JP3407396B2 - Liquid crystal display device - 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,
In particular, it relates to an active matrix type liquid crystal display element.

[0002]

2. Description of the Related Art A conventional active matrix liquid crystal display device includes a display pixel substrate 110 shown in FIG.
The counter substrate 130 shown in (B) is joined by a sealant with a spacer interposed therebetween, and is formed by filling a liquid crystal between these substrates. The display pixel substrate 110 is
As shown in FIG. 10A, a data line 112, a gate line 113, a thin film transistor (TFT) 114, a pixel electrode 115, a compensation capacitance line 116, a counter electrode connection pad 117, and a data terminal 11 are formed on a glass substrate 111.
8, the gate terminal 119, the compensation capacitance terminal 120, and the counter electrode input terminal 121 are arranged.
In addition, the counter substrate 130, as shown in FIG.
It is formed by disposing one counter electrode 133 on the glass substrate 131.

[0003]

This liquid crystal display device is
Since the counter electrode 133 is formed of a transparent conductive material having a relatively high resistivity, such as ITO (Indium-Tin), when the display device is enlarged to have a large area, a voltage drop occurs in the counter electrode 133. Occurs, the voltage of each part on the counter electrode 133 is not constant, and display unevenness occurs. Therefore, conventionally, as shown in FIG. 10A, a plurality of counter electrode input terminals 121 and a plurality of counter electrode connection pads 117 are arranged, and a plurality of counter electrodes 133 and counter electrode connection pads 117 are connected, The voltage of each part of the counter electrode 133 is made constant. However, with such a configuration,
The number of the counter electrode input terminals 121 is increased and the terminal configuration is complicated, and the wiring from the outside to the counter electrode input terminals 121 is complicated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an active matrix liquid crystal display device which can obtain good characteristics with a simple terminal structure. Another object of the present invention is to provide an active matrix liquid crystal display device capable of maintaining the voltage of each part on the counter electrode at a uniform value with a simple terminal configuration.

[0005]

In order to achieve the above object, a liquid crystal display element according to the present invention comprises a first substrate having electrodes formed thereon, a plurality of liquid crystal driving elements arranged in a matrix. A pixel electrode facing the electrode and connected to the liquid crystal driving element, a signal input terminal to which a signal to be supplied to the electrode is input, and a larger number than the number of the signal input terminals are arranged. A plurality of connection pads for transmitting an input signal to an input terminal to the electrode; and a second substrate on which the signal input terminal and the plurality of connection pads and an annular connection wiring connecting the connection pads are arranged. and bonding the first substrate and the second substrate, the entering
The same voltage of the signal supplied to the
Connection means for transmitting from each of the connection pads connected by a continuous wiring to a corresponding position of the electrode.

[0006]

According to the above structure, the ring-shaped connection is formed on the second substrate.
Since connecting between connected connection pad and the input terminal wiring, even if the signal input terminal is less than the connection pads,
It is possible to set the connection pads to the same voltage.
Therefore, the voltage of each part of the electrode (counter electrode) can be uniformly maintained with a simple terminal configuration. Further, the connection wiring is an annular wiring, and the annular wiring and the gate line and / or
Or by connecting via the protection element data lines, etc., the connection wiring can be made to function as a protection circuit for protecting a semiconductor device from static electricity or the like.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An active matrix liquid crystal display device according to embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) As shown in FIG. 2, the active matrix liquid crystal display element of this embodiment has a display pixel substrate 10 and a counter substrate 30 which are joined by a seal material 41 with a gap material 43 interposed therebetween. A liquid crystal 45 is filled between the substrate 10 and the counter substrate 30, and polarizing plates 47 and 49 are arranged on both sides of the liquid crystal 45.

As shown in FIG. 1A, the display pixel substrate 10 includes a glass substrate 11 and data lines (drain lines) 1 arranged in a matrix on the glass substrate 11.
2 and the gate line 13, and the drain is connected to the corresponding data line 12, and the gate is the corresponding gate line 1
3 and the thin film transistor 14, the pixel electrode 15 connected to the source of the thin film transistor 14, and the compensation capacitance line 16 facing the pixel electrode 15 via an insulating film.
And four counter electrode connection pads 17A to 17C connected to the connection pads 35 of the counter electrode 33 arranged on the counter substrate 30.
17D, a data terminal 18 connecting the data line 12 to an external drive circuit, a gate terminal 19 connecting the gate line 12 to an external drive circuit, and a counter electrode / compensation capacitance input terminal 20.

On the other hand, as shown in FIG. 1B, the counter substrate 30 is disposed on the glass substrate 31 and the glass substrate 31, and the counter electrode connection pads 17A to 17D are provided with an anisotropic conductive adhesive or the like. Pads 35A to 35D connected by
The counter electrode 33 is provided with.

In the structure shown in FIG. 1, the input terminal for setting the voltage of the counter electrode 33 and the terminal for setting the voltage of the compensation capacitance line 16 are the counter electrode / compensation capacitance input terminal 2.
0 is shared. Also, four counter electrode connection pads 1
7A to 17D are connected to each other by a compensation capacitance line 16 made of a material having high conductivity such as aluminum, aluminum alloy, and chromium, and counter electrode connection pads 17A to 17D.
D is connected to the pads 35A to 35D, respectively.

According to this structure, in order to maintain the compensation capacitance line 16 and the counter electrode 33 at a predetermined potential (generally the ground potential), only one counter electrode / compensation capacitance input terminal 20 needs to be provided, and the display pixel The terminal configuration of the substrate 10 is simplified. In addition, a plurality of counter electrode connection pads 17A to 17
Since D is connected to each other through the compensation capacitance line 16 and maintained at the same voltage, the pads 35A to 35 of the counter electrode 33 are connected.
The voltage of D is also maintained at the same value, and the voltage of each part on the counter electrode 33 is also maintained at the same value.

The active matrix liquid crystal display device having the above structure is manufactured, for example, as follows. First,
Aluminum, aluminum alloy, on the glass substrate 11,
A conductive film of chromium or the like is formed by sputtering, vapor deposition or the like. By patterning this conductive film, as shown in FIG. 3, the gate electrode GE of the thin film transistor 14 (FIG. 4),
A gate line 13 connected to the gate electrode GE, a gate terminal 19 connected to the gate line 13, four counter electrode connection pads 17A to 17D, a compensation capacitance line 16 (a line 16 connecting the counter electrode connection pads 17A and 17B).
(Except A).

Next, as shown in FIG. 4, an insulating film (gate insulating film of the thin film transistor 14) 51 is formed on the entire surface of the substrate, and a semiconductor layer 53 having a channel region and source / drain regions is formed on the insulating film 51. To do. The portions of the insulating film 51 on the counter electrode connection pads 17A and 17B and the portions on the left end of each compensation capacitance line 16 are etched to expose them. Next, a metal film is deposited on the entire substrate and patterned to form a source electrode SE and a drain electrode DE of the thin film transistor 14, a data line 12 and a data terminal 18 connected to the drain electrode DE, and a compensation capacitance line 16A. To form.

After that, a transparent conductive film such as ITO is formed,
This is patterned to form the pixel electrode 15 connected to the source electrode SE. Next, a protective film 55 is formed on the entire surface of the substrate.
To form. The portion of the protective film 55 on the pixel electrode 15 and the counter electrode connection pads 17A of the protective film 55 and the insulating film 51.
17D, the data terminal 18, the gate terminal 19, and the portion on the counter electrode / compensation capacitance input terminal 20 are etched to expose them.

On the other hand, for the counter substrate 30, a transparent conductive film such as ITO is formed on the glass substrate 31 and patterned to form a counter electrode 33 shown in FIG. 1 (B). After that, the two substrates are bonded together via the spacer 43 and the sealing material 41. At this time, the counter electrode connection pads 17A to 17D
Anisotropic conductive adhesive material (anisotropic conductive material) 57 or the like is applied to the pads 35A to 35D of the counter electrodes facing each other.
As shown in, the anisotropic conductive adhesive 57 is compressed when the two substrates 11 and 31 are bonded. By the compression, the particles of the conductive material contained in the adhesive material are diffused, and the counter electrode connection pad 17A is formed.
-17D and the pads 35A-35D of the counter electrode 33 are electrically connected.

Next, the glass substrates 11 and 31 and the sealing material 4
Liquid crystal 45 is injected into the portion surrounded by 1 by a vacuum injection method or the like, and polarizing plates 47 and 49 are arranged to complete the active matrix liquid crystal display element of the first embodiment.

(Second Embodiment) In the first embodiment, the counter electrode connection pads 17A to 17D are connected to each other by the compensation capacitance line 16, but as shown in FIG. 6, the compensation capacitance line 16 and the compensation capacitance terminal 71 are connected. The counter electrode connection pads 17A to 17D may be connected to each other by using the dedicated line 71 and the counter electrode input terminal 73 which are formed separately. The dedicated line 71 and the counter electrode input terminal 73 are formed using a material having a low resistance, for example, aluminum, aluminum alloy, chromium or the like.

According to the structure of FIG. 6, only one counter electrode input terminal 72 is required to maintain the counter electrode 33 at a predetermined potential (generally the ground potential), and the terminal structure is simplified. In addition, since the counter electrode connection pads 17A to 17D are connected to each other by the low resistance dedicated line 71 and maintained at the same voltage, each part of the counter electrode 33 is also maintained at the same potential.

The display pixel substrate having the structure shown in FIG. 6 is formed, for example, as follows. First, a metal film is formed on the glass substrate 11 and patterned to form the dedicated line 71 and the counter electrode input terminal 72. Next, a transparent insulating film made of a silicon nitride film or the like is formed on the entire surface of the substrate.
Then, on the transparent insulating film, the data line 12, the gate line 13, the thin film transistor 14, the pixel electrode 15, the compensation capacitance line 16, the data terminal 18, the gate terminal 19, the compensation capacitance terminal 71, etc. are formed by using a normal manufacturing method. To form. After that, a protective film is formed on the entire surface of the substrate. The display pixel substrate 10 is completed by etching and exposing the pixel electrode 15, the terminals 18, 19, 71, 73 and the insulating film and the protective film on the counter electrode connection pads 17A to 17D.

According to the second embodiment, the voltage of each part of the counter electrode 33 can be set to a desired value by using the counter electrode input terminals 73 of which the number is smaller than that of the counter electrode connection pads 17A to 17D, and the terminal configuration can be made. It is simplified. The counter electrode input terminal 72 and the counter electrode connection pads 17A to 17 are made of a material having a low resistivity, such as aluminum.
D and the dedicated line 72 can be formed at the same time.

(Third Embodiment) In the second embodiment, the counter electrode connection pads 17A to 17D are connected to each other by the dedicated line 71, but the dedicated line 71 is used as a countermeasure against static electricity in the manufacturing stage of the liquid crystal display element. It can also be used as a short line to be used. Hereinafter, a third embodiment in which the line for connecting the counter electrode connection pad is used as a short line will be described.

FIG. 7 shows the display pixel substrate 10 in the manufacturing process. In FIG. 7, the same parts as those in FIG. 6 are designated by the same reference numerals. As shown in the figure, the display pixel substrate 10 of this embodiment has a data line 12, a gate line 13, a thin film transistor 14, and a pixel electrode 15 on a glass substrate 11.
(Not shown), compensation capacitance line 16, counter electrode connection pads 17A to 17D, data terminal 18, gate terminal 19,
Compensation capacitance terminal 71, counter electrode input terminal 72, internal short line 81, varistor 82, external short line 83
Are arranged. The symbol CLC means a capacitance formed by the pixel electrode 15, the counter electrode 33 and the liquid crystal between them, and the symbol CS means a capacitance formed by the pixel electrode 15 and the compensation capacitance line 16 facing each other.

The internal short line 81 is an annular wiring made of metal or the like, and has four counter electrode connection pads 17
A to 17D are connected to each other and also connected to each data line 12 and each gate line 13 via a non-linear two-terminal element 82 such as a varistor having the characteristics shown in FIG.
As the non-linear two-terminal element 82, for example, as shown in FIG. 9, an element having a structure in which a gate electrode is removed from a thin film transistor can be adopted. In FIG. 9, reference numeral 91 is a data line 12 and a gate line 13.
Is an intrinsic semiconductor layer connected to the terminal electrode 91, and 93 is the other terminal electrode connected to the internal short line 81.

The data terminal 18, the gate terminal 19, the compensation capacitance terminal 71, and the counter electrode input terminal 72 are connected to the external short line 83, respectively. The external short line 83 is an annular wiring arranged along the side of the glass substrate 11.

According to this structure, even if static electricity is generated in the process of forming the liquid crystal display element, this static electricity is circulated and consumed in each wiring including the short line 81 and the external short line 83. Therefore, the thin film transistor 1
A situation in which an abnormally high voltage is applied to 4 and the element is destroyed is prevented.

When the manufacturing of the liquid crystal display device is completed, the peripheral portion of the glass substrate 11 is cut off and the external short line 83 is formed.
To remove. On the other hand, the internal short-circuit line 81 is left as it is and functions as a wiring for connecting the four counter electrode connection pads 17A to 17D to each other, like the dedicated line 72 of the second embodiment.

According to this structure, at the manufacturing stage of the liquid crystal display element, the internal short line 81 functions as a structure for preventing static electricity, and after the manufacturing is completed, the four counter electrode connection pads 17A to 17D are mutually connected. Functions as a connecting wire. Therefore, it is possible to take measures against static electricity with a simple structure and to maintain the voltage of the counter electrode at a constant value.

The present invention is not limited to the first to third embodiments described above, and various applications and modifications are possible. For example, in the first to third embodiments, the counter electrode connection pad 17A
-17D and the number of pads of the counter electrode 33 is four,
The number of pads may be any of 3, 5, 6 ... Further, the number of counter electrode input terminals is not limited to one, and may be two or three. However, in order to simplify the terminal configuration, it is desirable to suppress the number to about two. Further, in the third embodiment, the compensation capacitance terminal 71 and the counter electrode input terminal 72 are individually arranged,
It may be common as in the first embodiment. In addition, the materials, manufacturing methods, and the like shown in the examples are merely examples, and other materials and manufacturing methods may be used. For example, a high concentration semiconductor layer or the like for ensuring ohmic contact may be arranged between the semiconductor layer and the electrode layer. Further, as the structure of the thin film transistor, any structure such as stagger, inverted stagger and coplanar can be adopted.

[0029]

As described above, according to the liquid crystal display element of the present invention, a plurality of pairs connected by the annular connection wiring are provided.
The counter electrode connection pad is provided, and the counter electrode input terminals of which the number is smaller than that of the counter electrode connection pad are arranged on the substrate. Therefore, the terminal structure is simplified, and since the counter electrode input terminal and the connection pad are connected by the ring-shaped connection wiring, the voltage of each part on the counter electrode can be maintained at a constant value. In addition, the connection wiring forms an annular wiring, and
Lines and gate lines and / or data lines are protection elements
Since it is connected via, the annular connection wiring,
Functions as a protection circuit that protects semiconductor elements from static electricity
And prevent damage to the semiconductor device due to static electricity.
You can

[Brief description of drawings]

FIG. 1A is a plan view showing a configuration of a display pixel substrate of an active matrix liquid crystal display element according to a first embodiment of the present invention. FIG. 3B is a plan view showing the structure of the counter substrate of the active matrix liquid crystal display element according to the first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which the substrates shown in FIGS. 1A and 1B are joined.

3A to 3D are process diagrams for explaining an example of a method for manufacturing the display pixel substrate shown in FIG.

4A to 4C are process diagrams for explaining an example of a method for manufacturing the display pixel substrate shown in FIG.

FIG. 5 is a cross-sectional view for explaining a method of joining the substrates shown in FIGS. 1A and 1B.

FIG. 6 is a plan view showing a configuration of a display pixel substrate of an active matrix liquid crystal display element according to a second embodiment of the present invention.

FIG. 7 is a plan view showing a configuration of a display pixel substrate of an active matrix liquid crystal display element according to a third embodiment of the present invention.

FIG. 8 is a diagram showing an example of characteristics of the protection element shown in FIG.

9 is a diagram showing an example of a structure of the protection element shown in FIG.

FIG. 10A is a plan view showing a configuration of a display pixel substrate of a conventional active matrix liquid crystal display element.
FIG. 1B is a plan view showing the configuration of a counter substrate of a conventional active matrix liquid crystal display element.

[Explanation of symbols]

10 ... Display pixel substrate, 11 ... Glass substrate, 12 ... Data line, 13 ... Gate line, 14 ... Thin film transistor, 15 ... Pixel electrode, 16 ... Compensation capacitance line, 1
7 ... Counter electrode connection pad, 18 ... Data terminal, 19 ...
・ Gate terminal, 20 ・ ・ ・ Counter electrode / compensation capacity input terminal, 3
0 ... Counter substrate 31 ... Glass substrate, 33 ... Counter electrode, 35 ... Pad, 41 ... Sealing material, 43 ... Spacer, 45 ... Liquid crystal, 47, 49 ... -Polarizing plate, 51 ... Insulating film, 53 ... Semiconductor layer, 55 ... Protective film, 57 ... Anisotropic conductive adhesive (anisotropic conductive material), 71 ... Compensating capacitance terminal ,
71 ... Dedicated line, 72 ... Counter electrode input terminal, 81 ...
・ Internal short line, 82 ... Non-linear 2-terminal element, 83
... External short line, 110 ... Display pixel substrate, 13
0 ... Counter substrate, 111 ... Glass substrate, 112 ... Data line, 113 ... Gate line, 114 ... Thin film transistor, 115 ... Pixel electrode, 116 ... Compensation capacitance line, 117 ... Counter electrode connection pad, 118 ... Data terminal, 119 ... Gate terminal, 120 ... Compensation capacitance terminal, 1
21 ... Counter electrode input terminal, 130 ... Counter substrate, 131
... Glass substrate, 133 ... Counter electrode

Claims (4)

(57) [Claims] 1. A first substrate having electrodes formed thereon, a plurality of liquid crystal driving elements arranged in a matrix,
A pixel electrode facing the electrode and connected to the liquid crystal driving element, a signal input terminal for inputting a signal to be supplied to the electrode, and a larger number of signal input terminals than the signal input terminals are arranged. A plurality of connection pads for transmitting an input signal to an input terminal to the electrodes, and a ring connecting the signal input terminal and the plurality of connection pads and the connection pads.
And a second substrate on which the connection wiring is arranged, the first substrate and the second substrate are joined, and the input terminal is connected.
The same voltage of the signal supplied to the child is connected to the ring connection
A liquid crystal display device, comprising: connecting means for transmitting from each of the connection pads connected by lines to a corresponding position of the electrode. 2. The connection pads are four corners of the second substrate.
The annular connection wiring is arranged in a rectangular annular connection.
Wiring is formed, and from the four corners of the electrode by the connecting means.
The voltage according to claim 1 is supplied with the same value.
The liquid crystal display element described . Wherein the second substrate includes a gate line and a data line connected to the liquid crystal driving element, contact with at least a hand of the gate lines and the data lines of the annular
The liquid crystal display element according to claim 1 or 2, further comprising a protection element for connecting a continuous wiring. 4. The protection element comprises a non-linear two-terminal element.
The liquid crystal display element according to claim 3, wherein the liquid crystal display element is a liquid crystal display element.