JP2803792B2 - Active matrix type liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display having thin film transistors.

[0002]

2. Description of the Related Art FIG. 1 shows the configuration of wiring and a drive circuit of an active matrix substrate constituting an active matrix type liquid crystal display device.

In this active matrix substrate, a plurality of scanning signal wirings 101 and a plurality of data signal wirings 102 are arranged orthogonally to each other on an insulating base substrate 113. In each region surrounded by the signal wiring 102, a thin film transistor 105 (ThinFi) serving as a switching element of the picture element 107 is provided.
lm Transistor, hereinafter abbreviated as TFT. ) Is provided. An additional capacitor 106 is also provided in parallel with the picture element 107, and a data signal is written to the picture element 107 and the additional capacity 106. An electrode different from each drain electrode of each picture element 107 and each additional capacitance 106 is connected to one additional capacitance wiring 108 disposed in parallel with the scanning signal wiring 101. These additional capacitance lines 10
8 is further integrated into one line and one common electrode 111
It is connected to the. The common electrode 111 is further connected to a counter electrode (not shown) on a counter substrate (not shown). A seal member 110 of a predetermined width made of resin is formed around the display area including all the picture elements 107 so as to surround the display area.
Are bonded between a counter substrate (not shown) disposed opposite to the base substrate 113 and the base substrate 113 with a liquid crystal interposed therebetween.

The scanning signal line driving circuit 104 and the data signal line driving circuit 103 are provided outside the closed region formed by the seal member 110, respectively. This is the sealing member 110
This is because the yield of the driving circuits is reduced when the driving circuits 104 and 103 are formed so as to overlap with each other. Further, the common electrode 111 of the additional capacitance wiring 108 is also
Counter electrode (not shown) formed on the outside of the counter substrate
Connected to.

As described above, the scanning signal line driving circuit 104, the data signal line driving circuit 103, and the common electrode 111 of the additional capacitance wiring 108 are formed outside the seal member 110, so that the scanning signal line 101 and the scanning signal line driving Circuit 104
, A wiring connecting the data signal wiring 102 and the data signal line driving circuit 103, and an additional capacitance wiring 108.
The wiring connecting the common electrode 111 of the additional capacitance wiring 108 and the common electrode 111 has a structure that passes directly below the seal member 110.

[0006]

By the way, in an active matrix substrate having a structure in which wiring is provided directly below the seal member 110, many disconnections occur in the manufacturing process, and a liquid crystal display device having an active matrix substrate having this structure is provided. However, there is a problem that the production yield of the semiconductor device is reduced. The cause of the disconnection will be described below.

In the manufacturing process of a liquid crystal display device, a procedure for bonding an active matrix substrate and its counter substrate with a seal member is generally performed as follows.

First, a predetermined pattern is formed by printing a resin for the seal member 110 on the opposing substrate. Next, the active matrix substrate and the opposing substrate are bonded together while being positioned with a precision of several μm in the horizontal direction, and pressed so that the distance between the substrates in the vertical direction is 5 μm. In this case, a fiber or the like having a diameter corresponding to a desired substrate interval is mixed in the resin. When the desired position is reached, the resin is heated and the resin is cured by irradiation with UV light or the like. Approximately 20 for this vertical positioning
A large pressure of kgf / cm ² is required. For this reason, a large force is applied to the wiring formed immediately below the seal member, and a defect such as disconnection occurs.

The likelihood of disconnection depends on the cross-sectional structure of the active matrix substrate.

FIG. 6 shows a TFT on an active matrix substrate.
5 shows an example of a cross-sectional configuration of a portion including the portion 105.

An active matrix substrate is formed on a transparent insulating base substrate 113 on a semiconductor portion 1 of a TFT 105.
14, the source electrode 115a of the TFT 105, the TFT 10
5, a drain electrode 115b and a lower electrode 116 of an additional capacitor are formed, and a gate insulating film 117 is provided on the entire substrate so as to cover them. The gate electrode 11 of the TFT 105 is formed on the gate insulating film 117.
8. An upper electrode 119 of additional capacitance is formed, and an interlayer insulating film 120 is formed over the entire surface of the substrate to cover them. Data signal wiring 1 on interlayer insulating film 120
21 is formed, and a second interlayer insulating film 122 is formed over the entire surface of the substrate 21 so as to cover it. Then, a pixel electrode 123 made of a transparent conductive film is pattern-formed on the second interlayer insulating film 122. The pixel electrode 123 is connected to the TFT 105 via a contact hole formed through the gate insulating film 117, the first interlayer insulating film, and the second interlayer insulating film at the position where the drain electrode 115b of the TFT 105 is formed. It is connected to the drain electrode 115b. It is desirable that the wiring passing directly below the seal has a low resistance, but further low resistance is required in order to suppress delay and rounding of data signals. It is common to use a low resistance metal such as Al together with the signal wiring. Further, it is desirable to increase the film thickness to some extent in order to reduce the resistance, but it is difficult to flatten Al having a large film thickness. Therefore, the portion where the wiring is formed is very uneven, and the sealing member 11 just above the wiring is formed.
The wire is easily affected by the force applied to 0, so that disconnection is likely to occur. The wiring passing directly below the seal member 110 depends on the number of elements of the display portion, but is generally in the unit of several hundred to several thousand. If any one of these wires is broken, it is fatal for a display device. It becomes a defect.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and in an active matrix type liquid crystal display device, disconnection of a wiring disposed immediately below a seal member of an active matrix substrate. It is an object of the present invention to provide a liquid crystal display device having an active matrix substrate having a structure capable of suppressing the occurrence of defects and capable of manufacturing with high yield.

[0013]

In the active matrix type liquid crystal display device according to the present invention, a liquid crystal layer is sandwiched between a pair of insulating substrates which are arranged to face each other, and one of the pair of insulating substrates is closer to the liquid crystal layer. Pixel electrodes are arranged in a matrix on the surface of each of the pixels, and a plurality of scanning signal wirings and a plurality of data signal wirings are arranged so as to cross each other around each of the pixel electrodes. A switching element provided in the vicinity of an intersection of wiring is an active matrix liquid crystal display device connected to a pixel electrode, wherein the display region is provided outside a display region in which the pixel electrode is provided in a matrix. , And the liquid crystal is sealed by a seal member provided between the pair of insulating substrates, and each scanning signal line and each data signal line extend outside the seal member. Each scan Each of the seal member and the overlapped portion of the No. wiring and the data signal lines is composed of a plurality of branch lines, by the above-described object is achieved.

Further, each of the scanning signal wiring portions and each of the data signal wiring portions overlapping the seal member may be formed with a thickness of 300 nm or more.

Further, at least one of the branch lines may be formed on the same plane as the scanning signal wiring, and at least one of the other branch lines may be formed on the same plane as the data signal wiring.

Further, a driving circuit for supplying a signal to the scanning signal wiring and / or the data signal wiring may be provided on the same substrate.

[0017]

According to the present invention, each scanning signal wiring and each data signal wiring of the active matrix type liquid crystal display device extend outside the liquid crystal sealing member, and each scanning signal wiring and each data signal wiring are provided. A section sandwiching a portion overlapping each of the seal members is constituted by a plurality of branch lines. Therefore, even if one branch line is broken, conduction is enabled by the remaining branch lines.

[0018]

Embodiments of the present invention will be described below.

[First Embodiment] FIG. 1 shows a part of a circuit configuration of an active matrix substrate constituting an active matrix type liquid crystal display device according to the present invention.

A plurality of scanning signal wirings 1 and a plurality of data signal wirings 2 are arranged on an insulating base substrate 20 at right angles to each other, and adjacent scanning signal wirings 1 and data signal wirings 2 are connected to each other. In each of the surrounding areas, a thin film transistor 5 (Thin Film) which is a switching element of the picture element 7 is provided.
Transistor, hereinafter abbreviated as TFT. ) Is provided. The thin film transistor 5 is connected to one of the scanning signal wirings 1 and the data signal wirings 2 constituting the region. Each picture element 7 is also provided with an additional capacitor 6 in parallel with each picture element 7. When the TFT 5 is turned on, a data signal is written into the picture element 7 and the additional capacity 6. An electrode different from the drain electrode of each picture element 7 and each additional capacitance 6 is connected to one additional capacitance wiring 8 arranged in parallel with the scanning signal wiring 1. These additional capacitance lines 8 are further integrated into one line to form one common electrode 11.
It is connected to the. The common electrode 11 is further connected to a counter electrode (not shown) on a counter substrate (not shown).

A seal member 10 of a predetermined width made of resin is formed around the display area including all the picture elements 7 so as to surround the display area, and the seal member 10 faces the base substrate 20. A liquid crystal (not shown) is interposed between a counter substrate (not shown) and a base substrate 20 which are arranged, and the two substrates are bonded to each other.

The scanning signal line driving circuit 4, the data signal line driving circuit 3, and the common electrode 11 of the additional capacitance line 8 are provided outside the seal member 10, that is, outside the display area. The wiring connecting the signal line driving circuit 4, the wiring connecting the data signal wiring 2 and the data signal line driving circuit 3, and the wiring connecting the additional capacitance wiring 8 and the common electrode 11 of the additional capacitance wiring 8 are each formed of the sealing member 10. Pass directly below. The wiring passing directly below the seal member 10 is formed using the same low-resistance metal as the data signal wiring 2, and each of the wirings in this section is provided with a branch line 12 of this wiring.

FIG. 2 shows in detail the structure of the wiring passing directly below the seal member 10 and the branch line 12 thereof. The branch line 12 of the wiring runs parallel to the wiring, and two branch points where the branch line 12 branches from the wiring are provided inside (on the display area side) and outside the seal member 10, respectively. Due to such a structure, even if one of the wiring and the branch line 12 is broken, if the wiring of the remaining route or the branch line 12 is not broken, the display device will not be defective.

Therefore, it can be expected that a good yield can be obtained even if a thick wiring is used for the wiring and the branch line 12 in order to reduce the resistance, and the same low resistance metal as the data signal wiring 2 is used. It is also possible to use one having a thickness of 300 nm or more.

In this embodiment, only one branch line 12 is provided for one wiring, but a plurality of branch lines 12 may be provided for one wiring.

[Second Embodiment] In the second embodiment, as shown in FIG. 3, a wiring runs between a wiring in a section directly below the seal member 10 and a branch line 12 running parallel to the wiring. A plurality of branch paths 13 are provided perpendicular to the direction, and the wiring and the branch line 12 are connected by these branch paths 13. Therefore, the number of detours is increased as compared with the case where the branch line 12 of the wiring immediately below the seal member 10 is a structure having only a path running parallel to the wiring as in the first embodiment. Has become.

[Third Embodiment] FIG. 4 shows a wiring structure immediately below a seal member 10 according to a third embodiment of the present invention.

In the third embodiment, as shown in FIG. 4A, wirings formed in the same layer as the scanning signal wiring 1 are provided at points outside and inside the seal member 10 of the wiring. The branch lines 12 formed in the same layer as the data signal wiring 2 are connected in parallel via the contact holes 14. In this embodiment, the wiring has the same layer as the scanning signal wiring 1 and the branch line has the same layer as the data signal wiring 2, but the wiring has the same layer as the data signal wiring 2. Alternatively, a branch line having the same layer as the scanning signal wiring 1 may be used. FIG. 4B shows that the contact hole 14 is formed not only on the outside and inside of the seal member 10 but also on the seal member 1.
A case is also shown in which a section is provided immediately below 0. Also in the case of (b) of the third embodiment, since the structure is such that the number of detours of the wiring directly below the seal member 10 is increased as compared with the first embodiment, the probability of avoiding a disconnection failure is high.

In the third embodiment, one of the wirings immediately below the seal member 10 is formed in the same layer as the scanning signal line 1, but this scanning signal line 1 is often formed using Si. Since Si has higher heat resistance than a metal and can use a higher temperature process, it is easy to flatten the difference. Therefore, the wiring formed by using Si in the third embodiment can be easily flattened, and the generation of uneven force applied to the wiring when applying pressure to the sealing member 10 and bonding the substrate is suppressed. It can be expected that the occurrence of disconnection at the time of forming the seal portion can be further suppressed in combination with the above structure.

[0030]

As described above in detail, according to the structure of the active matrix substrate of the present invention, since each of the wirings disposed immediately below the sealing resin is provided with multiple paths, each wiring and its multiple paths are provided. Even if one of them is disconnected, it is not a failure unless the other is disconnected, so that the occurrence of disconnection failure during the manufacturing process can be suppressed. Therefore, according to the configuration of the active matrix substrate of the present invention, a liquid crystal display device with few disconnection defects can be manufactured with high yield.

[Brief description of the drawings]

FIG. 1 is a diagram showing wiring and a circuit configuration of an active matrix substrate of a liquid crystal display device according to the present invention.

FIG. 2 is a diagram showing a wiring immediately below a seal member of the active matrix substrate and a branch line thereof according to the first embodiment of the present invention.

FIG. 3 is a view showing a wiring immediately below a seal member and a branch line thereof on an active matrix substrate according to a second embodiment of the present invention.

FIG. 4 is a view showing a wiring immediately below a seal member of an active matrix substrate and a branch line thereof according to a third embodiment of the present invention. (A) shows a case where the contact holes 14 are provided only on both sides of the seal member 10, and (b) shows a case where the contact holes 14 are also provided in a section directly below the seal member 10.

FIG. 5 is a diagram showing a wiring and drive circuit configuration of an active matrix substrate according to a conventional example.

FIG. 6 is a cross-sectional view of a portion including a TFT of an active matrix substrate.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 scanning signal wiring 2 data signal wiring 3 data signal line driving circuit 4 scanning signal line driving circuit 5 thin film transistor (TFT) 6 additional capacitance 7 picture element 8 additional capacitance wiring 10 sealing member 11 common electrode 12 wiring branch line 13 branch line Branch 14 Contact hole 20 Base substrate

Continued on the front page (72) Inventor Yoji Yoshimura 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Masumi 22-22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (58 ) Surveyed field (Int.Cl. ⁶ , DB name) G02F 1/1345 G02F 1/1339

Claims (4)

(57) [Claims] 1. A liquid crystal layer is sandwiched between a pair of insulating substrates arranged opposite to each other, and picture element electrodes are arranged in a matrix on a surface of one of the pair of insulating substrates on a liquid crystal layer side. In addition, a plurality of scanning signal wirings and a plurality of data signal wirings are provided so as to cross each other through the periphery of each picture element electrode, and a switching element provided near an intersection of the two signal wirings is a picture element. An active matrix liquid crystal display device connected to electrodes, wherein the pixel electrodes surround the display region outside a display region provided in a matrix, and are provided between the pair of insulating substrates. The liquid crystal is sealed by the provided sealing member,
Each scanning signal line and each data signal line extend outside the seal member, and a portion of each scan signal line and each data signal line overlapping with each seal member is constituted by a plurality of branch lines. Active matrix type liquid crystal display device. 2. The active matrix type liquid crystal display device according to claim 1, wherein each scanning signal wiring portion and each data signal wiring portion overlapping the seal member are formed with a thickness of 300 nm or more. 3. The semiconductor device according to claim 1, wherein at least one of the branch lines is formed on the same plane as the scanning signal wiring, and at least one of the other branch lines is formed on the same plane as the data signal wiring.
Or an active matrix liquid crystal display device according to 2. 4. The active matrix type liquid crystal display device according to claim 1, wherein a driving circuit for supplying a signal to said scanning signal wiring and / or said data signal wiring is provided on the same substrate.