JP2003121860A - Liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active matrix type liquid crystal display panel wherein adhesive strength and moisture preventing properties of a sealing part are improved, display unevenness due to seal peeling and moisture intrusion is not generated and gap unevenness at a peripheral part is not generated either by optimizing the constitution of a seal 4 and an organic insulating film 3. SOLUTION: The liquid crystal display panel has the parts where the organic insulating film on an array substrate is positioned and is not positioned in the width direction, respectively, in the nearly entire circumference of the seal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display panel having an organic insulating film other than an alignment film on the array substrate side by optimizing the panel structure including the organic insulating film. The present invention relates to high reliability and high quality technology.

[0002]

2. Description of the Related Art In recent years, liquid crystal display panels, particularly active matrix types, have been improved for display characteristics and have a larger screen size for use in PC monitors and televisions, and have improved reflective and semi-transmissive types for mobile terminals. Widely used for mobile phone monitors.

The structure of a typical conventional active matrix type reflective liquid crystal display panel will be described below with reference to FIG.

A counter substrate 2 made of transparent glass having a transparent common electrode 11, a color filter layer 10 for three colors of R, G and B, and a black matrix layer 14 for shielding light leakage around the screen, and a metal thin film. The plurality of active elements 5 and the electric wirings and the array substrate 1 having the reflective pixel electrodes 6 arranged in a matrix are made to face each other with their film surfaces facing each other through the liquid crystal layer 9 of about 5 μm, and the organic adhesive is arranged around the screen. It is adhered by a sealant 4 made of a chemical.

Here, an organic insulating film 3 of about 2.0 um is formed on the entire surface between the active element 5 and the electric wiring of the array substrate 1 and the reflective pixel electrode 6 for the purpose of interlayer insulation and formation of the uneven shape of the reflective electrode. Be prepared for. In addition, a large number of holes are formed in the organic insulating film 3 of the pixel portion in order to form unevenness of the reflective electrode.

Alignment films 7a, 7 made of an alignment-treated polyimide material are formed on the inner surfaces of both substrates in contact with the liquid crystal layer 9.
b is formed. This alignment film is formed by offset printing only on the screen portion, not on the seal portion. In addition, the retardation plate and the polarizing plate 15 in which the retardation direction and the polarization axis direction are respectively set to appropriate directions are arranged outside the counter substrate.

Further, in order to form a gap in the liquid crystal layer 9, bead spacers 13 made of spherical fine particles of resin having a diameter of about 3 μm are randomly arranged between the substrates, and glass fibers having a diameter of about 4 μm are contained in the sealing agent 4. The spacer 12 is mixed.

[0008]

The active matrix type liquid crystal panel as described above is required to be able to withstand a harsh environment for expanding its use, especially for portable use.

However, the organic insulating film 3 on the array substrate 1 is formed on almost the entire surface (Japanese Patent Laid-Open No. 2000-02).
Although it is also formed on the seal portion 4, this organic insulating film is inferior in adhesive strength to the underlying surface and moisture resistance as compared with the seal adhesive, so that the screen due to peeling of the seal in the strength test is displayed. This is a major problem because it causes air bubbles to occur in the parts and causes display unevenness due to water infiltration in a high temperature and high humidity environment test.

The organic insulating film 3 on the array substrate 1 is generally made of an acrylic resin material. However, since the leveling property, heat resistance, and high transmittance are required, the material selectivity is narrow, and Material improvement is difficult.

On the other hand, in order to solve the problem of the seal 4, the organic insulating film 3 on the array substrate 1 may be formed only on the screen portion and not on the seal portion 4 (Japanese Patent Laid-Open No. 08-095063). However, in this case, since the organic insulating film 3 has a relatively large film thickness and it is difficult to apply the film with a constant film thickness between and within the substrates, the fiber spacer 12 mixed in the sealant 4 is used. There is a problem in that the balance with the diameter of the liquid crystal is often lost, unevenness of the gap, which is the liquid crystal layer thickness in the peripheral portion, is likely to occur, and the display quality is often impaired.

The present invention solves the above-mentioned conventional problems. By optimizing the configuration of the seal 4 and the organic insulating film 3, the adhesion strength and moisture resistance of the seal portion are improved, and peeling of the seal and moisture are prevented. It is an object of the present invention to provide an active matrix type liquid crystal display panel in which display unevenness due to penetration does not occur and also gap unevenness in the peripheral portion does not occur.

[0013]

To achieve this object, an active matrix type liquid crystal display panel of the present invention has a structure having an organic insulating film 3 other than an alignment film in a display region of an array 1 substrate. The seal 4 is configured to have a portion where the organic insulating film 3 is located and a portion where the organic insulating film 3 is not located on the array substrate in the width direction over the entire circumference.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is
At least a counter substrate and an array substrate having a plurality of active elements are adhered to each other through a seal made of a resin material provided in a peripheral portion, and a liquid crystal display having a plurality of pixels in which a gap between the both substrates is filled with liquid crystal In the panel, an alignment film for aligning liquid crystal molecules is provided between both substrates and the liquid crystal, and the display region of the array substrate has an organic insulating film other than the alignment film, The active matrix type liquid crystal display panel is characterized in that it has a portion where the organic insulating film on the array substrate is positioned and a portion where the organic insulating film is not positioned in the width direction over substantially the entire circumference of the seal.

Further, a liquid crystal panel according to a second aspect of the present invention is the active matrix type liquid crystal display panel according to the first aspect, wherein the array substrate is provided on a substantially half area in the width direction on substantially the entire circumference of the seal. Is characterized in that the edge of the organic insulating film is located.

The invention according to claim 3 of the present invention is the active-matrix type liquid crystal display panel according to claim 1, wherein the organic material on the array substrate is formed at a substantially central portion in the width direction on substantially the entire circumference of the seal. It is characterized in that the end portion of the insulating film is located and the organic insulating film on the array substrate is not located at the outer peripheral portion of the seal.

Further, a liquid crystal panel according to a fourth aspect of the present invention is the active matrix type liquid crystal display panel according to the first aspect, wherein the liquid crystal panel is provided on the array substrate at a substantially central portion in the width direction over substantially the entire circumference of the seal. The organic insulating film is formed in a stripe shape, and the organic insulating film on the array substrate is not located in the inner peripheral portion and the outer peripheral portion of the seal.

Further, a liquid crystal panel according to a fifth aspect of the present invention is the active matrix type liquid crystal display panel according to the first aspect, wherein the liquid crystal panel is provided on the array substrate at a substantially central portion in the width direction over substantially the entire circumference of the seal. It is characterized in that the organic insulating film is formed in a dot shape.

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment of the Invention) FIG. 1 is a diagram showing a sectional structure of an active matrix type reflective color liquid crystal display panel showing a first embodiment of the present invention.

An array substrate 1 mainly including a thin film transistor 5 and a signal line, an organic insulating film 3 having a concave shape, and a reflective pixel electrode 6 made of an aluminum thin film formed on the organic insulating film, and a color filter 10. And a counter substrate 2 provided with a transparent common electrode 11 made of ITO, and a liquid crystal layer 9 formed in a gap between these two substrates and a seal 4 in the peripheral portion.

Regarding the method for producing the array substrate 1, the thin film transistor 5 is made of amorphous silicon by P-CVD, the signal wiring uses an aluminum thin film having a film thickness of 0.3 μm, and the interlayer insulation between these is made of an inorganic insulating film. Is also formed by sputtering and patterned by a photo-etching process.

Further, the organic insulating film 3 is applied to a film thickness of about 1 μm by spin coating and patterned by a photoetching process to form a contact hole for connecting to the thin film transistor 5 and a concave shape for diffuse reflection. . Further, the organic insulating film 3 is patterned so that the end of the organic insulating film 3 is located substantially in the center of the seal portion 4 located around the screen.

Thereafter, the aluminum reflecting electrode 6 is sputtered.
Is formed into a film, and is further patterned by a photo etching process. Further, a polyimide type alignment film 7a is applied and cured thereon, and then an alignment treatment is performed in a predetermined direction by a rubbing method to complete the array substrate 1.

On the other hand, after the alignment film 7b is similarly formed on the counter substrate 2 on which the color filter 10 is formed and the alignment treatment is performed, the sealant 4 made of an epoxy adhesive is applied to the peripheral portion of the screen by the screen printing method. Print in a predetermined pattern.
2 wt% of glass fiber spacers 12 having a diameter of 4.0 μm are mixed in the sealant 4 in advance, and printing is performed so as to have a size of 0.3 mm after printing.

Further, a diameter of 3.0 μm is formed on the entire surface of one substrate.
Approximately 15 beads spacers 13 per 1 mm x 1 mm
After spraying 0 randomly, these two substrates are accurately positioned at a predetermined position, and bonded and pressed for 150 times.
The sealing agent 4 is cured by heating at a temperature of ℃ for a predetermined time.

Here, by heating by bonding, the height of the sealant 4 is 4.0 μm at the portion where the organic insulating film 3 is present.
m, 5.0 μm in the portion without the organic insulating film 3, and the width of the seal pattern was 0.9 mm. In the present embodiment, the organic insulating film is present inside the seal pattern and the width of the seal 4 is 0.4 m over the entire circumference excluding the injection port.
m, the organic insulating film is removed on the outer side of the seal pattern, and the width at which this portion and the seal 4 hang is 0.5 mm.

After that, the above substrate is divided into individual pieces by the scribe-break method, the liquid crystal 9 is filled by the vacuum injection method from the injection port provided in the seal pattern, and the liquid crystal 9 is sealed by the UV curable resin. Furthermore, after cleaning this panel,
A liquid crystal panel is completed by sticking a polarizing plate 15 having a polarization axis set in a predetermined direction on the display surface side.

As described above, since the organic insulating film 3 exists up to almost the central portion of the seal pattern, the sealant 4 is formed.
Is determined by the film thickness of the organic insulating film 3 and the fiber spacer 12 mixed in the sealant 4, and
Since the thickness of the liquid crystal layer 9 in the display region located inside is also determined by the thickness of the organic insulating film 3 and the bead spacers 13 scattered on the substrate, even if the thickness of the organic insulating film 3 varies, the height of the sealant and the liquid crystal The layer thickness relationship is constant, and it is possible to display a uniform display over the entire surface.

On the other hand, since the organic insulating film 3 does not exist on the outer peripheral portion of the seal pattern, the inorganic insulating film of the array substrate 1 and the sealant are irrelevant to each other regardless of the adhesive strength of the organic insulating film having relatively weak adhesive strength. You can get a strong adhesive force.

Generally, the external force for peeling the two substrates acts from the outer periphery of the seal pattern, but since the adhesive force of the outer peripheral portion of the seal pattern is strong as in this construction, practical peeling is performed. The strength becomes even stronger.

Further, in this structure, since the organic insulating film 3 having a slightly inferior moisture resistance does not exist in the outer peripheral portion of the seal pattern, it is excellent in the reliability test under high temperature and high humidity, and the electric current at 85 ° C. and 85% is applied. Even in the test, the result that the display unevenness and the like did not occur for 500 hours or more was obtained.

Further, in this structure, since a step is formed in the central part of the seal by the organic insulating film parallel to the seal pattern, when the seal is thermally cured, the bubble does not pass even if the seal pass failure occurs across the seal. Continuity is hindered at the stepped portion, and the trapped portion is easily trapped, which is less likely to occur and is also effective in improving the yield in the production process.

As described above, according to the present embodiment, the adhesive strength and moisture resistance of the seal portion are improved, the display unevenness due to the peeling of the seal and the infiltration of water is not generated, and the gap unevenness in the peripheral portion is not generated. A matrix type reflective color liquid crystal display panel can be obtained.

(Embodiment 2) Embodiment 2 of the present invention will be described below with reference to the drawings.

FIG. 2A shows a sectional structure of an active matrix type reflective color liquid crystal display panel showing a second embodiment of the present invention, and FIG. 2B shows a planar structure.

The basic structure is the same as that of the first embodiment, but shows a case where the organic insulating film 3 on the array substrate 1 is present in a stripe shape in the central portion of the seal pattern.
In the case of the present embodiment, the seal pattern width is 1.2 mm, which is effective when the seal pattern width is relatively wide, and the width of the stripe pattern of the organic insulating film is 0.6 mm.

In this structure, since the organic insulating film 3 is not provided on the inner surface of the seal pattern, the structure is strong against peeling force from the inside of the panel. This is an effective configuration.

Further, in this structure, since the unevenness in the stripe shape of the organic insulating film parallel to the seal pattern is formed in the central portion of the seal, when the seal is heat-cured, a bubble passing through the seal causes a defective seal path. Also,
Since air bubbles are trapped in the convex portions of the organic insulating film, almost all the bubbles can be prevented, which is very effective in improving the yield in the production process.

Further, by making the pattern of the seal portion 4 of the organic insulating film 3 into a dot shape as shown in FIG. 3, the peel strength can be further enhanced.

Although the reflection type has been described in the embodiment of the present invention, the same effect can be obtained by applying the transmission type or the semi-transmission type.

[0042]

As described above, the present invention has a structure in which the organic insulating film on the array substrate has a portion and a portion which does not have the portion in the width direction over substantially the entire circumference of the seal.
It is possible to obtain an active matrix type liquid crystal display panel in which the adhesion strength and moisture resistance of the seal portion are improved, display unevenness due to peeling of the seal and water penetration does not occur, and gap unevenness in the peripheral portion does not occur.

[Brief description of drawings]

FIG. 1 is a sectional structural view of a liquid crystal display panel which is a first embodiment of the present invention.

FIG. 2 is a sectional structural view and a plan structural view of a liquid crystal display panel which is a second embodiment of the present invention.

FIG. 3 is a plan structure diagram of a liquid crystal display panel No. 2 according to a second embodiment of the present invention.

FIG. 4 is a sectional structural view of a liquid crystal display panel showing a conventional example.

[Explanation of symbols]

1 Array substrate 2 Counter substrate 3 Array substrate Organic insulating film 4 seals 6 Reflective pixel electrode 7a Array substrate alignment film 7b Counter substrate alignment film 9 LCD 12 Fiber spacer in seal 13 Bead spacer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H089 HA15 HA17 LA05 LA07 LA49                       NA37 NA41 NA48 QA14                 2H092 JB04 KB22 KB24 KB25 MA02                       MA05 MA08 MA10 MA17 NA01                       NA18 NA29 PA01 PA02 PA03                       PA04

Claims (5)

[Claims] 1. At least a counter substrate and an array substrate having a plurality of active elements are adhered to each other through a seal made of a resin material provided in a peripheral portion, and a plurality of gaps between the two substrates are filled with liquid crystal. A liquid crystal display panel having pixels, comprising an alignment film for aligning liquid crystal molecules between both substrates and the liquid crystal, and having an organic insulating film other than the alignment film in a display region of the array substrate. An active matrix type liquid crystal display panel, characterized in that it has a configuration in which a portion where the organic insulating film on the array substrate is located and a portion where the organic insulating film is not located are arranged in the width direction over substantially the entire circumference of the seal. 2. An active matrix type liquid crystal display panel according to claim 1, wherein the organic insulating film end on the array substrate is located in a substantially half region in the width direction on substantially the entire circumference of the seal. . 3. An end of the organic insulating film on the array substrate is located at a substantially central portion in the width direction over substantially the entire circumference of the seal, and the organic insulating film on the array substrate is located at an outer peripheral portion of the seal. The active matrix type liquid crystal display panel according to claim 1, wherein the liquid crystal display panel is not provided. 4. An organic insulating film on an array substrate is formed in a stripe shape at a substantially central portion in the width direction over substantially the entire circumference of the seal,
2. The active matrix type liquid crystal display panel according to claim 1, wherein the organic insulating film on the array substrate is not located on an inner peripheral portion and an outer peripheral portion of the seal. 5. The active matrix type liquid crystal display according to claim 1, wherein an organic insulating film on the array substrate is formed in a dot shape at a substantially central portion in the width direction over substantially the entire circumference of the seal. panel.