JPH11109887A - Liquid crystal display panel and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a breakage by static electricity at the time of production and to surely detect the disconnection and short-circuit of bus lines, by providing the panel with a protective wiring connected to capacitor electrodes and a high-resistance wiring connecting driving terminals and the protective wiring. SOLUTION: The capacitor electrodes 15 are formed above or below the driving terminals 24 and capacitors are formed between the capacitor electrodes 15 and the driving terminals 24. As a result, the failure of the bus lines by the static electricity may be averted in a production stage for the liquid crystal display panels. The capacitor electrodes 15 are connected to the protective wiring 13 and the respective bus lines 21 are connected to each other via the high-resistance wiring 33. If, therefore, the resistance value between adjacent terminals 25 for inspection is measured, the value adding the resistance value of the bus lines 21 and the resistance value of the high-resistance wiring 33 is attained. If, on the other hand, the short-circuit arises between the adjacent bus lines 21, the resistance value between the adjacent terminals 25 for inspection diminishes by as much as at least the respective value-component of the high-resistance wiring 33 and the generation of the short-circuit is surely detected.

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 panel capable of preventing breakage due to static electricity generated at the time of manufacture and detecting a disconnection and a short circuit of a bus line with high accuracy, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Liquid crystal display panels have the advantages that they are thin and lightweight, can be driven at a low voltage, and consume little power. In recent years, liquid crystal display panels have been widely used for displays of personal computers and televisions. General T
An N (Twisted Nematic) liquid crystal display panel has a structure in which liquid crystal is sealed between two transparent glass substrates.
Of two surfaces (opposing surfaces) of the glass substrates facing each other, a black matrix, a color filter, a counter electrode, an alignment film, and the like are formed on one surface side, and a TFT ( Thin film transistor), a pixel electrode, an alignment film, and the like. Further, a polarizing plate is attached to a surface of each glass substrate opposite to the facing surface. These two polarizing plates are arranged, for example, such that the polarization axes of the polarizing plates are orthogonal to each other. According to this, a mode in which light is transmitted when no electric field is applied and light is blocked when an electric field is applied, That is, a normally white mode is set. When the polarization axes of the two polarizing plates are parallel to each other, the mode is a mode in which light is blocked when no electric field is applied and light is transmitted when an electric field is applied, that is, a normally black mode.

By the way, in order to improve the production yield of the liquid crystal display panel, it is necessary to carry out an inspection before forming a panel by combining two substrates, and to correct a defective portion when there is a defect. FIG. 7 is a schematic view showing a conventional method for inspecting a liquid crystal display panel. A plurality of drain bus lines 53 are provided on the glass substrate 50 to be inspected.
Also, a plurality of gate bus lines 54 are formed.
Each drain bus line 53 is arranged in parallel with each other, and each gate bus line 54 is
Are arranged at right angles to each other. A pixel electrode (not shown) made of ITO (indium tin oxide) is formed in each rectangular pixel region defined by the drain bus line 53 and the gate bus line 54.

One end of each drain bus line 53 is connected to a drive terminal 55, and the other end is connected to a test terminal 5.
6 is connected. The driving terminals 55 are linearly arranged along one side of the substrate 50. Drain bus lines 53 due to static electricity are provided outside these drive terminals 55.
Protection wiring 51a for preventing damage to the
Each drive terminal 55 is electrically connected to the protection wiring 51a.

Similarly, one end of each gate bus line 54 is connected to a drive terminal 57, and the other end is connected to an inspection terminal 58. The driving terminals 57 are linearly arranged along the other side of the substrate 50, and a protective wiring 51b is formed outside the driving terminals 57. Each drive terminal 57 is electrically connected to the protection wiring 51b. Protection wiring 51a and protection wiring 51b
Are connected via the inter-protection wiring resistance element 52.

In the process of manufacturing a liquid crystal display device, when inspecting a substrate formed as shown in FIG.
The probe is brought into contact with the terminals 6, 58, and the resistance value and the current value between the terminals 56, 58 are measured. Thereby, the presence or absence of a defect such as a disconnection or a short circuit is checked. When a defect is detected, the defect is repaired. When no defect is detected, the inspection terminals 55 and 57 and the protection wirings 51a and 51b are cut to form a substrate on which the counter electrode and the color filter are formed. Combine and form a panel. Thereafter, liquid crystal is sealed in the panel, and a driving circuit board is connected to the driving terminals 56 and 58.

[0007]

However, in the above-mentioned conventional method, the driving terminal 55 is connected to the protection wiring 51a and the driving terminal 57 is connected to the protection terminal 51b. Two adjacent in the neighborhood of
If a short circuit occurs between the drain bus lines 53, the change in resistance value may be small and the short circuit may not be detected.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display panel capable of preventing breakage due to static electricity at the time of manufacturing, and reliably detecting disconnection and short circuit of a bus line, and a method of manufacturing the same.

[0009]

The above-mentioned object is achieved by providing a transparent substrate, a plurality of bus lines formed on the transparent substrate to partition an area on the transparent substrate into a plurality of pixel regions, A transparent pixel electrode disposed above, a driving terminal connected to one end of each of the plurality of bus lines, and an inspection terminal connected to each other end of the plurality of bus lines; and an upper or lower part of the driving terminal. A capacitor electrode disposed to form a capacitor together with the drive terminal; a protection wire connected to the capacitor electrode; and a material having a higher resistance than a material of the protection wire, the drive terminal and the protection wire. And a high resistance wiring for connecting the liquid crystal display panel and the liquid crystal display panel.

[0010] The above-mentioned problem is to form a first conductive film on a transparent substrate and pattern the first conductive film to form a gate bus line, a capacitor electrode, and a protection wiring connected to the capacitor electrode. Forming a first substrate on the entire surface of the transparent substrate;
Forming an insulating film, and forming a second insulating film on the first insulating film.
Forming a conductive film, and patterning the second conductive film to form a drain bus line, a driving terminal connected to one end of the drain bus line and facing the capacitance terminal, and another end of the drain bus line. Forming a test terminal connected to the transparent substrate, forming a second insulating film on the entire surface of the transparent substrate, and forming a first contact on the second insulating film to contact the driving terminal. Forming a hole, a second contact hole communicating with the inspection terminal, and a third contact hole communicating with the protection wiring, and a transparent conductive film made of indium tin oxide over the entire surface of the transparent substrate Forming a pixel electrode by patterning the transparent conductive film and forming a high resistance wiring connected to the protection wiring and the driving terminal. It is solved by a method of manufacturing a liquid crystal display panel according to claim.

The operation of the present invention will be described below. In the liquid crystal display panel of the present invention, a capacitor electrode is formed above or below the drive terminal, and a capacitor is formed between the capacitor electrode and the drive terminal. Further, the capacitance electrode is connected to a protection wiring. Thus, in the manufacturing process of the liquid crystal display panel, even if electric charges are accumulated in the bus line due to the influence of static electricity, the electric charge accumulated in the bus line is transferred to the protective wiring via the capacitor formed by the driving terminal and the capacitor electrode. And the bus line is prevented from being damaged by static electricity.

Further, in the liquid crystal display panel of the present invention, each bus line is connected via a high resistance wiring. For this reason, when the resistance value between the adjacent test terminals is measured, it is a value obtained by adding the resistance value of the bus line and the resistance value of the high resistance wiring in a normal case. On the other hand, when a short circuit occurs between adjacent bus lines, the resistance value between the adjacent test terminals decreases by at least the resistance value of the high-resistance wiring,
The occurrence of a short circuit can be reliably detected. Further, when a disconnection occurs in one of the adjacent bus lines, the resistance value between the adjacent test terminals becomes infinite, and the occurrence of the disconnection can be detected.

As described above, the liquid crystal display panel of the present invention comprises:
It is possible to prevent damage due to static electricity at the time of manufacturing, and it is possible to reliably detect short-circuit and disconnection during inspection. In addition, in the method of the present invention, the capacitor electrode and the protection wiring are formed together with the gate bus line, the driving terminal is formed together with the drain bus line, and the high-resistance wiring is formed together with the pixel electrode. In addition, the liquid crystal display panel having the above configuration can be manufactured.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 3 are views showing a method of manufacturing a liquid crystal display panel according to an embodiment of the present invention in the order of steps, and FIG. 4 is a schematic perspective view showing a liquid crystal display panel manufactured by the same method.

First, as shown in FIG.
A Cr layer is sputtered thereon to form a Cr layer with a thickness of about 2500 °, and the Cr layer is patterned and connected to a plurality of gate bus lines 11 arranged in parallel with each other and the gate bus lines 11. A gate electrode 12, a protection wiring 13 arranged outside the display area, and a protection wiring 13
Is formed with the capacitor electrode 15 connected to.

Next, an insulating layer (not shown) made of SiN is formed on the entire surface of the substrate 10 to a thickness of about 4000 °.
Then, a silicon layer (not shown) serving as an active layer of the TFT is selectively formed above the gate electrode 12. Next, as shown in FIG. 2, Ti is sputtered on the entire surface of the substrate 10 to form a Ti layer having a thickness of about 2000 °.
By patterning the i-layer, a plurality of drain bus lines 21 orthogonal to the gate bus line 11, a drain electrode 22, a source electrode 23, a driving terminal 24 connected to one end of the drain bus line 21, and a drain An inspection terminal 25 connected to the other end of the bus line 21 is formed. In this case, the drain electrode 22 and the source electrode 23 are arranged with the gate electrode 12 interposed therebetween, and the drain electrode 22 is connected to the drain bus line 21. Further, a capacitance C (see FIG. 4) is formed by the driving terminal 24, the capacitance electrode 15 therebelow, and the insulating film between them.

Next, an insulating film (not shown) made of, for example, SiN is formed on the entire surface of the substrate 10 by the CVD method. Then, a contact hole (not shown) connected to the source electrode 23, a contact hole 26a (see FIG. 4) connected to the drive terminal 24, and an inspection terminal are formed in the insulating film by RIE (reactive ion etching). A contact hole 26b (see FIG. 4) connecting to the protection wiring 13 is opened.

Next, an ITO film is formed on the entire surface of the
It is formed to a thickness of 0 nm. This ITO film is connected to the source electrode 23 and the terminal 2 via the contact holes 26a to 26c.
4 and 25 and the protection wiring 13. Next, the ITO film is patterned, as shown in FIG.
The pixel electrode 31, the terminal protection film 32, and the high resistance wiring 33 are formed. The pixel electrode 31 is electrically connected to the source electrode 23 via a contact hole (not shown), and the terminal protection film 32 is connected to the inspection terminal 25 via the contact hole 26b.
Is connected to the contact hole 26a.
Through the contact hole 26c, and is electrically connected to the protection wiring 13 through the contact hole 26c.

An inspection is performed on the substrate of the liquid crystal display panel thus formed before assembling the panel.
This inspection is performed, for example, by measuring a resistance value between adjacent terminals. FIG. 5 shows an adjacent drain bus line 2
FIG. 3 is a diagram illustrating an equivalent circuit when inspecting for defects between the two. In FIG. 5, reference numerals 25a and 25b denote test terminals connected to the adjacent drain bus lines 21.
6a and 26b are driving terminals connected to the adjacent drain bus line 21 similarly. R0 indicates the resistance value of the drain bus line 21, and R indicates the terminal 24a,
The resistance value of the high resistance wiring 33 between 24b is shown.

When the drain bus line 21 is normal, the resistance between the inspection terminals 25a and 25b is (2 × R0 +
R). On the other hand, as shown in FIG. 6, when the adjacent drain bus lines 21 are short-circuited, if the resistance value of the drain bus lines 21 from the inspection terminals 25a, 25b to the short-circuit point is R1, Terminal 25
The resistance value between a and 25b is (2.times.R1), and the resistance value is extremely small as compared with the normal case. When at least one of the adjacent drain bus lines 21 is disconnected, the resistance value between the terminals 25a and 25b becomes infinite.

As described above, according to the present embodiment, by measuring the resistance value between the adjacent test terminals 25,
Disconnection and short circuit of the gate bus line 21 can be reliably detected. In the present embodiment, as described above, the drain bus line 21 and the protection wiring 1 are connected via the capacitor C constituted by the terminal 24 and the terminal 15 therebelow.
3 is capacitively coupled, it is possible to prevent the drain bus line 21 from being damaged by static electricity even before the drain bus line 21 and the protection wiring 13 are connected by the high resistance wiring 33.

In the above embodiment, the case where the capacitance electrode 15 is formed simultaneously with the gate bus line 11 and the high resistance wiring 33 is formed simultaneously with the pixel electrode 31 has been described. The high-resistance wiring 33 may be formed in a process different from that of the pixel electrode 31 in a process different from that of the line 11. Further, in the above-described embodiment, the case has been described where the capacitance is formed between the drive terminal connected to the end of the drain bus line 21 and the capacitor electrode disposed below the drive terminal. May be formed above the capacitor electrode. Further, by forming the capacitor electrode above or below the drive terminal of the gate bus line, damage to the gate bus line due to static electricity can be prevented.

[0023]

As described above, according to the liquid crystal display panel of the present invention, a capacitor electrode disposed above or below a driving terminal and forming a capacitor together with the driving terminal;
Since the protection wiring and the high-resistance wiring for connecting the drive terminal and the protection wiring are provided, static electricity flows to the protection wiring via the capacitor, and damage to the bus line due to the static electricity can be avoided. Further, since each bus line is connected via the high-resistance wiring, a change in resistance at the time of short-circuit is large, so that not only disconnection of the bus line but also occurrence of short-circuit can be reliably detected.

According to the method of manufacturing a liquid crystal display panel of the present invention, the capacitance electrode and the protection wiring are formed at the same time as the gate bus line, and the high-resistance wiring is formed at the same time as the pixel electrode. The above-mentioned liquid crystal display panel can be formed while suppressing the above.

[Brief description of the drawings]

FIG. 1 is a diagram (part 1) illustrating a method for manufacturing a liquid crystal display panel of an embodiment of the present invention.

FIG. 2 is a diagram (part 2) illustrating the method for manufacturing the liquid crystal display panel of the embodiment of the present invention.

FIG. 3 is a diagram (part 3) illustrating the method for manufacturing the liquid crystal display panel of the embodiment of the present invention.

FIG. 4 is a schematic perspective view showing a liquid crystal display panel according to an embodiment of the present invention.

FIG. 5 is a diagram showing an equivalent circuit when a defect between adjacent drain bus lines is inspected.

FIG. 6 is a diagram showing an equivalent circuit when a short circuit occurs between adjacent drain bus lines.

FIG. 7 is a schematic view showing a conventional liquid crystal display panel.

[Explanation of symbols]

 10, 50 Glass substrate 11, 54 Gate bus line 13, 51a, 51b Protection wiring 15 Capacitance electrode 21, 53 Drain bus line 24, 55, 57 Driving terminal 25, 56, 58 Inspection terminal 26a, 26b, 26c Contact hole 31 pixel electrode 32 terminal protection film 33 high resistance wiring

Claims (3)

[Claims] A transparent substrate; a plurality of bus lines formed on the transparent substrate to partition a region on the transparent substrate into a plurality of pixel regions; and a transparent pixel electrode disposed on the pixel region. A drive terminal connected to one end of each of the plurality of bus lines and a test terminal connected to each other of the plurality of bus lines; and a capacitor disposed above or below the drive terminal and having a capacitance together with the drive terminal. And a protection wiring connected to the capacitance electrode, and a high resistance wiring made of a material having a higher resistance than the material of the protection wiring and connecting the driving terminal and the protection wiring. A liquid crystal display panel comprising: 2. The liquid crystal display panel according to claim 1, wherein said high resistance wiring is formed of the same material as said pixel electrode. 3. A method for forming a first conductive film on a transparent substrate, patterning the first conductive film, forming a gate bus line,
Forming a capacitor electrode and a protective wiring connected to the capacitor electrode; forming a first insulating film on the entire surface of the transparent substrate; and forming a second conductive film on the first insulating film Is formed, and the second conductive film is patterned to be connected to a drain bus line, one end of the drain bus line, a driving terminal facing the capacitor terminal, and the other end of the drain bus line. A step of forming an inspection terminal; a step of forming a second insulating film on the entire surface of the transparent substrate; a first contact hole communicating with the driving terminal in the second insulating film; Forming a second contact hole connected to the inspection terminal and a third contact hole connected to the protection wiring; and forming a transparent conductive film made of indium tin oxide on the entire surface of the transparent substrate. Process , Thereby forming a pixel electrode by patterning the transparent conductive film, a method of manufacturing a liquid crystal display panel; and a step of forming a high-resistance wiring to be connected to the protective wiring and the drive terminals.