JPH0627473A - Liquid crystal display panel and its production - Google Patents

Abstract

PURPOSE:To maintain a stable spacing without floating of spacing members. CONSTITUTION:This liquid crystal display panel 10 is constituted by oppositing and sealing a TFT substrate 1 juxtaposed with TFTs(thin-film transistors) 1a and a CF substrate 2 juxtaposed with color filter layers 2a via the spacing members 3 and encapsulating a liquid crystal 4 therebetween. The above- mentioned CF substrate 2 is constituted by first applying a soln. of a transparent and photosensitive coupling member 5 on a common electrode 2c, then spraying the spacing members 3 on the film of the coupling member 5, binding these members by heating, then exposing the coupling member 5 so as to allow only the regions of the color filter layers 2a to remain and developing the exposed coupling member 5 to remove the spacing members 3 so that the spacing members 3 scatter only in the regions of the color filter layers 2a.

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 panel and a method of manufacturing the same, and a liquid crystal display panel capable of maintaining a stable cell thickness by selectively fixing a spacing member to a region of a color filter layer of a CF substrate. It relates to a manufacturing method.

In recent years, as electronic devices such as semiconductor devices have been downsized, electronic devices have been downsized. Also, in the display device which is one of the element devices of the interface between the machine and the human, the liquid crystal display device is attracting attention as a light and thin new display device which replaces a heavy and unsuitable CRT display device.

A liquid crystal display device has become a display device having a display performance comparable to that of a CRT display device due to recent progress such as the development of new liquid crystal materials and driving methods and the improvement of the manufacturing technique of liquid crystal display panels. It's starting. As the demand further expands, there is an urgent need to improve manufacturing technology such as improvement of display quality and price reduction.

[0004]

2. Description of the Related Art A liquid crystal display panel is intended to obtain a display device by moving a large molecule of viscous liquid crystal sandwiched between two glass plates and utilizing an optical effect such as polarized light. Is slow to respond. Therefore, it has been said that the liquid crystal display device is not suitable for a fast-moving display such as a moving image.

However, a new liquid crystal material called TN (twisted nematic) liquid crystal or STN (super twisted nematic) liquid crystal and its alignment method have been developed, or a so-called active matrix method in which TFTs (thin film transistors) are arranged in each pixel. For example, the function of the liquid crystal display device is approaching that of the CRT display device.

By the way, a basic constituent element of a liquid crystal display device is a liquid crystal display panel in which liquid crystal is sandwiched between two substrates provided with electrodes. When the voltage is intermittently applied to the liquid crystal display panel to change the alignment state of the liquid crystal molecules, light can be transmitted or blocked to display an image.

FIG. 3 is a sectional view schematically showing an example of a TFT drive type liquid crystal display panel. In the figure, 1 is T
FT substrate, 1a is TFT, 1b is protective film, 1c is pixel electrode, 2
Is a CF substrate, 2a is a color filter layer, 2b is a smooth layer, 2c is a common electrode, 2d is a black matrix, 3 is a spacing member,
Reference numeral 4 is a liquid crystal, 6a and 6b are alignment films, 7 is a cell thickness, and 10 is a liquid crystal display panel.

The liquid crystal display panel 10 exemplified here is of an active matrix system in which a plurality of TFTs 1a are arranged in a grid pattern corresponding to pixels, and has a structure capable of color display.

One substrate of the liquid crystal display panel 10 is a TFT
Since it is provided with 1a, it is generally called a TFT substrate 1. The general structure of this TFT substrate 1 is that tens of thousands to hundreds of thousands of TFTs 1a are provided on the surface of a transparent glass plate corresponding to the pixels of the display screen, and the TFTs 1a are covered with a protective film 1b. . A pixel electrode 1c is provided on the protective film 1b in the vicinity of the TFT 1a.

The pixel electrode 1c corresponds to each pixel of the display screen of the liquid crystal display panel 10, and is made of a transparent and conductive ITO (Indium Tin Oxide) film. The pixel electrode 1c is connected to the drain or source of the TFT 1a. Then, the pixel electrode 1c is switched by the TFT 1a.

An alignment film 6a is deposited on the pixel electrode 1c. The alignment film 6a is for aligning the molecules of the liquid crystal 4 in parallel with the rubbing direction. The TFT substrate 1 having such a configuration has a film thickness of several hundreds nm to
Since it is several μm, it is macroscopically smooth, but in a microscopic cross-sectional shape, the region where the TFT 1a is provided, for example, the portion where the drain electrode is provided has a protruding shape of, for example, about 1 μm.

Since the other substrate of the liquid crystal display panel 10 is provided with the color filter layer 2a, it is generally called a CF (color filter) substrate 2. The CF substrate 2 has various configurations depending on the method of forming the color filter layer 2a. For example, the black matrix 2d is formed in a frame shape on the surface of a transparent glass plate by a light-shielding thin film such as chromium. ing. This black matrix
The opening 2d corresponds to each pixel of the display screen, and the color filter layer 2a corresponding to RGB is provided in this opening.

The color filter layer 2a is formed of a colored resin in a dot shape by a printing method or the like, and has a layer thickness of, for example, several μm.
There is also a step because there is also. Therefore, a transparent resin smoothing layer 2b is applied to smooth the surface, and then a common electrode 2c made of an ITO film is provided. Then, the alignment film 6b is deposited on the common electrode 2c, and the CF substrate 2 is completed. Therefore, the CF substrate 2 is entirely flat.

The liquid crystal display panel 10 has a structure in which a spacing member 3 is appropriately scattered in the gap between the TFT substrate 1 and the CF substrate 2 thus configured to face each other. At that time, so that the molecular arrangement of the enclosed nematic liquid crystal 4 is twisted,
The rubbing direction of the alignment film 6a provided on the TFT substrate 1 and the rubbing direction of the alignment film 6b provided on the CF substrate 2 are crossed to each other, and
A liquid crystal display panel 10 called a mold or an STN type is used.

The distance between the TFT substrate 1 and the CF substrate 2 is, for example, 5 μm or 7 μm in the cell thickness 7 of a so-called liquid crystal display element.
And very narrow. Therefore, as the spacing member 3, finely cut glass fibers or resin spheres having a diameter corresponding to the cell thickness 7 are used, but recently, since the area of the pixel is small, the shadow of the spacing member 3 is reduced. A spherical resin is often used to reduce the area.

[0016]

By the way, the CF substrate 2
Has a flat surface and little unevenness, but the TFT substrate 1 is
The area of FT1a is protruding. Therefore, this TF
When the spacing member 3 is located in the region of T1a, the spacing between the substrates 1 and 2 is determined accordingly.

However, the area of the TFT 1a is only a part of the area of the entire panel. Therefore, it is difficult to maintain the cell thickness 7 accurately and stably. Further, the spacing member 3 interposed between the essential surface portions of the pixel electrode 1c and the color filter layer 2a floats, which often adversely affects the display quality.

Therefore, the present invention provides a liquid crystal display panel in which a spacing member is selectively fixed to a region of a color filter layer of a CF substrate, and a stable cell thickness can be maintained without a floating spacing member. It is intended to provide a manufacturing method thereof.

[0019]

[Means for Solving the Problems] The above-mentioned problems are caused by the TF
In a liquid crystal display panel in which a TFT substrate in which Ts are arranged in parallel and a CF substrate in which color filter layers are arranged in parallel are oppositely sealed via a spacing member and liquid crystal is sealed, the spacing member is the color In a liquid crystal display panel configured to be scattered only in a region of a filter layer and a CF substrate of the liquid crystal display panel, in a first step, a solution of a transparent and photosensitive coupling member is used in common. It is applied in a film form on the electrodes, and in the second step, the spacing member is sprayed on the film of the coupling member and fixed by heating, and in the third step, the coupling member of the color filter layer is formed. A method for manufacturing a liquid crystal display panel, which is configured to perform exposure so that only the region remains, and in a fourth step, developing the exposed coupling member to remove the spacing member.

[0020]

It is important to make the cell thickness of the liquid crystal display panel uniform by using the spacing member, but according to the conventional configuration, the spacing is determined by the area of the protruding TFT. There was a spacing member that would float and cause problems. On the other hand, in the present invention, the spacing members are fixed so as not to float, and all the spacing members contribute to maintaining a stable spacing.

That is, a transparent and photosensitive coupling member is applied through the smoothing layer and the common electrode provided on the color filter layer of the CF substrate, and the spacing members are appropriately scattered and fixed to the coupling member. I am trying. Then, the coupling member is exposed and developed so that the coupling member remains only in the region of the color filter layer. Then, when the CF substrate is superposed on the TFT substrate, the spacing member abuts the pixel electrode of the TFT substrate so that it does not exist in the TFT region.

In this case, the spacing member is fixed and does not move, and the gap between the TFT substrate and the CF substrate is uneven.
The cell thickness of the liquid crystal display device can be stable and uniform because it is determined regardless of the region.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view schematically showing a main part of an embodiment of the present invention, and FIG. 2 is a manufacturing process drawing of the embodiment of the present invention. In the figure, 1 is a TFT substrate, 1a is a TFT, 1b is a pixel electrode, 1c is a protective film, 2 is a CF substrate, 2a is a color filter layer, 2b is a smooth layer, 2c is a common electrode, 2d is a black matrix, and 3 is Spacing member, 4 is a liquid crystal, 5 is a coupling member, 6a,
6b is an alignment film, 7 is a cell thickness, and 10 is a liquid crystal display panel.

In FIG. 1, the liquid crystal display panel 10 is a TF.
The T substrate 1 and the CF substrate 2 are laminated together. The TFT substrate 1 has a glass substrate on which TFTs 1a are juxtaposed, and a protective film 1b is formed on the TFT 1a.
And a pixel electrode 1c is juxtaposed near the TFT 1a. The entire surface is covered with the alignment film 6a and TF
The T substrate 1 is configured.

Like the conventional substrate, the CF substrate 2 has a black matrix 2d arranged in parallel on the glass substrate corresponding to the TFT 1a of the TFT substrate 1 facing the glass substrate, and the color filter layer 2a is formed in the opening of the black matrix 2d. It is provided. Then, after being smoothed by the smoothing layer 2b, the common electrode 2c is deposited on the entire surface.

In the area corresponding to the color filter layer 2a,
For example, a coupling member 5 made of a photoresist of acrylic resin is provided in a film shape, and the spacing member 3 is fixed to the coupling member 5. The spacing member 3 is a gap between the TFT substrate 1 and the CF substrate 2, that is, the cell thickness 7 in which the liquid crystal 4 is enclosed.
For example, a polycarbonate sphere having a uniform diameter. Then, the exposed common electrode 2c and the coupling member 5
The CF substrate 2 is formed by covering the upper part with the alignment film 6b.

In the liquid crystal display panel 10 constructed as described above, when the two substrates 1 and 2 are stacked, the spacing member 3 fixed only to the area of the color filter layer 2a of the CF substrate 2 is formed on the TFT substrate 1. It collides only with the area of the pixel electrode 1c,
It does not exist in the area of TFT1a. Therefore, a stable cell thickness 7 can be obtained.

By the way, in the manufacturing process of the CF substrate 2 having such a structure, first, in FIG. 2A, the black matrix 2d and the color filter layer 2a are provided, and the smoothing layer 2b and the common electrode 2c are provided thereon. Set up. Next, in FIG. 2B, the coupling member 5 is applied onto the common electrode 2c by a rotary coating method, a printing method, or the like. Then, FIG. 2 (C)
In, the spacing members 3 are scattered so as to be scattered in the region of the color filter layer 2a. Next, the joining member 5 is heated to fix the spacing member 3. Then, FIG. 2 (D)
In, the coupling member 5 is exposed so that only the region of the color filter layer 2a remains. Next, in FIG. 2 (E), the joining member 5 is developed to remove the joining member 5 and the spacing member 3 adhered to the region of the black matrix 2d.

Thus, when the CF substrate 2 is superposed on the TFT substrate 1 so as to face each other, the spacing members 3 are scattered only in the region of the pixel electrode 1c, so that the spacing is selectively provided only in the region of the color filter layer 2a. The member 3 can be fixed.

If the bonding member 5 is selectively applied only to the area of the color filter layer 2a by a printing method or the like, it is exposed to light,
It is not necessary to go through a process such as development, and it is also possible to selectively fix the spacing member 3 to the coupling member 5 only in the region of the color filter layer 2a by using an ultraviolet effect type resin instead of the photoresist, Various modifications can be made to the means for selectively providing the spacing member 3 on the coupling member 5.

[0031]

According to the present invention, the gap between the panels in the liquid crystal display panel is regulated by the TFT substrate in which the TFT region is protruding, and the floating spacing member causes a problem. A spacer is selectively fixed to the color filter layer region of the CF substrate so that the spacer does not exist in the TFT region.

As a result, not only is there no floating spacing member, but it is also possible to maintain a stable cell thickness, and TFTs that are expected to expand in use in the future
The present invention largely contributes to the development of the active matrix type liquid crystal display device using the.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a main part of an embodiment of the present invention.

FIG. 2 is a manufacturing process diagram of an example of the present invention.

FIG. 3 is a cross-sectional view schematically showing an example of a TFT drive type liquid crystal display panel.

[Explanation of symbols]

1 TFT substrate 1a TFT 1b
Pixel electrode 1c Protective film 2 CF substrate 2a Color filter layer 2b
Smoothing layer 2c Common electrode 2d Black matrix 3 Spacing member 4 Liquid crystal 5 Coupling member 6a, 6b Alignment film 7 Cell thickness 10 Liquid crystal display panel

Claims (5)

[Claims] 1. A TFT substrate (1) having TFTs (thin film transistors) (1a) arranged side by side and a CF substrate (2) having color filter layers (2a) arranged side by side with a spacing member (3) interposed therebetween. In the liquid crystal display panel sealed oppositely and in which the liquid crystal (4) is sealed, the spacing member (3) is scattered only in the region of the color filter layer (2a). Liquid crystal display panel. 2. The spacing member (3) is made of a spherical resin and includes a smoothing layer (2b) and a common electrode (2c) which are adhered to the color filter layer (2a) of the CF substrate (2). A liquid crystal display panel characterized by being fixed by a transparent connecting member (5) applied via 3. The CF substrate (2) for a liquid crystal display panel according to claim 1, wherein a solution of a transparent and photosensitive coupling member (5) is formed on the common electrode (2c) in a first step. In a second step, the spacing member (3) is sprinkled on the film of the binding member (5) and fixed by heating in the second step, and in the third step, the binding member (5) is A liquid crystal display characterized by exposing so that only the color filter layer (2a) area remains, and developing the exposed coupling member (5) in the fourth step to remove the spacing member (3). Panel manufacturing method. 4. The method of manufacturing a liquid crystal display panel according to claim 3, wherein the coupling member (5) is made of photoresist. 5. The method of manufacturing a liquid crystal display panel according to claim 3, wherein in the first and second steps, the spacing member (3) is dispersed and applied in a solution of the bonding member (5).