JPH08114819A - Active matrix liquid crystal display device - Google Patents

Abstract

PURPOSE: To prevent the reflection of a laser light by wiring surfaces at the time of subjecting the gate wirings and drain wirings of an active matrix liquid crystal display device to local formation of metallic films by using a laser at the points where correction is made necessary by a disconnection, etc. CONSTITUTION: This active matrix liquid crystal display device has plural thin- film transistor(TFT) elements arranged in matrix directions, the gate wirings 3 commonly connected with the gate electrodes of the TFT elements by each of the respective rows and the drain wirings 4 commonly connected with the drain electrodes of the TFT elements by each of the respective columns. The liquid crystal display device described above is provided with coating layers 5a, 5b having low reflectivity above the gate wirings 3 and the drain wirings 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring structure of an active matrix liquid crystal display device driven by using a thin film transistor (hereinafter abbreviated as TFT) element.

[0002]

2. Description of the Related Art A conventional active matrix liquid crystal display device has a circuit configuration as described in Japanese Patent Publication No. 3-32231, and includes a TFT gate, a source,
The wiring connected to each electrode of the drain had a single-layer wiring structure formed of a metal such as aluminum.

[0003]

In the active matrix liquid crystal display device, a gate wiring or a drain wiring is formed due to foreign matter such as dust in the manufacturing process, defective etching, or unevenness of the substrate surface due to various patterns formed on the substrate. There may be a disconnection. Then, a method of locally forming a metal film or the like at the disconnection point to correct the connection is used for a substrate having relatively few disconnection points of the wiring. As a correction method, a method of forming a metal film using a laser is known. In this correction method, a laser beam is selectively irradiated to a disconnection point in a source gas containing a metal to be formed, and the source gas adsorbed on the substrate surface is decomposed and reacted by the laser light energy to form a metal film. To form. Alternatively, a film forming material containing a metal to be formed is applied to the surface of the substrate in advance, and then,
There is also a method of selectively irradiating a broken portion with a laser to decompose and react with the thermal energy of the laser to form a metal film.

However, in the above-mentioned conventional active matrix liquid crystal display device, since the wiring is a single layer wiring made of metal such as aluminum, the reflectance of the wiring surface is high. Therefore, when forming a repairing metal film or the like on the wiring, since the laser light is reflected on the wiring surface, the light energy necessary for the reaction cannot be obtained on the wiring and the repairing metal film It was difficult to form. In particular, when repairing a wire break near a wire intersection, it is necessary to form a repair metal wire that has a length that crosses the wire intersection on the wire that has the wire breakage. It was easy for thin metal wires and wire breakage to occur. Further, in the case of forming a correction metal wiring on the wiring by using the thermal energy of the laser, the heat generated at the portion irradiated with the laser light is generated by the TFT element on the substrate,
There is a problem that it adversely affects the insulating film, metal wiring, transparent electrode, and the like. The present invention solves at least one of the above problems, and a metal film can be locally formed on a wiring that needs to be repaired due to a disconnection or the like by using a laser. It is also an object of the present invention to provide an active matrix liquid crystal display device in which deterioration of TFT elements, wirings and the like due to heat generated at the time of correction is small.

[0005]

In order to solve the above problems, an active matrix liquid crystal display device of the present invention has a plurality of thin film transistor elements arranged in a matrix direction and a common gate electrode of the thin film transistor element for each row. In an active matrix liquid crystal display device comprising a connected gate wiring and a drain wiring commonly connected to the drain electrodes of thin film transistor elements in each column, a low reflectance coating layer is provided above the gate wiring and the drain wiring. It is characterized by being provided. The low reflectance coating layer can be formed by forming the gate wiring and the drain wiring into a multi-layer wiring structure having a low reflectance coating layer, or by providing a low reflectance coating provided above the gate wiring. It is also possible to form the layer and the low reflectance coating layer provided above the drain wiring in the same layer. An insulating film may be interposed between the gate wiring and drain wiring and the coating layer having a low reflectance. Further, in the case of the above-mentioned multilayer wiring structure, a coating layer having a low reflectance may be laminated on each of the gate wiring and the drain wiring. Alternatively, a structure in which a coating layer having a low reflectance is provided on the surfaces of the gate wiring and the drain wiring may be used.

[0006]

In the present invention, since the coating layer having a low reflectance is provided above the gate wiring and the drain wiring, the laser light is reflected by the coating layer even when the laser is irradiated onto these wirings. Can be prevented, and the loss of laser light energy can be suppressed. by this,
Even on wiring with high reflectance, where it needs to be corrected,
The metal film can be reliably formed by using the laser light. Further, by interposing an insulating film between the gate wiring and the drain wiring and the coating layer having a low reflectance, heat generated by irradiating laser light onto these wirings is blocked by the insulating film. Therefore, it is possible to reduce thermal adverse effects on the TFT element, the insulating film, the metal wiring, the transparent electrode, etc. on the substrate.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the active matrix liquid crystal display device according to the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. 1 is a cross-sectional view of a wiring intersection in an active matrix liquid crystal display device according to the present invention. In FIG. 1, reference numeral 1 is a glass substrate, 2a and 2b are insulating films, 3
Is a gate wiring, 4 is a drain wiring, and 5a and 5b are coating layers. FIG. 2 is a circuit configuration diagram of one pixel in the active matrix liquid crystal display device according to the present invention. In FIG. 2, reference numeral 9 is a semiconductor layer, 10 is a drain electrode, 11 is a source electrode, 12 is a gate electrode, 13a,
Reference numerals 13b and 13c denote through holes, and 14 denotes a transparent electrode. The same components as those in FIG. 1 are designated by the same reference numerals. FIG. 3 shows an example of repairing a defect in a disconnection portion in an active matrix liquid crystal display device according to the present invention.
FIG. 3A is a top view of the defect repairing section, and FIG. 3B is a sectional view of the defect repairing section. In FIG. 3, reference numeral 6a,
6b is a through hole, 7 is a repairing metal wiring, and 8 is a disconnection point, and the same components as those in FIG.

As shown in FIG. 1, an insulating film 2a is formed on a glass substrate 1, and a gate wiring 3 is formed thereon. A coating layer 5a having a low reflectance is formed on the gate wiring 3. Further, an insulating film 2b is formed thereon, and a drain wiring 4 is formed on the insulating film 2b.
A coating layer 5b having a low reflectance is formed on the drain wiring 4. As shown in FIG. 2, the structure of the pixel portion includes the semiconductor layer 9
The drain electrode 10 is arranged on one side and the source electrode 11 is arranged on the other side. A gate electrode 12 is arranged on the upper layer of the semiconductor layer 9 with a gate insulating film interposed therebetween.
The gate wiring 3 is arranged on the upper layer of the gate electrode 12 with an insulating film interposed therebetween, and the through hole 13a connects the gate electrode 12 and the gate wiring 3. The drain wiring 4 is disposed on the upper layer of the drain electrode 10 via an insulating film, and the through hole 13b is formed.
The drain electrode 10 and the drain wiring 4 are connected with each other. A coating layer having a low reflectance is formed on each of the gate wiring 3 and the drain wiring 4. The transparent electrode 14 is arranged above the source electrode 11 via an insulating film, and the source electrode 11 and the transparent electrode 14 are connected to each other through the through hole 13c.

In this embodiment, the coating layer 5a having a low reflectance is used.
And 5b are formed on each of the gate wiring 3 and the drain wiring 4, and the gate wiring 3 and the drain wiring 4 have a two-layer wiring structure including a metal wiring layer and a coating layer. Further, the gate wiring 3 and the drain wiring 4
It is also possible to form the metal wiring layer constituting the above-mentioned metal wiring layer to have a multi-layer structure made of different metals. In this case, the gate wiring 3 and the drain wiring 4 have a multi-layer wiring structure of three layers or more including a coating layer having a low reflectance. An insulating film may be interposed between each of the gate wiring 3 and the drain wiring 4 and the coating layers 5a and 5b having a low reflectance. When the gate wiring 3 and the drain wiring 4 have a multi-layer wiring structure as described above, the coating layers 5a and 5b having a low reflectance have such a multi-layer wiring structure that the reflection of the laser beam emitted from above can be prevented. Is formed on the top layer of. However, it is possible to provide a layer capable of transmitting laser light on the coating layer having a low reflectance, if necessary. Here, the low reflectance coating layers 5a and 5b
Appropriate ones can be used as long as the reflectance of the irradiated laser light is low. For example, a colored transparent layer that absorbs the irradiated laser light, or a treatment so that the surface does not become a mirror surface. A transparent layer roughened with a liquid or the like can be preferably used.

In such an active matrix liquid crystal display device, for example, as shown in FIGS. 3 (a) and 3 (b), the drain wiring 4 is disconnected at the wiring intersection of the gate wiring 3 and the drain wiring 4 (reference numeral in the drawing). 8 indicates a disconnection point), the wiring can be corrected as follows. First, two through holes 6a and 6b are formed by using a cutting laser on both sides of the disconnection point 8 of the drain wiring 4 and on both sides of the wiring intersection of the gate wiring 3 and the drain wiring 4. After that, a defect is repaired by forming a repairing metal wiring 7 connecting the two through holes 6a and 6b by a repairing method using a laser. That is, in the raw material gas containing the metal to be formed, the modified portion is selectively irradiated with a laser to decompose the raw material gas adsorbed on the surface of the coating layer 5b by the light energy of the laser,
The metal wiring 7 is formed by reacting. Alternatively, the film forming material containing the metal to be formed is previously coated with the coating layer 5b.
Alternatively, a method may be used in which the metal wiring 7 is formed by applying it on the surface of, and then selectively irradiating the corrected portion with laser to decompose and react with the thermal energy of the laser.

According to the present embodiment, as shown in FIG. 3B, since the coating layer 5b having a low reflectance is provided on the drain wiring 4, the above laser is provided on the drain wiring 4. Even when the repairing metal wiring 7 is formed by the repairing method used, the coating layer 5b reduces the reflection of the laser light, and the repairing metal wiring 7 can be reliably formed. As a result, it is possible to eliminate thinning or disconnection of the repair wiring 7 when the repair metal wiring 7 is formed by the repair method using a laser, and it is possible to easily repair the defect. When an insulating film is interposed between the gate wiring 3 and the drain wiring 4 and the low-reflectance coating layers 5a and 5b, a repair metal is used on the coating layers 5a and 5b by a correction method using a laser. When the wiring 7 is formed, heat generated by laser irradiation is insulated by the insulating film, so that the TFT element, the insulating film, the metal wiring, the transparent electrode and the like below the insulating film are deteriorated by the heat. To be prevented. Further, when the covering layers 5a, 5b and the insulating film and the like formed above the gate wiring 3 and the drain wiring 4 are formed of transparent layers, the gate wiring 3 and the drain wiring 4 can be visually observed, and the appearance inspection can be performed. It is possible to easily confirm the location of the wire breakage.

Next, a second embodiment of the active matrix liquid crystal display device according to the present invention will be described with reference to FIG. FIG. 4 shows a wiring intersection in the second embodiment of the active matrix liquid crystal display device according to the present invention.
4, the same components as those in FIG. 1 are designated by the same reference numerals. In this embodiment, as shown in FIG. 4, the insulating film 2a is formed on the glass substrate 1 and the gate wiring 3 is formed thereon. The insulating film 2b is formed on the gate wiring 3, and the drain wiring 4 is further formed. A coating layer 5c having a low reflectance is formed on the upper layer so as to cover the gate wiring 3 and the drain wiring 4 via the insulating film 2c. The coating layer 5c is made of an insulating material, and is a single layer film formed in a lattice shape to cover the gate wirings 3 and the drain wirings 4 arranged in parallel in the row direction and the column direction.

In the active matrix liquid crystal display device of the present invention, the low reflectance coating layer may be formed above the gate wiring 3 and above the drain wiring 4 as in the first embodiment, but They can be formed in the same layer as in this embodiment. In the present embodiment, since the coating layer 5c covering the gate wiring 3 and the drain wiring 4 is a single layer film, the forming process is only required once and the manufacturing is simple. When the coating layer 5c that covers the gate wiring 3 and the drain wiring 4 is integrated as in the present embodiment, the coating layer 5c needs to be formed of an insulator. Thereby, even if the repair metal wirings are formed at a plurality of locations on the coating layer 5c with respect to a plurality of disconnection locations, the repair metal wirings are electrically insulated from each other to prevent a short circuit between the wirings. be able to. Here, the low reflectance coating layer 5c
Is a low reflectance of the irradiated laser light, if appropriate, it can be used, for example, a colored transparent insulating layer that absorbs the irradiated laser light, or,
A transparent insulating layer roughened with a treatment liquid or the like so that the surface does not become a mirror surface can be preferably used.

In such an active matrix liquid crystal display device, when a disconnection occurs, the repair metal wiring can be formed in the same manner as in the first embodiment.
In the present embodiment, the coating layer 5c has a low reflectance and the reflection of the irradiated laser is reduced, so that the formation reaction of the metal film is reliably performed and the correction metal wiring can be easily formed. Therefore, even on the gate wiring 3 and the drain wiring 4 having high reflectance, a repairing metal wiring can be easily formed by a repairing method using a laser. Also, the coating layer 5c
Since heat generated by laser irradiation is thermally insulated by the insulating film 2c provided in the lower layer of the covering layer 5c when the repairing metal wiring is formed on the upper side by the repairing method using the laser, the insulating film 2c is formed. The TFT elements, the insulating film, the metal wirings, the transparent electrodes, and the like below it are prevented from being deteriorated by heat. Further, when the covering layer 5c and the insulating films 2c and 2b formed above the gate wiring 3 and the drain wiring 4 are formed of transparent layers, the gate wiring 3 and the drain wiring 4 can be visually observed, and the appearance inspection can be performed. It is possible to easily confirm the location of the wire breakage.

A third embodiment of the active matrix liquid crystal display device according to the present invention will be described with reference to FIG. Figure 5
FIG. 8 shows a wiring intersection in a third embodiment of the active matrix liquid crystal display device according to the present invention.
The same components as those in FIG. 1 are designated by the same reference numerals. In this embodiment, as shown in FIG. 5, the insulating film 2a is formed on the glass substrate 1 and the gate wiring 3 is formed thereon. The insulating film 2b is formed on the gate wiring 3, and the drain wiring 4 is further formed. In this upper layer,
Gate wiring 3 and drain wiring 4 through the insulating film 2c
A coating layer 5d having a low reflectance is formed so as to cover the.
The coating layer 5d is formed so as to be divided at each wiring intersection of the gate wiring 3 and the drain wiring 4. Further, the divided covering layer 5d may be further divided into a plurality of pieces. Here, the coating layer 5d having a low reflectance has a low reflectance of the irradiated laser light, and an appropriate one can be used if it is present. For example, a colored transparent insulation that absorbs the irradiated laser light. A layer, or a transparent insulating layer roughened with a treatment liquid or the like so that the surface does not become a mirror surface can be preferably used.

In such an active matrix liquid crystal display device, when a disconnection occurs, the repair metal wiring can be formed in the same manner as in the first embodiment.
According to this embodiment, the gate wiring 3 and the drain wiring 4
Since the coating layer 5d having a low reflectance is provided on the upper portion, the reflection on the surface of the laser is reduced, and the metal wiring for correction can be easily formed even on the wiring having a high reflectance by the correction method using the laser. . Further, when the repair metal wiring is formed on the coating layer 5d by a repair method using a laser, the heat generated by the laser irradiation is insulated by the insulating film 2c provided below the coating layer 5d. It is possible to prevent the TFT element, the insulating film, the metal wiring, the transparent electrode, and the like on the substrate from being deteriorated by heat. Further, the coating layer 5d and the insulating film 2c formed above the gate wiring 3 and the drain wiring 4,
When 2b is formed of a transparent layer, the gate wiring 3 and the drain wiring 4 can be visually observed, and the divided coating layer 5d
These wirings can be visually observed through the gaps, and the appearance inspection and the disconnection point can be more easily performed.

A fourth embodiment of the active matrix liquid crystal display device according to the present invention will be described with reference to FIG. FIG. 6 shows a fourth active matrix liquid crystal display device according to the present invention.
3 is a view showing a wiring crossing portion showing the embodiment of FIG. The same components as those in FIG. 1 are designated by the same reference numerals. In this embodiment, as shown in FIG. 6, the insulating film 2a is formed on the glass substrate 1 and the gate wiring 3 is formed thereon. A coating layer 5e is formed on the surface of the gate wiring 3, that is, on the upper surface and the side surface. An insulating film 2b is formed thereon, and a drain wiring 4 is further formed thereon. A coating layer 5f is formed on the surface of the drain wiring 4, that is, on the upper surface and the side surface, in the same structure as the gate wiring 3. The structure as in the present embodiment is obtained by a film forming method or the like in which the gate wiring 3 and the drain wiring 4 are respectively formed, and then a film is grown on their surfaces. Here, as the coating layers 5e and 5f having a low reflectance, an appropriate one can be used as long as the reflectance of the irradiated laser light is low, and for example, a colored transparent material that absorbs the irradiated laser light. An insulating layer or a transparent insulating layer roughened with a treatment liquid or the like so that the surface does not become a mirror surface can be preferably used.

In such an active matrix liquid crystal display device, when a disconnection occurs, the repair metal wiring can be formed in the same manner as in the first embodiment.
According to this embodiment, the gate wiring 3 and the drain wiring 4
Since the coating layers 5e and 5f having a low reflectance are provided on the surface of the, the reflection of the irradiated laser is reduced, and even the wiring having a high reflectance can be easily repaired by the repair method using the laser. And reliably. Further, when the cover layer formed on the surfaces of the gate wiring 3 and the drain wiring 4 is formed of a transparent layer, the gate wiring 3 and the drain wiring 4 can be visually observed, and the appearance inspection and the confirmation of disconnection points can be performed. It can be done easily.

[0019]

As described above, in the active matrix liquid crystal display device of the present invention, a plurality of thin film transistor elements arranged in a matrix direction, and a gate wiring in which the gate electrodes of the thin film transistor elements are commonly connected to each row,
An active-matrix liquid crystal display device comprising a drain wiring in which the drain electrodes of thin film transistor elements are commonly connected for each column, characterized in that a coating layer having a low reflectance is provided above the gate wiring and the drain wiring. It is what Therefore, even when the laser is irradiated onto the gate wiring and the drain wiring, it is possible to prevent the laser light from being reflected by the coating layer, and it is possible to suppress the loss of the optical energy of the laser. That is, it is possible to reliably form the metal film using the laser beam even on the wiring having a high reflectance.
Therefore, it is possible to easily and surely form the metal wiring for correction at the portion on the wiring where the correction is required. further,
By interposing an insulating film between the gate wiring and the drain wiring and the coating layer having a low reflectance, it is possible to easily and surely form a repairing metal wiring using a laser beam at a repaired portion of the wiring. At the same time, heat generated by irradiating the laser beam onto these wirings is blocked by the insulating film, so that the TFT element on the substrate, the insulating film,
It is possible to reduce adverse thermal effects on metal wiring, transparent electrodes, and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a wiring intersection in an active matrix liquid crystal display device according to the present invention.

FIG. 2 is a configuration diagram of one pixel in an active matrix liquid crystal display device according to the present invention.

3A and 3B show an example of defect correction of a disconnection portion in an active matrix liquid crystal display device according to the present invention, FIG. 3A being a top view and FIG. 3B being a sectional view.

FIG. 4 is a cross-sectional perspective view of a wiring intersection showing a second embodiment of the active matrix liquid crystal display device according to the present invention.

FIG. 5 is a cross-sectional perspective view of a wiring crossing portion showing a third embodiment of the active matrix liquid crystal display device according to the present invention.

FIG. 6 is a cross-sectional view of a wiring intersection showing a fourth embodiment of the active matrix liquid crystal display device according to the present invention.

[Explanation of symbols]

 2a, 2b, 2c ... Insulating film, 3 ... Gate wiring, 4 ... Drain wiring, 5a, 5b, 5c, 5d, 5e, 5f ... Covering layer, 10 ... Drain electrode 12 ... Gate electrode

Claims (6)

[Claims] 1. A plurality of thin film transistor elements arranged in rows and columns, a gate wiring in which a gate electrode of the thin film transistor element is commonly connected to each row, and a drain wiring in which a drain electrode of the thin film transistor element is commonly connected to each column. An active matrix liquid crystal display device comprising: a gate electrode and a drain wiring, and a coating layer having a low reflectance provided above the gate wiring and the drain wiring. 2. The gate wiring and the drain wiring,
The active matrix liquid crystal display device according to claim 1, wherein the active matrix liquid crystal display device has a multilayer wiring structure having a coating layer having a low reflectance. 3. The active matrix liquid crystal display device according to claim 2, wherein a covering layer having a low reflectance is laminated on each of the gate wiring and the drain wiring. 4. A low reflectance coating layer provided above the gate wiring and a low reflectance coating layer provided above the drain wiring are formed in the same layer. Item 1. The active matrix liquid crystal display device according to item 1. 5. The active matrix liquid crystal according to claim 1, wherein a coating layer having a low reflectance is provided above the gate wiring and the drain wiring via an insulating film. Display device. 6. The active matrix liquid crystal display device according to claim 1, wherein a coating layer having a low reflectance is provided on the surfaces of the gate wiring and the drain wiring.