JPH11183936A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device suppressed in display unevenness and improved in display quality by positively providing a difference between a cell gap in a peripheral area and a cell gap in a central part. SOLUTION: After dispersing spacers 16 made of plastic bead between an active matrix substrate 20 and an opposed substrate 19, the substrates are stuck together via a sealing agent mixed with spacers made of glass fiber and filled with liquid crystal. Then, in the space between both substrates 19, 20, two or more hues 17 of color filters are laminated in the peripheral area 3, but the display areas 2a and 2b are narrower than the peripheral area 3 by the portion forming an interlayer insulating film 12, and since the cell gap 15 is determined by the spacers 16 existing in the display areas 2a, 2b and those in a sealing part 18, a uniform cell gap 15 can be obtd. in the display areas 2a and 2b.

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 device used for AV equipment such as a television and information equipment such as a personal computer.

[0002]

2. Description of the Related Art FIG. 8 is a sectional view of a conventional liquid crystal display device. As shown in FIG. 8, the active matrix substrate 20
The liquid crystal display device is constituted by bonding the substrate and the counter substrate 19 together. At this time, in order to obtain a uniform thickness of the liquid crystal layer, that is, a so-called cell gap 15, a spacer 16 such as a plastic bead is sprayed between the substrates 19 and 20, and then a sealing material mixed with a spacer such as a glass fiber is used. And stuck together.

At this time, a method for flattening the active matrix substrate 20 including the seal portion 18 is disclosed in Japanese Patent Laid-Open No. 7-12 / 1995.
No. 8670 discloses this. Also, the sealing portion 18
A method for removing the interlayer insulating film 12 is disclosed in
No. 80 is disclosed.

In such a liquid crystal display device, a color filter is generally formed on the counter substrate 19 in order to realize color display. For this color filter, a method of forming a black matrix is used to prevent color mixing or light leakage.

On the other hand, in the case where the wiring formed on the active matrix substrate 20 is used as a light shielding film and the black matrix is not formed on the counter substrate 19, the light shielding of the peripheral region 3 is required to prevent light leakage. Is the issue.

As a solution to this, there is a structure in which the peripheral region 3 is shielded by superposing two or more color filters of the hue 17. In a conventional liquid crystal display device, when a black matrix is not formed on the counter substrate 19, in order to prevent light leakage and to shield the peripheral region 3,
If two or more hues 17 are overlapped on the opposing substrate 19 to form a light-shielding pattern, the transmittance becomes about 1%, and light-shielding of the peripheral region 3 becomes possible.

[0007]

However, when a light-shielding pattern is formed by laminating two or more color filters of two or more hues 17, the opposing substrate 1 in the peripheral region 3 is formed.
9 becomes thicker than the thickness 24a of the opposing substrate 19 in the display regions 2a and 2b. Therefore, when the cell gap 15 is controlled by the spacer 16, it is difficult to control the gap between the display regions 2a and 2b. .

When the cell gaps 15 near the display regions 2a and 2b and the seal portion 18 are substantially equal, for example, when the difference between the cell gaps 15 between the display regions 2a and 2b and the peripheral region 3 is within 0.3 μm. In addition, uncured components included in the seal portion 18 protrude into the liquid crystal layer, and ionic impurities lower the time constant of the liquid crystal, causing deterioration in display quality.

The present invention has been made in view of the above-mentioned conventional problems, and suppresses display unevenness by positively providing a difference between a cell gap in a peripheral region and a cell gap in a central portion. It is another object of the present invention to provide a liquid crystal display device having improved display quality.

[0010]

According to a first aspect of the present invention, there is provided a liquid crystal display device comprising: a pair of substrates bonded to each other via a sealing material; In a liquid crystal display device having a layer and a non-display area near the seal material, the thickness of the liquid crystal layer is formed to be thicker in the non-display area than in the display area.

The liquid crystal display device according to the second aspect is the first aspect.
In the liquid crystal display device described in the above, one of the pair of substrates is a color filter substrate on which a color filter is formed, and the non-display region is shielded by stacking different hues of the hues of the color filter. It is characterized by being a film.

The liquid crystal display device according to the third aspect is the first aspect.
3. The liquid crystal display device according to claim 2, wherein one of the pair of substrates is provided with an interlayer insulating film covering a gate signal line, a source signal line, and a switching element, and a contact hole is provided on the interlayer insulating film. An active matrix substrate provided with a picture element electrode connected to the switching element through the inter-layer insulating film, wherein the non-display area is removed or the non-display area is formed thinner than the display area. It is characterized by having.

According to a fourth aspect of the present invention, there is provided a liquid crystal display device.
3. The liquid crystal display device according to claim 1, wherein the interlayer insulating film is formed with two or more layers, and the interlayer insulating film in the non-display region is formed with one or more layers smaller than the display region. .

According to the liquid crystal display device of the present invention, the thickness of the liquid crystal layer is formed thicker in the non-display area than in the display area. Can be performed easily and accurately. Further, by increasing the difference in cell gap between the display area and the non-display area, it is possible to prevent the uncured component contained in the sealing resin from projecting.

One of the pair of substrates is a color filter substrate on which a color filter is formed, and the non-display area is a light-shielding film formed by stacking different hues of the hues of the color filters. Even so, when controlling the cell gap by the spacer, the gap control of the display region can be easily and accurately performed. Further, by increasing the difference in cell gap between the display area and the non-display area, it is possible to prevent the uncured component contained in the sealing resin from projecting.

Further, one of the pair of substrates is provided with an interlayer insulating film covering the gate signal line, the source signal line and the switching element, and is connected to the switching element via a contact hole on the interlayer insulating film. An active matrix substrate provided with a pixel electrode, the non-display region of the interlayer insulating film is removed, or the non-display region is formed thinner than the display region. In addition, the gap control of the display area can be easily and accurately performed. Further, by increasing the difference in cell gap between the display area and the non-display area, it is possible to prevent the uncured component contained in the sealing resin from projecting.

Further, the interlayer insulating film is formed of two or more layers,
Since the interlayer insulating film in the non-display region is formed of one or more layers less than the display region, the wiring formed under the interlayer insulating film does not become exposed, and the wiring due to the adhesion of foreign matter or the like does not occur. A short circuit between them can be prevented.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

(Embodiment 1) FIG. 1 is a plan view showing a configuration of a peripheral portion of a liquid crystal display device according to the present invention. As shown in FIG. 1, the light-shielding film in the peripheral region 3 is formed by providing a pattern in which two hues of the color filter 4 having a thickness of 1.5 μm are overlapped.

At this time, the two hues are configured such that red and blue are superimposed, because this combination can minimize the transmittance. In this combination, the transmittance of the peripheral region 3 can be approximately 1%, and the peripheral region 3 can be shielded from light without forming a black matrix on the counter substrate (color filter substrate).

On the active matrix substrate where two hues of the color filter 4 are overlapped, the interlayer insulating film between the source signal line and the pixel electrode is removed when forming the contact hole.

FIG. 2 is a sectional view showing an active matrix substrate constituting the liquid crystal display device according to the present invention. As shown in FIG. 2, the active matrix substrate 20 is composed of a gate insulating film 8, a gate insulating film 8, a channel protective film 9, an N-type silicon layer serving as a source electrode 6, and an N-type serving as a drain electrode 7 on a transparent insulating substrate. A silicon layer is formed, and a source signal line 10 and a drain signal line 11 are sequentially formed by a sputtering method, and are patterned by a photolithography process.

Since the source signal line 10 has a two-layer structure of a metal layer and an ITO layer, even if a part of the metal layer has a defect, the source signal line 10 is electrically connected by the ITO. In addition, there is an advantage that disconnection of the source signal line 10 can be prevented.

Further, a photosensitive organic insulating film having a thickness of 3 μm is formed as an interlayer insulating film 12 by a spin coating method.
A contact hole (not shown) is formed in the interlayer insulating film 12 by the exposure step and the development step. Further, the pixel electrode 2
A transparent conductive film to be No. 2 is formed by a sputtering method and patterned by a photolithography method.

The pixel electrode 22 is connected to the drain electrode 7 of the TFT via a contact hole (not shown) penetrating the interlayer insulating film 12. With such a structure, in the display region, all regions to which no electric field is applied to the liquid crystal are shielded from light by the source signal lines 10 and the drain signal lines 11, so that a structure without a black matrix can be obtained. it can.

FIG. 3 is a circuit diagram on a substrate of the liquid crystal display device according to the present invention. As shown in FIG. 3, one of the input terminals 1 is connected to the source signal line 10 and the other input terminal 1 is connected to the gate signal line 23. The active matrix substrate includes the signal lines 10 and 23, the TFT 13, and the storage capacitor (Cs) 14.

FIG. 4 is a sectional view showing the liquid crystal display device according to the first embodiment. As shown in FIG. 4, after the spacers 16 made of plastic beads are sprayed between the active matrix substrate 20 and the counter substrate 19, they are bonded via a sealing material mixed with a spacer made of glass fiber, and the liquid crystal is injected. I do.

At this time, the distance between the two substrates 19 and 20 is such that two or more hues 1
7, the display regions 2a and 2b are narrower than the peripheral region 3 by the formation of the interlayer insulating film 12, and the cell gap 15 is smaller than the display regions 2a and 2b.
Is determined by the spacer 16 existing in the display region and the spacer (not shown) in the seal portion 18.
In a and 2b, a uniform cell gap 15 is obtained.

Furthermore, if the difference in cell gap 15 between the display regions 2a and 2b and the peripheral region 3 is set to 0.3 μm or more, the uncured component of the seal portion 18 protrudes into the liquid crystal layer, and ionic impurities are removed from the liquid crystal layer. By lowering the time constant, display quality does not deteriorate.

(Embodiment 2) FIG. 5 is a sectional view showing a liquid crystal display device according to Embodiment 2. As shown in FIG. 5, after the spacers 16 made of plastic beads are sprayed between the active matrix substrate 20 and the counter substrate 19, they are bonded together via a sealing material mixed with a spacer made of glass fiber, and the liquid crystal is injected. .

Here, the interlayer insulating film is formed of a silicon nitride film 2
As a two-layer structure of 1 and the interlayer insulating film 12, only the interlayer insulating film 12 in the peripheral region 3 is removed at the time of forming the contact hole.

At this time, the distance between the two substrates 19 and 20 is such that two or more hues 1
7, the display regions 2a and 2b are narrower than the peripheral region 3 by the formation of the interlayer insulating film 12, and the cell gap 15 is smaller than the display regions 2a and 2b.
Is determined by the spacer 16 existing in the display region and the spacer (not shown) in the seal portion 18.
In a and 2b, a uniform cell gap 15 is obtained.

Further, if the difference in cell gap 15 between the display regions 2a and 2b and the peripheral region 3 is set to 0.3 μm or more, the uncured component of the seal portion 18 protrudes into the liquid crystal layer and ionic impurities are removed from the liquid crystal layer. By lowering the time constant, display quality does not deteriorate.

Further, in this structure, since the interlayer insulating film 12 is formed on the wiring, a short circuit between the wirings can be prevented.

(Embodiment 3) FIG. 6 is a sectional view showing a liquid crystal display device according to Embodiment 3. As shown in FIG. 6, after a spacer 16 made of plastic beads is scattered between the active matrix substrate 20 and the counter substrate 19, they are bonded via a sealing material mixed with a spacer made of glass fiber, and liquid crystal is injected. .

Here, the interlayer insulating film 12 in the peripheral region 3 is removed when forming the contact hole.

At this time, the distance between the substrates 19 and 20 is smaller in the display regions 2a and 2b than in the peripheral region 3 by the formation of the interlayer insulating film 12, and the cell gap 15 is smaller than the display region 2a. And the spacers (not shown) in the seal portion 18 present in the display regions 2a and 2b, a uniform cell gap 15 is obtained in the display regions 2a and 2b.

Further, if the difference in cell gap 15 between the display regions 2a and 2b and the peripheral region 3 is set to 0.3 μm or more, the uncured component of the seal portion 18 protrudes into the liquid crystal layer, and ionic impurities are removed from the liquid crystal. By lowering the time constant, display quality does not deteriorate.

(Embodiment 4) FIG. 7 is a sectional view showing a liquid crystal display device according to Embodiment 4. As shown in FIG. 7, after the spacers 16 made of plastic beads are sprayed between the active matrix substrate 20 and the counter substrate 19, they are pasted together via a sealing material mixed with a spacer made of glass fiber, and liquid crystal is injected. .

Here, the interlayer insulating film 12 is formed using a photosensitive organic insulating film, the exposure amount is changed between the display regions 2a and 2b and the peripheral region 3, and the interlayer insulating film composed of the photosensitive organic insulating film in the peripheral region 3 is formed. The insulating film 12 is formed to have a display area
And 2b so as to be thinner than the photosensitive organic insulating film.

At this time, the distance between the substrates 19 and 20 is smaller in the display regions 2a and 2b by the thickness of the interlayer insulating film 12 than in the peripheral region 3 and the cell gap 1
5 is a spacer 16 existing in the display areas 2a and 2b.
And a spacer (not shown) in the seal portion 18, a uniform cell gap 15 is obtained in the display regions 2a and 2b.

Further, since the difference in cell gap 15 between the display regions 2a and 2b and the peripheral region 3 is 0.3 μm or more, the uncured component of the seal portion 18 projects into the liquid crystal layer and the ionic impurities are liquid crystal. By lowering the constant, display quality does not deteriorate.

Further, in this structure, since the interlayer insulating film 12 is formed on the wiring, a short circuit between the wirings can be prevented.

[0044]

As described above, according to the liquid crystal display device of the present invention, since the thickness of the liquid crystal layer is larger in the non-display area than in the display area, the gap control of the display area is achieved. Can be performed easily and accurately. Further, it is possible to prevent the display quality from deteriorating due to the protrusion of the uncured component contained in the sealing resin.

One of the pair of substrates is a color filter substrate on which a color filter is formed, and the non-display area is a light shielding film formed by stacking different hues of the hues of the color filters. Even so, gap control of the display area can be performed easily and accurately. Further, it is possible to prevent the display quality from deteriorating due to the protrusion of the uncured component contained in the sealing resin.

One of the pair of substrates is provided with an interlayer insulating film covering the gate signal line, the source signal line and the switching element, and is connected to the switching element via a contact hole on the interlayer insulating film. An active matrix substrate provided with a pixel electrode, the non-display region of the interlayer insulating film is removed, or the non-display region is formed thinner than the display region, so that the gap control of the display region is easy and easy. Can be done accurately. Further, it is possible to prevent the display quality from deteriorating due to the protrusion of the uncured component contained in the sealing resin.

Further, the interlayer insulating film is formed of two or more layers,
Since the interlayer insulating film in the non-display region is formed of one or more layers less than the display region, the wiring formed under the interlayer insulating film does not become exposed, and the wiring due to the adhesion of foreign matter or the like does not occur. A short circuit between them can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a peripheral portion of a liquid crystal display device according to the present invention.

FIG. 2 is a cross-sectional view illustrating an active matrix substrate included in the liquid crystal display device according to the present invention.

FIG. 3 is a circuit diagram on a substrate of the liquid crystal display device according to the present invention.

FIG. 4 is a sectional view showing the liquid crystal display device according to the first embodiment.

FIG. 5 is a sectional view showing a liquid crystal display device according to a second embodiment.

FIG. 6 is a sectional view showing a liquid crystal display device according to a third embodiment.

FIG. 7 is a sectional view showing a liquid crystal display device according to a fourth embodiment.

FIG. 8 is a sectional view showing a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input terminal 2a Display area center part 2b Display area peripheral part 3 Peripheral area 4 Color filter 5 Gate electrode 6 Source electrode 7 Drain electrode 8 Gate insulating film 9 Channel protective film 10 Source signal line 11 Drain signal line 12 Interlayer insulating film 13 TFT DESCRIPTION OF SYMBOLS 14 Auxiliary capacitance (Cs) 15 Cell gap 16 Spacer 17 Two or more hues 18 Seal part 19 Counter substrate 20 Active matrix substrate 21 Silicon nitride film 22 Pixel electrode 23 Gate signal line 24a Thickness of counter substrate in display area 24b In peripheral area Opposite substrate thickness

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Ichijun Mitsumoto 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Inside Sharp Corporation

Claims (4)

[Claims] 1. A liquid crystal display device in which a pair of substrates are bonded to each other with a sealing material interposed therebetween, a liquid crystal layer is provided between the pair of substrates, and a non-display region is in the vicinity of the sealing material. Wherein the non-display area is formed thicker than the display area. 2. One of the pair of substrates is a color filter substrate on which a color filter is formed, and the non-display region is formed as a light shielding film by stacking different hues of the hues of the color filters. The liquid crystal display device according to claim 1, wherein 3. One of the pair of substrates is provided with an interlayer insulating film covering a gate signal line, a source signal line, and a switching element, and the switching element is provided on the interlayer insulating film via a contact hole. An active matrix substrate provided with a pixel electrode connected to the semiconductor device, wherein the interlayer insulating film has the non-display region removed or the non-display region is formed thinner than the display region. The liquid crystal display device according to claim 1 or 2, wherein: 4. The method according to claim 1, wherein the interlayer insulating film is formed of two or more layers.
4. The liquid crystal display device according to claim 3, wherein the interlayer insulating film in the non-display area is formed of one or more layers less than the display area.