JP2001330850A - Liquid crystal display device and its defect rectifying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the manufacturing yield of a liquid crystal display device by providing a liquid crystal display device having structure which facilitates rectifying of a display defect due to the defect of an auxiliary capacitance and its defect rectifying method. SOLUTION: An auxiliary capacitance electrode 14 has a first area 14a, a second area 14a and a third area 14c. The first area 14a includes a connection terminal 14t to be connected to a connecting wiring 24 and a contact part 14h to be exposed in a first contact hole 19a and the second area 14b is electrically connected to the first area 14a via the third area 14c whose width is narrower than that of the first area 14a and the second area 14b. Then, the display failure due to the defect of the second area 14b is rectified by disconnecting electrically the first area 14a from the second area 14b each other while disconnecting the third area 14c of the auxiliary capacitance 14.

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 and a method of repairing a display defect thereof, and more particularly, to a liquid crystal display device capable of repairing a display defect caused by a defect of an auxiliary capacitance and a method of repairing the defect.

[0002]

2. Description of the Related Art Liquid crystal display devices have been put to practical use in fields such as OA equipment and AV equipment because of their advantages such as small size, light weight, thin shape and low power consumption. In particular, a thin film transistor (hereinafter abbreviated as “TFT”) as a switching element.
Active matrix type liquid crystal display device using
This is referred to as a “TFT type liquid crystal display device”. ) Is capable of displaying fine moving images and is used as various displays.

FIG. 3 schematically shows the structure of a conventional TFT type liquid crystal display device. The TFT liquid crystal display device 400 includes a plurality of pixel capacitors 40 arranged in a matrix and
Thin film transistor 5 electrically connected to each of
0. Each of the pixel capacitors 40 is a liquid crystal capacitor 4
2 and an auxiliary capacitor 44 electrically connected in parallel with the liquid crystal capacitor 42.

The gate electrode G of the TFT 50 is connected to a scanning line 52.
And a scanning voltage is applied. TFT50
Is connected to the signal wiring 54, and a signal voltage is applied. The drain electrode D of the TFT 50 is connected to one end of the pixel capacitor 40. One electrode of each of the liquid crystal capacitor 42 and the auxiliary capacitor 44 constituting the pixel capacitor 40 is connected to the drain electrode of the TFT 50, and a signal voltage is applied to these electrodes via the TFT 50. A counter voltage is applied to the other electrodes of the liquid crystal capacitance 42 and the auxiliary capacitance 44.

[0005] For example, 60
By sequentially applying the scanning voltage at a frequency of Hz, the TFTs 50 are sequentially turned on, and the pixel capacitors 40 to which the signal voltage is applied are sequentially selected (line sequential scanning).
The signal voltage is synchronized with this scanning, and has a gradation voltage value corresponding to each pixel capacitor 40. Picture element capacity 4
0 holds the voltage applied during the period when the TFT 50 is in the ON state for one field period (or one frame period). If the pixel capacitor 40 is composed of only the liquid crystal capacitor 42, the voltage drops due to the leakage current of the liquid crystal capacitor 42. Therefore, an auxiliary capacitor 44 is provided to suppress and prevent this.

The specific configuration of the picture element region of the TFT type liquid crystal display device 400 will be described with reference to FIG. FIG.
FIG. 2 is a schematic plan view of a picture element region of the TFT liquid crystal display device 400 (for example, see Japanese Patent Application Laid-Open No. 9-281524). The TFT type liquid crystal display device 400 includes a TFT substrate,
It has a color filter substrate (or a counter substrate) and a liquid crystal layer provided therebetween. For simplicity,
FIG. 4 shows only the configuration of the TFT substrate.

The TFT substrate 400a includes a transparent substrate (eg, a glass substrate) and a TFT formed on the glass substrate.
And a scanning line 52, a signal line 54, and a pixel electrode 42a connected to the TFT 50. TFT
The substrate 400a further has an auxiliary capacitance electrode 44 and an auxiliary capacitance common wiring 46.

The gate electrode G of the TFT 50 and the scanning wiring 52
Typically, a gate insulating film (not shown) is formed on substantially the entire surface of the TFT substrate 400a so as to cover the auxiliary capacitance common wiring 46. TF on the gate insulating film
A semiconductor layer (including a source region, a channel region, and a drain region) forming T50, a signal wiring 54, an auxiliary capacitance electrode 44, and a connection wiring 64 are formed. The connection wiring 64 electrically connects the drain electrode D of the TFT 50 and the auxiliary capacitance electrode 44a to each other.

Further, an insulating layer (not shown) is formed on almost the entire surface of the TFT substrate so as to cover them, and a picture element electrode 42a is formed on the insulating layer. The picture element electrode 42a is formed in the contact hole portion 44 of the auxiliary capacitance electrode 44 in the contact hole formed in the insulating layer.
h. That is, the picture element electrode 42
a is via the auxiliary capacitance electrode 44 and the connection electrode 64,
It is electrically connected to the drain electrode D of the TFT 50.

The liquid crystal capacitor 42 includes a picture element electrode 42a, a counter electrode (not shown) facing the picture element electrode 42a, and a liquid crystal layer (not shown) therebetween. The auxiliary capacitance 44 is composed of an auxiliary capacitance electrode 44 and an auxiliary capacitance common wiring 46.
And a gate insulating film (not shown) located therebetween. The picture element electrode 42a and the auxiliary capacitance electrode 44 are connected to the drain electrode D of the TFT 50, and are configured such that the same voltage as that of the counter electrode (not shown) is applied to the auxiliary capacitance common wiring 46. In this way, the liquid crystal capacitance 42 and the auxiliary capacitance 44 connected in parallel to the liquid crystal capacitance 42 constitute the pixel capacitance 40. The liquid crystal layer takes an alignment state according to the voltage applied to the liquid crystal capacitor 42, and its optical characteristics change (electro-optical characteristics).
The display is performed using.

TFT type liquid crystal display devices using various types of liquid crystal layers have been put to practical use. In particular, a twisted nematic (hereinafter, referred to as a “TN type”) liquid crystal display device using a nematic liquid crystal layer having a 90 ° twist alignment is most widely used. The TN type liquid crystal display device is generally used as a normally white mode (hereinafter, referred to as “NW mode”) for performing white display when no voltage is applied.

[0012]

Although the TFT type liquid crystal display device is widely used, the structure of the TFT substrate is complicated, and the number of picture elements is reduced as the display panel becomes larger and higher definition. Due to the increase and miniaturization, the rate of occurrence of picture elements serving as display defects is increasing. That is, there is a problem that the production yield of the TFT type liquid crystal display device is low.

Until now, in order to correct display defects caused by defective TFTs and wirings (scanning wirings and signal wirings), a plurality of TFTs and a plurality of wirings are provided for one picture element. However, a structure and a method for correcting a display defect caused by an auxiliary capacitor have not been studied.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a liquid crystal display device having a structure in which a display defect caused by a defect in an auxiliary capacitor can be easily corrected, and a method for correcting the defect. In this case, the manufacturing yield of the liquid crystal display device is improved.

[0015]

A liquid crystal display device according to the present invention includes a plurality of pixel capacitors arranged in a matrix and a thin film transistor electrically connected to each of the plurality of pixel capacitors. , Each of the plurality of pixel capacitors has a liquid crystal capacitor and an auxiliary capacitor electrically connected in parallel to the liquid crystal capacitor, and the liquid crystal capacitor has a pixel electrode formed on a first substrate, A counter electrode formed on the second substrate, and a liquid crystal layer provided between the picture element electrode and the counter electrode, wherein the auxiliary capacitance is common to the auxiliary capacitance formed on the first substrate. A wiring, an auxiliary capacitance electrode, and a first insulating layer provided between the auxiliary capacitance common wiring and the auxiliary capacitance electrode, wherein the first substrate is connected to the thin film transistor and a gate electrode of the thin film transistor Scanning wiring and the thin film A signal line connected to the source electrode of the transistor, a first connection line electrically connecting the drain electrode of the thin film transistor and the auxiliary capacitance electrode to each other, and at least the drain electrode, the auxiliary capacitance electrode, and the first connection The second formed on the wiring
An insulating layer, wherein the picture element electrode is formed on the second insulating layer, and in a first contact hole formed in the second insulating layer located on the auxiliary capacitance electrode, Connected to the auxiliary capacitance electrode, the auxiliary capacitance electrode has first, second, and third regions, wherein the first region has a connection end connected to the connection wiring and the first contact A contact portion exposed in the hole, wherein the second region is electrically connected to the first region through the first region and the third region having a width smaller than that of the second region. The third region has a configuration in which the third region is formed at a position that does not overlap with the auxiliary capacitance common line, thereby achieving the above object.

The defect repair method for a liquid crystal display device according to the present invention comprises:
For the liquid crystal display device having the above-described configuration, a step of specifying a picture element capacitance exhibiting a display defect from among the plurality of picture element capacitances, and the third region of the auxiliary capacitance electrode of the specified picture element capacitance. The cutting includes electrically cutting the first region and the second region from each other, whereby the object is achieved.

In the liquid crystal display device according to the present invention, the first substrate further has a repair connection electrode formed below the first insulating layer, and the picture element electrode is provided on the repair connection electrode. In the second contact hole formed in the first insulating layer located, the connection hole is connected to the repair connection electrode, and the third contact hole of the auxiliary capacitance electrode is connected to the third connection hole from the drain electrode.
A part of a connection path leading to a region and a part of the second region of the auxiliary capacitance electrode or a second connection wiring extending from the second region are connected to the repair connection via the first insulating layer. It is preferable to have a configuration arranged so as to face the electrode.

Preferably, the repair connection electrode is formed of the same conductive layer as the gate electrode, the scan wiring, and the auxiliary capacitance common wiring.

The defect correcting method for a liquid crystal display device according to the present invention comprises:
About the above-described liquid crystal display device including the connection electrode for correction,
A step of specifying a picture element capacitance presenting a display defect from among the plurality of picture element capacitances, and cutting the third area of the auxiliary capacitance electrode of the specified picture element capacitance to thereby form the first area and the first area. A step of electrically disconnecting the second region from each other; a step of electrically disconnecting the picture element electrode and the auxiliary capacitance electrode from each other; a connection end of the first connection electrode wiring and the auxiliary capacitance electrode Electrically disconnecting from each other, and connecting from the drain electrode to the third region of the auxiliary capacitance electrode, the connection being arranged to face the repair connection electrode via the first insulating layer. Electrically connecting the part of the path and the part of the second region of the auxiliary capacitance electrode or the second connection wiring extending from the second region to the repair connection electrode, respectively. May be included No.

A step of electrically shorting the source electrode and the drain electrode to each other via the gate electrode; a step of electrically disconnecting the gate electrode and the scanning line from each other; The method may include a step of disconnecting an electrical connection between the part of the second region or the second connection wiring extending from the second region and the repair connection electrode.

The operation of the present invention will be described below.

The auxiliary capacitance electrode provided in the liquid crystal display device of the present invention has first, second and third regions. Third
Since the region has a smaller width than the first and second regions, it can be easily cut by, for example, irradiating a laser beam. Since the second region is connected to the first region connected to the drain electrode through the third region, the second region is electrically disconnected from the drain electrode by cutting the third region. You. Therefore, a display defect involving the second region of the auxiliary capacitance electrode (for example, a defect caused by a short circuit between the second region of the auxiliary capacitance electrode and the auxiliary capacitance common line) is corrected by the above operation.

If the third region is formed at a position that does not overlap with the auxiliary capacitance common line, it is possible to prevent the auxiliary capacitance common line from being damaged in the step of irradiating the third region with laser light and to cut the third region. The position to be set can be easily confirmed optically (for example, using a loupe).

In the above-described configuration, a display defect involving the first region of the auxiliary capacitance electrode (for example, a defect caused by a short circuit between the first region of the auxiliary capacitance electrode and the auxiliary capacitance common line) cannot be corrected. By adopting the following configuration, it is possible to correct a display defect involving the first region.

A repair connection electrode is provided below the first insulating layer (that is, at the same level as the auxiliary capacitance common wiring), and the repair connection electrode is connected to the pixel electrode through a second contact hole provided in the first insulating layer. Are electrically connected to each other. Part of the connection path from the drain electrode to the third region of the auxiliary capacitance electrode (that is, part of the first region of the connection electrode or the auxiliary capacitance electrode) and part of the second region or the second region of the auxiliary capacitance electrode A second connection wiring extending from is arranged so as to face this repair connection electrode via the first insulating layer. As-produced state (until defect is corrected)
In this case, the repair connection electrode is not electrically connected to any electrode or wiring other than the picture element electrode.

As described above, when the display defect is not corrected even when the second region of the auxiliary capacitance electrode is electrically disconnected from the drain electrode, as described above, the first region of the auxiliary capacitance electrode is connected to the drain electrode. The second region is electrically connected to the drain electrode again while being electrically disconnected from the pixel electrode. That is, it is used to correct a display defect involving the first region of the auxiliary capacitance electrode.

The repair connection electrode is electrically connected to the drain electrode and the second region of the auxiliary capacitance electrode as follows.

For example, a laser beam is applied to a part (conductor layer) of a connection path from the drain electrode to the third region of the auxiliary capacitance electrode formed so as to face the repair connection electrode via the first insulating layer. By the irradiation, a contact hole is formed in the first insulating layer, the conductor layer melted by the laser beam flows into the contact hole formed in the first insulating layer, and the repair connection electrode is formed by the drain electrode. Is electrically connected to Similarly, a second connection wiring (conductor layer) formed so as to be opposed to the repair connection electrode via the first insulating layer and extending from a part of the second region or the second region of the auxiliary capacitance electrode. For example, by irradiating a laser beam, a contact hole is formed in the first insulating layer, and the conductor layer melted by the laser beam flows into the contact hole formed in the first insulating layer, and is repaired. Connection electrode is electrically connected to the second region of the auxiliary capacitance electrode. The step of electrically cutting the first region of the auxiliary capacitance electrode from the drain electrode and the pixel electrode includes:
For example, it can be performed by laser light irradiation.

If the above operation does not correct the display defect, the source electrode and the drain electrode are electrically short-circuited to each other via the gate electrode, the gate electrode is electrically disconnected from the scanning wiring, and By disconnecting the electrical connection between the second region of the auxiliary capacitance electrode and the repair connection electrode, the potential of the pixel electrode can always be made equal to the potential of the source electrode. Therefore, the picture element which has exhibited the display defect is always turned on, and is difficult to be visually recognized. In particular,
In the NW mode liquid crystal display device, since the bright spot defect becomes a dark spot defect, a decrease in display quality is effectively suppressed.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A TFT type liquid crystal display device according to an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, but can be widely applied to a TFT type liquid crystal display device having an auxiliary capacitance.

Referring to FIGS. 1, 2A and 2B, a TFT type liquid crystal display device 10 according to an embodiment of the present invention will be described.
0 will be explained. The liquid crystal display device 100 is represented by the equivalent circuit shown in FIG. 3, similarly to the conventional TFT liquid crystal display device 400 shown in FIG. It differs from the conventional TFT-type liquid crystal display device 400 in that it has a structure for correcting a defect of the auxiliary capacitance. 2A and 2B are cross-sectional views taken along lines 2A-2A 'and 2B-2B' in FIG. 1, respectively.

The TFT substrate 100a of the liquid crystal display device 100
Are a transparent substrate (for example, a glass substrate) 11, a TFT 50 formed on the glass substrate, a scanning wiring 52, a signal wiring 54, and a pixel electrode 42a connected to the TFT 50.
And The TFT substrate 100a further includes an auxiliary capacitance electrode 14, an auxiliary capacitance common line 16, a repair connection electrode 18, a first connection line 24, and a second connection line 26.
And

The gate electrode G of the TFT 50 and the scanning wiring 5
2. Auxiliary capacitance common wiring 16 and repair connection electrode 26
Are formed by patterning the same metal layer (for example, a Ta layer). By adopting such a configuration, an advantage that an increase in the number of manufacturing processes can be suppressed can be obtained. Needless to say, a laminated structure including another conductive layer (for example, an ITO layer) may be employed.

The gate electrode G of the TFT 50 and the scanning wiring 5
2. A gate insulating film (for example, a SiNx layer) 17 is typically formed on substantially the entire surface of the TFT substrate 100a so as to cover the auxiliary capacitance common wiring 16 and the repair connection electrode 26. On the gate insulating film 17, a semiconductor layer (including a channel region (for example, an a-Si layer), a source region and a drain region (n ⁺ -Si layer): not shown) constituting the TFT 50, a source electrode S, and a drain The electrode D, the signal wiring 54, the auxiliary capacitance electrode 14, the first connection wiring 24, and the second connection wiring 26 are formed. Source electrode S, drain electrode D, signal wiring 54, auxiliary capacitance electrode 1
4. The first connection wiring 24 and the second connection wiring 26 are formed by patterning the same metal layer (for example, a Ta layer). Of course, other conductive layers (for example, ITO
Layer).

The storage capacitor electrode 14 includes a first region 14a,
It has a second region 14b and a third region 14c. First region 14a and second region 14b of auxiliary capacitance electrode 14
Are wider than the auxiliary capacitance common line 16 and
4c is formed to be narrower than the first region 14a and the second region 14b. In other words, the auxiliary capacitance electrode has a narrowed (narrow) region (third region 14c) in the center. Further, the third region 14c is formed at a position that does not overlap with the auxiliary capacitance common line 16. The storage capacitor electrode 14 faces the storage capacitor common line 16 via the gate insulating film 17 and forms a storage capacitor 44 (see FIG. 3).

The first connection wiring 24 electrically connects the drain electrode D of the TFT 50 and the auxiliary capacitance electrode 14 to each other, and a part of the branch portion 24 a is connected via the gate insulating film 17 for repair. It is formed so as to face the connection electrode 18. A connection end 14t where the first connection electrode 24 and the auxiliary capacitance electrode 14 are connected to each other is in the first region 14a of the auxiliary capacitance electrode 14. The second connection wiring 26 extends from the second region 14 b of the auxiliary capacitance electrode 14, and a part thereof is formed so as to face the repair connection electrode 18 via the gate insulating film 17.

Further, an insulating layer (for example, a resin layer of about 2 μm) 19 is formed on substantially the entire surface of the TFT substrate 100a so as to cover them, and a picture element electrode (for example, an ITO layer) is formed on the insulating layer 19. 42a are formed. TFT
When the relatively thick insulating layer 19 that can make the surface of the substrate 100a almost flat is formed, the pixel electrode 42a can be formed so as to overlap a part of the TFT 50, the scanning wiring 52, and the signal wiring 54, so that the aperture ratio is improved. be able to. Insulation layer 1
9 may be formed from a plurality of layers (for example, a laminated structure of a layer made of an inorganic material such as SiNx and a resin layer).

The pixel electrode 42a is electrically connected to the contact hole 14h of the auxiliary capacitance electrode 14 in the contact hole 19a formed in the insulating layer 19 (see FIG. 2A). Contact hole portion 14h in which pixel electrode 42a and auxiliary capacitance electrode 14 are electrically connected.
Are formed in the first region 14a, similarly to the connection end 14t where the auxiliary capacitance electrode 14 is electrically connected to the drain electrode D. The picture element electrode 42a is formed between the contact hole 19a formed in the insulating layer 19 and the gate insulating layer 1
7, is electrically connected to a contact region 18h of the repair connection electrode 18 via a contact hole 17a. In the manufacturing process of the TFT substrate 100a,
The repair connection electrode 18 is not connected to any electrode or wiring other than the pixel electrode 42a, and the pixel electrode 42a is electrically connected to the drain electrode D of the TFT 50 via the auxiliary capacitance electrode 14 and the first connection electrode 24. It is connected to the.

The TFT substrate 10 having the above configuration
0a can be manufactured by a known manufacturing process.
Using the obtained TFT substrate 100a and a separately formed color filter substrate (not shown), the liquid crystal display device 100 can be manufactured according to an ordinary method. Color filter substrate (counter substrate) used for liquid crystal display device in the present invention
There is no particular limitation on the liquid crystal layer.

The liquid crystal display device 100 having the above configuration
Can be corrected as follows. In the liquid crystal display device 100, the display defect is a defect of the auxiliary capacitance 44 (for example, the auxiliary capacitance electrode 14 and the auxiliary capacitance common line 1).
6) can be corrected.

First, a picture element capacitance 40 exhibiting a display defect is specified from the picture element capacitances 40. For example, the display operation of the liquid crystal display device 100 is performed, and a defective picture element is visually identified (for example, using a loupe). For example, the third region 14c of the auxiliary capacitance electrode 14 of the specified pixel capacitance 40 is irradiated with a laser beam to electrically cut off the first region 14a and the second region 14b from each other (a cut portion: in FIG. 1). X1). The cutting of the third region 14c of the auxiliary capacitance electrode 14 by laser beam irradiation can be performed by a known method.

Since the third region 14c has a narrower width than the first region 14a and the second region 14b, it can be easily cut. Further, since the third region 14c is formed at a position that does not overlap with the auxiliary capacitance common line 16, in the step of irradiating the third region with laser light, it is possible to prevent the auxiliary capacitance common line 16 from being damaged. The position to be cut can be easily checked optically.

Thus, the second capacitance of the auxiliary capacitance electrode 14 is
When the region 14b is electrically disconnected from the first region 14a,
For example, a display defect caused by a short circuit between the second region 14b and the auxiliary capacitance common line 16 is corrected.

Thereafter, it is confirmed whether or not the above-mentioned display defect has been corrected. If the display defect has not been corrected, the following operation is carried out, whereby the auxiliary capacitance electrode 14 is removed.
The first region 14a is electrically disconnected from the drain electrode D and the pixel electrode 42a of the TFT 50, and the second region 14b is electrically connected to the drain electrode D again through the repair connection electrode 18. That is, a display defect caused by a short circuit between the first region 14a of the auxiliary capacitance electrode 14 and the auxiliary capacitance common line 16 is corrected.

First, the first region 14a of the auxiliary capacitance electrode 14
The step of electrically disconnecting from the drain electrode D and the pixel electrode 42 will be described. The first region 14a of the auxiliary capacitance electrode 14 is electrically cut off from the pixel electrode 42 by irradiating, for example, a laser beam to the periphery of the contact hole 14h (a location X2 indicated by a broken line in FIG. 1). In addition, for example, by irradiating a laser beam between the branch portion 24a formed so as to overlap the repair connection electrode 18 of the first connection wiring 24 and the connection end 14t (X3 in FIG. 1), the first The region 14a is electrically disconnected from the drain electrode D.

The repair connection electrode 18 is connected to the second region 14b of the auxiliary capacitance electrode 14 and the TFT 5 as follows.
0 is electrically connected to the drain electrode D.

A part of the connection path (here, the first path) from the drain electrode D to the third region 14 c of the auxiliary capacitance electrode 14, which is formed to face the repair connection electrode 18 via the gate insulating film 17. In the branch portion 24a) of the connection electrode 24,
For example, by irradiating the laser light, a contact hole is formed in the gate insulating film 17, and the metal forming the first connection electrode 24 melted by the laser light is applied to the contact hole formed in the gate insulating film 17. And the connection electrode 18 for correction is connected to the drain electrode D.
(The connection point Y1 in FIG. 1).

Similarly, the second region 14 formed so as to face the repair connection electrode 18 with the gate insulating film 17 interposed therebetween.
By irradiating, for example, a laser beam to the second connection wiring 26 extending from b, a contact hole is formed in the gate insulating film 17, and the metal melted by the laser beam irradiation is applied to the gate insulating film 17. The repair connection electrode 18 flows into the formed contact hole, and is electrically connected to the second region 14b of the auxiliary capacitance electrode 14 (connection point Y2 in FIG. 1). Although the second connection wiring 26 is provided here, the second region 14b of the auxiliary capacitance electrode 14 is provided.
Can be adopted in which a part of the part overlaps with the correction connection electrode 18.

It should be noted that the first of the storage capacitor electrodes 14
Either the step of electrically cutting the region 14a from the drain electrode D and the pixel electrode 42a of the TFT 50, or the step of electrically connecting the second region 14b to the drain electrode D again via the repair connection electrode 18. May be executed first. Further, there is no limitation on the order in which disconnection or connection is performed in each step.

After that, it is checked whether or not the above display defect has been corrected. If the display defect has not been corrected due to, for example, a shortage of the auxiliary capacitance value, the source electrode S and the drain electrode D are electrically short-circuited to each other via the gate electrode G, the gate electrode is electrically disconnected from the scanning wiring, and the second region 1 of the auxiliary capacitance electrode 14 is
The electrical connection between 4b and the repair connection electrode 18 is cut off. In this way, the potential of the pixel electrode 42a can always be made equal to the potential of the source electrode S (that is, the signal wiring 54). Therefore, the picture element which has exhibited the display defect is always turned on, and is difficult to be visually recognized. In particular,
In the NW mode liquid crystal display device, since the bright spot defect becomes a dark spot defect, a decrease in display quality is effectively suppressed.

The step of electrically short-circuiting the source electrode S and the drain electrode D of the TFT 50 is described in JP-A-7-10431.
It can be performed using the method disclosed in Japanese Patent Publication No. By irradiating a laser beam to a superposed portion (Y3 and Y4 in FIG. 1) of the source electrode S and the drain electrode D and the gate electrode G, a contact hole is formed in a semiconductor layer (not shown) and the laser beam is irradiated. The metal melted by the irradiation flows into the formed contact hole, and the source electrode S and the drain electrode D are electrically connected to each other via the gate electrode G.

In the above embodiment, the repair connection electrode 18
Has been described, and a display defect caused by a defect in the first region 14a of the auxiliary capacitance electrode 14 can be corrected. However, even if the repair connection electrode 18 is omitted, the auxiliary capacitance electrode 1
Since a display defect caused by a defect in the second region 14b of No. 4 can be corrected, the manufacturing yield of the liquid crystal display device can be improved as compared with the conventional case.

In the above embodiment, the auxiliary capacitance electrode 14 is divided into two regions (the first region 14a and the second region 14b).
However, it may be divided into three or more regions. However,
If the area of the auxiliary capacitance electrode used after the correction is too small, the auxiliary capacitance value will be insufficient, so the illustrated two-part structure is preferable. Also, the first region 14a and the second region 14b
Is preferably set such that the capacitance values of the respective regions are substantially equal. When the repair connection electrode 18 is omitted and only the first region is used, the capacitance value of the first region is larger than the capacitance value of the second region so that the capacitance value of the first region is sufficiently obtained. Thus, the auxiliary capacitance electrode 14 may be divided.

[0054]

According to the present invention, there is provided a liquid crystal display device having a structure capable of easily correcting a display defect caused by a defect of an auxiliary capacitor, and a method of correcting the defect. As a result, the manufacturing yield of the liquid crystal display device is reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a TFT liquid crystal display device 100 according to an embodiment of the present invention.

FIG. 2A is a schematic cross-sectional view of the liquid crystal display device 100, and shows a cross section taken along line 2A-2A ′ in FIG.

FIG. 2B is a schematic cross-sectional view of the liquid crystal display device 100, showing a cross section taken along line 2B-2B 'in FIG.

FIG. 3 is a schematic diagram showing an equivalent circuit of a conventional TFT liquid crystal display device 400 having an auxiliary capacitance.

FIG. 4 is a schematic plan view of a conventional TFT liquid crystal display device 400.

[Explanation of symbols]

 Reference Signs List 11 transparent substrate 14 auxiliary capacitance electrode 14a first region of auxiliary capacitance electrode 14b second region of auxiliary capacitance electrode 14c third region of auxiliary capacitance electrode 14t connection end of auxiliary capacitance electrode 16 auxiliary capacitance common wiring 17 gate insulating film 18 for correction Connection electrode 24 First connection wiring 24a Branch of first connection wiring 26 Second connection wiring 40 Pixel capacitance 42 Liquid crystal capacitance 44 Auxiliary capacitance 50 TFT 52 Scanning wiring 54 Signal wiring 100 Liquid crystal display device 100a TFT substrate

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 2H092 JA26 JB56 JB69 JB72 JB73 KA12 KB22 MA37 MA47 MA52 NA13 NA29 PA08 5C094 AA42 AA45 BA03 BA43 CA19 EA04 EA05 EB02 ED02 HA08 5F110 AA27 BB01 CC07 DD02 FF15 NN03 NN02 NN NN73 5G435 AA17 AA19 BB12 GG12 KK05 KK10 LL04 LL08

Claims (6)

[Claims] A plurality of pixel capacitors arranged in a matrix and a thin film transistor electrically connected to each of the plurality of pixel capacitors; A capacitor and an auxiliary capacitor electrically connected in parallel to the liquid crystal capacitor;
The liquid crystal capacitor has a pixel electrode formed on a first substrate, a counter electrode formed on a second substrate, and a liquid crystal layer provided between the pixel electrode and the counter electrode. The storage capacitor includes a storage capacitor common line and a storage capacitor electrode formed on the first substrate, and a first insulating layer provided between the storage capacitor common line and the storage capacitor electrode. The first substrate electrically connects the thin film transistor, a scanning wiring connected to a gate electrode of the thin film transistor, a signal wiring connected to a source electrode of the thin film transistor, a drain electrode of the thin film transistor, and the auxiliary capacitance electrode. A first connection wiring connected to each other, and a second insulating layer formed on at least the drain electrode, the auxiliary capacitance electrode, and the first connection wiring; Serial is formed on the second insulating layer,
In a first contact hole formed in the second insulating layer located on the storage capacitor electrode, the first contact hole is connected to the storage capacitor electrode, and the storage capacitor electrode connects first, second, and third regions. Wherein the first region includes a connection end connected to the connection wiring, and a contact portion exposed in the first contact hole, and the second region includes the first region and the second region. The third region is electrically connected to the first region through the third region having a width smaller than that of the region.
A liquid crystal display device formed at a position that does not overlap with the auxiliary capacitance common line. 2. The method according to claim 1, wherein the first substrate further includes a repair connection electrode formed below the first insulating layer, and the picture element electrode is located on the repair connection electrode. A part of a connection path from the drain electrode to the third region of the auxiliary capacitance electrode, which is connected to the repair connection electrode in a second contact hole formed in the layer; A second region extending from a part of the second region or the second region;
2. The liquid crystal display device according to claim 1, wherein the connection wiring is arranged to face the correction connection electrode via the first insulating layer. 3. 3. The liquid crystal display device according to claim 2, wherein the repair connection electrode is formed of the same conductive layer as the gate electrode, the scan line, and the auxiliary capacitance common line. 4. The method for correcting a defect of a liquid crystal display device according to claim 1, wherein a step of specifying a picture element capacitance exhibiting a display defect from among the plurality of picture element capacitances; The third of the auxiliary capacitance electrodes of the pixel capacitances;
By cutting a region, the first region and the second region
Electrically disconnecting the region from each other.
Defect repair method for liquid crystal display device. 5. The method for correcting a defect of a liquid crystal display device according to claim 2, wherein a step of specifying a picture element capacitance exhibiting a display defect from among the plurality of picture element capacities; The third capacitance of the auxiliary capacitance electrode of the pixel capacitance
By cutting a region, the first region and the second region
Electrically disconnecting the region from each other; electrically disconnecting the picture element electrode and the auxiliary capacitance electrode from each other; and connecting the first connection electrode wiring and the connection end of the auxiliary capacitance electrode to each other. Electrically disconnecting the connection path from the drain electrode to the third region of the auxiliary capacitance electrode, the connection path being arranged to face the repair connection electrode via the first insulating layer. Electrically connecting the part and the second connection wiring extending from the part or the second region of the second region of the auxiliary capacitance electrode to the correction connection electrode, respectively. A defect repair method for a liquid crystal display device, including: 6. a step of electrically short-circuiting the source electrode and the drain electrode to each other via the gate electrode; a step of electrically disconnecting the gate electrode and the scanning line from each other; Further comprising a step of disconnecting the second connection wiring extending from the part of the second region or the second region of the electrode and the correction connection electrode. Item 6. The defect repair method for a liquid crystal display device according to Item 5.