JPH06118432A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To improve the adhesion and moisture resistance of substrate adhering parts and to eliminate the need for a special process to protect driver circuits by forming a driver circuit within the display part of the liquid crystal display device. CONSTITUTION:Source wirings and pixel electrodes 8 of thin-film transistors(TFTs) are insulated by org. insulating films 11 and are formed in respectively different layers. The org. insulating films 11 are formed at the sealing points of the liquid crystal display device and the upper part of the driver circuits 3 for driving the TFTs. The driver circuits 3 are formed within the display part of the liquid crystal display device and a counter electrode 7 of a counter substrate 2 is removed only on the opposite side of the driver circuits 3. The formation of the driver circuit 3 for driving the TFTs is, therefore, formed within the display part of the liquid crystal display device. Then, the need for the special sealing operation for protecting the driver circuits 3 is eliminated and the adhesiveness to org. adhesives 5 is improved. The moisture resistance is thus improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active type liquid crystal display device which performs display by using liquid crystal sealed between two substrates.

[0002]

2. Description of the Related Art FIG. 3 is a view showing a joint portion of a conventional liquid crystal display device. 1 shows a liquid crystal display device including a transparent substrate 1 such as quartz or glass on which a thin film transistor and a driver circuit for driving the thin film transistor are formed, and a transparent substrate 2 on which a counter electrode is formed. Wiring 4 made of a metal such as Cr, Al, or Ta for transmitting the signal from 3 is shown. The driver circuit 3 is formed on the substrate 1 at the same time as the thin film transistor. In FIG. 3, reference numeral 5 indicates an organic adhesive such as an epoxy resin that bonds the transparent substrates 1 and 2. 4 is a cross-sectional view of the AA portion in FIG. 3, and in FIG. 4, 1 and 2 are transparent substrates, 3 is a driver circuit for driving a thin film transistor, 4 is wiring, 5 is an organic adhesive, and 6 is a liquid crystal. Layer, 7 is I
A counter electrode made of a transparent conductive film such as TO, 8 is a pixel electrode of a thin film transistor, and 9 is an input terminal of the driver circuit 3. Conventionally, the driver circuit 3 is formed outside the display unit 10 of the liquid crystal display device. However,
In this method, a sealing material is required above the driver circuit 3 in order to improve the moisture resistance and prevent damage of the driver circuit 3 in the outer peripheral portion. Further, as the liquid crystal display device becomes finer, the number of wirings 4 increases, water easily enters the liquid crystal layer 6 along the wirings 4, and deterioration of the liquid crystal display device starts to occur from the outer peripheral portion.

[0003]

The problem to be solved by the present invention is to improve the reliability of the liquid crystal display device by devising a structure in which a driver circuit for driving a thin film transistor can be provided in the display portion of the liquid crystal display device. To improve productivity and productivity.

[0004]

The liquid crystal display device of the present invention is to solve the above-mentioned problems, and the source wiring of the thin film transistor and the pixel electrode are insulated by an organic insulating film and formed in different layers. The organic insulating film is formed on the sealing portion of the liquid crystal display device and on the driver circuit for driving the thin film transistor, the driver circuit is formed in the display portion of the liquid crystal display device, The counter electrode is characterized in that only the counter side of the driver circuit is removed.

[0005]

The liquid crystal display device of the present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 is a diagram showing an embodiment of the liquid crystal display device of the present invention. In FIG. 1, 1 and 2 are transparent substrates and 3
Is a driver circuit for driving the thin film transistor, Cr,
Wirings 4 and 5 using a metal such as Al and Ta are organic adhesives such as epoxy resin, 6 is a liquid crystal layer, 7 is a counter electrode made of a transparent conductive film such as ITO, 8 is a pixel electrode of a thin film transistor, and 9 is An input terminal 11 of the driver circuit 3 is an insulating film for insulating the source wiring of the thin film transistor and the pixel electrode into different layers and protecting the driver circuit 3. As the insulating film 11, it is possible to use an organic material such as polyimide or acrylic, an inorganic material such as SiO ₂ or SiN _x , or a combination of the organic material and the inorganic material.

2A and 2B are a plan view and a sectional view of a thin film transistor used in the liquid crystal display device of the present invention. 1 is a transparent substrate, a channel region 12 of the thin film transistor, a gate insulating film 13 of the thin film transistor,
A source / drain region 14 of the thin film transistor, a gate wiring 15 of the thin film transistor, a source wiring 16 of the thin film transistor, a first insulating film 17 made of an inorganic material such as SiO ₂ or SiN _x for insulating the gate wiring 15 and the source wiring 16 from each other, The pixel electrode 8 of the thin film transistor, and the second insulating film 18 made of an organic material such as polyimide or acrylic that insulates the source wiring 16 from the pixel electrode 8 are shown. The insulating film 11 in FIG. 1 is formed using the second insulating film 18 in FIG.

According to this embodiment, the driver circuit for driving the thin film transistor can be formed in the display portion of the liquid crystal display device. Therefore, no special sealing work is required to protect the driver circuit. Further, if an organic insulating film is provided immediately below the sealing portions of the substrates 1 and 2, the adhesiveness with the organic adhesive 5 is improved and the moisture resistance can be expected to be improved.

[0009]

As described above, the following effects can be obtained by the present invention.

(1). A liquid crystal display device having improved adhesiveness at the substrate adhesion portion and good moisture resistance can be obtained.

(2). A driver circuit for driving a thin film transistor can be formed in the display portion of a liquid crystal display device, and a special step for protecting the driver circuit is unnecessary, and at the same time, damage to the driver circuit (a flaw, It is possible to prevent disconnection) and improve yield.

(3). Since the wiring length between the driver circuit for driving the thin film transistor and the thin film transistor can be shortened, the liquid crystal display device can be downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a liquid crystal display device of the present invention.

2A and 2B are a plan view and a cross-sectional view of a thin film transistor used in the liquid crystal display device of the present invention.

FIG. 3 is a diagram showing a joint portion of a conventional liquid crystal display device.

FIG. 4 is a sectional view of an AA portion in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ...- Transparent substrate on which a thin film transistor is formed 2 ...- Transparent substrate on which a counter electrode is formed 3 ...- Driver circuit for driving a thin film transistor 4 ... Wiring 5 ... Organic adhesive 6 ... Liquid crystal layer 7 ... Counter electrode 8 ... Pixel electrode 9 ... Driver driver input terminal 10 ... Display portion of liquid crystal display device 11 ... Insulating film 12 .... Channel region of thin film transistor 13 ... Gate insulating film of thin film transistor 14 ... Source / drain region of thin film transistor 15 ... Gate wiring of thin film transistor 16 ... Source wiring of thin film transistor 17 ... .... First insulating film 18 ... Second insulating film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyuki Kitazawa 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Takashi Nakazawa 3-3-5 Yamato, Suwa-shi, Nagano Seiko In Epson Corporation (72) Inventor Kiyofumi Kitawada 3-5 Yamato, Suwa, Nagano Seiko Epson Corporation (72) Inventor Junri Shimone 3-5 Yamato, Suwa City, Nagano Seiko Epson Shares In-company (72) Inventor Hideyuki Akanuma 3-5-3 Yamato, Suwa, Nagano Seiko Epson Corporation

Claims (4)

[Claims] 1. A substrate on which a thin film transistor and a driver circuit for driving the thin film transistor are formed, and an opposite substrate on which an opposite electrode is formed are sealed with an organic adhesive and sealed between the two substrates. A liquid crystal display device that performs display using the generated liquid crystal, wherein the driver circuit is formed in a display portion of the liquid crystal display device. 2. The liquid crystal display device according to claim 1, wherein the counter electrode is removed only on the opposite side of the driver circuit. 3. The liquid crystal display device according to claim 1, wherein the source wiring of the thin film transistor and the pixel electrode are insulated by an organic insulating film and are formed in different layers. 4. The liquid crystal display device according to claim 1, wherein the organic insulating film is formed on a sealing portion of the two substrates and on an upper portion of the driver circuit.