JPH09258205A - Color liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the constitution of electrode terminal part, to suppress the occurrence of electrical defect, to improve the adhesion property between a TFT substrate and a CF substrate, to improve the yield of production, and to decrease the number of production stages by forming the electrode terminal at the electrode terminal as a single layer. SOLUTION: An auxiliary electrode 26 consisting of CR is formed on the CF substrate 24 side. A gate electrode 22 consisting of AL and gate terminal 23 consisting of ITO are connected by a connector 28 consisting of Ag paste with the auxiliary electrode 26 as a joiner. The electrode terminal part of the TFT substrate 21 side is composed of the signal layer of the gate terminal 23 along in this constitution and therefore, the possibility that the electric defect arises is low. The adhesion property of the case the TFT substrate 21 and the CF substrate 24 are such to each other by using a sealing material 29 is good. Both of the gate electrode 22 and the gate terminal 23 are the single layers but the conductive connection is executed without direct contact with each other and, therefore, the problem of insufficient adhesion property does not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter substrate and a thin film transistor (TFT).
Stor) substrate and an improved electrode terminal structure.

In general, liquid crystal display devices are widely used in various fields by taking advantage of thinness, light weight, low power consumption, etc., and are required to be large in size, high in definition, large in capacity, and color. However, improvement of manufacturing yield and improvement of quality have become problems.

According to the present invention, it is possible to provide one means for responding to the above-mentioned requirements or problems.

[0004]

2. Description of the Related Art At present, as a liquid crystal driving method, a TFT driving method is mainly used and a high quality display image can be obtained, but a multilayer laminated structure is required.

FIG. 5 is a cutaway side view of a main part showing a structure of a TFT substrate in a liquid crystal display device according to a conventional TFT driving method.

In the figure, 1 is a glass substrate in a TFT substrate, 2 is a gate terminal made of Al, 3 is a disconnection prevention film made of SiN, 4 is an intermediate electrode layer made of Ti, and 5 is S.
The disconnection prevention film made of iN, 6 is ITO (indium)
A gate terminal made of tin oxide, and 7 are electrode terminal portions, respectively.

The intermediary of the intermediate electrode layer 4 made of Ti for connecting the gate terminal 2 made of Al and the gate terminal 6 made of ITO is that the adhesion between ITO and Al is poor and the contact resistance is high. This is to eliminate the problem.

The disconnection prevention film 3 or 5 made of SiN is
It plays a role of preventing disconnection due to a step generated by stacking each electrode / wiring.

The reason why the gate terminal 6 made of ITO is the uppermost layer is that the TAB (tape automated) is used.
It is possible to mount it on a metal electrode such as Al, but it is not practically used because it has low adhesion. .

[0010]

As described above, the conventional TFT driving type liquid crystal display device has a problem that the manufacturing process is complicated and the cost is high because of the multi-layer structure. In particular, in the electrode terminal portion, due to the multi-layer structure, electrical defects such as conduction defects and short circuits between adjacent conductive patterns are likely to occur.

Further, the TFT substrate and the color filter (c
A color filter (CF) substrate is provided with a sealing material on the electrode terminal portion to be bonded.

FIG. 6 is a side sectional view showing a main part of a liquid crystal display device for explaining a case where a TFT substrate and a CF substrate are bonded together.

In the figure, 11 is a TFT substrate, 12 is a multi-layered electrode terminal portion, 13 is a CF substrate, 14 is a sealing material, 1
Reference numerals 5 denote liquid crystal layers, respectively.

Due to such a structure, if the electrode terminal portion is a multi-layer structure, the adhesive force between the TFT substrate 11 and the CF substrate 13 is naturally small as compared with the case where the electrode is a single layer. .

The present invention simplifies the structure of the electrode terminal portion in the liquid crystal display device, suppresses the occurrence of electrical defects, improves the adhesion between the TFT substrate and the CF substrate, and improves the manufacturing yield and manufacturing. We try to realize the reduction of the number of processes.

[0016]

According to the present invention, the electrode terminal in the electrode terminal portion is made into a single layer to improve the adhesion when the TFT substrate and the CF substrate are bonded together.

FIG. 1 is a sectional side view of a main part of the liquid crystal display device for explaining the principle of the present invention, particularly showing the vicinity of the electrode terminal part.

In the figure, 21 is a TFT substrate, 21A is a glass substrate, 22 is a gate electrode made of Al, and 23 is I.
A gate terminal made of TO, a CF substrate 24, a glass substrate 24A, and a black matrix 25 made of Cr.
A pattern, 26 is an auxiliary electrode made of Cr, 27 is a CF pattern, 28 is a connection body made of Ag paste, and 29 is a sealant.

As is clear from the figure, in the present invention, CF
An auxiliary electrode 26 made of Cr is formed on the substrate 24 side, and the auxiliary electrode 26 is used as a relay for the TFT substrate 21.
In the above, the gate electrode 22 made of Al and the gate terminal 23 made of ITO are connected by the connection body 28 made of Ag paste.

From the above, in the liquid crystal display device according to the present invention,

(1) A pair of substrates facing each other (for example, TF)
An electrode (for example, Al) formed on one of the T substrate 21 and the CF substrate 24 (for example, the TFT substrate 21)
Gate electrode 22) and a single-layer terminal (for example, a gate terminal 2 made of ITO) that is electrically isolated from the electrode and is formed on the same substrate and leads the electrode to the outside.
3) and the other substrate of the pair of substrates (for example, C
An auxiliary electrode (for example, an auxiliary electrode 26 made of Cr) formed on the F substrate 24) so as to face a region where the electrode and the terminal are separated from each other, and the electrode, the auxiliary electrode, and the terminal. A sealant provided for electrically bonding a connector (for example, a connector 28 made of Ag paste) and at least a part of the sealant which is interposed to bond the pair of opposed substrates to each other. (For example, a sealing material 29), or

(2) In the above (1), the pair of substrates facing each other is a TFT substrate and a color filter substrate, and the auxiliary electrode is a black matrix pattern (eg, a black matrix pattern) on the color filter substrate. Material film (eg, Cr) forming the black matrix pattern 25
Film) is formed by utilizing a part of the film, or

(3) In (1), the pair of substrates facing each other are a TFT substrate and a color filter substrate, and the auxiliary electrode is a display electrode (for example, the display electrode 35) on the color filter substrate. : See FIG. 2), which is formed by utilizing a part of a material film (for example, an ITO film) constituting the film, or

(4) In the above (1), the pair of substrates facing each other are a TFT substrate and a color filter substrate, and the auxiliary electrodes form a black matrix pattern on the color filter substrate. Characterized in that it is formed by using a laminated material film for forming the material film and the material film forming the display electrode, or

(5) In the above (1), (2) or (4), the auxiliary electrode is made of an opaque material (for example, a metal film) and the position of the connecting body is provided near the connecting portion with the connecting body. It is characterized by comprising an auxiliary electrode in which a notch portion (for example, notch portion 33A: see FIG. 4) for visual recognition is formed, or

(6) In any one of the above (1) to (5), the connecting body is a bump made of metal.

By adopting the above means, since the electrode terminal portion on the TFT substrate side is composed of a single layer of only the gate terminal made of ITO, the possibility of electrical failure is extremely low, and Adhesion when a TFT substrate and a CF substrate are bonded together by using a sealing material is much better than that in the case of a multi-layer structure, and the gate electrode and the gate in the electrode terminal portion of the TFT substrate are much better. Although the terminals are both single-layered, their conductive connections are made without direct contact, so that the problem of poor adhesion between them does not occur.

Since the structure is simple as described above,
Compared with the case of a multi-layer structure, the number of steps can be reduced throughout the pattern formation process such as film formation process, lithography process, etching process, etc., so improvement of manufacturing yield and high quality can be easily achieved. can do.

[0029]

2 and 3 are side sectional views showing a liquid crystal display device in a process key point for explaining a case of manufacturing an embodiment according to the present invention. Description will be given with reference to these drawings.

See FIG. 2A. 2- (1) By applying the sputtering method, the glass substrate 3
A Cr film having a thickness of, for example, 0.1 [μm] is formed on 1.

2- (2) Resist process in lithography technology, and
By applying the wet etching method using an aqueous solution of ceric ammonium nitrate as an etchant, the Cr film formed in the step 2- (1) is etched to perform the black matrix pattern 32 and the auxiliary electrode 3.
Form 3

As described above, in order to form the auxiliary electrode 33, a separate step is not necessary, and the auxiliary electrode 33 can be formed simultaneously by using the step of forming the black matrix pattern 32. There is no increase in the number of processes.

2- (3) By applying the spin coating method, red, green,
The thickness obtained by dispersing any one of the blue pigments is, for example, 1.
An ultraviolet curable resin film of 5 μm is formed on the entire surface.

2- (4) Exposure to ultraviolet rays is carried out through a mask to carry out the step 2
-Selectively cure the pigment-containing ultraviolet curable resin film formed in (3).

2- (5) A color filter pattern is obtained by immersing in an alkaline developing solution and removing the uncured ultraviolet curable resin film.

2- (6) In the steps 2- (3) to 2- (5), a red color
Repeated to create each of the filters, green color filter, blue color filter, in the figure,
The color filter pattern thus formed is generally designated by the reference numeral 34.

2- (7) By applying the sputtering method, an ITO layer having a thickness of, for example, 0.1 [μm] is formed.

2- (8) Resist process in lithography technology, and
By applying a wet etching method using an iron chloride salt aqueous solution as an etchant, the display layer 35 is formed by etching the ITO layer formed in the step 2- (7). The CF substrate is completed as described above.

Referring to FIG. 2 (B) 2- (9) Next, the TFT substrate will be described. However, it goes without saying that the order of forming the CF substrate and the order of forming the TFT substrate may be any, and both may be bonded together. Therefore, it is desirable to supply both at the same time.

In the TFT substrate shown in the figure, a TFT (not shown) is formed on the glass substrate 41 by a usual technique, and a gate electrode 42 made of Al and a gate terminal 43 made of ITO are formed. Be present.

Although not shown, an alignment film layer obtained by applying a polyimide-based alignment material and then rubbing is formed on both the TFT substrate and the CF substrate.

See FIG. 3. 3- (1) By applying the screen printing method, a connecting body 51 made of Ag paste is formed on either the CF substrate side or the TFT substrate side, and a sealing material 52 is applied to both sides. The substrates are bonded together and heat treatment is performed to cure the connector 51 and the sealing material 52.

As the sealing material 52, for example, acrylic resin mixed with glass fiber may be used.
In this case, the glass fiber is mixed to adjust the height of the sealing material 52.

3- (2) After that, by applying a normal technique such as filling with liquid crystal,
Complete a color liquid crystal display device.

The present invention is not limited to the color liquid crystal display device described as the embodiment, and many other modifications can be realized.

For example, as the auxiliary electrode 33, black
Although a part of the Cr film forming the matrix pattern 32 is used, a part of the ITO film forming the display electrode 35 can be used as an alternative.

In order to reduce the resistance of the auxiliary electrode 33, a structure in which a Cr film forming the black matrix pattern 32 and an ITO film forming the display electrode 35 are laminated may be used.

Furthermore, the auxiliary electrode 33 and the gate electrode 42
Also, instead of the connection body 51 made of Ag paste for connecting to the gate terminal 43, a bump made of gold (Au) may be formed on the auxiliary electrode 33 by applying an electrolytic plating method. However, in that case, it is necessary to cover with a mask such as a resist film other than the place where the bump is to be formed.

As described above, when the auxiliary electrode 33 is formed, whether the Cr film for forming the black matrix pattern 32 or the ITO film for forming the display electrode 35 is used. It has been explained that either means is available.

At this time, I, which is a constituent material of the display electrode 35, is used.
If the TO film is used, since it is transparent, when the connecting body 51 made of Ag paste is formed, print misalignment and the like can be visually recognized, but it is a constituent material of the black matrix pattern 32. When a Cr film is used, it is difficult to visually recognize it because it is opaque, and therefore some measure is required.

FIG. 4 is a plan view of an essential part for explaining the structure of the auxiliary electrode having a countermeasure, and the same symbols as those used in FIGS. 2 to 3 represent the same parts or have the same meanings. I have it.

In the figure, 33A is a notched portion formed at both ends of the auxiliary electrode 33, and 61 is a conductive film made of ITO for reducing the resistance value increased due to the formation of the notched portion 33A. There is.

As is apparent from FIGS. 4A and 4B, since the notch 33A is formed at both ends of the auxiliary electrode 33, that is, at the position where the connection body 51 made of Ag paste is to be contacted. When the connection body 51 made of Ag paste is formed, it is possible to easily confirm the positional deviation and the like.

However, by doing so, the contact area between the auxiliary electrode 33 and the connecting body 51 becomes small and the contact resistance becomes high. Therefore, as is apparent from FIG. 4C, in the vicinity of the notch 33A, or The conductive film 61 made of ITO may be formed on the entire surface to avoid it.

[0055]

In the color liquid crystal display device according to the present invention, the electrodes formed on one of the pair of substrates and the electrodes are electrically isolated from each other and formed on the same substrate. A single-layer terminal for leading out the electrode to the outside, an auxiliary electrode formed on the other substrate of the pair of substrates so as to face a separated region between the electrode and the terminal, and the electrode and the auxiliary A connection body that electrically connects the electrodes and the terminals, and a seal material that is interposed to bond the pair of substrates and that is provided so as to hang at least a part of the terminals are provided.

By adopting the above structure, since the electrode terminal portion on the TFT substrate side is composed of a single layer of the gate terminal made of ITO, the possibility of electrical failure is extremely low, and Adhesion when a TFT substrate and a CF substrate are bonded together by using a sealing material is much better than that in the case of a multi-layer structure, and the gate electrode and the gate in the electrode terminal portion of the TFT substrate are much better. Although the terminals are both single-layered, their conductive connections are made without direct contact, so that the problem of poor adhesion between them does not occur.

Thus, since the structure is simple,
Compared with the case of a multi-layer structure, the number of steps can be reduced throughout the pattern formation process such as film formation process, lithography process, etching process, etc., so improvement of manufacturing yield and high quality can be easily achieved. can do.

[Brief description of drawings]

FIG. 1 is a sectional side view of a main part of a liquid crystal display device for explaining the principle of the present invention, particularly showing the vicinity of an electrode terminal part.

FIG. 2 is a side sectional view showing a main part of a liquid crystal display device at a process step for explaining a case of manufacturing an embodiment according to the present invention.

FIG. 3 is a side sectional view showing a main part of a liquid crystal display device at a process key point for explaining a case of manufacturing an embodiment according to the present invention.

FIG. 4 is a plan view of relevant parts for explaining the configuration of an auxiliary electrode having a countermeasure.

FIG. 5 is a cutaway side view of a main part showing a configuration of a TFT substrate in a liquid crystal display device according to a conventional TFT driving method.

FIG. 6 is a side sectional view showing a main part of a liquid crystal display device for explaining a case where a TFT substrate and a CF substrate are bonded together.

[Explanation of symbols]

 21 TFT substrate 21A Glass substrate 22 Gate electrode made of Al 23 Gate terminal made of ITO 24 CF substrate 24A Glass substrate 25 Black matrix pattern made of Cr 26 Auxiliary electrode made of Cr 27 CF pattern 28 Connection made of Ag paste 29 Seal material

Claims (6)

[Claims] 1. An electrode formed on one of a pair of substrates facing each other, and an electrode electrically isolated from the electrode and formed on the same substrate and for leading out the electrode to the outside. A single-layer terminal; an auxiliary electrode formed on the other substrate of the pair of substrates so as to face a region where the electrode and the terminal are separated from each other; the electrode, the auxiliary electrode, and A connecting body for electrically connecting the terminals, and a sealing material interposed to bond the pair of substrates facing each other and at least partially hooked on the terminals. Characteristic color liquid crystal display device. 2. A pair of substrates facing each other is a TFT substrate and a color filter substrate, and the auxiliary electrode is the color substrate.
2. The color liquid crystal display device according to claim 1, wherein the color liquid crystal display device is formed by using a part of a material film forming a black matrix pattern on the filter substrate. 3. A pair of substrates facing each other is a TFT substrate and a color filter substrate, and an auxiliary electrode is the color substrate.
2. The color liquid crystal display device according to claim 1, wherein the color liquid crystal display device is formed by using a part of a material film forming a display electrode on the filter substrate. 4. A pair of substrates facing each other is a TFT substrate and a color filter substrate, and the auxiliary electrode is the color substrate.
2. The color liquid crystal display device according to claim 1, wherein the filter substrate is formed by using a laminate of a material film forming a black matrix pattern and a material film forming a display electrode. 5. The auxiliary electrode is made of an opaque material, and the auxiliary electrode is provided with a notch portion for visually recognizing the position of the connection body in the vicinity of the connection portion with the connection body. Item 5. A color liquid crystal display device according to item 1, 2 or 4. 6. The color liquid crystal display device according to claim 1, wherein the connection body is a bump made of metal.