JPH09160051A - Active matrix type liquid crystal display element having transverse electric field structure and its production as well as liquid crystal display device formed by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the display element so as to have a uniform liquid crystal thickness. SOLUTION: One electrode substrate 10 which has one orientation control film 15 on the common electrodes 11, gate insulating films 12 and electrodes, such as source electrodes 13 and drain electrodes 15 laminated on a substrate 10 and another electrode substrate 20 which has another orientation control film 23 on the light shielding films 21 and color filters 22 laminated on the substrate 20 are disposed to face each other via spacer materials 19 for regulating the spacing between both electrodes 10 and 20. Liquid crystals are packed into the spacing. At least either of the orientation control film 15 or 23 consists of a photosetting material or thermosetting material. The spacer materials 19 are directly fixed onto the uncured parts 18 on the orientation control film 15 or 23 formed by irradiating the thermosetting materials or thermosetting materials with light or heat so that electric fields are directly impressed on the surfaces of both electrode substrates 10, 20 in the direction parallel therewith from the respective electrodes 11, 13, 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display element having a lateral electric field structure, a method for manufacturing the liquid crystal display element, and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art In a conventional active matrix type liquid crystal display device having a horizontal electric field structure, as a method of dispersing and fixing a spacer material that regulates the liquid crystal thickness, 1) a black matrix portion is used as disclosed in JP-A-4-136916. A structure in which only a spacer material is dispersed and fixed, 2) JP-A-4-6051
No. 7, the spacer material has a structure in which the spacer material is dispersed and fixed only in the region corresponding to the black matrix portion. 3) As in JP-A-4-243230, an adhesive layer is formed on the surface. A liquid crystal display device having a structure in which the formed spacer material is dispersed and fixed on an alignment film, a manufacturing method, and the like have been proposed.

[0003]

In the above-mentioned prior art method of dispersing / fixing a spacer material, the spacer material is arranged under the orientation control film, or the spacer material is placed on the orientation control film via an adhesive. It is a method of arranging, 1) the liquid crystal thickness cannot be defined only by the size of the spacer material, 2) the dispersion density and the dispersion position of the spacer material cannot be accurately defined, and 3) the dispersion density of the spacer material without lowering the contrast. It is difficult to significantly increase the number, 4) the utilization efficiency of the spacer material is low, and 5) the orientation control film surface is easily contaminated during the photolithography process and the dispersion / fixing of the spacer material.

Therefore, an object of the present invention is to provide an active matrix type liquid crystal display device having a horizontal electric field structure having a uniform liquid crystal thickness and a method for manufacturing the same, and using the active matrix type liquid crystal display device having the horizontal electric field structure. ,
An object of the present invention is to provide a liquid crystal display device capable of obtaining a high-quality image that is uniform and has no light leakage.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
One electrode substrate provided with one orientation control film on the plurality of electrodes laminated on the substrate, and the other electrode substrate provided with the other orientation control film on the light shielding film and the color filter laminated on the other substrate, A transverse electric field facing each other through a spacer material for defining a gap between the two electrode substrates, the gap being filled with liquid crystal, and an electric field being applied from each of the electrodes in a direction parallel to the surfaces of the two electrode substrates. In the active matrix liquid crystal display element having a structure, at least one of the alignment control films is made of a photo-curable material or a thermosetting material, and the alignment control film made of the photo-curable material or the thermosetting material is This is achieved by irradiating and directly fixing the spacer material at a predetermined position on the orientation control film.

Further, the spacer material is made of a material which is coated with a photo-curing material or a thermosetting material, and the spacer material which is coated with the photo-curing material or the thermosetting material is oriented in the direction of irradiation with light or heat. It may be directly fixed to a predetermined position on the control film.

Further, a method of manufacturing an active matrix type liquid crystal display device having a lateral electric field structure for achieving the above object comprises a step of laminating a photosensitive resin thin film on a substrate having a plurality of electrodes to form one electrode substrate, Irradiating light or heat on the photosensitive resin thin film to selectively form an uncured portion,
A step of dispersing a spacer material on the photosensitive resin thin film including the uncured portion, and curing the uncured portion by irradiating light or heat to fix only the spacer material dispersed on the uncured portion A step of removing the unfixed spacer material, and a non-photosensitive material on the substrate having the light-shielding film and the color filter on the one electrode substrate having the spacer material remaining fixed on the uncured portion. And a step of stacking the other electrode substrate formed by laminating resin thin films.

Then, by using the active matrix type liquid crystal display device of the horizontal electric field structure having a uniform liquid crystal thickness according to the present invention, a liquid crystal display device of a high quality image which is homogeneous and does not leak light can be obtained.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings, taking an active matrix type liquid crystal display device (hereinafter, simply referred to as a liquid crystal display device) suitable for carrying out the present invention. To do. In this embodiment, the display scale is 640 × 480 dots (pixel pitch: 0.33 mm ×
0.33 mm, pixel size: 0.30 mm x 0.30 m
m, screen diagonal size: 10.4 inches), mainly the active matrix type liquid crystal display element (hereinafter, simply referred to as liquid crystal display element) for VGA compatible notebook type personal computer (hereinafter, referred to as notebook PC). To do.
A method of manufacturing a liquid crystal display device having a horizontal electric field structure, which can obtain a uniform liquid crystal thickness without forming an adhesive or a similar layer on the surface of the spacer material according to the present invention, will be described.

FIG. 1 is a diagram showing a manufacturing process of a liquid crystal display device according to an embodiment of the present invention. As shown in the figure,
(A) A plurality of electrodes as a scanning signal electrode, a video signal electrode, and a pixel electrode for driving a liquid crystal of 640 × 480 dots by the photolithography method, that is, a common electrode 11 (material: aluminum, thickness: 3000Å) , Substrate 10 having source electrode 13, drain electrode 14 and gate insulating film 12 (alkali-free glass: Corning 705
9, thickness: 0.7 mm), and an alignment control film 15 for controlling the molecular alignment of liquid crystal by spin coating or printing.
(Photosensitive polyimide resin, thickness: 0.1 μm) are laminated to form one electrode substrate. That is, an electrode substrate corresponding to a liquid crystal display element having a structure in which an electric field is applied in a direction parallel to the electrode substrate surface (hereinafter referred to as a lateral electric field structure) is formed.

(B) A photomask 16 having a mask pattern 16a having a lattice pattern (about 25 μm pitch × 313 μm pitch) having a width of 5 μm and an ultraviolet ray 17 are used to form an ultraviolet ray on each electrode region on one alignment control film 15. An uncured portion 18 is formed as a non-irradiated portion where 17 is not irradiated. In other words, it can be said that the uncured portion 18 on the orientation control film 15 is formed at a predetermined position on the orientation control film 15 which is not irradiated with light or heat. Each electrode region where the uncured portion 18 is formed is also referred to as a light shielding portion (width: 7 μm, gap between electrodes). Further, generally, a light-shielding film region, which will be described later, is arranged at a position facing each electrode region.

(C) A spacer material 19 (manufactured by Sekisui Chemical Co., Ltd .: polymer beads, particle diameter: 4.0 ± 0.2 μm) having a predetermined uniform size is dispersed (dispersed) on the orientation control film 15 on which the uncured portion 18 is formed. ) Do. (D) Ultraviolet 17 irradiation or heat ray 1
The uncured portion 18 on the alignment control film 15 is cured by the irradiation of 7a or the combined use of the ultraviolet ray 17 and the heat ray 17a, and only the spacer material 19 dispersed on the uncured portion 18 is directly fixed. Therefore, the alignment control film 15 is irradiated with light or heat, and the spacer material 1 is placed at a predetermined position on the alignment control film 15.
9 is directly fixed. (E) The unfixed spacer material 19 that is not fixed is removed from the orientation control film 15. (F) Alignment control film 1 to which the spacer material 19 is fixed
5 is rubbed with a roller 30 equipped with a rubbing cloth made of cellulose and nylon to perform orientation treatment.

(G) One electrode substrate having the spacer material 19 remaining and fixed on the uncured portion as described above, and a pigment corresponding to a pitch of 640 × 3 × 480 dots or less by photolithography. Alternatively, on a substrate 20 (alkali-free glass: Corning 7059, thickness: 0.7 mm) provided with a light-shielding film 21 made of a metal such as chromium and a color filter 22 made of a pigment or a dye,
The other alignment control film 23 (non-photosensitive polyimide resin, thickness: 0.1 μm) is formed, cured, and rubbed to form the other electrode substrate, and each electrode region on both electrode substrates and a light-shielding film. Both alignment control film surfaces are opposed to each other so that the light-shielding film region made of 21 faces each other, and an epoxy-based adhesive as a sealant is arranged around both electrode substrates to overlap each other.

By overlapping the electrodes formed on both the electrode substrates and the color filters in a one-to-one correspondence, the alignment control films of the two electrode substrates facing each other are made uniform by the spacer material. A substrate gap is formed. That is, a uniform liquid crystal thickness is ensured.

After that, a liquid crystal material is injected and sealed in the above-mentioned substrate gap by a pressure reduction method. Then, a tape carrier package (hereinafter, referred to as TCP
Drive circuit, control circuit, power supply circuit, etc., cold cathode fluorescent tube (1 lamp, tube diameter: 3 mm), light guide
A liquid crystal display device is manufactured by combining a backlight composed of (material: acrylic resin, shape: wedge shape), a prism sheet, etc. and using a resin case and a metal frame to make a module.

In other words, the above-mentioned method for manufacturing a liquid crystal display device is a step of forming an alignment control film made of a photosensitive resin in a predetermined thickness on an electrode substrate having a plurality of electrodes formed on one substrate. A step of selectively forming an uncured portion for dispersing and fixing the spacer material on the orientation control film, a step of dispersing the spacer material on the orientation control film on which the uncured portion is formed, and a spacer material The process of curing the uncured portion of the alignment control film made of a photosensitive resin in which is dispersed to fix the spacer material, the process of removing the unfixed spacer material on the alignment control film, and the dispersion and fixation of the spacer material. Of the alignment control film on the other electrode substrate subjected to the alignment treatment after the alignment treatment is performed on the aligned alignment control film and the alignment control film made of the non-photosensitive resin is formed on the light shielding film and the color filter. And face each other, and The process of stacking the poles and color filters so that they correspond uniquely and adhering them so as to form a predetermined gap (liquid crystal thickness) between both electrode substrates, and injecting and sealing liquid crystal into the gap between both electrode substrates And the step of performing.

Although the non-photosensitive polyimide resin as the thermosetting material is used as the other orientation control film 23 in the above embodiment, a photosensitive polyimide resin as the photocuring material may be used. It is also possible to manufacture one of the orientation control films 15 with a non-photosensitive polyimide resin and the other of the orientation control films 23 with a photosensitive polyimide resin in the reverse process of the above embodiment.

That is, in the steps corresponding to the above (a), (b), (c), and (d), light shielding of the other alignment control film 23 of the other electrode substrate having the light shielding film 21, the color filter 22, etc. An uncured portion 18 is formed on the film region, and the spacer material 19 is left and fixed. After that, in the steps corresponding to (e), (f), and (g), the spacer material 1 remaining and fixed on the uncured portion 18
One electrode substrate having a plurality of electrodes is superposed on the other electrode substrate having the electrode 9. Furthermore, it can be said that the spacer material 19 can be fixed if at least one of the one orientation control film 15 and the other orientation control film 23 is a photo-curing material or a thermosetting material.

In brief, the liquid crystal display device according to the present invention is composed of a pair of electrode substrates each including a substrate having a plurality of electrodes on one side and a substrate having a color filter on the other side. At least one of the orientation control films is a thin film made of a photocurable material or a thermosetting material, and the pacer material is directly dispersed on the light of the orientation control film at a predetermined position without interposing an adhesive layer or a similar layer. After fixing, by facing the orientation control film surface of the other electrode substrate and adhering the periphery of both electrode substrates with a sealing material,
A predetermined gap (predetermined liquid crystal thickness) for enclosing the liquid crystal is formed. That is, the problem is solved by a novel method of dispersing and fixing the spacer material. Further, in the above steps, 1) the unnecessary spacer material can be collected and reused, 2) there are no steps such as patterning, dyeing and printing, so that the surface of the alignment control film is not contaminated 3) Since it is fixed on the alignment control film without forming an adhesive on the surface of the spacer material, it has the advantage that the missing parts of the spacer material, the movement path, etc. do not cause display defects, thus reducing the production cost, that is, the liquid crystal. This has the effect of reducing the price of the display device.

Further, by using a flattening film made of acrylic resin or epoxy resin to reduce surface irregularities due to electrodes on the electrode substrate having thin film transistors or irregularities on the color filter, a more uniform liquid crystal thickness can be obtained. It has been confirmed that the liquid crystal display element of can be obtained. further,
Forming the color filter on the side of the electrode substrate having each electrode eliminates the need for alignment between the two electrode substrates and greatly simplifies the device fabrication, which is highly effective in reducing costs.

Summarizing the above, the feature of the present invention is to use a photo-curing material or a thermo-curing material as a fixing material for fixing the spacer material, and to irradiate light or heat only on the selected prescribed portion, Since the photo-curable material or the thermo-curable material is cured and the spacer material is fixed only to the selected prescribed portion, the spacer material can be fixed uniformly at a predetermined dispersion position and dispersion density. In one example, the alignment control film is composed of a photo-curing material or a thermosetting material, and the alignment control film is selectively irradiated with light or heat, and only the spacer material dispersed in the irradiated portion is alignment-controlled. It adheres directly to the membrane. In the above examples, the fixing material is expressed as a photo-curing material or a thermosetting material, but any material having a function of fixing the spacer material by irradiating light or heat may be adopted as the fixing material. Needless to say.

In other words, a function of fixing the spacer material to the alignment control film made of a material having a function of fixing the spacer material by irradiation of light or heat, or a photocurable material or a thermosetting material as described later is used. This is a method of giving a role of fixing to the coated spacer material itself. Since a predetermined position for irradiating light or heat can be accurately defined by using a photomask or the like, this is also a method of accurately defining the dispersed position and dispersed density of the spacer material.

According to the above method, the spacer material can be directly fixed on the alignment control film in contact with the liquid crystal with a uniform and high dispersion density, so that the thickness of the liquid crystal can be formed to the specified dimension. Therefore, a uniform liquid crystal thickness can be easily obtained over the entire surface of the liquid crystal display device by using the above-mentioned active matrix type liquid crystal display device of the horizontal electric field structure, and there is no factor that deteriorates the display performance and the refractive index of the liquid crystal molecules. Since the drive system does not change, a liquid crystal display device of an image having high contrast and no angle dependence can be obtained.

Next, the formation of the uncured portion of the alignment control film for fixing the spacer material, which is the point of the present invention, will be described with reference to FIG.
It will be described in detail with reference to FIG. FIG. 2 is a diagram showing an example of an uncured portion formed on the orientation control film. As shown in the drawing, on the alignment control film corresponding to each electrode region of the common electrode 11, the source electrode 13, the drain electrode 14, the gate electrode 24, or the like, the alignment corresponding to the light-shielding film region arranged in parallel with the color filter 22. The uncured portions 18 are formed on the control film in a lattice (or linear) pattern shape.

In particular, a liquid crystal display device having a structure for applying an electric field in a direction parallel to the electrode substrate surface according to the present invention, that is, a lateral electric field structure, has a plurality of electrodes (for example, common electrodes) within the same dot of the color filter 22. Electrode 11 and source electrode 13)
As a result, the uncured portions 18 can be formed with a narrower pitch than in the conventional liquid crystal display device having a vertical electric field structure in which an electric field is applied in a direction perpendicular to the electrode substrate surface. That is, it can be said that the spacer material 19 can be dispersed at a narrow pitch.

Specifically, in FIG. 2, the size of one pixel is 330 μm in width × 330 μm in length. The size of one dot is 100 μm in width × 330 μm in length. Three common electrodes 11, two source electrodes 13, and one drain electrode 14 are arranged in one dot. That is, one dot is horizontally divided into four. Therefore, when the uncured portions 18 are formed in the portions corresponding to the respective electrode regions, the lattice pattern of "about 25 μm pitch × 313 μm pitch" is obtained as described above. On the other hand, in the case of the conventional liquid crystal display element having the vertical electric field structure, since it is impossible to divide the electrodes as described above, the grid pattern is “100 μm pitch × 313 μm pitch”. From this, 4.0μ
Compared with the conventional case in which the spacer material 19 is arranged at a pitch of 100 μm with respect to the particle diameter of the spacer material 19 at the m-th position, the span in the case of the present invention in which the spacer material 19 is arranged at a pitch of about 25 μm is shorter, that is, The "span / particle size ratio" becomes smaller,
A much more uniform liquid crystal thickness can be obtained.

In other words, if the uncured portion 18 is formed with a pitch size smaller than the dot pitch of the color filter 22 (divided size of one dot in the horizontal direction in FIG. 2), the spacer material 19 is dispersed and fixed at a narrow pitch. It can be said that a liquid crystal display device having a uniform liquid crystal thickness can be obtained, a uniform image can be displayed, and unnecessary light leakage can be eliminated to improve the contrast. Of course, a pitch dimension equivalent to the dot pitch of the color filter 22 (one dot dimension in the horizontal direction in FIG. 2)
It is also possible to form the uncured portion 18 with. As a result, the liquid crystal can be made uniform in thickness and arranged at the same height, and the monodispersity ratio and dispersion density of the effective spacer material are improved.
In particular, it has been found to be effective for making the liquid crystal thickness uniform.

As described above, the feature of the present invention is that the spacers can be arranged with a high dispersion density on each electrode region serving as a light shielding part or on the light shielding film region formed on the color filter side, so that the conventional vertical electric field structure liquid crystal. Compared with the device, it has a feature that a uniform liquid crystal thickness can be easily formed. In the embodiment of FIG. 2,
Although the description has been given of the electrode configuration in which one dod is divided into four, it is not limited to this, and the number of divisions is increased to drive at a low voltage, the width of the electrode is reduced, or the film thickness is increased. It goes without saying that it may be devised depending on the case. Further, it is also obvious that if the number of electrodes is increased by increasing the number of divisions, the dispersion density of the spacer material can be improved, so that the uniformity of the liquid crystal thickness is further improved.

The color filter is of a pigment dispersion type or a dye type, for example, and the light shielding film is of a pigment dispersion type or chrome. The present invention is also
A thin film transistor portion 26R, 26G, 26B as an active element composed of the silicon portion 25 is a driving system in which a voltage is applied between the common electrode 11 and the source electrode 13 to change only the direction of liquid crystal molecules in the same plane. It was also confirmed that the angle dependence, which is a drawback of the liquid crystal display having a vertical electric field structure in which the refractive index of liquid crystal molecules changes depending on whether or not a voltage is applied, can be eliminated.

Further, the width or length of the uncured portion 18 of the orientation control film is formed to be equal to or smaller than the grain size of the spacer material 19 having a predetermined dimension, whereby the uncured portion 1 is formed.
Since the number of the spacer materials 19 to be fixed to 8 is defined (for example, only one is surely fixed), the above-mentioned electrode substrate gap is kept constant, and a liquid crystal display element having a uniform liquid crystal thickness is obtained. . As a result, a liquid crystal display device achieving uniform display and high contrast over the entire display surface was obtained. Further, when the uncured portions 18 are arranged in a stripe shape only in the vertical or horizontal direction, almost the same liquid crystal thickness uniformity as that in a lattice shape is obtained.

Next, a method for easily obtaining a desired spacer material dispersion density without aggregation of the spacer material will be described with reference to FIG. FIG. 3 is a diagram showing another example of the uncured portion formed on the orientation control film. As shown in the drawing, the size (area) of the uncured portion 18 of the alignment control film in which the spacer material 19 is dispersed and adhered is set to an area sufficient for adhering one spacer material 19, for example, the spacer material 19 Of the common electrode 11, the source electrode 13,
Light or heat is applied only to the portions corresponding to the light-shielding electrode regions or the light-shielding film regions such as the drain electrode 14 and the gate electrode 24, and the uncured portions 18 are formed in dots.

As a result, the dispersion density of the spacer material (in other words, the number of spacer materials fixedly defined on the uncured portion)
Is capable of being controlled with higher accuracy. By forming the uncured portion 18 for dispersing and fixing the spacer material in a dot shape only on each electrode or the light-shielding film, a liquid crystal display having a uniform liquid crystal thickness that is not affected by light leakage from the spacer material. A liquid crystal display device having high contrast and uniform image quality using the device and the liquid crystal display device has been achieved.

Next, as an effective dispersion / fixing method of the spacer material, the uncured portion 18 is formed in the same direction as the alignment treatment direction such as rubbing, and the spacer material is dispersed / fixed in the same direction as the alignment treatment direction. An example according to the present invention will be described. FIG. 4 is a diagram showing another example of the uncured portion formed on the orientation control film. FIG. 5 is a diagram showing the relationship between the dispersion direction of the spacer material and the moving direction of the rubbing roller in the embodiment of FIG. As shown in the figure, the uncured portion 18 of the orientation control film is formed by a roller 30 on which a rubbing cloth is mounted.
Are formed in the same direction as the moving direction 31 of.
Then, by fixing the spacer material 19 to the uncured portion 18 formed in the array, another effect that the alignment process of the rubbing or the like does not cause the liquid crystal alignment defect in the vicinity of the spacer material 19 is obtained. It was

In the active matrix type liquid crystal display device of the horizontal electric field structure of this embodiment, the spacer material is arranged in a region other than the pixel portion and the dispersion density thereof is 2500.
It was set to a range of 0 to 50,000 pieces / cm ² . It has been found that it is desirable to set the dispersion density of the spacer material in the range of 25,000 to 40,000 / cm ² in order to obtain a more uniform liquid crystal thickness in the plane of the liquid crystal display element. On the other hand, in the case of the conventional liquid crystal display device having the vertical electric field structure, it is impossible to subdivide as described above.
It was in the range of 0000 to 20000 pieces / cm ² .

However, the preferable dispersion density of the spacer material differs depending on the elastic modulus of the spacer material, the size of the liquid crystal display element, the thickness of the glass substrate, the element structure, etc., and is not limited to the above numerical values. In addition, a liquid crystal display device having a horizontal electric field structure having a thin liquid crystal thickness (about 2 to 4 μm) manufactured according to the present invention has a dispersion density of a spacer material significantly larger than that of a conventional liquid crystal display device having a vertical electric field structure. Since it can be increased and the spacer material is arranged on each electrode, it is very effective without adversely affecting the contrast.

Next, an example in which the present invention is applied to a TFT color liquid crystal display device will be described. FIG. 6 is a sectional view showing a color liquid crystal display device according to an embodiment of the present invention. In the figure, a color liquid crystal display element and a backlight portion are shown, and a portion of the liquid crystal display element is shown in cross section. FIG.
FIG. 7 is a cross-sectional view of a backlight unit of the color liquid crystal display device of FIG. The figure shows the sectional structure of the entire color liquid crystal display device. In the figure, a liquid crystal display device 50 includes an upper substrate 20 and a lower substrate 10 (alkali-free glass: Corning 7059, thickness: 0.7 mm), a liquid crystal 27 (Merck: nematic mixed liquid crystal), and upper and lower polarizing plates. 28,2
9 (manufactured by Nitto Denko: G1220DU, transmittance: 40%).

On the upper substrate 20, an insulating black light-shielding film 21 (pigment dispersion type, film thickness: 0.5 to 2.0 μm), red,
Three primary color filters of green and blue (pigment dispersion type, film thickness: 1.0 to 1.8 μm), flattening film 32 (epoxy resin, film thickness: 1.0 to 2.0 μm), orientation control film 23 Spacer material 19 (made by Sekisui Chemical Co., Ltd .: polymer beads, particle diameter: 4.0) on (photosensitive polyimide resin, thickness: 0.1 μm)
± 0.2 μm) was formed.

On the other hand, the common electrode 1 is provided on the lower substrate 10.
1 (material: aluminum, film thickness: 3000Å, electrode width: 7μ
m), the gate insulating film 12 (material: silicon nitride, film thickness: 1
000-5000Å), source electrode 13 (material: aluminum, film thickness: 3000Å, electrode width: 7 μm), drain electrode 11 (material: aluminum, film thickness: 3000Å, electrode width: 7 μ)
m) Gate electrode not shown (material: aluminum, film thickness: 30
00Å), a flattening film 32 (material: epoxy resin, film thickness: 1.0 to 2.0 μm), an alignment control film 15 (non-photosensitive polyimide resin, thickness: 0.05 to 0.15 μm). Formed. However, the gap between the common electrode 11 and the source electrode 13 was 16 μm.

As shown in the figure, the spacer material 19 for stacking the upper and lower electrode substrates, which is a feature of the present invention, to form a desired liquid crystal thickness is a light-shielding film 21 or electrodes 11, 1.
It was dispersed and fixed to the orientation control film corresponding to 3, 14, and 28 (non-opening portion).

Further, the color liquid crystal display element 5 having the above structure
On one electrode substrate side of 0, the cold cathode fluorescent tube 53, the light guide 5
4 (material: acrylic, thickness: 2 mm), diffusion plate 55 (material: polyester, thickness: 0.125 mm), prism sheet 56, reflection sheets 57, 58 (material: polyester, thickness: 0.125 mm), Reflective film 59 (material:
Polyester (with silver thin film), thickness: 0.125m
m), a backlight composed of the adhesive tape 60 is arranged. Further, the color liquid crystal display element 50 is connected to a TCP 51 having an integrated circuit for controlling a thin film transistor formed for each pixel and a printed board 52 having a power supply circuit and a drive control circuit. . Although not shown in FIG. 7, the color liquid crystal display device 50, the backlight, and the like were built in a housing such as a resin case and a metal frame to manufacture a color liquid crystal display device.

Next, another embodiment suitable for carrying out the present invention will be described. FIG. 8 is a diagram showing a manufacturing process of a liquid crystal display device according to another embodiment of the present invention. As shown in the figure, (a) the common electrode 11 (material: aluminum, film thickness: 3000Å, width: 7 μm) formed on the glass electrode substrate 10.
m), gate insulating film 12 (material: silicon nitride, film thickness: 1
000-5000Å), source electrode 13 (material: aluminum,
Film thickness: 3000 Å, width: 7 μm), drain electrode 14 (material: aluminum, film thickness: 3000 Å, width: 7 μm), each having a thin film transistor composed of a gate electrode and an amorphous silicon portion, which are not shown in the figure. An alignment control film 15 made of a non-photosensitive polyimide resin is applied on the electrodes by a spin coating method or a printing method to a thickness of 1000 Å and cured to form one electrode substrate.

(B) On the electrode substrate, a semi-cured photosensitive polyimide-based resin (that is, a material having a function of fixing the spacer material by irradiation of light) or a non-photosensitive polyimide-based resin (that is, a heat-sensitive polyimide resin). The spacer material 19 whose surface is covered with a material having a function of fixing the spacer material by irradiation) is dispersed. (c) The semi-cured resin formed on the surface of the dispersed spacer material 19 is regulated at a predetermined location using the photomask 16 (for example,
Light is irradiated (targeting the source electrode 13 and the drain electrode 14). Then, the spacer material 19 is directly fixed to a predetermined position on the alignment control film 15 irradiated with light (in other words, a necessary portion on the alignment control film 15). The irradiation may be performed with ultraviolet rays 17 or heat rays 17a, or a combination of light and heat. After that, (d) the unnecessary spacer material 19 that is not fixed is removed.

(E) The orientation control film 15 on which the spacer material 19 is dispersed and fixed is oriented by the roller 30 to which a rubbing cloth of cellulose or nylon is attached.
(F) The one substrate is made to face the other substrate on which a light-shielding film 21 made of a metal such as a pigment or chromium, a color filter 22 made of a pigment or a dye, and an alignment control film 23 are formed on a glass substrate 20. , And the two electrode substrates are superposed with an epoxy adhesive disposed so as to seal the periphery.

After that, a nematic mixed liquid crystal is filled in the gap between the electrodes by a decompression method, and the liquid crystal injection port is sealed with a photosensitive epoxy sealant. Then, a polarizing plate or a polarizing plate with a retardation plate is attached to both sides of the substrate, and a drive circuit and a control circuit are connected to form a liquid crystal display element.
This is a process of manufacturing a liquid crystal display device by mounting a backlight and the like inside a housing such as a resin case and a metal frame.

Also in this embodiment, the spacer material is arranged even in the inner region of the pixel portion, and the dispersion density thereof is set to the range of 25,000 to 50,000 pieces / cm ² .
Further, in order to obtain a more uniform liquid crystal thickness in the display element plane, the dispersion density of the spacer material is set to 25000-40.
It is desirable to set in the range of 000 pieces / cm ² . However, the preferable dispersion density of the spacer member varies depending on the elastic modulus of the spacer material, the size of the liquid crystal display element, the thickness of the glass substrate, the element configuration, etc., and is not limited to the above numerical values.

Further, even if the spacer material is dispersed only in one of the electrode substrates or in both electrode substrates, a liquid crystal display element having a uniform liquid crystal thickness can be obtained. However, when the spacer material is dispersed only in one of the substrates, the dispersion density must be twice as high as that in both electrode substrates. Furthermore, in this embodiment, as the orientation control film,
The photosensitive polyimide resin was used for one of the substrates on which the spacer material is dispersed and fixed, and the non-photosensitive polyimide resin was used for the other substrate, but even when the photosensitive polyimide resin is used for both substrates. It has been confirmed that equivalent effects can be obtained.

A flattening film made of acrylic resin, epoxy resin, or the like is used to reduce the unevenness on the surface due to the electrodes on the electrode substrate having the thin film transistor or the unevenness on the color filter. It has also been confirmed that a liquid crystal display device having a thickness can be obtained. It was also confirmed that the same effect can be obtained by fixing the spacer material to the flattening film and subjecting it to an alignment treatment such as rubbing for alignment treatment.

As described above, according to the present invention, the spacer material can be easily dispersed on the alignment control film in contact with the liquid crystal layer with a narrow dispersion pitch and dispersion density so as to obtain a desired liquid crystal thickness.
Since they can be fixed, a liquid crystal display device having a uniform liquid crystal thickness can be easily obtained. Therefore, it is possible to form a liquid crystal display device and a liquid crystal display device that can form an alignment control film having a uniform alignment control force and can obtain a clear image with a wide viewing angle without display defects. Furthermore, by dispersing and fixing the spacer material in the same direction as the alignment processing direction such as rubbing, it is possible to perform rubbing processing without disturbing the molecular alignment of the liquid crystal around the spacer material, and to obtain a more uniform image quality. A device and a liquid crystal display device can be achieved.

Furthermore, the semi-cured (non-sticky) adhesive formed on the surface of the spacer material, which is the point of this embodiment, is light, heat-curable or light-curable if it is of a type that is once softened and then cured. A curing type that uses both heat and heat may be used. It is more effective to select the adhesive in consideration of the heat resistance of the alignment control film as well as the heat resistance of the spacer material (inorganic material such as silica beads, organic material such as polymer beads).

Regarding the photo-curing material or the thermosetting material as the fixing material in this embodiment, only the polyimide resin has been explained, but the polyamide resin, the polyimideamide resin, the epoxy resin, the acrylic resin, the polyurethane resin. It has been found that similar effects can be obtained with resins, polyester resins, polyether resins, and the like.

According to the fixing method of the present invention as described above, the spacer material is directly fixed on the alignment control film without interposing a general adhesive layer or a similar layer (without using the adhesive). Therefore, it is possible to avoid the conventional contamination of the surface of the alignment control film with the adhesive. By the way, in the present invention, in consideration of the deviation of the particle size of the spacer material to be used, the elastic coefficient, etc., the shape and pitch of the individual spacer materials to be dispersed and fixed on the orientation control film can be determined by There is an advantage that the liquid crystal thickness can be controlled with higher accuracy.

Next, another embodiment for dispersing and fixing a spacer material having a semi-cured fixing material on the surface will be described. FIG. 9 is a diagram showing a manufacturing process of a liquid crystal display device according to another embodiment of the present invention. As shown in the figure, (a) an alignment control film 15 is formed on a substrate 10 on which electrodes such as a common electrode 11, a source electrode 13, a drain electrode 14 and a gate electrode are formed by spin coating or printing.
(B) Spacer material 1 having a semi-cured fixing material on the surface
9 is dispersed and arranged on the orientation control film 15 corresponding to the non-opening portion which is the gap between the electrodes by using the spacer material dispersing device 33 which pushes and disperses the spacer material 19 by the pulsed air pressure 34, and (c ) UV light 1 is applied using the photomask 16.
7 or heat rays 17a to directly fix the spacer material 19 to a predetermined position, and (d) unnecessary spacer material 1 which is not fixed.
9 is removed, and (e) the alignment control film 15 having the spacer material 19 dispersed and fixed thereon is subjected to the alignment treatment by the rubbing roller 30, and (f) the alignment control film 23 is formed on the light shielding film 21 and the color filter 22. The substrate 20 is opposed.

After that, the periphery of the electrode substrate is sealed with an adhesive, liquid crystal is injected into the gap between both electrode substrates by a decompression method, sealed with a photosensitive adhesive, and a polarizing plate or a polarizing plate with a retardation plate is attached. The process of connecting the drive circuit and the control circuit, and incorporating the liquid crystal display element and the backlight into the housing was the process of manufacturing the liquid crystal display device. This spacer material dispersion method also has the same advantages as those described above. In addition, although an active matrix type TFT liquid crystal display device having a horizontal electric field structure has been described in the present embodiment, the present invention is not limited thereto and a simple matrix is used. Type TN or STN liquid crystal display device, ferroelectric liquid crystal display device, polymer dispersion type liquid crystal display device and the like. Especially,
The active matrix type TFT liquid crystal display device of the lateral electric field structure of the present invention and the STN that positively utilize the birefringence of the liquid crystal.
In a liquid crystal display device, the accuracy of the liquid crystal thickness determines the display performance, so that a display device with a uniform liquid crystal thickness can be easily obtained, and a uniform, wide-viewing image that does not cause display defects can be obtained. It is effective because it can be achieved.

Further, in a liquid crystal display element having metal wiring or the like, by irradiating light from the glass substrate side, it is not possible to fix the spacer material to the alignment control film portion on the metal wiring without using a photomask. It is possible to form a hardened portion, which is effective for cost reduction. Whether the spacer material is fixed to the opening or the non-opening can be determined by selecting either a positive type or a negative type photosensitive material.

Finally, an embodiment of an active matrix type TFT liquid crystal display device having a vertical electric field structure will be described. FIG. 10 is a sectional view showing a liquid crystal display device having a vertical electric field structure according to an embodiment of the present invention. The liquid crystal display element having the TFT structure of the vertical electric field structure shown in FIG. 10 is a general one used in a VGA to XGA compatible liquid crystal display device having a size of 10 to 13 inches. One of the electrode substrates is a glass substrate 10 on which a gate electrode 80, a storage capacitor electrode 81,
Insulating film 44, amorphous silicon channel layer 82, drain electrode 83, source electrode 84, transparent electrode 1 of pixel portion
It is formed from 1. After forming the orientation control film 15 on this electrode substrate, an uncured portion is formed on the orientation control film 15 on the gate electrode 80 having the highest height using a photomask, and the spacer material 19 is dispersed in the portion.・ Stuck. Then, it is combined with the other electrode substrate on which the color filter is formed via an adhesive.

As shown in the drawing, by dispersing and fixing the individual spacer materials 19 only on the alignment control film 15 on the gate electrode 80, a liquid crystal display element having a uniform liquid crystal thickness could be achieved. Further, by fixing each spacer material 19 on the metal wiring, a liquid crystal display device which can obtain a uniform image with high contrast without light leakage from the spacer material 19 can be achieved. However, the shape, size, pitch, etc. of the uncured portions 18 formed on the alignment control film 15 were set to the same conditions as those of the above-mentioned active matrix type TFT liquid crystal display device of the horizontal electric field structure.

In addition, the gate electrode 80 and the storage capacitor electrode 8
To disperse and fix the spacer material 19 in the non-opening portion on the gate electrode 1, the gate electrode 80, the drain electrode 83, the source electrode 8
4 and the storage capacitor electrode 81 may function as a photomask, and light irradiation may be performed from the glass substrate 10 side. This method has an advantage that the spacer material 19 can be surely dispersed and fixed to the non-opening portion without using a photomask.

In the facing electrode substrate, the spacer material 1 is formed on the alignment control film 15 corresponding to the gate electrode 80.
As described above, even if 9 is dispersed and fixed, the same effect can be obtained.

Further, in a reflection type liquid crystal display device in which a polarizing film or a reflecting film is built in a liquid crystal element, since they are easily damaged by heat, the alignment control film is cured by light or a combination of light and heat. Moreover, the present invention, which can fix the spacer material, is a particularly effective method. However, with respect to the uniformity of the liquid crystal layer, the lateral electric field structure having a large number of electrode wiring portions is advantageous in that many spacer materials can be dispersed at a narrow pitch as compared with the vertical electric field structure. However, the aperture ratio of the lateral electric field structure is lower than that of the vertical electric field structure in principle because the lateral electric field structure has many electrode wiring portions.

The present invention is a method which can disperse and fix the spacer material with high precision in the existing manufacturing equipment and is effective for cost reduction. Further, although only the color liquid crystal display device has been specifically described in the present embodiment, a uniform liquid crystal thickness and a desired spacer material dispersion density can be easily obtained in a similar manufacturing process even for a black and white liquid crystal display device. With respect to the black and white liquid crystal display device, it is possible to obtain the effect of improving display quality such as contrast.

As described above, the liquid crystal display device of the present invention has a small angle dependence of contrast and can achieve a uniform image display, and can be used for a notebook PC, a notebook type word processor (notebook WP), a television receiver and Personal Digital Assistant (PDA),
It is effective as a display mounted on a workstation or the like. In particular, the effect is remarkable for a large-screen display for which uniform image display is difficult to obtain. The point of the present invention is to propose a novel method in which individual spacer materials are directly dispersed / fixed to a portion in contact with the liquid crystal surface (on the alignment control film) at an arbitrary position and dispersion density without interposing an adhesive or the like. However, the invention is not limited to forming the gap of the liquid crystal display element.

[0062]

According to the spacer material dispersion / fixing method of the present invention, each spacer material can be uniformly dispersed / fixed only on the orientation control film corresponding to the non-opening portion without interposing an adhesive or the like. Therefore, 1) the spacer material can be dispersed with a narrow pitch and high density, 2) the dispersion density of the spacer material can be accurately defined, and 3) each spacer material can be fixed to any position and shape in contact with the liquid crystal. ) A patterning process and an adhesive material are not required, so that the alignment control film is not contaminated, and a liquid crystal display element having a uniform liquid crystal thickness and a high-quality image that does not have unnecessary light leakage or display defects and has no angle dependence The liquid crystal display device can be obtained.

Further, 5) a dispersion density that achieves a desired liquid crystal thickness can be achieved with a minimum amount of spacer material (easy to collect and reuse), 6) curing of the alignment control film in a short time by light irradiation and the like. Since the spacer material can be fixed, it is effective for cost reduction.

Therefore, according to the present invention, there is provided a liquid crystal display device suitable for a display mounted on a popular (low-priced) notebook PC, a notebook WP, a television receiver, a PDA, a workstation, etc., which is excellent in portability. Can be achieved. In particular, the effect is remarkable in a large-screen display having a wide viewing angle range and in which it is difficult to obtain a uniform image.

[Brief description of the drawings]

FIG. 1 is a diagram showing a manufacturing process of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an uncured portion formed on an orientation control film.

FIG. 3 is a diagram showing another example of an uncured portion formed on the orientation control film.

FIG. 4 is a diagram showing another example of an uncured portion formed on the orientation control film.

5 is a diagram showing a relationship between a dispersion direction of a spacer material and a moving direction of a rubbing roller in the embodiment of FIG.

FIG. 6 is a cross-sectional view showing a color liquid crystal display device of one embodiment according to the present invention.

7 is a cross-sectional view of a backlight unit of the color liquid crystal display device of FIG.

FIG. 8 is a diagram showing a manufacturing process of a liquid crystal display device according to another embodiment of the present invention.

FIG. 9 is a diagram showing a manufacturing process of a liquid crystal display device according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a liquid crystal display device having a vertical electric field structure according to an embodiment of the present invention.

[Explanation of symbols]

10, 20 ... Substrate, 11 ... Common electrode (transparent electrode), 12
... Gate insulating film, 13 ... Source electrode, 14 ... Drain electrode, 15, 23 ... Orientation control film, 16 ... Photomask, 16
a ... mask pattern, 17 ... ultraviolet, 17a ... heat rays, 1
8 ... Unhardened part, 19 ... Spacer material, 21 ... Light-shielding film, 22
... color filter, 24 ... gate electrode, 25 ... amorphous silicon part, 26 ... transistor part, 27 ... liquid crystal, 28, 29 ... polarizing plate, 30 ... roller, 31 ... moving direction, 32 ... flattening film, 33 ... spacer Material disperser, 34
... air pressure, 44 ... insulating film, 50 ... color liquid crystal display element,
51 ... Tape carrier package, 52 ... Printed board, 5
3 ... Cold cathode fluorescent tube, 54 ... Light guide, 55 ... Diffusion plate, 5
6 ... Prism sheet, 57, 58 ... Reflective sheet, 59 ...
Reflective film, 60 ... Adhesive tape, 80 ... Gate electrode,
81 ... Storage capacitor electrode, 82 ... Amorphous silicon
Channel layer, 83 ... Drain electrode 84 ... Source electrode

Claims (6)

[Claims] 1. An electrode substrate having one alignment control film on a plurality of electrodes laminated on a substrate, and another electrode having the other alignment control film on a light-shielding film and a color filter laminated on the other substrate. The substrate faces each other via a spacer material for defining a gap between the two electrode substrates, the gap is filled with liquid crystal, and an electric field is generated from each of the electrodes in a direction parallel to the surfaces of the two electrode substrates. In an active matrix type liquid crystal display element having an applied transverse electric field structure, at least one of the alignment control films is made of a photo-curable material or a thermosetting material, and the alignment control film made of the photo-curable material or the thermosetting material is An active matrix type liquid crystal display device having a lateral electric field structure, characterized in that a spacer material is directly fixed to a predetermined position on the alignment control film by being irradiated with light or heat. 2. One electrode substrate having one alignment control film on a plurality of electrodes laminated on a substrate, and the other electrode having a light-shielding film laminated on the other substrate and the other alignment control film on a color filter. The substrate faces each other via a spacer material for defining a gap between the two electrode substrates, the gap is filled with liquid crystal, and an electric field is generated from each of the electrodes in a direction parallel to the surfaces of the two electrode substrates. In an active matrix type liquid crystal display device having a lateral electric field structure to be applied, the spacer material is made of a material coated with a photo-curing material or a thermosetting material, and the spacer material is coated with the photo-curing material or a thermosetting material. Is an active matrix type liquid crystal display device having a lateral electric field structure, which is directly fixed to a predetermined position on the alignment control film irradiated with light or heat. 3. The predetermined position on the alignment control film irradiated with the light or heat according to claim 1 or 2,
An active-matrix liquid crystal display device having a horizontal electric field structure, which has a pitch dimension equivalent to a dot pitch of the color filter or a pitch dimension smaller than the dot pitch. 4. The predetermined position on the alignment control film irradiated with the light or heat according to claim 1 or 2,
An active matrix type liquid crystal display element having a horizontal electric field structure, which is located on each electrode region of the one alignment control film or on the light shielding film region of the other alignment control film. 5. A step of laminating a photosensitive resin thin film on a substrate having a plurality of electrodes to form one electrode substrate, and irradiating light or heat onto the photosensitive resin thin film to selectively form an uncured portion. A step of forming, a step of dispersing a spacer material on the photosensitive resin thin film including the uncured portion, and a spacer dispersed on the uncured portion by irradiating light or heat to cure the uncured portion A step of fixing only the material, a step of removing the unfixed spacer material, and a light-shielding film and a color filter on the one electrode substrate having the spacer material remaining fixed on the uncured portion And a step of stacking the other electrode substrate formed by laminating a non-photosensitive resin thin film on the substrate, the manufacturing method of an active matrix type liquid crystal display device having a lateral electric field structure. 6. An active matrix type liquid crystal display device having a horizontal electric field structure having a uniform liquid crystal thickness according to any one of claims 1 to 4 or an active matrix type liquid crystal display device according to claim 5. A liquid crystal display device using an active matrix type liquid crystal display element having a lateral electric field structure, in which a liquid crystal is manufactured to have a uniform thickness using a manufacturing method.