JPH0259727A - active matrix substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an active matrix substrate used in a liquid crystal display panel.

BACKGROUND OF THE INVENTION In recent years, with the miniaturization of industrial equipment, there has been a demand for thin flat display devices to replace conventional display devices.Among the various flat display devices, display devices using liquid crystals consume less power. It is attracting attention because it is easy to display in full color. In particular, active matrix liquid crystal display panels in which each display pixel is provided with a switching element have excellent display image quality and are therefore being applied to portable televisions and the like.

FIG. 4 is an equivalent circuit diagram showing the structure of a conventional active matrix substrate. In FIG. 4, 51 is a thin film transistor, 52 is a metal film pattern for shorting signal lines, X1 to Xm are scanning signal lines, and Yl-Yn are video signal lines.

However, active matrix substrates have the problem that static electricity that builds up on the substrate during the manufacturing process destroys the insulation film at the intersections of switching elements and scanning signal lines and video signal lines, resulting in short circuits. Ta. As a measure to prevent damage to the insulating film due to static electricity,
Conventionally, a method has been used in which all terminals of an active matrix substrate are short-circuited with a metal film pattern 52, as shown in FIG. Also, JP-A-61-4897
As seen in Japanese Patent No. 8, a method has also been proposed in which only one side of the scanning signal line and video signal line of the active matrix substrate is short-circuited. FIG. 5 shows a block diagram of an active matrix substrate produced by this method.

Problems to be Solved by the Invention However, in the conventional method for preventing breakdown of an insulating film due to static electricity as shown in Fig. 4, all terminals are short-circuited, so it is necessary to cut off the short-circuited parts after the active matrix substrate is completed. Until now, it was not possible to inspect short-circuit defects such as disconnection defects due to signal line disconnections, short-circuit defects between adjacent scanning signal lines or video signal lines, and short-circuits between scanning signal lines and video signal lines. Also, the fifth
Although the method disclosed in Japanese Patent Application Laid-Open No. 61-48978 shown in the figure can inspect for disconnection defects, it is impossible to inspect for short-circuit defects in the substrate until the short-circuit portion of the signal line is cut.

The present invention has been made in view of these points, and an object of the present invention is to provide an active matrix substrate that prevents breakdown of an insulating film due to static electricity and allows defect inspection.

Means for Solving the Problems The present invention solves the above-mentioned problems by using a metal film formed on a glass substrate for every other scanning signal line and video signal line of a switching element of an active matrix substrate. The semiconductor film is used to connect a plurality of signal lines to a common electrode pattern formed outside the input terminal of the signal line.

Effect of the present invention With the above-described configuration, the present invention prevents breakdown of the insulating film due to static electricity on an active matrix substrate, and also inspects for disconnection of signal lines and short-circuit defects between a plurality of connected scanning signal line groups and video signal line groups. It is possible to do this.

EXAMPLE Hereinafter, an active matrix substrate according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram of an active matrix substrate in one embodiment of the present invention. In FIG. 1, 1 is a thin film transistor, 2 is an input terminal for a scanning signal line and a video signal line, 3 is a metal film pattern for short-circuiting a plurality of scanning signal lines and video signal lines, and 4 is an input terminal for a signal line. A common electrode pattern formed of a metal film as a common electrode on the outside; 5 a semiconductor film connecting the metal film pattern 3 in which a plurality of signal lines are short-circuited and the common electrode pattern 4; X1;
~Xm is a scanning signal line, Y1~Yn is a video signal line 0
In this embodiment, as shown in FIG. 1, every other scanning signal line and video signal line is connected to the metal film pattern 3, and the semiconductor film 5
It is connected to the common electrode pattern 4 via.

Figure 2 shows metal film pattern 2 and common electrode metal film pattern 3.
is a structural diagram of part A in Fig. 1, and Fig. 3 is a structural diagram of part A in Fig. 2.
FIG. 3 is a schematic cross-sectional view at section a'.

The structure of this embodiment will be explained with reference to FIGS. 2 and 3. When forming the input terminal 2 of the signal line on the glass substrate 10, a metal film pattern 3 for shunting the signal line is also formed at the same time. Next, when forming a switching element, a semiconductor film 5 is formed on the metal film pattern 3 at the same time. Finally, the metal film 1 uses the common electrode pattern 4 as a reinforcing film for the signal line.
It is formed at the same time when forming 2. The semiconductor film 5 has a high resistance value when performing a defect inspection by applying a voltage of several volts, but it has a resistance value of several 100 to several kV due to static electricity.
When a high voltage of 2 is applied to the signal line, the resistance becomes sufficiently low and a current due to static electricity can flow through the common electrode pattern 4.

With this configuration, it is possible to take measures to prevent insulation film breakdown due to static electricity without increasing the number of photomasks. In addition, the reinforcing metal film 12 is not formed at the connection portion between the signal line and the metal film pattern 3 shown in part b in FIG. 2 so that it can be easily cut with a laser beam or the like after the inspection is completed.

Next, a defect inspection method according to this embodiment will be explained. To test for disconnection of the signal line, since the terminals on one side of both the scanning signal line and the video signal line are not connected, the inspection can be performed by connecting the metal film pattern 3 and the input terminal 210-b needle and measuring the resistance value. Can be done.

To inspect for short defects between adjacent signal lines, every other signal line is connected to the metal film pattern 3, so by connecting a probe needle to the metal film pattern 3 and measuring the resistance value, it is possible to detect short defects in the block. Short defect inspection can be performed. In addition, when inspecting for short defects between the scanning signal line and the video signal line, since each metal film pattern 3 is connected via the semiconductor film 5, the electrical resistance is sufficiently high, and the metal film on the scanning signal line side By connecting a probe needle to the pattern and the metal film pattern on the video signal line side and measuring the resistance value, short-circuit defects in the block can be inspected.

Effects of the Invention As explained above, the present invention connects every other signal line of a switching element of an active matrix substrate with a metal film formed on a glass substrate, and By connecting the metal film pattern formed on the outside and the group of connected signal lines with a semiconductor film, it is possible to protect the insulation film from breakdown due to static electricity, and also to inspect for disconnection defects in scanning signal lines and video signal lines. This has an excellent effect in that short defect inspection can be performed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an active matrix substrate according to an embodiment of the present invention, FIG. 2 is a structural diagram of section A in FIG. 1, and FIG. 3 is a schematic sectional view taken along section a-a'' in FIG. Figure 4,
FIG. 5 is a block diagram showing the structure of a conventional active matrix substrate. 1... Thin film transistor, 2... Input terminal, 3... Metal film pattern, 4...
Common electrode pattern, 5... Semiconductor film, x1-X
m...Scanning signal line, Y1-Yn...Video signal line. Name of agent: Patent attorney Shigetaka Awano 1 person 3- Metal film pattern 4- Common pattern 5- Semiconductor #Zen diagram Figure

Claims (3)

[Claims] (1) An active matrix substrate in which switching elements are arranged in a matrix on a glass substrate, wherein every other signal line of the switching elements is connected by a metal film formed on the glass substrate, and . An active matrix substrate, characterized in that a metal film pattern formed on the outside of the input terminal of the signal line and the plurality of connected signal lines are connected by a semiconductor film. (2) The active matrix substrate according to claim 1, wherein the metal film pattern formed outside the input terminal of the signal line is sufficiently thicker than the pattern width of the signal line to serve as a common electrode. (3) The active matrix substrate according to claim (1), wherein the switching element is composed of a two-terminal element or a thin film transistor.