JPH06250222A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To assure the uniformity of a cell gap even if a pixel is provided with a thick interlayer insulating films by forming driver in the outer peripheral part of a sealing part and forming both the first and second interlayer insulating films in an adhering part as well. CONSTITUTION:The active matrix substrate of the liquid crystal display device of the driver 103-contg. active matrix system has the first interlayer insulating film 112 for interlayer sepn. of gate wiring and source wiring and the second interlayer insulating film 104 for interlayer sepn. of source wiring and pixel electrode 106. The driver is formed in the outer peripheral part of the sealing part and both the first and second interlayer insulating films 112, 104 are formed in the sealing part as well. The interlayer insulating film 104 is formed in the sealing part as well in such a manner and, therefore, there are substantially no level differences between the pixel part and the sealing part. Then, there is no need for changing the diameter of the spacer in the sealing part and the spacer in the pixel part and the uniformity of the cell gap is easily controllable.

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.

[0002]

2. Description of the Related Art As a conventional example characterized in that a pixel electrode is formed on an organic thin film, Japanese Patent Publication No. 1-35351 can be cited. In this example, aluminum is used as the pixel electrode to form a reflective liquid crystal display device.

In general, when a driver is built in an active matrix substrate, the driver is arranged outside the adhesive portion (hereinafter referred to as a seal portion) between the substrates with respect to the pixel portion, as in JP-A-64-68725. Moreover, in order to improve the moisture resistance of the driver, it is sealed with an organic resin film such as polyimide.

As a method of controlling the distance between opposed substrates, if a small substrate having a diagonal size of about 1 inch is used, a spacer is arranged only in the adhesive portion to secure a distance between the substrates of about 5 to 6 μm. . On the other hand, since it is difficult to control the distance between the substrates only by the adhesive portion in the case of a medium-sized to large-sized substrate having a diagonal of 1 inch or more, a spacer is injected at the same time when the liquid crystal is injected between the substrates.

[0005]

With respect to the structure of the adhesive portion,
In the conventional example, when a thick interlayer insulating film is provided in the pixel portion,
The distance between the substrates is extremely different between the pixel part and the adhesive part. Therefore, in order to secure a proper distance between the substrates, the spacer diameter of the pixel portion and the adhesive portion must be changed. There is a problem that it is difficult to maintain the distance.

An object of the present invention is to provide a structure of a liquid crystal display device capable of ensuring uniformity of cell gap even if a thick interlayer insulating film is provided in a pixel portion.

[0007]

According to the present invention, in an active matrix type liquid crystal display device with a built-in driver, an active matrix substrate includes a first interlayer insulating film for separating a gate wiring and a source wiring from each other, a source wiring and a pixel electrode. A second interlayer insulating film for interlayer separation, wherein the driver is formed on the outer peripheral portion rather than the seal portion, and both the first and second interlayer insulating films are formed also on the adhesive portion. .

[0008]

1 is a plan view of a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA '.
Shown in. A pixel switching TFT (hereinafter referred to as a pixel TFT) 102 including an intrinsic semiconductor, a conductive semiconductor, a gate insulating film, a gate electrode, a source electrode, and a first interlayer insulating film 112 on an insulating substrate 101 such as a glass substrate.
And at the same time, a driving TFT (hereinafter referred to as a driver) 103 of the pixel TFT group is formed. Next, for example, polyimide is applied as the second interlayer insulating film 104 so as to have a film thickness of about 2 μm. After drying the polyimide,
A chromium thin film is deposited on the surface of about 1000 Å and patterned to form an etching mask 105. After that, the second interlayer insulating film 104 is patterned by the dry etching method.
At this time, the etched portion of the second interlayer insulating film 104 is a portion including the driver 103 on the outer periphery of the pixel electrode connection portion of the pixel TFT, the conduction portion between the counter electrode and the active matrix substrate, and the seal portion 110. . After the etching is completed, the etching mask 105 is removed and the pixel electrode 106 is formed of ITO. Next, bonding is performed at the seal portion 110, but at this time, bonding is performed with an adhesive containing a spacer.
Finally, the liquid crystal containing the spacer is sealed.

Although chromium is used as the etching mask in the above embodiments, another material such as a silicon nitride film or a silicon dioxide film may be used as long as it serves as an etching mask.

If the etching mask is an insulator, it is not always necessary to remove the etching mask, and it is possible to form a pixel electrode on the upper layer of the interlayer insulating film through the etching mask. In this case, since the etching mask removing step is omitted, damage to the interlayer insulating film can be further reduced. Further, if the photoresist is peeled off after patterning the etching mask, the etching mask is easily exposed to etching gas and damaged during etching of the second interlayer insulating film 104. Therefore, the photoresist is not peeled off and the interlayer insulating film is not peeled off. It is desirable to perform the etching.

The above is one embodiment of the present invention, but since the interlayer insulating film 104 is formed also in the seal portion 110, there is almost no step between the pixel portion 111 and the seal portion 110. Therefore, it is not necessary to change the diameter of the spacer of the seal portion and the diameter of the spacer of the pixel portion, and it becomes easy to control the uniformity of the cell gap.

[0012]

According to the present invention, since an interlayer insulating film having the same film thickness as that of the pixel portion is present in the seal portion, there is almost no step between the pixel portion and the seal portion. Therefore, the spacer diameters of the pixel portion and the seal portion are the same. Therefore, the uniformity of the cell gap is improved.

[Brief description of drawings]

FIG. 1 is a plan view of a liquid crystal display device described in an embodiment.

FIG. 2 is a cross-sectional view taken along the line AA ′ of the liquid crystal display device described in the embodiment.

FIG. 3 is a cross-sectional view showing a process of an example.

FIG. 4 is a cross-sectional view of a conventional liquid crystal display device.

[Explanation of symbols]

 101 glass substrate 102 pixel TFT 103 driver 104 second interlayer insulating film 105 etching mask 106 pixel electrode 107 counter substrate 108 adhesive 109 counter electrode 110 seal part 111 pixel part 112 first interlayer insulating film

Claims (2)

[Claims] 1. In an active matrix type liquid crystal display device with a built-in driver, an active matrix substrate comprises a first interlayer insulating film for separating a gate wiring and a source wiring from each other and a second interlayer insulating film to separate a source wiring and a pixel electrode from each other. An insulating film is provided, and the driver is formed on an outer peripheral portion of an adhesive portion between two opposing substrates, and both first and second interlayer insulating films are formed on the adhesive portion. Liquid crystal display device. 2. The liquid crystal display device according to claim 1, wherein the second interlayer insulating film is made of an organic resin such as a polyimide resin, a polyamide resin, or a polyamideimide resin.