass substrates, a polyimide thin film having a thickness of 500 mm was formed instead, and a rubbing roll was rubbed on the polyimide thin film to perform an orientation treatment. Next, a panel sample was obtained by bonding with a sealant with a cell gap equivalent to that of the previous example. The entire surface of the panel sample was irradiated with ultraviolet rays using a 4 KW water-cooled metal halide lamp to cure the sealant. The UV intensity on the panel sample surface is 80m
W / cm ² (365 nm). Further, the temperature of the glass substrate during ultraviolet irradiation was controlled to be about 50 ° C. The curing condition of the sealing agent is 1500 mJ / cm ^2.
It is. For the panel sample thus obtained, 10
A liquid crystal material having a specific resistance of ¹³ (Ω · cm) was injected, and after injection, a current was applied to the electrodes of the liquid crystal panel and the specific resistance of the liquid crystal layer was measured. The specific resistance was about 10 ⁹ (Ω · cm).
The specific resistance decreased by four orders of magnitude from the previous example. This is because the polyimide thin film was directly irradiated with ultraviolet rays, so that a part of the polyimide thin film was damaged and mixed into the liquid crystal, and a part of the polyimide thin film or a part of the rubbing roll hair by the rubbing treatment of the polyimide thin film. It is considered that a part of the residue remaining on the surface of the polyimide thin film at the time of rubbing remains on the surface of the alignment film and is mixed into the liquid crystal with the injection of the liquid crystal.

[Comparative Example 2] Under the same manufacturing conditions as in Comparative Example 1, a panel sample was prepared under the condition that the polyimide thin film was covered using a mask when irradiating ultraviolet rays and only the sealant was irradiated with ultraviolet rays. A liquid crystal material having a specific resistance of 10 ¹³ (Ω · cm) was injected into the panel sample thus obtained, and after injection, a current was supplied to the electrodes of the liquid crystal panel to measure the specific resistance of the liquid crystal layer. The specific resistance is about 10 ¹¹ (Ω
Cm), and the specific resistance was reduced by two orders of magnitude compared to the previous example. This is because part of the polyimide thin film or part of the rubbing roll bristles due to the rubbing treatment of the polyimide thin film or part of the residue remaining on the surface of the polyimide thin film during rubbing remains on the alignment film surface. It is considered that the result was mixed into the liquid crystal.

Comparative Example 3 The polyimide thin film used in Comparative Example 1 was used as an alignment film, and a thermosetting epoxy resin was used as a sealant. A panel sample was prepared by heating to cure the sealant. A liquid crystal material having a specific resistance of 10 ¹³ (Ω · cm) was injected into the panel sample thus obtained, and after injection, a current was supplied to the electrodes of the liquid crystal panel to measure the specific resistance of the liquid crystal layer. The specific resistance is about 10 ¹¹ (Ω
Cm), and the specific resistance was reduced by two orders of magnitude compared to the previous example. In Comparative Example 3, no ultraviolet irradiation was performed, but since an alignment film of a polyimide thin film was used, it is considered that contaminants caused by this alignment film were mixed in the liquid crystal.

Comparative Example 4 The same obliquely deposited SiO film as in the previous example was used as the alignment film, and the same sealant was used.
A portion other than the sealant was covered using a mask, and only the sealant portion was irradiated with ultraviolet rays to prepare a panel sample.
With respect to the panel sample thus obtained, 10 ¹³ (Ω ·
cm), a specific resistance of about 10 ¹¹ (Ω · cm) was obtained when the specific resistance of the liquid crystal layer was measured by applying a current to the electrodes of the liquid crystal panel and then measuring the specific resistance of the liquid crystal layer. The resistivity decreased by two orders of magnitude. In Comparative Example 4,
Since the SiO oblique deposition film was not irradiated with ultraviolet rays, impurities and residues remaining on the surface portion of the oblique deposition film or other portions of the panel were mixed into the liquid crystal. It is thought that the resistivity decreased by two orders of magnitude.

"Comparative Example 5" A panel sample was prepared using an obliquely deposited SiO film equivalent to that of the previous example as an alignment film and a thermosetting sealant. A liquid crystal material having a specific resistance of 10 ¹³ (Ω · cm) was injected into the panel sample thus obtained, and after injection, a current was supplied to the electrodes of the liquid crystal panel to measure the specific resistance of the liquid crystal layer. The specific resistance was about 10 ¹¹ (Ω · cm), which was two orders of magnitude lower than in the previous example. In Comparative Example 5, since the SiO oblique deposition film was not irradiated with ultraviolet rays, impurities and residues remaining on the surface portion of the oblique deposition film or other portions of the panel were mixed into the liquid crystal. As a result, it is considered that the specific resistance was reduced by two orders of magnitude as compared with the previous example.

[0045]

As described above, according to the present invention, there is a feature that it is possible to provide a liquid crystal device which is free from defective alignment due to impurities and residues, has a high specific resistance, and can realize a uniform liquid crystal alignment. . That is, when the specific resistance of the liquid crystal decreases, the voltage holding ratio decreases, and there is a possibility that display defects such as a decrease in contrast and flicker may easily occur. However, the method of the present invention can provide a liquid crystal device which does not cause these problems.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a liquid crystal display device to which a method according to the present invention is applied.

FIG. 2 is a schematic plan view of the liquid crystal display device shown in FIG.

3A and 3B show an example of an assembling order of a liquid crystal panel. FIG. 3A is a cross-sectional view of one substrate, and FIG.
3B is a cross-sectional view showing a state in which an electrode and an alignment film are formed on one substrate, FIG. 3C is a cross-sectional view of the other substrate, and FIG.
(D) is a sectional view showing a state in which the substrates are bonded and irradiated with ultraviolet rays.

FIG. 4 is a cross-sectional view showing one structural example of an oblique deposition film according to the present invention.

5A and 5B show a second example of a liquid crystal display device to which the method according to the present invention is applied. FIG. 5A is a perspective view of the entire liquid crystal display device, and FIG. FIG. 3 is an enlarged perspective view illustrating one pixel portion of the display device.

6A and 6B show a third example of a liquid crystal display device to which the method according to the present invention is applied. FIG. 6A is a perspective view of the entire liquid crystal display device, and FIG. FIG. 3 is an enlarged perspective view illustrating one pixel portion of the display device.

FIGS. 7A and 7B show an example of an electronic device provided with a liquid crystal device obtained by the method of the present invention. FIG. 7A is a perspective view of a mobile phone, and FIG. FIG. 7C is a perspective view of a portable information terminal, which is a wristwatch-type portable information terminal.

FIG. 8 is a diagram showing an example of a projection display device provided with a liquid crystal device according to the method of the present invention.

FIG. 9 is a cross-sectional view showing a state in which a liquid crystal display device is irradiated with ultraviolet rays in a conventional liquid crystal display device manufacturing method.

[Explanation of symbols]

 A Liquid crystal device 10, 20 Substrate 11, 21 Alignment film 30 Sealing material 40 Liquid crystal layer 61, 62 Substrate 63, 73 Sealing material 74, 75 Substrate 500, 600, 700 Electronic equipment 501, 602, 701 Display unit (display means)

Continued on the front page F term (reference) 2H089 NA09 NA25 NA44 QA14 QA16 TA04 TA09 TA12 TA16 TA17 TA18 2H090 HD14 LA03 LA04 LA12 LA15 LA16 LA20 MA11 MB06

Claims (5)

[Claims] A pair of substrates; a liquid crystal layer sandwiched between the substrates by a sealing material formed between the substrates;
When manufacturing a liquid crystal device comprising an alignment film formed on the liquid crystal layer side of the substrate, at least one of the substrates is made of a translucent material,
The alignment film is composed of an obliquely deposited film made of an inorganic material, and the sealing material is composed of an ultraviolet-curable sealing material.
At the same time as disposing a sealing material between the substrates and laminating both substrates, or after laminating both substrates and before injecting liquid crystal between the substrates, ultraviolet light is applied to the laminated substrates. A method for manufacturing a liquid crystal device, comprising: irradiating the entire surface to cure the sealant and burning out contaminant organic substances on the surface of the alignment film. 2. The method according to claim 1, wherein the oblique deposition is performed at 70 to 85 from the normal of the substrate.
2. The method for manufacturing a liquid crystal device according to claim 1, wherein the method is performed from a direction inclined at an angle. 3. A substrate provided with an electrode for driving liquid crystal is used as the substrate, and the specific resistance of the liquid crystal layer measured after injecting the liquid crystal between the substrates is smaller than the specific resistance of the liquid crystal before the injection between the substrates. The method for manufacturing a liquid crystal device according to claim 1, wherein a decreasing rate is set to 1/10 or less. 4. A liquid crystal device obtained by the manufacturing method according to claim 1. 5. An electronic apparatus comprising the liquid crystal device according to claim 4 as display means.