JP3519272B2 - Liquid crystal display device and method of manufacturing the same - Google Patents

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 used for OA (office automation) equipment, AV (audiovisual) equipment and the like as a display of a word processor, a computer, a navigation system and the like, and a manufacturing method thereof . ,
More specifically, the present invention relates to a liquid crystal display device including a three-terminal switching element such as a thin film transistor and a manufacturing method thereof .

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices using nematic liquid crystal have been widely used in segment type liquid crystal display devices such as watches and calculators, and in recent years, they have been made use of features such as thinness, light weight and low power consumption. The market is expanding as a display for OA (office automation) devices such as word processors, computers, navigation systems, and AV (audiovisual) devices. Among them, in particular, a thin film transistor (TF
An active matrix type liquid crystal display device in which pixels are arranged in a matrix by using active elements such as T: Thin Film Transistor as switching elements is widely used.

Compared with a cathode ray tube (CRT), the active matrix type liquid crystal display device can be remarkably thinner in thickness (depth), consumes less power, and is easy to realize full color display. Therefore, as a display device such as a personal computer, various monitors, portable televisions, and cameras, demand in a wider field is increasing.

The schematic structure of the conventional active matrix type liquid crystal display device will be described below. Figure 6
FIG. 7 is a circuit diagram showing a configuration of a conventional active matrix type liquid crystal display device including an active matrix substrate, and FIG. 7 is a sectional view of a TFT portion of the active matrix substrate shown in FIG.

In the above liquid crystal display device, a plurality of pixel electrodes 51 for applying a voltage to the liquid crystal layer are formed in a matrix on the active matrix substrate as shown in FIG. The scanning lines 53 and the signal lines 54 are provided around the pixel electrodes 51.
Are provided so as to be orthogonal to each other (overlap) in the outer peripheral portion of.

Further, at the intersection of the scanning line 53 and the signal line 54, a TFT 52 is formed as an active element which is connected to the pixel electrode 51 and is a switching means for selectively driving the pixel electrode 51. A scanning line 53 is connected to the gate electrode of the TFT 52, and the TFT 52 is driven and controlled by a gate signal input via the scanning line 53. A signal line 54 is connected to the source electrode of the TFT 52, and the TFT is further connected via the signal line 54.
When driving 52, a data signal (display signal) is input to the pixel electrode 51 via the TFT 52.

Further, the drain electrode of the TFT 52 is connected to the pixel electrode 51 via a metal layer, which will be described later, which will be a drain wiring, and a contact hole, and between the active matrix substrate and the counter electrode via the metal layer. It is connected to one electrode of an additional capacitor that holds the voltage applied to the liquid crystal layer sandwiched between. The liquid crystal layer usually has a thickness of 4.3 μm to 4.5 μm and forms a liquid crystal capacitor. The additional capacitors 55 connected to the TFTs 52 are connected in parallel with the liquid crystal capacitor. The other electrode of the additional capacitor 55 (that is, the electrode facing the above-mentioned electrode via the insulating layer) is connected to the common wiring 56.

Further, on the active matrix substrate or a counter substrate of the active matrix substrate, color filter layers (not shown) of red, blue and green for color display are formed.

The TFT 52 will be described in more detail. As shown in FIG. 7, the TFT 52 includes a gate electrode 62 and a gate insulating film 6 on a transparent insulating substrate 61.
3, semiconductor layer 64, channel protective film 65, source electrode 6
6a and a microcrystalline n ⁺ Si layer to be the drain electrode 66b are sequentially laminated.

In the above structure, the gate insulating film 63 is
The semiconductor layer 64 is formed so as to cover the gate electrode 62 formed on the insulating substrate 61, and the semiconductor layer 64 is formed on the gate electrode 62 via the gate insulating film 63. The channel protection film 65 is formed on the upper center of the semiconductor layer 64, the source electrode 66a is formed on the source part side of the channel protection film 65 and the semiconductor layer 64, and the drain electrode 66b is formed on the drain part side. ing.

A metal layer 67a to be a source wiring is connected to the source electrode 66a, and a metal layer 67b to be a drain wiring is connected to the drain electrode 66b. The surface of the TFT 52 is covered with an interlayer insulating film 68, and the metal layer 67b is a pixel electrode made of a transparent conductive film provided on the interlayer insulating film 68 through a contact hole 69 penetrating the interlayer insulating film 68. It is connected to 51. As the interlayer insulating film 68 and the gate insulating film 63, conventionally, a transparent insulating film made of an inorganic thin film such as a SiN _x film is used, and the SiN _x film has a film thickness of about 300 nm or more by using, for example, a CVD method. Has been formed.

An alignment film (not shown) for aligning liquid crystals is formed on the pixel electrode 51 almost uniformly over the entire display area. The active matrix substrate thus formed and a counter substrate not shown. A transparent active matrix type liquid crystal display device is formed by bonding and liquid crystal into the gap.

However, in the above-mentioned active matrix type liquid crystal display device, as the interlayer insulating film 68, a transparent insulating film such as SiN _x , SiO ₂ or TaO _x is formed by CVD.
When the film is formed by the sputtering method or the sputtering method, the unevenness of the underlying metal surface is reflected in the interlayer insulating film 68, and there is a problem that unevenness occurs on the surface of the interlayer insulating film 68.

Moreover, in the above-mentioned active matrix type liquid crystal display device, the scanning lines 53 and the signal lines 54 are arranged in a matrix on the same substrate, that is, the insulating substrate 61. Are arranged so as to be orthogonal to each other on the outer circumference of. Therefore, the scanning line 53
.. and signal lines 54 .. have cross-sections by the signal lines 54 ..

Therefore, the scanning lines 53 ... And the signal lines 54
.. has a problem that cracks are likely to occur in the gate insulating film 63 and the signal lines 54, which are the upper layers, are easily broken during manufacturing. Further, there is a problem in that the pinholes in the gate insulating film 63 cause insulation failure, and the signal lines 54, which are the upper layers, and the scanning lines 53, which are the lower layers, are short-circuited to reduce the yield. Further, in such a step portion, new cracks are generated over time due to the influence of film formation residual stress or the like, and the cracks previously generated are likely to spread. Occurrence and expansion of such cracks are
There is a risk that defects will occur, and reliability will be reduced.

Therefore, in recent years, a liquid crystal display device in which scanning lines and signal lines are formed on different substrates has been developed. For example, JP-A-5-27264 and JP-A-7-1286.
Japanese Patent No. 87 proposes a liquid crystal display device having a structure in which signal lines are formed on the counter substrate side (hereinafter referred to as a counter substrate signal line structure). As shown in FIG. 5, the liquid crystal display device having the counter substrate signal line structure has one substrate 7
0 is provided with three-terminal switching elements 71 ... Of amorphous silicon semiconductor or the like provided in a matrix. A scanning line 72 is connected to a first terminal of the switching element 71 for each column of the switching elements 71, and a second terminal of the switching element 71 is a reference for each column of the switching elements 71. The signal line 73 is connected, and the pixel electrode 74 is connected to the third terminal of the switching element 71. The signal lines 76 are arranged on the counter substrate 75, which is the other substrate facing the substrate 70, so as to be orthogonal to the scanning lines 72 provided on the substrate 70. In the liquid crystal display device having the above structure, the signal line 76 also serves as a counter electrode at a portion where the signal line 76 and the pixel electrode 74 face each other.

As described above, in the liquid crystal display device having the above structure, since the intersections of the scanning lines 72 ... And the signal lines 76 ... Do not exist on the same substrate, the above-mentioned reduction in yield and reliability is solved. It

[0018]

However, in general,
The reference signal line (reference signal line 73 in the liquid crystal display device shown in FIG. 5) used in the liquid crystal display device having the counter substrate signal line structure is made of aluminum or the like and has a size of ten and several μm.
It is a thin metal layer (metal line) having the following width. In the liquid crystal display device having the above-described configuration, the reference signal line made of such a thin metal layer has a length of several cm or more and is formed by counting 100 or more lines. ing. Therefore, in the liquid crystal display device having the above-mentioned configuration, the reference signal line is broken due to foreign matter or the like during manufacturing, and the yield is likely to decrease. Further, particularly in a large-sized liquid crystal display device, if the reference signal line is long, or particularly in a small-sized high-definition liquid crystal display device, the reference signal line becomes thin, the resistance capacitance increases, and there is a possibility that display becomes impossible. is there.

The present invention has been made in view of the above problems, and an object thereof is to improve the yield and to stabilize the display quality, and to provide a more reliable liquid crystal display device .
And a method of manufacturing the same.

[0020]

[Means for Solving the Problems] Claim 1 according to the present invention
The liquid crystal display device described, in order to solve the above problems,
Three-terminal switching elements provided in a matrix, a scanning line connected to the first terminal of the switching element for each column of the switching element, and a column parallel to the scanning line and each column of the switching element. A pixel substrate having a reference signal line connected to the second terminal of the switching element, a pixel electrode connected to the third terminal of the switching element, and a pixel electrode connected to the third terminal, and the pixel electrode facing the pixel substrate. A liquid crystal display device comprising a counter substrate having a counter electrode facing each other and a signal line connecting the counter electrodes for each row, and a liquid crystal layer sandwiched between the pixel substrate and the counter substrate. The reference signal line has a laminated structure,
Between the lower layer and the upper layer of the signal line,
An interlayer insulating film which covers at least a part and covers the above scanning lines
Is provided, and the scanning line proximity side of the lower layer of the reference signal line is
Said layer covering at least part of the longitudinal edges on different sides
Connected to the switching element in the next row on the inter-insulation film
A pixel electrode is provided, and the upper layer is the pixel electrode.
The same material or Rannahli and, in the pixel electrode near the side length and
At the edge in the hand direction, the interlayer insulating film is a layer below the reference signal line.
Cover at least a part of the longitudinal edge on the pixel electrode proximity side.
Step formed by the interlayer insulating film
The side surface in the longitudinal direction on the pixel electrode proximity side of the upper layer is the above.
Does not protrude from the longitudinal side surface of the lower layer adjacent to the pixel electrode
And the scanning line proximity side of the upper layer above.
The side surface in the longitudinal direction of the
At least a part of the longitudinal edge of the lower layer near the scanning line
Step formed by the interlayer insulating film by covering
Longitudinal direction on the scanning line proximity side of the above lower layer so as to completely cover the part
It is characterized in that it is provided so as to protrude from the facing side surface.

According to the above structure, the signal line and the scanning line do not intersect on the same substrate, and the gate insulating film is formed at the intersection of the signal line and the scanning line like the conventional active matrix substrate. Defects due to cracks and pinholes do not occur.

Further, by forming the reference signal line into a laminated structure made of a conductive material , even if a part of one layer of the reference signal line has a defect, the remaining layers provide electrical connection. Since it is maintained, the disconnection failure rate is significantly reduced.

Therefore, the yield can be improved and the cost can be significantly reduced, and the deterioration of reliability due to cracks or the like generated over time can be suppressed. Further, according to the above configuration, the reference signal line is electrically conductive.
By using a laminated structure made of a conductive material , it is possible to reduce the wiring resistance and further improve the yield.
It is possible to stabilize the display quality.

Further, according to the above configuration, after forming the lower layer of the reference signal lines, by providing the interlayer insulating film between the lower layer and the upper layer, to protect the coated lower surface by the interlayer insulating film be able to. As a result, it is possible to prevent the occurrence of disconnection due to foreign matter or the like in a subsequent step in the region covered with the interlayer insulating film in the lower layer, or a trouble such as penetration of the etching agent.
Further, even when the substrate on which the lower layer of the reference signal line is formed is stored as it is in the state before the upper layer of the reference signal line is formed due to a trouble during manufacturing, the lower layer of the reference signal line is not By being protected by the insulating film, oxidative insulation, disappearance, alteration, etc. of the metal forming the lower layer can be reduced, and low resistance and reliability can be maintained.
Further, since the lower layer and the upper layer are formed in separate steps that are not directly continuous, the disconnection defect rate can be further reduced, and the yield and reliability can be further improved.

As described above , when at least a part of the longitudinal edges of the lower layer of the reference signal line is covered with the interlayer insulating film, the interlayer insulating film is provided at the longitudinal edges of the lower layer of the reference signal line. Follows the shape of the lower layer to form a step shape. Then, in such a step portion of the interlayer insulating film, the etching rate of the material of the upper layer is higher than that in other flat places.

Therefore, according to the above configuration, even if the upper layer of the reference signal line is patterned by using the same material as the pixel electrodes adjacent to each other, the two can be reliably separated to reduce the short circuit defect. You can Therefore, the yield can be further improved.

Further, according to the above structure, since the upper layer of the reference signal line is formed of the same material as the pixel electrode, extra steps and materials are required to form the reference signal line into a laminated structure. Therefore, the increase in cost can be suppressed.

Further, in the vicinity of the pixel electrode in the reference signal line.
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is a pixel electrode.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It

A liquid crystal display device according to a second aspect of the present invention is provided in a matrix form in order to solve the above problems.
3 terminal switching element, and the above switch
Connected to the first terminal of the switching element for each column of switching elements
The scan line that is parallel to the scan line and the switch
Each row of switching elements is connected to the second terminal of the switching element.
The connected reference signal line and the third end of the switching element
A pixel substrate having a child and a pixel electrode connected to each;
It faces the pixel substrate and faces each of the pixel electrodes.
Has a counter electrode and a signal line that connects the counter electrode for each row
It is sandwiched between the counter substrate and the pixel substrate and the counter substrate.
A liquid crystal display device having a liquid crystal layer
The signal line has a laminated structure, and the lower and upper layers of the reference signal line are
Covers at least a part of the longitudinal edge of the lower layer between
An inter-layer insulating film that covers the scanning lines is provided together with
Longitudinal direction on the side below the quasi-signal line that is different from the scanning line proximity side
On the interlayer insulating film that covers at least a part of the edge,
Provided with a pixel electrode connected to the switching element of the column
The upper layer is made of the same material as the pixel electrode.
And the longitudinal edge on the pixel electrode proximity side is
At the edge of the interlayer insulating film on the lower layer of the reference signal line,
The side surface in the longitudinal direction on the pixel electrode proximity side and the interlayer insulating film above
The longitudinal edge portion of the lower layer of the reference signal line on the pixel electrode proximity side
By covering at least a part of the interlayer insulating film,
So that the side surface in the longitudinal direction of the step formed by
Is formed on the scanning line near side of the upper layer.
On the side surface in the longitudinal direction, the interlayer insulating film is below the reference signal line.
Cover at least a portion of the longitudinal edge of the layer near the scan line.
Step formed by the interlayer insulating film
So that it completely covers
It is characterized in that it is provided so as to protrude from the side surface
It

According to the above arrangement, the signal line and the scanning line are
Do not cross on the same substrate, and the signal line and scan line
At the intersection of, like a conventional active matrix substrate
Defects caused by cracks and pinholes in the gate insulating film
do not do.

The reference signal line is made of a conductive material.
One of the above reference signal lines is formed by using a laminated structure
Even if some of the
Since the physical connection is maintained, the disconnection failure rate is significantly reduced.

Therefore, the yield is improved and the cost is significantly reduced.
It can be downed and occurs over time
It is possible to suppress deterioration of reliability due to cracks, etc.
It Further, according to the above configuration, the reference signal line is electrically conductive.
Wiring resistance is reduced by using a laminated structure made of a conductive material
And further improve the yield,
It is possible to stabilize the display quality.

Further , according to the above configuration, the reference signal line
After forming the lower layer, an interlayer insulating film is provided between the lower layer and the upper layer.
By providing, the lower layer surface covered by the interlayer insulating film
Can be protected. As a result,
Subsequent process in the area covered by the interlayer insulating film
Scratches due to foreign substances, etc. and permeation of etching chemicals
It is possible to prevent the occurrence of disconnection due to a trouble or the like.
In addition, due to problems such as manufacturing problems,
The lower layer of the reference signal line is formed before the upper layer is formed.
Even if the printed circuit board is stored as is, the reference signal above
Since the lower layer of the line is protected by the interlayer insulating film,
For example, the oxidation, disappearance, and alteration of the metal that constitutes the layer
It is reduced, and low resistance and reliability can be maintained.
In addition, the lower layer and the upper layer are not directly continuous.
By being formed in various processes, the disconnection failure rate can be further improved.
Decrease yields and improve yield and reliability.
The layer can be improved.

Further, according to the above arrangement, it is possible to form the longitudinal edges of the upper layer of the reference signal lines substantially flush with the longitudinal edges of the interlayer insulating film, the reference signal line It is possible to more reliably separate the upper layer and the adjacent pixel electrode. In this way, by surely dividing the upper layer of the reference signal line and the adjacent pixel electrode into two, the gap between the reference signal line and the pixel electrode adjacent to the reference signal line can be reduced. Therefore, the reference signal line can be thickened to reduce the resistance and capacitance, and the display quality can be stabilized.

In addition, in the vicinity of the pixel electrode in the reference signal line,
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is the pixel electrode.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It

In order to solve the above problems, a liquid crystal display device according to a third aspect of the present invention is provided with the reference signal line.
The lower layer is made of the same material as the scan line.
is doing.

According to the above arrangement, the portion below the reference signal line is
If the layer is made of the same material as the scan line, the reference signal line
No extra steps or materials are required to create a laminated structure,
The increase in cost can be suppressed.

In order to solve the above-mentioned problems, a method for manufacturing a liquid crystal display device according to a fourth aspect of the present invention provides a matrix.
A three-terminal switching element provided in a box shape,
The for each column of Sui switching element of the switching element 1
A scanning line connected to the terminal, parallel to the scanning line, and
For each column of switching elements,
A reference signal line connected to two terminals and the switching element
An image having a third terminal of the child and a pixel electrode connected to each
Each of the pixel electrodes faces the pixel substrate and the pixel substrate.
A counter electrode facing each other and a signal for connecting the counter electrode for each row
Between the counter substrate having a line and the pixel substrate and the counter substrate
Of manufacturing liquid crystal display device having liquid crystal layer sandwiched between layers
, The lower layer of the reference signal line is the same as the scanning line.
And the length of the lower layer of the reference signal line
Cover at least a part of the direction edge and cover the scanning line.
The step of forming an interlayer insulating film and
At least the longitudinal edge on the side different from the scanning line proximity side
Switching of the next row on the interlayer insulation film that covers a part
The pixel electrode connected to the element, and the upper layer of the reference signal line
And forming a pattern with the same material.
Pattern the pole and the upper layer of the reference signal line with the same material
In the step of
The longitudinal edge on the electrode proximity side has the interlayer insulating film as the base.
A small number of longitudinal edges on the pixel electrode proximity side of the lower layer of the quasi-signal line
By covering at least a part,
The length of the upper layer above the pixel electrode adjacent side
The side surface in the direction is the side surface in the longitudinal direction on the side closer to the pixel electrode in the lower layer.
The side surface in the longitudinal direction on the scanning line proximity side of the upper layer above does not protrude
However, the interlayer insulating film is close to the scanning line below the reference signal line.
By covering at least part of the tangential longitudinal edge
Completely covers the step formed by the interlayer insulating film.
So that it protrudes from the longitudinal side surface on the scanning line proximity side of the lower layer.
The feature is that it is formed so as to project.

According to the above structure, the reference signal line is electrically conductive.
The reference signal line can be
Even if one of the layers is defective, the remaining layers
Since the electrical connection is maintained by the
Decrease to.

Therefore, the yield is improved and the cost is significantly reduced.
It can be downed and occurs over time
It is possible to suppress deterioration of reliability due to cracks, etc.
It Further, according to the above configuration, the reference signal line is electrically conductive.
Wiring resistance is reduced by using a laminated structure made of a conductive material
And further improve the yield,
It is possible to stabilize the display quality.

Further , according to the above configuration, the reference signal line
After forming the lower layer, an interlayer insulating film is provided between the lower layer and the upper layer.
By providing, the lower layer surface covered by the interlayer insulating film
Can be protected. As a result,
Subsequent process in the area covered by the interlayer insulating film
Scratches due to foreign substances, etc. and permeation of etching chemicals
It is possible to prevent the occurrence of disconnection due to a trouble or the like.
In addition, due to problems such as manufacturing problems,
The lower layer of the reference signal line is formed before the upper layer is formed.
Even if the printed circuit board is stored as is, the reference signal above
Since the lower layer of the line is protected by the interlayer insulating film,
For example, the oxidation, disappearance, and alteration of the metal that constitutes the layer
It is reduced, and low resistance and reliability can be maintained.
In addition, the lower layer and the upper layer are not directly continuous.
By being formed in various processes, the disconnection failure rate can be further improved.
Decrease yields and improve yield and reliability.
The layer can be improved.

Then, as described above, the reference signal line is
At least part of the longitudinal edge of the lower layer is an interlayer insulating film.
When covered, the longitudinal edge in the layer below the reference signal line
Then, the interlayer insulating film follows the shape of the lower layer, and
Make a shape. Then, in such a step portion of the interlayer insulating film
Is a flat surface where the etching rate of the upper layer material is
Higher

Therefore, according to the above configuration, the reference signal
Use the same material for the pixel electrodes adjacent to the upper layer of the signal line
Even if a pattern is formed, it can be surely separated from each other to prevent short circuit defects.
It can be reduced. Therefore, the yield is further increased.
Can be improved.

Further , according to the above configuration, the reference signal
By forming the upper layer of the line with the same material as the pixel electrode,
Excessive steps and materials to make the reference signal line a laminated structure
It is possible to suppress an increase in cost without the need for.

Further, in the vicinity of the pixel electrode in the reference signal line,
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is the pixel electrode.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It

In order to solve the above-mentioned problems, a method for manufacturing a liquid crystal display device according to a fifth aspect of the present invention is a matrix.
A three-terminal switching element provided in a box shape,
A first switching element for each column of switching elements
A scanning line connected to the terminal, parallel to the scanning line, and
For each column of switching elements,
A reference signal line connected to two terminals and the switching element
An image having a third terminal of the child and a pixel electrode connected to each
Each of the pixel electrodes faces the pixel substrate and the pixel substrate.
A counter electrode facing each other and a signal for connecting the counter electrode for each row
Between the counter substrate having a line and the pixel substrate and the counter substrate
Of manufacturing liquid crystal display device having liquid crystal layer sandwiched between layers
, The lower layer of the reference signal line is the same as the scanning line.
And the length of the lower layer of the reference signal line
Cover at least a part of the direction edge and cover the scanning line.
The step of forming an interlayer insulating film and
At least the longitudinal edge on the side different from the scanning line proximity side
Switching of the next row on the interlayer insulation film that covers a part
The pixel electrode connected to the element, and the upper layer of the reference signal line
And forming a pattern with the same material.
Pattern the pole and the upper layer of the reference signal line with the same material
In the step of the pixel electrodes of the upper of the reference signal line near
Make sure that the longitudinal edge on the contact side is the interlayer on the lower layer of the reference signal line.
At the edge of the insulating film, in the longitudinal direction on the pixel electrode proximity side of the above upper layer
Pixels on the side surface and the interlayer insulating film below the reference signal line
Covering at least part of the longitudinal edge on the electrode proximity side
The length of the step formed by the interlayer insulating film
The side surface is formed so that it is flush with the side surface.
The upper layer of the reference signal line is the side surface in the longitudinal direction near the scanning line.
Is the step on the scanning line proximity side formed by the interlayer insulating film.
The length of the lower layer on the scanning line proximity side so as to completely cover the difference
The side closer to the scanning line above the reference signal line than the side surface in the hand direction
It is characterized in that it is formed so that the longitudinal side surface of
is doing.

According to the above structure, the reference signal line is electrically conductive.
The reference signal line can be
Even if one of the layers is defective, the remaining layers
Since the electrical connection is maintained by the
Decrease to.

Therefore, the yield is improved and
It can be downed and occurs over time
It is possible to suppress deterioration of reliability due to cracks, etc.
It Further, according to the above configuration, the reference signal line is electrically conductive.
Wiring resistance is reduced by using a laminated structure made of a conductive material
And further improve the yield,
It is possible to stabilize the display quality.

Further , according to the above configuration, the reference signal line
After forming the lower layer, an interlayer insulating film is provided between the lower layer and the upper layer.
By providing, the lower layer surface covered by the interlayer insulating film
Can be protected. As a result,
Subsequent process in the area covered by the interlayer insulating film
Scratches due to foreign substances, etc. and permeation of etching chemicals
It is possible to prevent the occurrence of disconnection due to a trouble or the like.
In addition, due to problems such as manufacturing problems,
The lower layer of the reference signal line is formed before the upper layer is formed.
Even if the printed circuit board is stored as is, the reference signal above
Since the lower layer of the line is protected by the interlayer insulating film,
For example, the oxidation, disappearance, and alteration of the metal that constitutes the layer
It is reduced, and low resistance and reliability can be maintained.
In addition, the lower layer and the upper layer are not directly continuous.
By being formed in people step, yo Ri further, the disconnection failure rate
Decrease yields and improve yield and reliability.
The layer can be improved.

According to the above construction, the interlayer insulation
The upper layer of the reference signal line is approximately flush with the longitudinal edge of the membrane.
Since the longitudinal edge can be formed, the reference signal
Separation between the upper layer of the signal line and the adjacent pixel electrode is further ensured.
It can be done really. And thus, the reference signal
Make sure that the upper layer of the line and the adjacent pixel electrode are bisected.
And the reference signal line and the pixel electrode adjacent to the reference signal line.
The gap between the
Stabilize display quality by thickening signal lines to reduce resistance and capacitance
can do.

Further, in the vicinity of the pixel electrode in the reference signal line.
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is the pixel voltage.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It

In order to solve the above-mentioned problems, a method for manufacturing a liquid crystal display device according to a sixth aspect of the present invention is a pattern.
The resist for use in the
The interlayer insulating film is located on the pixel electrode proximity side below the reference signal line.
By covering at least a portion of the longitudinal edge
Align with the longitudinal side surface of the step formed by the interlayer insulating film
By forming such a structure as described above,
Place the longitudinal edge on the electrode proximity side on the layer below the reference signal line.
It is characterized in that it is formed at the edge of the interlayer insulating film.

According to the above constitution, the base is formed by the above method.
By forming the upper layer of the quasi-signal line,
The layer and the pixel electrode adjacent to the upper layer are surely divided into two.
You can Therefore, between the reference signal line and the pixel electrode
The gap of the reference signal can be reduced.
Make the line thicker to reduce the resistance and capacitance and stabilize the display quality.
be able to.

[0058]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a sectional view showing a schematic structure in the vicinity of a switching element in a liquid crystal display device according to this embodiment, and FIG. 2 shows a schematic structure in the vicinity of a switching element in a pixel substrate of the liquid crystal display device. It is a top view.

As shown in FIGS. 1 and 2, in the pixel substrate of the liquid crystal display device according to the present embodiment, a plurality of pixel electrodes 14 for applying a voltage to the liquid crystal layer 15 are selectively driven.
A three-terminal switching element 11 ... Is provided in a matrix on a transparent insulating substrate 1 such as glass. Examples of the above-mentioned three-terminal switching element 11 used in the present embodiment include a TFT (a-SiTFT) using an amorphous silicon semiconductor.

In the switching element 11, a gate electrode 2 (first terminal), an interlayer insulating film 3 serving as a gate insulating film, a semiconductor layer 4, and a contact layer 5 are sequentially laminated on an insulating substrate 1, and this semiconductor layer is formed. 4 and the contact layer 5, the source electrode 6 (second terminal) is formed on the source side, and the drain electrode 7 (third terminal) is formed on the drain side.

Gate electrode 2 of the switching element 11
, The scanning line 1 for each column of the switching elements 11 ...
2 is connected to the source electrode 6, which is another terminal of the switching element 11, for each column of the switching element 11, ... A reference signal line 1 formed in parallel with the scanning line 12.
Three upper layers 13b, for example, are connected. The drain electrode 7, which is another terminal of the switching element 11, has a pixel electrode 14 formed on the interlayer insulating film 3.
Are connected to each switching element 11. In the present embodiment, part of the interlayer insulating film 3 forms a gate insulating film and covers part of the lower layer 13a of the reference signal line 13.

As a result, in the above liquid crystal display device, the scanning line 12 is close to one longitudinal side surface of the reference signal line 13 via the interlayer insulating film 3. In addition, the reference signal line 13
The pixel electrode 14 connected to the switching element 11 in the adjacent column is close to the other side surface in the longitudinal direction. Details of the structure of the reference signal line 13 will be described later.

A silicon nitride film (SiN _x film) having a film thickness of 2000 Å, for example, is laminated as the protective film 8 on the peripheral portion of the pixel electrode 14 and on the reference signal line 13 and the switching element 11. , Protects each wiring and prevents short circuit. Note that, in FIG. 2, the protective film 8 is shown by a chain double-dashed line.

On the other hand, in the counter substrate provided so as to face the pixel substrate with the liquid crystal layer 15 in between, the color filter 22 and the black matrix 23 are formed on the insulating substrate 21, and the overcoating as the flattening film is formed thereon. A film 24 is formed, and a signal line, eg, ITO, which is a transparent conductive film, is further formed on the film 24 via an interlayer insulating film (not shown).
The (indium tin oxide) film 25 is formed in a stripe shape.

The ITO film 25 is formed so as to be orthogonal to the scanning lines 12 provided on the pixel substrate.
It is provided opposite to.

That is, the ITO film 25 is used as the pixel electrode 14
The counter electrode serving as the counter electrode and the signal line connecting the counter electrodes for each row are also provided. The liquid crystal display device according to the present embodiment has a counter substrate signal in which the signal line is formed on the counter substrate side. It has a line structure.

Therefore, in the above liquid crystal display device, the signal line and the scanning line 12 do not intersect on the same substrate,
At the intersection of the signal line and the scanning line 12, defects due to cracks and pinholes in the gate insulating film unlike the conventional active matrix substrate do not occur. Therefore, the yield can be improved and the cost can be significantly reduced.
It is possible to suppress a decrease in reliability due to cracks or the like that occur over time.

Source electrode 6 and drain electrode 7
May be simultaneously patterned with the same material as the pixel electrode 14 (for example, ITO). In this case, the process can be shortened and the material cost can be saved.

The structure of the reference signal line 13 provided on the pixel substrate will be described below with reference to FIG. FIG. 3 is a sectional view of the pixel substrate shown in FIG.

The reference signal line 13 has a laminated structure of two or more layers (two layers in the present embodiment) made of a conductive material, and includes a lower layer 13a which is the first layer of the reference signal line 13 and a second layer. between the upper layer 13b is a layer, the interlayer insulating film 3 is interposed, thereby, covers at least a portion of the longitudinal edges 13a ₁ · 13a ₂ on the upper surface of the lower layer 13a.
The lower layer 13a and the upper layer 13b are in contact with each other at a portion where the interlayer insulating film 3 is not interposed, and contact is made at this portion.

The lower layer 13a of the reference signal line 13 is preferably made of the same material as that of the scanning line 12, and the upper layer 1
3b is preferably made of the same material as the pixel electrode 14.

The material of the lower layer 13a of the reference signal line 13, the scanning line 12, and the gate electrode 2 is, for example, T
Examples thereof include metals such as a, Al, and Al alloys, but are not limited thereto. Further, as the lower layer 13a of the reference signal line 13, the gate electrode 2, and the scanning line 12,
For example, you may have the laminated structure of the film which consists of the above-mentioned metal. That is, the reference signal line 13 may have a laminated structure in which two or more layers are laminated.

The upper layer 13b of the reference signal line 13 and the pixel electrode 14 may be, for example, a transparent conductive film made of ITO or the like. The material of the interlayer insulating film 3 is S
Examples thereof include iN _x , SiO ₂ , TaO _x, etc., but the interlayer insulating film 3 may also have a laminated structure.

As described above, by forming the reference signal line 13 into a laminated structure composed of two or more layers of conductive material, the wiring resistance can be reduced, the yield can be improved, and the display quality can be stabilized. Can be planned. Further, according to the above configuration, even if one layer of the reference signal line 13, for example, a part of the lower layer 13a or the upper layer 13b has a defect, the remaining layer (the other layer) provides electrical connection. Since it is maintained, the disconnection failure rate is significantly reduced. Therefore, the manufacturing cost is reduced and the reliability after commercialization is improved.

In this case, if the lower layer 13a of the reference signal line 13 is formed of the same material as that of the scanning line 12, no extra step or material is required to form the reference signal line 13 in a laminated structure, The increase in cost can be suppressed.
Similarly, if the upper layer 13b of the reference signal line 13 is formed of the same material as the pixel electrode 14, the reference signal line 13 is formed.
No additional process or material is required to form the laminated structure, and an increase in cost can be suppressed.

After forming the lower layer 13a of the reference signal line 13, the lower layer 13 is provided between the lower layer 13a and the upper layer 13b.
By providing the interlayer insulating film 3 that covers at least a part of the longitudinal edges 13a ₁ and 13a ₂ of a, the region (the surface of the lower layer 13a) covered by the interlayer insulating film 3 can be protected.

As a result, it is possible to prevent the occurrence of wire breakage due to scratches due to foreign matter or the like in the subsequent steps in this region or troubles such as penetration of etching chemicals. Further, the reference signal line 13 is used for reasons such as manufacturing troubles.
Of the reference signal line 13 before the upper layer 13b is formed.
Even when the substrate on which the lower layer 13a is formed is stored as it is, since the surface of the lower layer 13a is protected by the interlayer insulating film 3, for example, the above-described metal constituting the lower layer 13a is oxidized, eliminated, altered, etc. Can be reduced, and low resistance and reliability can be maintained. Then, the lower layer 13a
By forming the upper layer 13b and the upper layer 13b in separate steps that are not directly continuous, the disconnection failure rate can be further reduced, and the yield and reliability can be further improved.

Further, as described above, the reference signal line 1
When at least a part of the longitudinal edge portions 13a ₁ and 13a ₂ of the lower layer 13a of _No. 3 is covered with the interlayer insulating film 3, the shape of the interlayer insulating film 3 reflects the shape of the lower layer 13a serving as a base. Therefore, the longitudinal edge portion 13a _{1 of the} lower layer 13a
At 13a ₂ , the interlayer insulating film 3 covering the longitudinal edges 13a ₁ and 13a ₂ follows the shape of the lower layer 13a to form a step shape. Such a stepped portion 3a of the interlayer insulating film 3
In 3b, the etching rate of the material of the upper layer 13b formed of a transparent insulating film or the like is higher than that of other flat places.

Therefore, the lower layer 13a of the reference signal line 13 is
When at least part of the longitudinal edges 13a ₁ and 13a ₂ of the pixel electrode 14 is covered with the interlayer insulating film 3, the pixel electrode 14 adjacent to the reference signal line 13 (that is, the switching element 1 in the adjacent column)
Layer 13b made of the same material as the pixel electrode 14) connected to 1
When patterning, the upper layer 13b and the pixel electrode 14
In order to surely separate and the short-circuit defect, the upper layer 13b of the reference signal line 13 is a lower layer on the side close to the pixel electrode 14 and on the lower side where the longitudinal edge 13b ₁ is on the same side. It is preferably provided so as to be located on the step portion 3a formed by covering the longitudinal edge portion 13a ₁ of 13a with the interlayer insulating film 3.

The upper layer 13b of the reference signal line 13
Means that the longitudinal side surface 13b ₃ of the upper layer 13b close to the pixel electrode 14 is on the same side of the lower layer 13a (that is,
Longitudinal side surface 13 on the side close to the pixel electrode 14)
More preferably, it is provided so as not to project beyond a ₃ . In this case, as described above, even if the upper layer 13b is patterned using the same material as the pixel electrodes 14 that are adjacent to each other, it is possible to reliably separate the two regardless of the presence or absence of the interlayer insulating film 3, and to reduce the short circuit defect. The yield can be further improved.

The upper layer 13b of the reference signal line 13 is also
Is the longitudinal edge 13b of the upper layer 13b.
₁ is formed so as to be aligned in the longitudinal edge 3a ₁ of the upper surface of the interlayer insulating film 3 on the lower 13a of the reference signal line 13 (i.e., the longitudinal edges 3a ₁ of the upper surface of the step portion 3a) Preferably. That is, the reference signal line 1
It is more preferable that the longitudinal side surface 13b ₃ of No. ₃ and the longitudinal side surface 3a ₃ of the step 3a of the interlayer insulating film 3 are flush with each other.

Thus, the upper layer 13 of the reference signal line 13 is
By forming the longitudinal edge portion 13b ₁ of b in the longitudinal edge portion 3a ₁ of the interlayer insulating film 3, the upper layer 13b of the reference signal line 13 and the pixel electrode 14 adjacent to the upper layer 13b can be more reliably formed. Can be separated to reduce the short-circuit defect rate.

By the way, when the upper layer 13b of the reference signal line 13 is formed on the interlayer insulating film 3 as described above, as shown in FIG. When a transparent conductive film such as an ITO film is laminated as the upper layer 13b over the entire surface of the interlayer insulating film 3, the longitudinal edges 3a ₂ and 3b ₂ on the lower surface side of the step portions 3a and 3b of the interlayer insulating film 3 are formed. The laminated state of the transparent conductive film is often not so good.

Therefore, when the upper layer 13b is etched without using a resist for patterning or the like, stress is concentrated in the vicinity of the longitudinal edges 3a ₂ and 3b _{2 of the} interlayer insulating film 3 and cracks may occur. As shown in FIG. 4B, the crack penetrates the etching agent, and the stress is concentrated (in this case, the longitudinal edge 3a of the interlayer insulating film 3).
There is a risk that the etching will proceed faster only in ( ₂ vicinity).

Therefore, in particular, the longitudinal edge portion 13b ₁ of the upper layer 13b is replaced with the longitudinal edge portion 3a of the interlayer insulating film 3.
_In the case of forming the pattern 1 as shown in FIG. 4C, the pattern resist 31 is formed such that the longitudinal side surface 31 a of the resist 31 is the longitudinal side surface 3 of the step portion 3 a of the interlayer insulating film 3.
It may be formed so as to be aligned with a ₃ .

The upper layer 1b of the reference signal line 13 is formed by forming the upper layer 13b of the reference signal line 13 by the method described above.
3b and the pixel electrode 14 adjacent to the upper layer 13b can be surely bisected. Therefore, the gap between the reference signal line 13 and the pixel electrode 14 can be reduced, and the reference signal line 13 can be made thicker by that amount to reduce the resistance capacitance and stabilize the display quality. Specific values of the gap between the reference signal line 13 and the pixel electrode 14 adjacent to the reference signal line 13 are shown in FIG. It should be noted that the numerical values indicating the specific sizes of the respective components of the liquid crystal display device illustrated in the present embodiment do not particularly limit the configuration of the liquid crystal display device of the present application and can be set appropriately. is there.

The upper layer 13b of the reference signal line 13
3 is, as shown in FIG. 3, close to the side different from the side surface 13b _{3 in} the longitudinal direction on the side close to the pixel electrode 14, that is, close to the scanning line 12 connected to the same switching element 11 as the reference signal line 13. longitudinal side 13b ₄ side is preferably provided so as to protrude from the longitudinal sides 13a ₄ of the same side of the lower layer 13a. That is, on the side of the reference signal line 13 close to the scanning line 12, the scanning line 12 is formed in a process different from that of the upper layer 13 b of the reference signal line 13, and is completely covered with the interlayer insulating film 3. ing. Therefore, as described above, on the side of the reference signal line 13 close to the scanning line 12,
The upper layer 13b of the reference signal line 13 is formed so that its longitudinal sides 13b ₄ protrudes than the longitudinal side 13a ₄ of the lower layer 13a, thereby improving the pattern accuracy.

Further, in this case, since the upper layer 13b of the reference signal line 13 completely covers the step portion 3b of the interlayer insulating film 3 on the side close to the scanning line 12, the etching rate of the etching rate is increased as described above. Since the pattern is formed over a high place, the pattern accuracy can be further improved. Moreover, even if a part of the upper layer 13b of the reference signal line 13 is broken in the step portion 3b, the continuity can be maintained in the portion that escapes the break, so that the yield and reliability can be improved. .

Further, since the longitudinal side surface 13b ₄ of the upper layer 13b of the reference signal line 13 is projected more than the longitudinal side surface 13a ₄ of the lower layer 13a, the upper layer 13b of the reference signal line 13 and the scanning line are formed. There is an advantage that connection with 12 is easy.

The liquid crystal display device of the present invention is not limited to the above description, but may be appropriately modified or used in combination within the scope described in the claims and the above embodiments. Is.

[0092]

According to the liquid crystal display device of the invention described in claim 1,
As described above, the three-terminal switching elements provided in a matrix, the scanning line connected to the first terminal of the switching element for each column of the switching element, and the scanning line parallel to the scanning line, A pixel substrate having a reference signal line connected to the second terminal of the switching element for each column of the switching element, a pixel electrode connected to the third terminal of the switching element, and facing the pixel substrate. Then, a liquid crystal including a counter substrate having a counter electrode facing each of the pixel electrodes and a signal line connecting the counter electrodes for each row, and a liquid crystal layer sandwiched between the pixel substrate and the counter substrate. In the display device, the reference signal line has a laminated structure.
The length of the lower layer between the lower and upper layers of the reference signal line
While covering at least a part of the edge in the hand direction,
An inter-layer insulation film is provided to cover the lower layer of the reference signal line.
At least one of the longitudinal edges on the side different from the side close to the line
On the interlayer insulating film that covers the
The pixel electrode connected to the child is provided, and the upper layer
Is made of the same material as the pixel electrode, and
At the longitudinal edge on the side close to the element electrode, the interlayer insulating film is
The length of the longitudinal edge on the pixel electrode proximity side of the lower layer of the reference signal line is small.
By covering a part without
The length of the upper layer above the pixel electrode proximity side on the formed step
The side surface in the hand direction is the side surface in the longitudinal direction of the lower layer adjacent to the pixel electrode.
It is positioned so that it does not protrude more than
The interlayer insulating film is formed on the longitudinal side surface of the layer on the scanning line proximity side.
Of the longitudinal edge of the lower layer of the reference signal line on the scanning line proximity side
By covering at least a part of the interlayer insulating film,
Scan the lower layer to completely cover the step formed by
It is configured so as to project from the side surface in the longitudinal direction on the line proximity side .

According to the above structure, the signal line and the scanning line do not intersect on the same substrate, and the gate insulating film is formed at the intersection of the signal line and the scanning line like the conventional active matrix substrate. Defects due to cracks and pinholes do not occur. Further, by forming the reference signal line into a laminated structure made of a conductive material , even if a part of one layer of the reference signal line has a defect, the remaining layers maintain the electrical connection. Therefore, the disconnection failure rate is significantly reduced.

Therefore, the yield can be improved and the cost can be drastically reduced, and at the same time, the deterioration of reliability due to cracks generated over time can be suppressed. Further, according to the above configuration, the wiring resistance can be reduced, the yield can be further improved, and the display quality can be stabilized.

[0095] According to the above configuration, it is possible to protect the coated surface with an interlayer insulating film in the lower layer of the reference signal line, broken by scratching or penetration troubles of the etching agent caused by foreign matter in the manufacturing process Can be prevented. Further, since the lower layer and the upper layer of the reference signal line are formed in separate steps that are not directly continuous, it is possible to further reduce the disconnection defect rate, and further improve the yield and reliability. It also has the effect of being able to.

Therefore, according to the above configuration, the reference signal
Use the same material for the pixel electrodes adjacent to the upper layer of the signal line
Even if a pattern is formed, it can be surely separated from each other to prevent short circuit defects.
It can be reduced. Therefore, the yield is further increased.
It also has an effect of being able to improve.

Further, in the vicinity of the pixel electrode in the reference signal line.
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is the pixel electrode.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It also has the effect of

As described above, the liquid crystal display device according to the second aspect of the present invention is a switch having three terminals arranged in a matrix.
The switching element and the switching element for each row of the switching elements.
A scanning line connected to the first terminal of the
Parallel to the line and for each column of the switching element
A reference signal line connected to the second terminal of the switching element,
Image connected to the third terminal of the switching element
A pixel substrate having an element electrode, facing the pixel substrate,
A counter electrode facing each of the pixel electrodes and a counter electrode
A counter substrate having a signal line connected to each row, and the pixel substrate
A liquid crystal having a liquid crystal layer sandwiched between a plate and a counter substrate
In the display device, the reference signal line has a laminated structure.
The length of the lower layer between the lower and upper layers of the reference signal line.
Cover at least a part of the direction edge and cover the scanning line.
An interlayer insulating film is provided to scan the lower layer of the reference signal line.
At least a part of the longitudinal edge on the side different from the line proximity side
On the interlayer insulation film that covers the
And a pixel electrode connected to the
It is made of the same material as the pixel electrode, and
The longitudinal edge on the very close side is on the lower layer of the reference signal line.
At the edge of the interlayer insulating film, the length of the upper layer near the pixel electrode
Direction side surface and the interlayer insulating film of the lower layer of the reference signal line.
Cover at least a part of the longitudinal edge on the pixel electrode proximity side
Of the stepped portion formed by the interlayer insulating film
If it is formed so that the longitudinal side surface is flush with
In addition, the longitudinal side surface on the scanning line proximity side of the upper layer is
The length of the interlayer insulating film below the reference signal line is close to the scanning line.
Said layer by covering at least part of the hand side edge
To cover the stepped portion formed by the inter-layer insulation film completely.
It is installed so as to protrude from the longitudinal side surface of the lower layer on the scanning line proximity side.
It is a structure that is banned.

According to the above configuration, the signal line and the scanning line are
Do not cross on the same substrate, and the signal line and scan line
At the intersection of, like a conventional active matrix substrate
Defects caused by cracks and pinholes in the gate insulating film
do not do. In addition, the reference signal line is made of a conductive material.
By adopting a layered structure, one of the reference signal lines
Even if there is a defect in the
Since the continuity is maintained, the failure rate of wire breakage is significantly reduced.

Therefore, the yield is improved and
It can be downed and occurs over time
It is possible to suppress deterioration of reliability due to cracks, etc.
It Further, according to the above configuration, the wiring resistance is reduced,
In addition to improving the yield, display products
It also has the effect of stabilizing the position
It

Further, the edge portion in the longitudinal direction of the interlayer insulating film is almost the same.
Form the longitudinal edge of the upper layer of the reference signal line on the same plane.
Since it can be connected to the upper layer of the above reference signal line,
Separation of the picture element electrode can be performed more reliably the that
It Then, in this way, close to the upper layer of the reference signal line.
By surely dividing the pixel electrode with the reference signal line,
The gap between the pixel electrode adjacent to the reference signal line should be small.
The reference signal line can be thickened and
It is possible to reduce the anti-capacity and stabilize the display quality.
This effect is also played.

Further, in the vicinity of the pixel electrode in the reference signal line.
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is the pixel electrode.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It also has the effect of

In the liquid crystal display device according to the third aspect of the present invention, as described above, the lower layer of the reference signal line is the same as the scanning line.
It is composed of one material.

According to the above configuration, the reference signal line below
If the layer is made of the same material as the scan line, the reference signal line
No extra steps or materials are required to create a laminated structure,
It has the effect of suppressing the increase in cost.
It

Manufacture of a liquid crystal display device according to claim 4
As described above, the method has three ends arranged in a matrix.
Child switching elements and each row of the above switching elements
Scan line connected to the first terminal of the switching element for each
And parallel to the scanning line, and each of the switching elements
A reference connected to the second terminal of the switching element for each column
Connect the signal line to the third terminal of the switching element.
A pixel substrate having a continuous pixel electrode, and the pixel substrate
And a counter electrode facing each of the pixel electrodes and
A counter substrate having a signal line connecting the counter electrodes for each row;
A liquid crystal layer sandwiched between the pixel substrate and a counter substrate
In the manufacturing method of the liquid crystal display device, the reference signal
Forming the lower layer of the line with the same material as the scan line
And at least the longitudinal edge of the lower layer of the reference signal line.
An interlayer insulating film is provided to cover a part of the scanning line and the scanning line.
The process is different from the scanning line proximity side under the reference signal line.
Of the insulation layer covering at least a part of the longitudinal edge of the
Pixels connected to the switching element in the next column on the edge film
Pattern the electrode with the same material as the upper layer of the reference signal line.
And a step of forming the pixel electrode and the reference signal line.
In the process of patterning the upper layer with the same material,
The upper layer of the reference signal line is arranged in the longitudinal direction on the pixel electrode proximity side.
The edge is a pixel in which the interlayer insulating film is a layer below the reference signal line.
Covering at least part of the longitudinal edge on the electrode proximity side
On the step portion formed by the interlayer insulating film by
The longitudinal side surface of the upper layer close to the pixel electrode is the lower layer of the lower layer.
It does not protrude from the side surface in the longitudinal direction on the pixel electrode proximity side,
The longitudinal side surface of the layer near the scanning line is
Of the longitudinal edge of the lower layer of the reference signal line on the scanning line proximity side
By covering at least a part of the interlayer insulating film,
Scan the lower layer to completely cover the step formed by
It is configured so as to project from the side surface in the longitudinal direction on the line proximity side .

According to the above configuration, the reference signal line is guided.
By using a laminated structure made of an electrically conductive material, the above reference signal can be obtained.
Even if one of the lines has a defect,
The layers maintain the electrical connection, which improves the disconnection failure rate.
It gradually decreases.

Therefore, the yield is improved and the cost is significantly reduced.
It can be downed and occurs over time
It is possible to suppress deterioration of reliability due to cracks, etc.
It Further, according to the above configuration, the wiring resistance is reduced,
In addition to improving the yield, display products
It also has the effect of stabilizing the position
It

Further , according to the above configuration, the reference signal line
Protecting the surface covered with an interlayer insulating film in the lower layer
It is possible to prevent scratches due to foreign matter in the manufacturing process.
Wire breakage due to troubles such as penetration of etching chemicals
Can prevent life. Also, under the reference signal line
The layers and top layer are formed in separate steps that are not directly continuous.
It is possible to further reduce the disconnection defect rate.
And further improve yield and reliability.
It also has the effect of being able to.

Therefore, according to the above configuration, the reference signal
Use the same material for the pixel electrodes adjacent to the upper layer of the signal line
Even if a pattern is formed, it can be surely separated from each other to prevent short circuit defects.
It can be reduced. Therefore, the yield is further increased.
It also has an effect of being able to improve.

Further, in the vicinity of the pixel electrode in the reference signal line,
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is the pixel electrode.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It also has the effect of

Manufacture of the liquid crystal display device according to the fifth aspect of the invention.
As described above, the method has three ends arranged in a matrix.
Child switching elements and each row of the above switching elements
Scan line connected to the first terminal of the switching element for each
And parallel to the scanning line, and each of the switching elements
A reference connected to the second terminal of the switching element for each column
Connect the signal line to the third terminal of the switching element.
A pixel substrate having a continuous pixel electrode, and the pixel substrate
And a counter electrode facing each of the pixel electrodes and
A counter substrate having a signal line connecting the counter electrodes for each row;
A liquid crystal layer sandwiched between the pixel substrate and a counter substrate
In the manufacturing method of the liquid crystal display device, the reference signal
Forming the lower layer of the line with the same material as the scan line
And at least the longitudinal edge of the lower layer of the reference signal line.
An interlayer insulating film is provided to cover a part of the scanning line and the scanning line.
The process is different from the scanning line proximity side under the reference signal line.
Of the insulation layer covering at least a part of the longitudinal edge of the
Pixels connected to the switching element in the next column on the edge film
Pattern the electrode with the same material as the upper layer of the reference signal line.
And a step of forming the pixel electrode and the reference signal line.
In the process of patterning the upper layer with the same material,
Longitudinal edge in the upper layer of the reference signal line on the pixel electrode proximity side
On the edge of the interlayer insulating film on the lower layer of the reference signal line,
The side surface in the longitudinal direction of the above-mentioned layer on the side close to the pixel electrode and the interlayer insulation
The edge film is in the longitudinal direction on the side adjacent to the pixel electrode below the reference signal line.
By covering at least a part of the facing edge,
The longitudinal side surface of the step formed by the edge film is flush with
And the upper layer of the reference signal line.
The longitudinal side surface on the scanning line proximity side is the interlayer insulation
Completely covers the step formed on the scanning line proximity side
As compared to the longitudinal side surface on the scanning line proximity side of the lower layer
The longitudinal side surface on the scanning line proximity side of the upper layer of the reference signal line is
This is a structure that is formed so as to project.

According to the above configuration, the reference signal line is guided.
By using a laminated structure made of an electrically conductive material, the above reference signal can be obtained.
Even if one of the lines has a defect,
The layers maintain the electrical connection, which improves the disconnection failure rate.
It gradually decreases.

Therefore, the yield is improved and the cost is significantly increased.
It can be downed and occurs over time
It is possible to suppress deterioration of reliability due to cracks, etc.
It Further, according to the above configuration, the wiring resistance is reduced,
In addition to improving the yield , display products
It also has the effect of stabilizing the position
It

[0117] Further , the edges of the interlayer insulating film in the longitudinal direction are almost the same.
Form the longitudinal edge of the upper layer of the reference signal line on the same plane.
Since it can be connected to the upper layer of the above reference signal line,
Can be more reliably separated from the pixel electrodes
It Then, in this way, close to the upper layer of the reference signal line.
By surely dividing the pixel electrode with the reference signal line,
The gap between the pixel electrode adjacent to the reference signal line should be small.
The reference signal line can be thickened and
It is possible to reduce the anti-capacity and stabilize the display quality.
This effect is also played.

Further, in the vicinity of the pixel electrode in the reference signal line.
On the side opposite to the contact side (the scanning line proximity side), the pixel electrode
The pixel electrode and the layer made of the same material are not in close proximity.
Therefore, the upper side of the above-mentioned reference signal line is
By forming so as to project from the side surface in the longitudinal direction of
The pattern accuracy can be improved.

The upper layer of the reference signal line is the pixel electrode.
On the side opposite to the very close side, the above-mentioned interlayer insulating film is the above-mentioned reference
Formed by covering the longitudinal edges of the lower layers of signal lines
When the stepped portion is covered with a high etching rate
Since the pattern will be formed across the rollers,
The pattern accuracy can be improved. Moreover, above
If part of the upper layer of the reference signal line is broken at the step
Also, it is possible to maintain continuity at the part that escaped the disconnection
Can improve the yield and reliability.
It also has the effect of

Manufacture of the liquid crystal display device according to the sixth aspect of the invention.
As described above, the method uses the resist for patterning
The side surface in the longitudinal direction of the gist is the interlayer insulating film and the reference signal.
At least the longitudinal edge of the lower layer of the signal line near the pixel electrode
Formed by the interlayer insulating film by covering a part of
It should be formed so that it is aligned with the longitudinal side surface of the stepped portion.
In the longitudinal direction on the pixel electrode proximity side of the upper layer of the reference signal line.
The edge should be the edge of the interlayer insulation film above the reference signal line.
It is a structure to be formed.

According to the above constitution, the base is formed by the above method.
By forming the upper layer of the quasi-signal line,
The layer and the pixel electrode adjacent to the upper layer are surely divided into two.
You can Therefore, between the reference signal line and the pixel electrode
The gap of the reference signal can be reduced.
Make the line thicker to reduce the resistance and capacitance and stabilize the display quality.
There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration in the vicinity of a switching element in a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a schematic configuration in the vicinity of a switching element on a pixel substrate of the liquid crystal display device.

3 is a cross-sectional view of the pixel substrate shown in FIG. 2, taken along the line AA.

4A to 4C are explanatory views showing a method of manufacturing a reference signal line in the pixel substrate.

FIG. 5 is a diagram schematically showing a schematic configuration of a liquid crystal display device having a counter substrate signal line structure.

FIG. 6 is a circuit diagram showing a configuration of a conventional active matrix type liquid crystal display device including an active matrix substrate.

7 is a TFT of the active matrix substrate shown in FIG.
It is a sectional view of a part.

[Explanation of symbols]

1 Insulating Substrate 2 Gate Electrode (First Terminal) 3 Interlayer Insulating Film 3a Step 3a ₁ Longitudinal Edge 3a ₂ Longitudinal Edge 3a ₃ Longitudinal Side 3b Step 3b ₂ Longitudinal Edge 6 Source Electrode (first 2 terminals) 7 drain electrode (third terminal) 11 switching element 12 scanning line 13 reference signal line 13a lower layer 13a ₁ longitudinal edge 13a ₂ longitudinal edge 13a ₃ longitudinal side 13a ₄ longitudinal side 13b upper layer 13b ₁ longitudinal Direction edge 13b ₃ Longitudinal side 13b ₄ Longitudinal side 14 Pixel electrode 15 Liquid crystal layer 25 ITO film (counter electrode and signal line)

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Fujiwara 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Yasunobu Tabusa 22-22 Nagaike-cho, Abeno-ku, Osaka, Osaka Sharp shares In-house (56) Reference JP-A-4-294391 (JP, A) JP-A-5-297404 (JP, A) JP-A-6-160904 (JP, A) JP-A-7-128687 (JP, A) ) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/13-1/141

Claims (6)

(57) [Claims] 1. A three-terminal switching element provided in a matrix, a scanning line connected to a first terminal of the switching element for each column of the switching element, and parallel to the scanning line, A reference signal line connected to the second terminal of the switching element for each column of the switching element;
A pixel substrate having a third terminal of the switching element and a pixel electrode connected to each of the switching element, and facing the pixel substrate,
A liquid crystal display device including a counter substrate having a counter electrode facing each of the pixel electrodes, a signal line connecting the counter electrodes for each row, and a liquid crystal layer sandwiched between the pixel substrate and the counter substrate. In, the reference signal line has a laminated structure,
Between the lower layer and the upper layer, at least the longitudinal edge of the lower layer
An interlayer insulating film is provided to cover a part of the scanning line and the scanning line.
Side different from the scanning line proximity side of the lower layer of the reference signal line
Interlayer insulating film covering at least a part of the longitudinal edge of the
Above, the pixel electrode connected to the switching element in the next column
And the upper layer is the same as the pixel electrode.
A longitudinal edge made of material and located on the pixel electrode proximity side
In the part, the interlayer insulating film is a pixel electrode under the reference signal line.
To cover at least part of the longitudinal edge on the very close side
Therefore, on the step portion formed by the interlayer insulating film,
The side surface in the longitudinal direction on the side close to the pixel electrode of the upper layer is the image of the lower layer.
Be careful not to project beyond the longitudinal side surface near the element electrode.
And the longitudinal direction of the upper layer above the scanning line proximity side
On the opposite side, the above-mentioned interlayer insulating film runs under the reference signal line.
Cover at least a part of the longitudinal edge near the inspection line
Completely eliminates the step formed by the interlayer insulating film.
So that it covers the longitudinal side surface of the lower layer near the scanning line.
A liquid crystal display device characterized in that it is provided so as to protrude further . 2. A switch having three terminals arranged in a matrix.
The switching element and the switching element for each row of the switching elements.
A scanning line connected to the first terminal of the
Parallel to the line and for each column of the switching element
A reference signal line connected to the second terminal of the switching element,
Image connected to the third terminal of the switching element
A pixel substrate having an element electrode, facing the pixel substrate,
A counter electrode facing each of the pixel electrodes and a counter electrode
A counter substrate having a signal line connected to each row, and the pixel substrate
A liquid crystal having a liquid crystal layer sandwiched between a plate and a counter substrate
In the display device, the reference signal line has a laminated structure,
Between the lower layer and the upper layer, at least the longitudinal edge of the lower layer
An interlayer insulating film is provided to cover a part of the scanning line and the scanning line.
Side different from the scanning line proximity side of the lower layer of the reference signal line
Interlayer insulating film covering at least a part of the longitudinal edge of the
Above, the pixel electrode connected to the switching element in the next column
And the upper layer is the same as the pixel electrode.
A longitudinal edge made of material and located on the pixel electrode proximity side
Is the edge of the interlayer insulating film on the lower layer of the reference signal line,
The longitudinal side surface of the upper layer on the pixel electrode proximity side and the interlayer
The insulating film is the length of the side below the reference signal line near the pixel electrode
By covering at least a part of the direction edge,
The step portion formed by the insulating film is flush with the side surface in the longitudinal direction.
And the scanning of the upper layer above.
On the side surface in the longitudinal direction near the line, the interlayer insulating film is the reference.
At least the longitudinal edge of the lower layer of the signal line near the scanning line
Formed by the interlayer insulating film by covering a part of
Side near the scanning line so as to completely cover the stepped portion
A liquid crystal display device, wherein the liquid crystal display device is provided so as to protrude from a side surface in the longitudinal direction of the . 3. The lower layer of the reference signal line is the same as the scanning line.
The material according to claim 1 or 2, wherein the material is made of one material.
Liquid crystal display device. 4. A switch having three terminals arranged in a matrix.
The switching element and the switching element for each row of the switching elements.
A scanning line connected to the first terminal of the
Parallel to the line and for each column of the switching element
A reference signal line connected to the second terminal of the switching element,
Image connected to the third terminal of the switching element
A pixel substrate having an element electrode, facing the pixel substrate,
A counter electrode facing each of the pixel electrodes and a counter electrode
A counter substrate having a signal line connected to each row, and the pixel substrate
A liquid crystal having a liquid crystal layer sandwiched between a plate and a counter substrate
In the method of manufacturing a display device, the lower layer of the reference signal line is formed of the same material as the scanning line.
And at least a part of the longitudinal edge of the lower layer of the reference signal line.
A step of providing an interlayer insulating film that covers the scanning line and
And the length of the side different from the scanning line proximity side of the lower layer of the reference signal line.
On the interlayer insulating film that covers at least a part of the edge in the hand direction
The pixel electrode connected to the switching element in the next column
Pattern with the same material as the upper layer of the reference signal line.
And the upper layer of the reference signal line is made of the same material.
In the step of forming a turn, the upper layer of the reference signal line
The longitudinal edge of the pixel electrode near the
The edge film is in the longitudinal direction on the side adjacent to the pixel electrode below the reference signal line.
By covering at least a part of the facing edge,
The upper pixel electrode is formed on the step formed by the edge film.
The longitudinal side surface on the proximity side is the length on the proximity side of the lower layer pixel electrode.
Does not protrude from the side surface in the hand direction,
The longitudinal side surface is the interlayer insulating film below the reference signal line.
Cover at least a portion of the longitudinal edge of the layer near the scan line.
Step formed by the interlayer insulating film
So that it completely covers
Liquid characterized by being formed so as to protrude from the side surface
Of manufacturing a crystal display device. 5. A switch having three terminals arranged in a matrix.
The switching element and the switching element for each row of the switching elements.
A scanning line connected to the first terminal of the
Parallel to the line and for each column of the switching element
A reference signal line connected to the second terminal of the switching element,
Image connected to the third terminal of the switching element
A pixel substrate having an element electrode, facing the pixel substrate,
A counter electrode facing each of the pixel electrodes and a counter electrode
A counter substrate having a signal line connected to each row, and the pixel substrate
A liquid crystal having a liquid crystal layer sandwiched between a plate and a counter substrate
In the method of manufacturing a display device, the lower layer of the reference signal line is formed of the same material as the scanning line.
And at least a part of the longitudinal edge of the lower layer of the reference signal line.
A step of providing an interlayer insulating film that covers the scanning line and
And the length of the side different from the scanning line proximity side of the lower layer of the reference signal line.
On the interlayer insulating film that covers at least a part of the edge in the hand direction
The pixel electrode connected to the switching element in the next column
Pattern with the same material as the upper layer of the reference signal line.
And the upper layer of the reference signal line is made of the same material.
In the step of forming a turn, the upper layer of the reference signal line
Place the longitudinal edge on the pixel electrode proximity side under the reference signal line.
At the edge of the interlayer insulation film on the upper layer, the pixel electrode adjacent side of the upper layer
The side surface in the longitudinal direction of the
At least a part of the longitudinal edge of the lower layer adjacent to the pixel electrode
A step formed by the interlayer insulating film by covering the
If it is formed so that the longitudinal side surface of the difference portion is flush with
In addition, the upper layer of the above-mentioned reference signal line is
The side surface in the hand direction is the scanning line formed by the interlayer insulating film.
The scanning lines in the lower layer above so as to completely cover the steps on the near side.
Running above the reference signal line above the side surface in the longitudinal direction on the near side
Form so that the side surface in the longitudinal direction near the inspection line projects.
A method for manufacturing a liquid crystal display device, comprising: 6. A resist for a pattern is provided with a length of the resist.
The side surface in the hand direction is the interlayer insulating film below the reference signal line.
Cover at least a part of the longitudinal edge on the pixel electrode proximity side.
Step formed by the interlayer insulating film
By aligning with the longitudinal side surface of the
The longitudinal edge on the pixel electrode proximity side of the upper layer of the signal line is
Form on the edge of the interlayer insulation film above the reference signal line
The method for manufacturing a liquid crystal display device according to claim 5, wherein