JPH0833558B2 - Active matrix array - Google Patents

Description

TECHNICAL FIELD The present invention relates to an active matrix array used in a transmissive active matrix array type liquid crystal panel.

2. Description of the Related Art In recent years, as the number of picture elements in liquid crystal display devices has increased, the number of scanning lines has increased, and the display contrast and response speed of conventional simple matrix liquid crystal display devices have decreased. Active matrix type liquid crystal panels in which switching elements are arranged are being used. However, the active matrix array used for the active matrix type liquid crystal panel has to manufacture tens of thousands of thin film transistors (hereinafter referred to as TFTs) on a single substrate without defects, and thus the manufacturing yield is very high. It will be a big challenge. In order to manufacture an active matrix array with a high yield, it is necessary to manufacture it on the same level as an IC manufacturing line with a high degree of cleanliness, but if one or two defects should occur, this should be corrected. The method must be established. Hereinafter, an example of an active matrix array capable of correcting defects will be described with reference to the drawings.

FIG. 7A is a partially enlarged plan view of a conventional active matrix array. However, explanations are omitted where they are unnecessary. In addition, there are enlarged or reduced portions in the drawings. The above also applies to the following drawings. In FIG. 7 (a), 1a, 1b, 1c and 1d
Is a pixel electrode, 11 and 71 are insulator films, 12 is a gate signal line, 13
Is a source signal line, 14 is a drain terminal, and 72 is a metal thin film. FIG. 7 (b) is a sectional view taken along the line CC 'of FIG. 7 (a). In FIG. 7B, 73 is a glass substrate, 74 is an electrical connection pattern, and 75 is a contact hole. As shown in FIG. 7 (b), an electrical connection pattern 74 is formed on a glass substrate 73, an insulator film 71 is formed thereon, and a contact hole 75 is formed, and then the pixel electrodes 1a and 1c are formed. Form. Further, a metal thin film 72 is formed on the portion where the insulator film 71 and the pixel electrode 1c overlap. Hereinafter, components having the same numbers or the same symbols have the same or similar configurations or similar functions.

A method of correcting the active matrix array configured as described above will be described with reference to FIG. FIG. 8 is a partially enlarged plan view of the active matrix array. In FIG. 8, 81 is the TFT source.
It is a short circuit defect between drains. As mentioned earlier, there are at least tens of thousands of active matrix arrays.
TFT needs to be manufactured. But the above tens of thousands of TFTs
Is unlikely to be a good product. Therefore, in order to improve the yield, it is necessary to correct the picture elements driven by the defective TFT so that the picture elements are normally lit. As the above-mentioned defect mode, for example, when a short-circuit defect between the source and drain of the TFT occurs as shown in FIG.
A signal applied to the pixel electrode 1a flows into the pixel electrode 1a, and is always in a lighting state (hereinafter referred to as a white defect). Further, hereinafter, a defect which is always in a non-lighting state when a short circuit defect between the gate and the drain of the TFT occurs is called a black defect. The above
In the case of a TFT source-drain short-circuit defect, first, the DD ′ line is cut by laser light or the like so that a signal is not input to the pixel electrode 1a. Next, irradiate point a with laser light,
The metal thin film 72 is melted, and the pixel electrode 1c and the electrical connection pattern 74 are electrically connected via the metal thin film 72 as shown in FIG. Therefore, the pixel electrode 1a is connected to the electrical connection pattern 74
Is connected to the picture element electrode 1c via, and drives the picture element electrode 1c
It will be driven by the TFT and will be pseudo normal lighting. In the above-mentioned lighting state, the pixel electrodes 1a and 1c perform the same display, but when displaying a television image signal, it is visually the same as normal lighting. (For example, JP-A-56-10169
However, in the configuration of the active matrix array as described above, the pixel electrode and the electrical connection pattern 74 are electrically connected by irradiating the laser light to dissolve the metal thin film 72. are doing.

The metal thin film 72 is formed on the insulating film 71 having poor thermal conductivity, and its area is minute. Therefore, when the metal thin film 72 is irradiated with the laser light, the metal thin film 72 is not melted but is likely to be evaporated. Therefore, it is very difficult to set the laser conditions such as the laser power and the irradiation time for melting the metal thin film 72, which causes a connection failure. That is, it is difficult to correct the picture element defect. It should be noted that in JP-A-59-101693, it is also stated that the metal thin film 72 is not necessary, but the pixel electrode 1c
In addition, the insulator film 71 has a transparent color, and usually easily transmits laser light. Therefore, in the state where the metal thin film 72 is not formed, the laser light directly heats the electrical connection pattern 74, which makes a hole in the insulator film 71 by the heating and melts the constituent material of the pixel electrode to electrically. Nearly impossible to connect to.

Means for Solving the Problems In order to solve the above problems, in the active matrix array according to the first aspect of the present invention, a signal line is arranged between a first pixel electrode and a second pixel electrode, and the first pixel electrode is provided. A first metal thin film formed above and near the signal line;
A first insulator film covering the signal line and the first metal thin film, one end electrically connected to the second pixel electrode, and the other end viewed from above the active matrix array. A connection wire made of metal formed to overlap the first metal thin film, a second insulator film covering the connection wire, one end connected to the first pixel electrode, and another A second metal thin film is formed so that an end of the second metal thin film is overlapped with the first metal thin film when viewed from above the active matrix array. The active matrix array has a signal line arranged between a first pixel electrode and a second pixel electrode, and a first metal thin film formed on the first pixel electrode and in the vicinity of the signal line. , On the second pixel electrode, And a third metal thin film formed in the vicinity of the signal line, and a first insulator film covering the signal line, the first metal thin film, and the third metal thin film.
One end is formed so as to overlap with the first metal thin film when viewed from above the active matrix array, and
A connection wire made of a metal, the other end of which is formed so as to overlap the third metal thin film, and a second wire which covers the connection wire.
An insulator film of which one end is connected to the first pixel electrode,
And a fourth metal thin film formed so that the other end thereof overlaps the first metal thin film when viewed from above the active matrix array, one end of which is connected to the second pixel electrode, and the other end of which is Is a fifth metal thin film formed so as to overlap the third metal thin film when viewed from above the active matrix array.

The working wiring is formed in an insulating state from the first and second metal thin films. By irradiating the second metal thin film with light,
The metal thin film and the wiring are heated and melted, and the lower first and second insulating films are destroyed. Therefore, at least one of the first metal thin film and the wiring or the second metal thin film and the wiring is electrically connected.

Embodiment An embodiment of the active matrix array of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially enlarged plan view of an active matrix array according to the first embodiment of the present invention. In FIG. 1, reference numeral 15 is a connection wiring forming portion. FIG. 2 (a) is an enlarged plan view of the connection wiring formation portion of FIG. Further, FIG. 2 (b) is a sectional view taken along the line AA 'in FIG. 2 (a). First
As is clear from the figure, the connection wiring formation portion is formed on the source signal line 13. The forming portion is formed between at least one adjacent pixel electrode. In addition, FIG. 2 (a) (b)
As is clear from the figure, the metal thin film is
22a and 22b (hereinafter referred to as a first metal thin film) are formed.
The formation area of the thin film is 10 μ ² m or more, preferably 100 μm.
It is formed to a size of μ ² m or more. The larger the formation area, the wider the range of connection conditions described below. Also, the film thickness is 50
Form at least 0Å, preferably at least 1000Å. As the constituent substance, Cr / Al is preferable. The first metal thin film 22
An insulator film 21 (hereinafter referred to as a first insulator film) is formed on the a / 22b and the source signal line 13a. An inorganic substance such as SiN _x .SiO ₂ is used as the constituent substance of the first insulator film. Preferably, dense and hard formed SiN _X
Use a membrane. The film thickness is preferably 1 μm or less.
Form less than 2000Å. The first insulating film is formed on the first insulating film.
The connection wiring 23 is formed so as to overlap the formation region of the metal thin film 22a. One end of the connection wiring 23 passes through the upper layer portion of the source signal line 13 and is formed on the formation region of the first metal thin film 22b formed on the adjacent pixel electrode. As a constituent material of the connection wiring 23, Al or the like having a melting point and a boiling point different from each other is preferable, and the film thickness thereof is formed to 1000 Å or more, preferably 2000 Å or more. The second insulating film 24 is formed on the connection wiring 23.
(Hereinafter, referred to as a second insulator film) is formed. The constituent material is the same material as the first insulator film 21. The film thickness is formed thinner than the first insulator film 21. This is because the film thickness of the first insulator film is formed relatively thick in order to prevent short circuit between the connection wiring 23 and the source signal line 13 due to the pinhole. On the second insulator film 24,
The second metal thin film 25 so as to overlap the first metal thin films 22a and 22b.
a · 25b (hereinafter referred to as a second metal thin film) are formed, and the metal thin films 25a · 25b are electrically connected to the pixel electrodes 1a and 1C. The thickness of the metal thin film is 1000 Å or more, preferably 2000 Å or more. Further, as the constituent substance, Cr or the like having a relatively high light absorption rate is used. The
Although the metal thin films 21a and 25b are not shown in FIGS. 2 (a) and 2 (b) in order to make good connection with the pixel electrodes 1a and 1b, they are formed on the pixel electrodes at the same time when the connection wiring 23 is formed. A metal thin film is formed in advance to reduce the step due to the insulator films 21 and 24 and prevent the step from being broken.

A method of correcting the active matrix array of the present invention will be described below with reference to FIGS. 1 and 3. In FIG. 3, reference numeral 31 is a ray trajectory. The disconnection of the TFT drain terminal from the pixel electrode 1a is the same as in the conventional active matrix array. Next, the points b and c are irradiated with light. As the light, a light having a wavelength that is well absorbed by the second metal thin films 25a and 25b is preferable, and a light having a visible wavelength is usually used. Specifically, the focused light of a xenon lamp or the like is used. Irradiation power of the light source varies as compared with a laser or the like, but the device cost is low and the control is relatively easy. The heating condition is such that the power density of the condensing portion is relatively low and the light pulse is irradiated a plurality of times.
FIG. 3 is a cross-sectional view of the connection wiring forming portion when light is applied to points b and c to complete the connection process. In FIG. 3, b
At this point, the second metal thin film 25a and the second insulator film 24 are shaken and evaporated to connect the connection wiring 23 and the first metal thin film. Further, at the point c, the second metal thin film and the connection wiring are connected. In the connected state, a crack is generated in the insulator film, and the metal thin film that is in contact with the insulating film flows into the insulating film to establish an electrical connection. Further, even if the same power is used, the output optical power varies, and the second metal thin film or the like in the upper layer may evaporate as at point b. However, the connection wiring 23 is sandwiched by the first and second metal thin films. Therefore, electrical connection can be established with either the upper or lower metal thin film. Therefore, the range of light irradiation conditions is very wide. Also, the connection wiring is formed by the pin pole of the first insulator film.
23 and the source signal line 13, and when a short circuit occurs between the connection wiring 23 and the first metal thin film, the source signal line is always kept on the pixel electrode.
The signal applied to 13 is applied. Therefore, a white spot defect occurs, but the probability thereof is extremely small.

Incidentally, the irradiation direction of the light beam, the light beam is transmitted through the substrate 20,
Alternatively, the first metal thin films 22a and 22b may be heated directly. Also, even after the formation of the active matrix,
It is also possible to assemble the liquid crystal panel, display the liquid crystal panel, detect a defect, and irradiate the connection wiring forming portion of the picture element with a light beam. Since the black matrix is formed on the active matrix after the liquid crystal panel is formed, it is often impossible to make the light beam incident from the surface to correct the defect.

The second embodiment of the present invention will be described below. Fourth
FIG. 3A is a partially enlarged plan view of the connection wiring forming portion 15 in the active matrix array of the present invention. Also,
FIG. 4 (b) is a sectional view taken along line BB 'of FIG. 4 (a). In FIG. 4 (b), 41 is an insulator film. The difference between the second embodiment and the first embodiment of the present invention is the first metal thin film.
This is because the first insulator film 21 was not formed on 22b.
Therefore, the connection wiring 23 and the pixel electrode 1c are electrically connected. Other constituent materials and film thickness are the same as those in the first embodiment. In the second embodiment of the present invention, the pixel electrodes 1a and 1c can be formed by simply irradiating the point d in FIG.
Can be electrically connected. FIG. 5 is a sectional view of the connection wiring forming portion 15 when the above-mentioned connection is made.

In this embodiment, the first insulator film 21 is the insulator film 11
Although it is expressed as if they are different materials, it is clear that they may be the same material.

Although the first and second insulator films 21 and 24 are described as being formed only on a part of the signal line, the present invention is not limited to this.
Obviously, it may cover the entire signal line.

Further, in the second embodiment of the present invention, the connection wiring 21 and the picture element electrode 1c are illustrated as being electrically connected via the first metal thin film 22b, but the present invention is not limited to this. Obviously, the same effect can be obtained without the first metal thin film 22b.

Further, in the embodiment of the present invention, the connection wiring formation portion 15 is formed on the source signal line 13, but the present invention is not limited to this, and it is formed on the gate signal line 12 as shown in FIG. It is obvious that the same effect can be obtained with.

Further, although the focused light of the xenon light is used for the connection, it is not limited to this.

The active matrix array of the present invention has the connection wiring 23.
A metal thin film is formed on and under the insulating film. Therefore, by irradiating the light beam, the metal thin film and the connection wiring can be easily electrically connected, and therefore the adjacent pixel electrodes can be surely electrically connected to each other. Can be given to improve the yield. In addition, since the range of irradiation conditions of the light beam can be extremely wide, it is not necessary to use an expensive laser device. Further, the light can be transmitted through the substrate and the first metal thin film can be heated to connect with the connection wiring. Therefore, the defect can be corrected even after the liquid crystal panel is formed. From the above, the effect is great.

[Brief description of drawings]

FIG. 1 is a partially enlarged plan view of an active matrix array according to the first embodiment of the present invention, and FIGS. 2 (a) and 2 (b).
Is an enlarged plan view and cross-sectional view of the connection wiring forming portion, FIG.
FIG. 5 is a sectional view of the connection wiring forming portion, and FIGS. 4 (a) and 4 (b).
Is an enlarged plan view and a sectional view of a connection wiring forming portion of the active matrix array in the second embodiment of the present invention;
FIG. 6 is a partially enlarged plan view of an active matrix array in another embodiment of the present invention, and FIGS. 7 (a) and 8 are partially enlarged plan views of a conventional active matrix array, FIG. 7 (b). ) FIG. 9 is a cross-sectional view of a pattern portion for electrical connection. 1a, 1b, 1c, 1d …… Pixel electrode, 11 …… Insulator film, 12 …… Gate signal line, 13 …… Source signal line, 14 …… Drain terminal, 15 …… Connection wiring formation part, 20… … Substrate, 21 …… first insulator film, 22a, 22b …… first metal thin film, 23 …… connection wiring, 2
4 …… Second insulator film, 25a, 25b …… Second metal thin film, 31 ……
Ray trajectory, 41,71 ... Insulator film, 72 ... Metal thin film, 73
…… Glass substrate, 74 …… Electrical connection pattern, 75 ……
Contact hole, 81 ... Short circuit defect.

Claims (3)

[Claims] 1. An active matrix array used for a liquid crystal panel, wherein a signal line is arranged between a first pixel electrode and a second pixel electrode, and the signal line is arranged on the first pixel electrode and on the signal line. A first metal thin film formed in the vicinity, a first insulator film covering the signal line and the first metal thin film, one end electrically connected to the second pixel electrode, and A connecting wire made of metal formed so that the other end thereof overlaps the first metal thin film when viewed from above the active matrix array, a second insulating film covering the connecting wire, and one end of the connecting wire. A second metal thin film is formed, which is connected to the first pixel electrode and has the other end overlapping the first metal thin film when viewed from above the active matrix array. Active matri Kusuarei. 2. An active matrix array used for a liquid crystal panel, wherein a signal line is arranged between a first pixel electrode and a second pixel electrode, and the signal line is arranged on the first pixel electrode and on the signal line. A first metal thin film formed in the vicinity, a third metal thin film formed on the second pixel electrode and in the vicinity of the signal line, on the signal line and on the first metal thin film And a first insulator film covering the third metal thin film, one end of which is formed so as to overlap the first metal thin film when viewed from above the active matrix array, and
A connection wire made of metal formed so that the other end of the one end overlaps with the third metal thin film, a second insulator film covering the connection wire, and one end of the first pixel electrode A fourth metal thin film, which is connected to the second pixel electrode, the other end of which is formed so as to overlap with the first metal thin film when viewed from above the active matrix array, and one end of which is connected to the second pixel electrode, and And a fifth metal thin film formed so that the other end thereof overlaps with the third metal thin film when viewed from above the active matrix array. 3. An active matrix array characterized in that the film thickness of the first insulator film is 1 μm or less, and the connection wiring is formed of aluminum having a thickness of 1000 Å or more.