JP3175362B2 - Liquid crystal display - Google Patents

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 device.

[0002]

2. Description of the Related Art An example of a conventional liquid crystal display device will be described with reference to FIG.

FIG. 1 is an external view of a liquid crystal display device.

A pixel area 105 is arranged on a substrate 101 made of glass, quartz or the like as shown in FIG. 1A, and driver circuits 103 and 104 each composed of an integrated circuit of a thin film transistor are arranged around the pixel area. The counter substrate 102 is
It is fixed to the substrate 101 by a sealing material 106 such as an ultraviolet curing resin so that the edge is located between the pixel area 105 and the driver circuits 103 and 104. The potential of the transparent electrode on the opposite substrate is fixed at a common potential through a pad 107 on the substrate side by a conductive adhesive.

This is to prevent as much as possible moisture from flowing into the liquid crystal sealed between the element substrate 101 and the counter substrate 102, and furthermore, a driver circuit or a wiring around the driver circuit having the same potential as the power supply is provided. This is because an electric field is not applied to the liquid crystal due to the presence of the liquid crystal.

FIG. 1B is a sectional view of the structure taken along the line AA ′ in FIG. A thin film transistor 113 made of polycrystalline silicon or the like is formed over a substrate 101. Although the thin film transistor, the source wiring, and the pixel electrode 114 are covered with the second interlayer insulating film 120, the upper part of the pixel electrode 114 is opened. The gate electrode of this transistor is finally connected to the wiring 117 via the contact hole at the terminal end 116, and the wiring 117 is connected to the driver circuit 103 formed outside the end of the opposing substrate and composed of an integrated circuit of transistors. are doing.

[0007] A transparent electrode 111 is formed on the entire surface of the opposing substrate 102, and a sealing material 106 such as an ultraviolet curable resin is used.
To the substrate. Substrate 101, counter substrate 1
02 is covered with an alignment film 112 such as polyimide.

FIG. 1C is a structural sectional view taken along the line BB 'of FIG. Wirings 306 are formed above the first interlayer insulating film 119 on the substrate 101, and these are further covered with a second interlayer insulating film 120 such as silicon oxide. There is a hole. An alignment film 112 such as polyimide is applied thereon. Since the pad 107 is wired so as to have a common potential, a conductive adhesive 118 is applied to this portion, and when the opposing substrate 102 is pressed, the opposing electrode 1 of the opposing substrate is pressed.
11 becomes the common potential.

FIG. 2A is a perspective view of the above-mentioned liquid crystal display device. As described above, the number of wirings crossing the sealing area is as large as about two to four times the number of pixels. FIG. 2B is a cross-sectional view of the source wiring crossing the seal. The source wiring formed on the first interlayer insulating film is 800
Aluminum of about 0 ° is covered with silicon oxide of 1 μm or less.

[0010]

However, in the prior art, since the driver circuit is disposed outside the seal area, the number of wirings crossing the seal area is as large as twice or more the number of pixels, and the step is tight. There is a possibility that water or the like that deteriorates the liquid crystal flows in.

[0011]

According to the present invention, a liquid crystal is held inside a seal portion between a pair of substrates, and a transistor is provided inside the seal portion of one of the pair of substrates. , and a pixel electrode disposed via an insulating film on the transistor, the insulating film, distribution of the pixel electrode
Over the area facing the location the pixel area on the sealing portion on the one substrate, moreover wires crossing the seal portion
The result is arranged to cover, on the outside of the sealing portion of the one substrate will be formed simultaneously with the driving circuit is the transistor for driving the transistor, the insulating film is disposed on the driving circuit And the pixel electrode is removed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 3A is a front external view of an example of the liquid crystal display device according to the present invention. A counter substrate 302 is fixed on an element substrate 301 by a sealing material 303 such as an ultraviolet curable resin, and liquid crystal is sealed. Driver circuit 30
Reference numeral 4 is disposed outside the seal area. The electrodes 305 at the four corners are for conducting to give a potential to the counter electrode of the counter substrate, and the potential is fixed to a certain potential given from the external connection terminal 306 of the element substrate using a conductive adhesive or the like. You.

FIG. 3B is a structural sectional view from the pixel area to the seal area. A pixel driving thin film transistor 313 is formed over a substrate 301. A driver circuit 304 composed of an integrated circuit of transistors is arranged outside the seal area, and the area from the pixel area to the lower part of the seal area of the element substrate is covered with a transparent organic insulating film 319 such as polyimide. A pixel electrode such as ITO 314 is formed on the transparent organic insulating film, and is connected to a drain electrode of the pixel transistor via a contact hole 315.

FIG. 3C is a structural sectional view from the pixel area to the seal area.

The potential of the opposing substrate 302 is controlled by the conductive adhesive 3
An electrode 305 such as ITO on a transparent organic insulating film through 20
, And this electrode is connected to a wiring 318 having a common potential thereunder and fixed at a common potential.

FIG. 3 is a cross-sectional view of a wiring crossing a seal in the liquid crystal display device. Since the organic film has less stress and has no problem such as cracking even if it is applied thicker than silicon oxide, the source wiring can be sufficiently buried, so that the surface becomes smoother than silicon oxide.

[0018]

By adopting the structure of the liquid crystal display device of the present invention, the unevenness at the lower part of the seal area is reduced, the inflow of moisture and the like into the sealed liquid crystal is reduced, and the deterioration of the liquid crystal is reduced over a long period of time. A high liquid crystal display device can be provided.

[Brief description of the drawings]

FIG. 1 is an external view showing a structure of a liquid crystal display device according to a conventional technique.

FIG. 2 is a perspective view showing a structure of a liquid crystal display device according to a conventional technique.

FIG. 3 is a cross-sectional view illustrating a structure of a liquid crystal display device according to the present invention.

[Explanation of symbols]

101, 201, 301 ... element substrate 102, 202, 302 ... counter substrate 113, 207, 313 ... pixel drive transistor 116, 316 ... gate electrode and gate wiring 106 of the pixel drive transistor 205, 303: Seal area 103, 104, 203, 204, 304: Driver circuit 117, 317: Wiring 105: Pixel area 114, 314: Pixel electrode 111, 311: Opposite Electrode 318: Wiring having common potential 107, 305: Pad having common potential 110, 310 ... Black matrix 115, 315: Contact hole with pixel electrode 118, 320 ... Conductive bonding Agent 319: Transparent organic insulating film 112, 312: Alignment film 119: First layer Insulating film 120 ... second interlayer insulating film 108,206,306 ... external connection terminal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1345 G02F 1/1339 505 G02F 1/1368 G09G 3/36

Claims (1)

(57) [Claims] 1. A liquid crystal is held inside a seal between a pair of substrates. A transistor is provided inside the seal of one of the pair of substrates, and an insulating film is formed on the transistor. and a pixel electrode disposed over the insulating film, the pixel
Over the pixel areas arranged electrodes in a region facing the sealing portion on the one substrate, yet the seal portion lateral
A drive circuit for driving the transistor is formed outside the seal portion of the one substrate at the same time as the transistor, and is arranged so as to cover the cut wiring .
The liquid crystal display device, wherein the insulating film is disposed on the drive circuit and the pixel electrode is removed.