JPH1138420A - Production of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for selectively spreading spacers to a black matrix part by a simple and easy process in an IPS type liquid crystal display device or a TN type liquid crystal display device in which selective spreading of the spacers is impossible by conventional methods. SOLUTION: In this manufacturing method of the liquid crystal display device, at least a color filter substrate 8 on which a black matrix 2 is laminated and an electrode substrate 9 are stuck together by interposing spacers 7 for holding a gap between two sheets of substrates and a liquid crystal material is inserted and held between the color filter substrate 8 and the electrode substrate 9. In this case, at the spreading of the spacers 7 for holding the gap between two sheets of substrates 8, 9, an insulating film 4 having approximately the same pattern is laminated on the black matrix 2, the insulating film 4 is charged with either of positive or negative polarity and then spacers 7 charged with polarity different from polarity of the insulating film 4 are spread to attain selective spreading of the spacers 7 on the black matrix 2 which does not transmit light owing to electrostatic attraction force between the insulating film 4 and the spacers 7.

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 display device, and more particularly to a method for selectively dispersing spacers for maintaining a uniform gap interval on a black matrix that does not transmit light in order to improve contrast. On how to do it.

[0002]

2. Description of the Related Art FIG. 7 is a cross-sectional view showing the structure of a conventional TN (twisted nematic) type TFT (thin film transistor) liquid crystal display device, in which a black matrix 2, a colored resin 3, a common electrode 10, A color filter substrate 8 on which an alignment film 5 is laminated, and an electrode substrate 9 on which a thin film signal line 11 and a display pixel portion 6 are arranged on a matrix on a glass substrate 1 are used for maintaining a uniform gap between cells. It has a structure in which a spherical or columnar spacer 7 having a uniform particle size is interposed and bonded.

In this method of manufacturing a liquid crystal display device, spacers 7 are scattered on a color filter substrate 8, an electrode substrate 9 is superposed on the color filter substrate 8, and a sealing material (not shown) is attached thereto. A method of injecting liquid crystal (not shown) between the substrates from the cut portion of the seal portion to seal the cut portion is adopted.

In the above-described manufacturing method, since the spacers 7 are scattered over the entire color filter substrate 8, the spacers 7 are also arranged on the display pixel portion 6 of the electrode substrate 9 facing the color filter substrate 8. Thus, the spacer 7
Is disposed in the display pixel section 6, since there is no liquid crystal at a place where the spacer 7 is present, for example, a conventional TN type normally black liquid crystal display device or an IPS (transverse electric field driving
T) In the liquid crystal display device, light is transmitted at a place where the spacer is in the off state, so that the contrast is reduced and the uneven distribution of the spacer 7 causes display unevenness. Also, in the TN type normally white liquid crystal display device, since light is partially transmitted by the liquid crystal molecules that are abnormally aligned around the spacers 7, there is a problem of a decrease in contrast and uneven display due to uneven distribution of the spacers 7.

As a method for solving these problems, Japanese Patent Laid-Open No.
There is a method disclosed in -76132. As shown in FIG. 8, when the spacers 7 are sprayed, the spacers 7 to be sprayed are positively or negatively charged, and the first spacers 7 are provided on the substrate on the side where the spacers 7 are to be sprayed.
A potential having the same sign as that of the spacer 7 is applied to the second electrode 13, and a potential having the same sign as that of the spacer 7 is applied to the second electrode 13 provided in an area where the spacer 7 is unnecessary on the substrate on which the spacer 7 is dispersed. By applying, the spacer 7 and the first electrode 1
2. A method of selectively dispersing the spacer 7 on the first electrode 12 by generating an electrostatic attraction between the first electrode 12 and the second electrode 13 and generating an electrostatic repulsion between the spacer 7 and the second electrode 13. Has been proposed.

[0006]

The above conventional method is applicable to a case where charges of different polarities can be applied to a region where spacers are scattered and a region where spacers are not scattered, and can be applied only to a substrate on which electrodes are independently formed. It is a way. Therefore, in a color filter substrate in which a single common electrode is formed over the entire surface such as a TN type TFT liquid crystal display device, it is not possible to selectively disperse spacers on a black matrix by the above-described method.

In order to selectively disperse spacers on the black matrix of the color filter substrate of the TN type TFT liquid crystal display device, it is necessary to form electrodes independently on the color filter and on the black matrix.
Since the number of steps is increased and the manufacturing cost is increased, the feasibility is poor.
Further, in the above-described method, it is necessary to apply different potentials to the first electrode (on the color filter) and the second electrode (on the black matrix) at the time of dispersing the spacer, which is a complicated process for manufacturing a liquid crystal display device. is there.

Further, the above-described method cannot be applied to a liquid crystal display device in which electrodes cannot be formed on a color filter substrate, such as an IPS (transverse electric field drive TFT) liquid crystal display device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an IPS type liquid crystal display device and a TN type liquid crystal display device which cannot selectively disperse spacers by a conventional method.
It is an object of the present invention to provide a method for performing selective spraying of spacers on a black matrix portion by a simple process in a liquid crystal display device.

[0010]

According to the present invention, an insulating film having a large relative dielectric constant and a large resistivity is laminated in substantially the same pattern on a black matrix of a color filter substrate, and peeling charging during rubbing or positive / negative charging is performed. After the insulating film laminated on the black matrix is positively or negatively charged by an ion blower that generates any ion in excess, a spacer charged to a polarity different from that of the insulating film is dispersed, and the spacer is formed by the black matrix. This is a method for manufacturing a liquid crystal display device that is selectively sprayed on the top.

The present invention is based on the following facts. IPS
For example, in a color filter substrate having no common electrode, since the common electrode is not provided, the color filter substrate is likely to be positively charged by peeling charging during rubbing. Table 1 (shown in the column of the embodiment of the invention) shows the relative permittivity and resistivity of the red, green, and blue colored resins and the overcoat film, respectively. The red colored resin has a higher relative dielectric constant and a resistivity two orders of magnitude higher than the green and blue colored resins. This is because green and blue colored resins contain metal in the pigment, but red colored resin does not contain metal. Therefore, in a positively charged color filter substrate, as a result, the amount of charge of the red coloring pigment is the largest. For this reason, if the spacers are sprayed without static elimination after rubbing, the spacers made of silica and acrylic resin are normally negatively charged due to air friction and collision between particles during spraying. Focus on filters. In order to prevent this, after the rubbing, the charge is usually removed by an ionizer or the like in order to reduce the charge amount of the substrate. However, sufficient charge removal cannot be performed on the production tact.

According to the present invention, the light-resistant insulating film laminated on the black matrix of the color filter substrate is charged by an ion blower that generates either positively or negatively charged ions during rubbing, and is different from the light-resistant insulating film. The spacers are selectively sprayed on the black matrix by spraying the spacers charged with polarity. Due to the electrostatic attraction between the spacer and the light-resistant insulating film laminated on the black matrix, the spacer is selectively dispersed only on the black matrix.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a TN type TFT liquid crystal display device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic sectional view showing the structure of the substrate used in the first embodiment, and FIG. 2 is a diagram for explaining the interaction between the scattered spacers and the charged substrate surface.
First, as shown in FIG. 1, a black matrix 2 made of photo black (acrylic resin) on a glass substrate 1, a colored resin 3 containing each pigment for each color, ITO
Electrode 10 made of polyimide and an alignment film 5 made of polyimide are laminated, and a red coloring pigment made of a diansuraquinone-based pigment is formed on the common electrode 10 and below the alignment film 5 in substantially the same pattern as the black matrix 2. The color filter substrate 8 having the thin film 4 is rubbed once with a rubbing roll made of rayon, and the color filter substrate 8 is positively charged by peeling charging. In the color filter substrate 8 which is positively charged, the upper surface of the colored resin 3 is ITO.
Is not charged because it is in contact with
Is positively charged because the upper surface is not in contact with ITO.

Next, spacers 7 made of acrylic resin are sprayed on the color filter substrate 8. Since the spacers 7 are negatively charged due to particle collision and air friction at the time of spraying, as shown in FIG. 2, the spacers 7 between the negatively charged spacers 7 and the red colored resin 4 on the positively charged black matrix 2 are used. An electrostatic attraction acts between them, and the spacers 7 are selectively spread on the black matrix 2. Then, the electrode substrate 9 and the color filter substrate 8 are overlapped and bonded via a sealing material (not shown), and a liquid crystal (not shown) is injected between the substrates through a cut portion of the seal portion, and the cut portion is sealed. Thus, a liquid crystal display device was manufactured.

A method for manufacturing an IPS liquid crystal display device according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a schematic sectional view showing the structure of the substrate used in the second embodiment, and FIG. 5 is a diagram for explaining the interaction between the scattered spacers and the charged substrate surface. First, as shown in FIG. 4, a black matrix 2 made of photo black (acrylic resin), a colored resin 3 made of each pigment for each color, an overcoat film 14 made of an acrylic resin, a polyimide An alignment film 5 made of
Below, a color filter substrate 8 on which a red coloring resin 4 made of a dianthraquinone pigment is disposed in a thin film form is rubbed once with a rubbing roll made of rayon, and the color filter substrate 8 is fixed with a release resin. To be charged.

As shown in Table 1, red colored resin 4
Has a higher relative dielectric constant and a two-digit higher resistivity than the overcoat film. For this reason, in the positively charged color filter substrate 8, the red colored resin 4 is more easily charged than the overcoat film 14. The most.

[0017]

[Table 1]

Next, spacers 7 made of divinylbenzene resin are sprayed on the color filter substrate 8. Spacer 7
Is positively charged due to particle collision and air friction at the time of spraying, as shown in FIG.
And the red colored resin 4 on the positively charged black matrix 2 generates an electrostatic attraction, and the spacers 7 are selectively dispersed on the black matrix 2.

Next, the electrode substrate 9 and the color filter substrate 8 are overlapped and bonded via a sealing material (not shown).
Liquid crystal (not shown) was injected between the substrates through the cut portion of the seal portion, and the cut portion was sealed to manufacture a liquid crystal display device.

In the first and second embodiments, the red colored resin 4 made of a dianthraquinone-based pigment is disposed on the black matrix 2. Any of them can be used.
The red colored resin 4 can be charged by an ion blower that generates either positive or negative ions, and a spacer charged to a polarity different from that of the red colored resin 4 can be dispersed.

In the first and second embodiments, there is a height difference between the colored resin 3 and the black matrix 2 portion. However, as shown in FIG. 3 or FIG.
To fill the gap between the two parts of the black matrix
When the red colored resin 4 is laminated on the black matrix 2, the surface of the color filter substrate 8 is flattened, and a gap failure caused when a spacer is arranged other than on the black matrix 2 due to vibration or the like after spraying is prevented. can do.

[0022]

As described above, according to the present invention,
Since the spacers are selectively scattered on the black matrix of the color filter substrate having the light shielding function, the spacers are not disposed in the display pixel portion of the electrode substrate corresponding to the position of the color filter substrate facing the color filters. For this reason, it is possible to prevent a decrease in contrast due to light leakage due to the spacer in the display pixel portion and display unevenness caused by uneven distribution of the spacer, and it is possible to manufacture a liquid crystal display device capable of high-quality display.

[Brief description of the drawings]

FIG. 1 shows a TN type TF according to a first embodiment of the present invention.
It is sectional drawing which shows the pixel structure outline of a T liquid crystal display device.

FIG. 2 shows a TN type TF according to the first embodiment of the present invention.
It is the schematic explaining the interaction of the spacer which was scattered and the charged substrate surface in the manufacturing method of a T liquid crystal display device.

FIG. 3 is a diagram used for describing a structure of a color filter substrate having a flattened surface according to the first embodiment of the present invention.

FIG. 4 is a schematic sectional view illustrating a structure of an IPS liquid crystal display device according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating an interaction between a scattered spacer and a charged substrate surface in a method for manufacturing an IPS liquid crystal display device according to a second embodiment of the present invention.

FIG. 6 is a view used to explain a structure of a color filter substrate having a flattened surface according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a method for manufacturing a conventional liquid crystal display device.

FIG. 8 is a diagram showing an interaction between a scattered spacer and an electrode substrate in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Black matrix 3 Colored resin 4 Red colored resin 5 Alignment film 6 Display pixel part 7 Spacer 8 Color filter substrate 9 Electrode substrate 10 Common electrode 11 Thin film signal line 12 First electrode 13 Second electrode 14 Overcoat film

Claims (5)

[Claims] 1. A color filter substrate on which at least a black matrix is laminated and an electrode substrate are bonded together with a spacer for holding a gap between the two substrates interposed therebetween, and a liquid crystal is interposed between the color filter substrate and the electrode substrate. In the method of manufacturing a liquid crystal display device filled with a material, on the black matrix of the color filter substrate,
An insulating film having a large relative dielectric constant and a large resistivity is laminated in substantially the same pattern, and after the insulating film is charged to either positive or negative, the spacer charged to a charge having a polarity different from that of the insulating film is used. A method for manufacturing a liquid crystal display device, comprising spraying. 2. The method for manufacturing a liquid crystal display device according to claim 1, wherein the insulating film provided on the black matrix is made of a material having the highest relative permittivity and the highest resistivity on the color filter substrate. A method for manufacturing a liquid crystal display device, comprising: 3. The method of manufacturing a liquid crystal display device according to claim 1, wherein the insulating film disposed on the black matrix uses a red colored resin made of a dianthraquinone pigment used for a color filter substrate. A method for manufacturing a display device. 4. The method for manufacturing a liquid crystal display device according to claim 1, wherein when the spacers are scattered, the insulating film laminated on the black matrix is charged.
A method for manufacturing a liquid crystal display device, wherein the spacer is charged with the opposite sign and then dispersed. 5. The method for manufacturing a liquid crystal display device according to claim 1, wherein the insulating film laminated on a black matrix of the color filter substrate eliminates a difference in height of the color filter substrate in a black matrix portion, A method for manufacturing a liquid crystal display device, wherein the surface of the color filter substrate is flattened.