JPH0711641B2 - Active matrix substrate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an active matrix substrate used for a liquid crystal display panel.

2. Description of the Related Art In recent years, with the miniaturization of industrial equipment, there has been a demand for a thin flat display device that replaces a conventional display device. Among various types of flat panel display devices, a display device using liquid crystal is drawing attention because it consumes less power and is easy to perform full-color display. In particular, an active matrix type liquid crystal display panel in which a switching element is provided in each of the display pixels has excellent display image quality and is therefore applied to portable televisions and the like.

FIG. 4 is an equivalent circuit diagram showing a configuration of a conventional active matrix substrate. In FIG. 4, 51 is a thin film transistor, 52 is a metal film pattern for making signal lines short-circuited, X1 to Xm are scanning signal lines, and Y1 to Yn are video signal lines. However, the active matrix substrate has a problem in that the static electricity charged on the substrate during the process of manufacturing the substrate destroys the insulating film at the intersections of the switching elements and the scanning signal lines and the video signal lines, resulting in a short circuit. It was As a measure for preventing the breakdown of the insulating film due to this static electricity, conventionally, as shown in FIG. 4, a method of short-circuiting all the terminals of the active matrix substrate with the metal film pattern 52 has been used. In addition, JP-A-61-48978
As disclosed in Japanese Patent Laid-Open Publication No. 2003-242242, a method of short-circuiting only one side of the scanning signal line and the video signal line of the active matrix substrate has been proposed. FIG. 5 shows a block diagram of an active matrix substrate by this method.

However, in the conventional method for preventing the breakdown of the insulating film due to static electricity as shown in FIG. 4, since all the terminals are short-circuited, the short-circuited portion is cut after the completion of the active matrix substrate. Up to now, it has not been possible to inspect for short-circuit defects such as disconnection defects due to disconnection of signal lines, short-circuit defects between adjacent scanning signal lines or video signal lines, and short circuits between scanning signal lines and video signal lines. Further, although the method according to Japanese Patent Laid-Open No. 61-48978 shown in FIG. 5 can inspect for a disconnection defect, the inspection for a short circuit defect in the substrate cannot be performed until the short portion of the signal line is cut.

The present invention has been made in view of the above points, and an object thereof is to provide an active matrix substrate capable of preventing damage to an insulating film due to static electricity and performing defect inspection.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention uses a metal film formed on a glass substrate by a plurality of scanning signal lines and video signal lines of switching elements of an active matrix substrate. The signal line group is connected to the common electrode pattern formed outside the input terminal of the signal line by a plurality of lines, and is connected by the semiconductor film.

Effect of the Invention The present invention has the above-described configuration to prevent the breakdown of the insulating film due to static electricity in the active matrix substrate, and also to perform a disconnection defect inspection of the signal lines and a short defect inspection between the scanning signal line group and the video signal line group connected by a plurality of lines. It is possible to do.

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

FIG. 1 is a block 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 scanning signal lines and video signal lines, 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 signal lines. A common electrode pattern 5 formed of a metal film as a common electrode on the outside is a semiconductor film for connecting the metal film pattern 3 and the common electrode pattern 4 which are short-circuited by a plurality of signal lines, X1
˜Xm are scanning signal lines, and Y1 to Yn are video signal lines. In this embodiment, as shown in FIG. 1, the scanning signal line and the video signal line are 1
Every other book is connected to the metal film pattern 3, and is connected to the common electrode pattern 4 via the semiconductor film 5.

FIG. 2 shows a metal film pattern 2 and a common electrode metal film pattern 3
FIG. 3 is a structural diagram of part A in FIG. 1, and FIG. 3 is a- in FIG.
It is a schematic sectional drawing in a'part. The structure of this embodiment will be described with reference to FIGS. At the same time when the signal line input terminal 2 is formed on the glass substrate 10, a metal film pattern 3 for short-circuiting the signal line is also formed. Next, the semiconductor film 5 is formed on the metal film pattern 3 at the same time when the switching element is formed. Finally, the common electrode pattern 4 is formed at the same time when the metal film 12 that uses the signal line reinforcing film is formed. The semiconductor film 5 has a high resistance value at the time of a defect inspection performed by applying a voltage of several V, but has a sufficiently low resistance when a high voltage of several 100 to several kV is applied to the signal line by static electricity. As a result, a current due to static electricity can be passed through the common electrode pattern 4.

With this configuration, it is possible to take measures to prevent the breakdown of the insulating film due to static electricity without increasing the number of photomasks. The connecting portion between the signal line and the metal film pattern 3 shown in part b of FIG. 2 is not formed with the reinforcing metal film 12 so as to be easily cut by a laser beam after the inspection.

Next, the defect inspection method according to this embodiment will be described. The signal line disconnection inspection can be performed by connecting the metal film pattern 3 to the input terminal 2 probe needle and measuring the resistance value, because neither the scanning signal line nor the video signal line is connected to one terminal. it can. For short-circuit defect inspection between adjacent signal lines, every other signal line is connected to the metal film pattern 3, so a probe needle is connected to the metal film pattern 3.
By measuring the resistance value, the short defect inspection in the block can be performed. In addition, the short-circuit defect inspection between the scanning signal line and the video signal line is performed for each metal film pattern 3
Is connected through the semiconductor film 5 and thus has a sufficiently high electrical resistance. A probe needle is connected to the metal film pattern on the scanning signal line side and the metal film pattern on the video signal line side to measure the resistance value. As a result, it is possible to perform the short defect inspection in the block.

EFFECTS OF THE INVENTION As described above, according to the present invention, the signal lines of the switching elements of the active matrix substrate are connected to each other by a plurality of metal films formed on the glass substrate, and the input terminals of the signal lines are connected. By connecting the pattern of the metal film formed on the outer side and the signal line group connected to each of the plurality of lines with a semiconductor film, the insulation film breakdown due to static electricity is protected, and the disconnection defect inspection of the scanning signal line and the video signal line is performed. It has an excellent effect that it is possible to perform a short defect inspection.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an active matrix substrate in one embodiment of the present invention, FIG. 2 is a structural diagram of a portion A in FIG. 1, and FIG. 3 is a schematic cross-sectional view in aa 'portion in FIG. Figure 4,
FIG. 5 is a configuration diagram showing a configuration 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 to Xm ... Scan signal line, Y1 to Yn ... Video signal line.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiro Yamashita 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP 59-91479 (JP, A) JP 62-297820 (JP, A) JP-A-63-292113 (JP, A)

Claims (3)

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