JP3050199B2 - Wiring terminal and method of forming the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wiring terminal and a method for forming the wiring terminal. More specifically, the present invention relates to a wiring terminal excellent in corrosion resistance, which is preferable as a wiring terminal for electrical connection with an external drive circuit in a matrix type liquid crystal display device (LCD panel), and a method for forming the same.

[0002]

2. Description of the Related Art In recent years, a matrix type liquid crystal display device (see FIG. 16) for obtaining an arbitrary image by appropriately selecting a matrix unit cell as shown in FIG. 16 and applying a predetermined voltage to the unit cell. LCD panels) are frequently used.

The structure of wiring terminals (sometimes referred to as external terminals) in this matrix type liquid crystal display device will be described with reference to FIGS. As shown in FIG. 16, a matrix type liquid crystal display device denoted by reference numeral 100 includes a scanning line 101 and a signal line 102, each of which is orthogonal to each other. These scanning lines 101 and signal lines 102 are entirely formed of a metal wiring film 103 formed of a metal material having a low resistance value.
4 is formed. Then, as shown in FIGS. 17 to 19, the metal wiring film 103 in the external terminal is covered with the protective insulating film 107 except for the terminal connection portion 105,
As shown in FIG. 16, the glass substrate 104 is drawn out to a panel peripheral portion 109 located around the liquid crystal injection portion 108. Therefore, in the terminal connection portion 105, as shown in FIGS.
F) A configuration is made such that the metal wiring film 103 and a TAB tape (not shown) connected to an external drive circuit (not shown) can be electrically connected via a 110.

Incidentally, the wiring terminals (scanning lines 101 and signal lines 102) of the matrix type liquid crystal display device are easily affected by changes in ambient humidity and temperature. In particular, in the directions shown by arrows in FIGS. There is a problem that water (H ₂ O) that has entered the interface between the protective insulating film 107 and the anisotropic conductive film 110 is easily corroded. In FIGS. 17 and 18, the direction of entry of moisture is indicated by an arrow (bold), and the corroded portion is indicated by the symbol a. As a result, not only the terminal connection area and the wiring cross-sectional area are reduced, and the image quality is deteriorated due to the delay of the wiring signal, but also in the worst case, the disconnection or the like occurs.

Therefore, the wiring terminal 10 shown in FIG.
In order to prevent the occurrence of corrosion at the terminal connection portion 105 in (6), for example, (1) Japanese Patent Application Laid-open No.
The structure of the wiring terminal is disclosed in (2) JP-A-3-72318 or (3) JP-A-7-92496.

A wiring terminal disclosed in Japanese Patent Application Laid-Open No. 63-276242 is formed by forming a metal wiring film by alloying molybdenum (Mo) having low corrosion resistance and tantalum (Ta) having high corrosion resistance. The structure is such that the corrosion resistance of the metal wiring film itself is improved. In addition, Japanese Unexamined Patent Publication No.
The wiring terminal disclosed in JP-A-72318 has a multilayer wiring structure in which an aluminum (Al) film having low corrosion resistance is covered with a tantalum (Ta) film having high corrosion resistance. Furthermore, the wiring terminal disclosed in JP-A-7-92496 has a structure in which the edge of the wiring terminal is covered with a corrosion-resistant material.

[0007]

However, in the wiring terminal disclosed in Japanese Patent Application Laid-Open No. 63-276242, the corrosion resistance is improved, but as the content of tantalum (Ta) or the like increases. There was a problem that the resistance value increased. Therefore, when a wiring terminal having such a structure is provided in a liquid crystal display device or the like, image quality is degraded due to signal delay.

Therefore, it has been proposed to increase the thickness and width of the metal wiring film and reduce the series resistance value of the wiring to prevent the image quality of the liquid crystal display device from deteriorating. However, when the thickness of the metal wiring film is increased,
When used in a liquid crystal display device, a disconnection occurs at an intersection between a scanning line and a signal line, or the surface unevenness of a metal wiring film increases, resulting in poor alignment of liquid crystal molecules. On the other hand, when the wiring width of the metal wiring film is increased, there is also a problem that when used in a liquid crystal display device or the like, the aperture ratio is reduced, which is likely to cause a deterioration in image quality.

Further, forming a wiring terminal composed of a metal wiring film disclosed in Japanese Patent Application Laid-Open No. 3-72318 requires a film forming step, a photolithography step, an etching step, and the like for each layer. The number was bulky, causing high costs. When a part of each metal wiring film is exposed in the process of forming a wiring terminal composed of a plurality of metal wiring films, overetching due to a so-called battery effect caused by the oxidation-reduction potential difference of each metal wiring film during the etching process. There is a problem that pattern defects such as etching and undercut are likely to occur. Therefore, the yield in manufacturing wiring terminals made of a metal wiring film has been reduced.

In addition, the wiring terminal disclosed in Japanese Patent Application Laid-Open No. 7-92496 has insufficient corrosion resistance,
When used in a liquid crystal display device or the like, there is a problem that image quality is deteriorated due to poor terminal connection, display defects, and the like are likely to occur.

The present invention has been made in view of such circumstances, and in a matrix type liquid crystal display device (LCD panel), image quality is reduced by improving the corrosion resistance of a metal wiring film constituting wiring terminals. It is an object of the present invention to provide a wiring terminal and a method of forming the wiring terminal, which can prevent the occurrence of display defects, display defects, and the like, and reduce the yield, and can reduce the manufacturing cost. It is another object of the present invention to provide a wiring terminal having a high degree of freedom in design and a method for forming the wiring terminal by relaxing restrictions on materials used in a matrix type liquid crystal display device.

[0012]

According to a first aspect of the present invention, there is provided a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device. protective insulating film above Yes and is provided, and a part of the protective insulating film, a contact hole for electrically connecting the external drive circuit via the anisotropic conductive film, is preferentially corroded
Was a atmospheric exposure portion in which a part of the wiring terminals for cathodic protection is exposed to is characterized in that is formed respectively. By configuring the wiring terminal in this manner, the exposed portion in the atmosphere is corroded before the electric connection portion (hereinafter, simply referred to as a terminal connection portion) with the external drive circuit via the anisotropic conductive film in the connection hole. Can be done. Therefore, the electrons generated at the time of this corrosion reaction move to the terminal connection portion, so that the terminal connection portion can be effectively subjected to cathodic protection. Further, since the corrosion resistance of the terminal connection portion is improved, although the corrosion resistance is poor, it is easy to form a metal wiring film, and a low-resistance metal, for example, a metal such as Al or Mo is used in a single layer. Can be. Therefore, it is possible to reduce the number of steps in manufacturing a wiring terminal made of a metal wiring film, and it is also possible to reduce the occurrence of pattern defects and the like as much as possible.

Further, the wiring terminal according to the second aspect is characterized in that the exposed part to the atmosphere is formed on both sides or any one side of the connection hole. Providing the air exposed portion in this manner does not hinder the arrangement of the terminal connection portion, and facilitates the layout design of the terminal connection portion and the air exposed portion itself in the entire wiring terminal. Further, when the exposed portions are provided on both sides of the connection hole, electrons generated during the corrosion reaction can be uniformly moved with respect to the terminal connection portion. Therefore,
Cathodic protection of the metal wiring film at the terminal connection portion can be more effectively achieved. Further, when a plurality of air-exposed portions are provided, the area of the air-exposed portion can be increased as a whole. Therefore, for the metal wiring film of the terminal connection portion,
The effect of cathodic protection can also be exhibited more effectively.

The wiring terminal according to the third aspect of the present invention may be arranged such that Al (aluminum), Cu (copper), Mo
At least one metal selected from a metal group consisting of (molybdenum) and W (tungsten) is exposed. In this way, by intentionally exposing the metal wiring film made of these metals to the exposed part of the atmosphere and corroding them preferentially, the effect of the cathodic protection on the metal wiring film of the terminal connection part is improved. It can be used effectively.

According to a fourth aspect of the present invention, in the wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, a protective insulating film is provided on the metal wiring film. A connection hole for electrically connecting an external drive circuit via an anisotropic conductive film is formed in a part of the film, and a groove is formed on both sides or any one side of the connection hole. It is characterized by the following. By providing the groove in this manner, the distance (creep distance) of moisture (H ₂ O) penetrating the interface between the protective insulating film and the anisotropic conductive film to reach the terminal connection portion is increased. Can be. Therefore, the time during which the terminal connection portion is corroded can be delayed. Also, when the groove is provided in this way,
Since the corrosion resistance of the metal wiring film at the terminal connection part can be improved, a metal having low corrosion resistance, such as Al and Mo, which is easily corroded but easy to form, can be used as the metal wiring film material. . Further, by forming the wiring terminal by providing the groove as described above, the region (near the region) of the metal wiring film adjacent to the groove is easily corroded first, so that the electrons generated by the corrosion move to the terminal connection portion. In addition, the terminal connection portion can be subjected to cathodic protection.

Further, the wiring terminal according to the fifth aspect is characterized in that the groove has a plane rectangular shape. With this configuration, it is possible to effectively cover the periphery of the terminal connection portion, and it is possible to effectively delay the time of entry of moisture or the like into the terminal connection portion. Moreover, since the shape of the groove is rectangular in a plane, it can be formed easily and accurately.

According to a sixth aspect of the present invention, there is provided a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, wherein a protective insulating film is provided on the metal wiring film. A connection hole for electrically connecting an external drive circuit via an anisotropic conductive film and an atmosphere-exposed portion where a part of a wiring terminal is exposed are formed in a part of the film. A groove is formed on both sides or one of the sides. By configuring the wiring terminal in this manner, both the effect of forming the above-described exposed portion and the effect of forming the groove portion, that is, the cathodic protection effect on the terminal connection portion and the penetration time of moisture and the like into the terminal connection portion , The corrosion resistance at the terminal connection portion can be synergistically improved.

According to a seventh aspect of the present invention, there is provided a wiring terminal, wherein the above-described wiring terminal is used for a scanning line and / or a signal line in a matrix type liquid crystal display device. The terminal connection portion of the scanning line and the signal line provided in the matrix type liquid crystal display device has a problem that it easily corrodes due to penetration of moisture. Cathodic protection or the progress of corrosion can be effectively suppressed. Therefore, it is possible to effectively prevent the deterioration of image quality, the occurrence of display defects, and the like, the reduction in yield, and the like in the matrix type liquid crystal display device.

The wiring terminal according to claim 8, wherein at least a part of the metal wiring film is made of Al (aluminum), C
It is characterized by being composed of at least one metal selected from a metal group consisting of u (copper), Mo (molybdenum) and W (tungsten). By using these metals for the metal wiring film, a wiring terminal (metal wiring film) having a low resistance value can be easily formed.

According to a ninth aspect of the present invention, a method of forming a wiring terminal provided in a matrix type liquid crystal display device includes the following steps (A) to (D). And (A) Step of forming a metal wiring film. (B) a step of covering the surface of the metal wiring film with a protective insulating film. (C) a step of forming a connection hole for electrically connecting an external drive circuit through an anisotropic conductive film in a part of the protective insulating film by removing a part of the protective insulating film. (D) By removing a part of the protective insulating film, a part of the protective insulating film is preferentially corroded to perform cathodic protection.
Forming an exposed part in the atmosphere exposing a part of the metal wiring film. By forming the connection hole and the exposed part in the air in a part of the protective insulating film in this manner, a wiring terminal including these can be efficiently manufactured. Therefore, a wiring terminal having an excellent anticorrosion effect can be provided at low cost.

According to a tenth aspect of the present invention, in the method of forming a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, the following steps (E) to (H) are provided. It is characterized by including. (E) a step of forming a metal wiring film having holes at positions corresponding to the grooves. (F) a step of covering the surface of the metal wiring film with a protective insulating film. (G) a step of forming a connection hole for electrically connecting an external drive circuit through a part of the anisotropic conductive film by removing a part of the protective insulating film; (H) a step of forming a groove by removing a part of the protective insulating film. By forming the connection hole and the groove in a part of the protective insulating film as described above, excellent corrosion resistance can be obtained, and a wiring terminal including these can be efficiently manufactured.

According to a tenth aspect of the present invention, in the method of forming a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, the following steps (I) to (M) are provided. It is characterized by including. (I) A step of forming a metal wiring film having a hole at a position corresponding to the groove. (J) a step of covering the surface of the metal wiring film with a protective insulating film. (K) a step of forming a connection hole for electrically connecting an external drive circuit through a part of the anisotropic conductive film by removing a part of the protective insulating film. (L) forming a part of the protective insulating film to be exposed to the atmosphere, in which a part of the wiring terminal is exposed, by removing a part of the protective insulating film; (M) a step of forming a groove by removing a part of the protective insulating film; By forming the connection hole, the exposed part to the atmosphere, and the groove part in a part of the protective insulating film as described above, excellent corrosion resistance can be obtained, and a wiring terminal including these can be efficiently manufactured. .

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to fifth embodiments of the present invention will be specifically described with reference to the drawings.

(1) First Embodiment FIG. 1 is a plan view showing a wiring terminal according to a first embodiment. FIGS. 2 to 4 show a state in which an anisotropic conductive film 4 is thermocompressed. FIG. 1 is a view cut along a line corresponding to the line AA in FIG. 1 and viewed from a direction indicated by an arrow (hereinafter, a cross-sectional view taken along the line AA);
A sectional view and a CC sectional view are shown, respectively. FIG.
4 to 4, the wiring terminal 1 according to the first embodiment is a wiring terminal for a scanning line or a signal line provided in a matrix type liquid crystal display device (not shown). These wiring terminals are basically composed of a metal wiring film 5 and a protective insulating film 6. The metal wiring film 5 is formed on the substrate 2 as an external terminal for inputting / outputting a signal and the like in order to electrically drive the matrix type liquid crystal display device. 6 is coated.

Then, the anisotropic conductive film 4 is thermocompression-bonded to a part of the protective insulating film 6, and a connection hole 6a for forming a terminal connection portion 3a and a through hole 6b are provided. The exposed portion 3b is formed with the exposed portion.
That is, in this example, the protective insulating film 6 is provided with a planar rectangular connection hole 6a and a through hole 6b, respectively, and by removing a part of the protective insulating film 6, the metal wiring film 5 is formed.
Are exposed to form a terminal connection portion 3a and an air exposure portion (sometimes referred to as a sacrificial corrosion portion) 3b.

The exposed part 3b is connected to the terminal connecting part 3a.
Is positioned on the opposite side of the matrix type liquid crystal display device (hereinafter, may be referred to as the left side of the terminal connection portion 3a), that is, from one end of the wiring terminal 1 to the atmosphere. The portion 3b, the terminal connection portion 3a, and the matrix type liquid crystal display device (not shown) are arranged in this order. In the example of the embodiment shown in FIG. 1, the air exposure part 3 b is provided only on the side of the terminal connection part 3 a opposite to the side of the matrix type liquid crystal display device (left side of the terminal connection part 3 a in the drawing). It may be provided only on the side of the matrix type liquid crystal display device of the terminal connection part 3a (hereinafter, may be referred to as the right side of the terminal connection part 3a), or in the drawing, on both left and right sides of the terminal connection part 3a, that is, terminal connection Atmospheric exposure portions 3b may be provided on the matrix liquid crystal display device side of the portion 3a and on the opposite side thereof.

Further, in FIG. 1, a portion where the anisotropic conductive film 4 is thermocompression-bonded is schematically indicated by a two-dot chain line. As shown in FIGS. 2 and 3, TAB for electrically connecting the anisotropic conductive film 4 to an external drive circuit (not shown) is connected to the metal wiring film 5 exposed at the terminal connection portion 3a. An electrical connection between the metal wiring film 5 and the TAB tape is obtained by thermocompression bonding a tape for tape (not shown) from above. Further, generally, the periphery of the terminal connection portion 3a of the wiring terminal 1 including the anisotropic conductive film 4 and the TAB tape is sealed with a sealing resin (not shown) such as a silicone resin or an acrylic resin. ) Is preferable.

Here, the metal corrosion in the terminal connection portion 3a will be briefly described. This metal corrosion is an electrochemical reaction that proceeds by a combination of an oxidation reaction of a metal (anode reaction) and a reduction reaction of an oxidant (cathode reaction),
The reaction direction and speed can be considered as an electrode reaction in which the potential (electrode potential) of electrons in the metal changes. Therefore, the corrosion reaction of the metal, that is, the corrosion reaction of the metal wiring film 5 in the example of FIG. 1 can be suppressed by suppressing one or both of the anode reaction and the cathode reaction of the metal.

[0029] More specifically, the anode reaction (M → M ^{+ +}
e ^-) metal inner electrons generated in association with the cathode reaction (2
H ⁺ + 2e ⁻ → H ₂ , O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O, O ₂ +
If not consumed by 2H ₂ O + 4e ⁻ → 4OH ⁻ ), the electrode potential of the metal shifts in the negative direction, and finally the potential region where the metal does not corrode (this is the potential where the metal corrosion starts in the inactive region) That is, it corresponds to a potential region on the negative side of the corrosion potential.) Therefore, corrosion of the metal is suppressed. Here, M is a metal atom, H is a hydrogen atom, O
Represents an oxygen atom.

In the first embodiment, the metal wiring film 5 is exposed in the exposed portion 3b and corrodes preferentially over the terminal connection portion 3a. Will occur. On the other hand, the metal wiring film 5 in the terminal connection part 3a does not corrode as compared with the atmosphere-exposed part 3b, and does not generate electrons due to the anode reaction of the metal. , That is, a potential difference is generated between the exposed portion 3b and the terminal connection portion 3a.

Therefore, the electrons generated in the exposed portion 3b partially move to the terminal connection portion 3a, and are transferred to the terminal connection portion 3a.
In this case, the electrode potential shifts to the negative side, so that corrosion hardly occurs (cathode protection). This is a method in which a cathodic protection method in which an electrode potential of a metal is electrically kept in a negative side (cathode side) inactive region to prevent corrosion is applied to the terminal connection portion 3a. The concept of so-called sacrificial anodic action, in which electrons are generated preferentially by corrosion and used as an anticorrosion current to suppress the corrosion reaction of the metal to be anticorrosive, is adopted.

On the other hand, when the electrode potential of the metal is positive (anode side)
The method of protecting the metal by maintaining it in the passivation region (a region where the metal surface is covered with a corrosion-resistant oxide film and where the corrosion reaction of the metal apparently does not proceed) is called an anode corrosion protection method. This method is unsuitable for metals that do not have a dynamic region or that have a narrow region.

As described above, in the present embodiment, the air-exposed portion 3b, which can be corroded, is formed adjacent to the terminal connection portion 3a to be protected from corrosion, and the terminal connection is formed by the above-described sacrificial anode action (cathodic protection). The feature is that the corrosion reaction of the portion 3a is suppressed.

Since the corrosion prevention efficiency of the terminal connection 3a due to the sacrificial anode action increases as the number of electrons moving to the terminal connection 3a increases, it is preferable to increase the area of the atmosphere exposed portion 3b. In the example of the embodiment shown in FIG. 1, as an example, the air-exposed portion 3 b is provided on the left side of the terminal connection portion 3 a in the drawing, and the area of the air-exposed portion 3 b is about ６ of the area of the terminal connection portion 3 a. There is. However, the position and area of the air-exposed portion 3b may be limited by the position of the terminal connection portion 3a, the pitch between terminals, the length of the terminal lead-out portion, and the like. May be changed as appropriate.

Further, as the number of metal atoms contributing to the corrosion of the exposed portion 3b increases, the anticorrosion effect of the terminal connecting portion 3a due to the sacrificial anodic action lasts longer. The corrosion life of the portion 3a is extended. Therefore, the metal wiring film 5 in the exposed part 3b
Is preferably larger than the thickness of the metal wiring film 5 in the terminal connection portion 3a.

Further, in order to preferentially cause corrosion of the metal wiring film 5 in the exposed portion 3b, the exposed portion 3b
It is also preferable to use a readily corrosive metal material as the metal exposed to the metal. Specifically, Al (aluminum),
It is preferable to use a metal selected from the group consisting of Cu (copper), Mo (molybdenum) and W (tungsten). In particular, Al and Mo are easily corroded, but are easy to form, have low resistance, and are less likely to cause environmental problems. Therefore, they are most suitable as materials used in the present embodiment.

It is to be noted that a corrosive metal material such as Al and Mo may be used as the metal exposed at least to the exposed portion 3b, and a metal material having excellent corrosion resistance may be used for the terminal connection portion 3a. preferable. With this configuration, corrosion of the metal wiring film 5 in the exposed portion 3b can be preferentially caused, and the anticorrosion effect in the terminal connection portion 3a can be more effectively exerted. However, since steps such as plating can be omitted, and the number of manufacturing steps is reduced, the entire or a part of the metal wiring film 5 is made of a readily corrosive metal material, and is exposed to the atmosphere. It is also preferable that the metal exposed to the terminal 3b and the metal exposed to the terminal connecting portion 3a be the same.

In the first embodiment, the metal wiring film 5 constituting the wiring terminal can be formed as a plurality of layers. However, a single layer or a plurality of layers may be formed as thin as possible. (Hereinafter, a thin layer) is also preferable. With this configuration, the number of forming steps and manufacturing time can be significantly reduced as compared with the multilayer wiring structure, while effectively suppressing metal corrosion of the terminal connection portion 3a. In addition, the metal wiring film 5
Is formed as a single layer or a thin layer, it is possible to prevent the occurrence of overetching, undercut, etc. of the wiring film due to different metal contact corrosion as in a multilayer wiring structure. Therefore, display defects due to wiring pattern defects can be reduced, and the yield can be significantly improved. Furthermore, by using a single-layer or thin-layer wiring structure, the limitations on the metal material used and the manufacturing process can be further relaxed.

Next, the wiring terminal 1 according to the first embodiment will be described.
(Steps (A) to (D)) will be briefly described. The order of steps (C) and (D) does not matter,
The step (D) may be performed before the step (C), or the number of steps can be reduced. Therefore, it is preferable to simultaneously perform the step (C) and the step (D).

(A) A metal wiring film 5 having a predetermined shape is formed on a substrate by combining sputtering, photolithography and the like through a predetermined mask pattern. In the example of the first embodiment, a substantially square (rectangular) metal wiring film 5 is formed. (B) Next, a protective insulating film 6 such as a CVD nitride film is uniformly and entirely formed on the metal wiring film 5. Therefore, the protective insulating film 6 is also formed between the metal wiring film 5 and an adjacent metal wiring film (not shown).

(C) A portion corresponding to the terminal connection portion 3 a in the coated protective insulating film 6 is removed by a mechanical or chemical method, and an external drive circuit is electrically connected via the anisotropic conductive film 4. Is formed to expose the metal wiring film 5 as a base. In the example of the first embodiment, the shape of the connection hole 6a is substantially a flat rectangular shape, and therefore, it can be formed accurately and easily.

(D) Similarly to the terminal connection portion 3a, a portion corresponding to the exposed portion 3b of the formed protective insulating film 6 is removed by a mechanical or chemical method, and the through hole 6 is removed.
is formed, and the metal wiring film 5 as a base is exposed to form an exposed portion 3b. In the example of the first embodiment, the shape of the through-hole 6b is a flat rectangular shape, and therefore, it can be formed accurately and easily.

(2) Second Embodiment Next, a second embodiment of the present invention will be specifically described with reference to FIGS. FIG. 5 is a plan view showing the structure of the wiring terminal 11 according to the second embodiment, and FIGS.
FIG. 6 is a cross-sectional view taken along line AA, BB, CC, and DD in FIG. 5 in a state where the anisotropic conductive film 4 is thermocompression-bonded. In FIGS. 5 to 9, the same members as those in FIGS. 1 to 4 according to the first embodiment are denoted by the same reference numerals, and hereinafter, differences from the wiring terminal 1 according to the first embodiment will be mainly described. Will be explained.

First, the wiring terminal 11 in FIG. 5 is such that the air-exposed portions 13b, 13c, and 13d are provided on both sides of the terminal connection portion 13a in the drawing. This is different from the first embodiment provided. Therefore, a large amount of electrons move uniformly and in large amounts from the air-exposed portions 13b to 13d provided on both sides of the terminal connection portion 13a, and a higher anticorrosion action as compared with the case where the air-exposed portion is provided on one side. Is obtained. Further, the degree of freedom in the layout design of the exposed portions 13b to 13d on the wiring terminal 11 is improved, and the formation becomes easier.

The wiring terminal 11 shown in FIG. 5 corresponds to the air exposed portion 1 provided on the right side of the terminal connection portion 13a in the drawing.
3c and 13d, that is, the air exposure portions 13c and 13d provided on the side of the matrix type liquid crystal display device (not shown) of the terminal connection portion 13a are divided into two, and independent air exposure portions 13c and 13d are respectively provided. The feature is that it is provided in parallel. The respective areas (exposed areas) of the air-exposed portions 13c and 13d provided in parallel are set to be smaller than the area of the air-exposed portion 13b provided on the left side of the terminal connection portion 13a in the drawing. (About 1/2). The reason for this is that the areas of the air-exposed sections 13c and 13d are
If the area is set to be equal to the area b, the metal wiring film 5 may be excessively corroded when a metal whose corrosion progresses due to a sequential oxidation reaction is used. Then, the corrosion also tends to spread around the air-exposed portions 13c and 13d, and in the worst case, there is a possibility that the wire may break. Therefore, the area of the exposed portions 13c and 13d is relatively small, and the independent exposed portions are used to control the corrosiveness of the metal wiring film 5 so that even when a readily corrosive metal is used. In addition, the tendency of the metal wiring film 5 to corrode excessively can be reduced.

In addition, in the second embodiment, since the effect of improving the corrosion resistance as already described in the first embodiment can be obtained, Al (Al) is used as the metal (terminal material) constituting the metal wiring film. One or more of Cu, Mo and W can be used. That is, it is possible to use a metal which is easily corroded but easy to form, has low resistance, and is less likely to cause environmental problems, as the material of the metal wiring film. In addition, when forming the wiring terminal of the second embodiment, the number of forming steps can be reduced, and furthermore, display defects and the like due to a wiring pattern defect can be reduced, so that a manufacturing advantage can be obtained. .

(3) Third Embodiment Next, a third embodiment of the present invention will be specifically described with reference to FIGS. FIG. 10 is a plan view showing the structure of the wiring terminal 21 according to the third embodiment. FIGS. 11 to 13 show the state where the anisotropic conductive film 4 is thermocompressed.
AA sectional view, BB sectional view and C-
It is C sectional drawing. 10 to 13, the same members as those in FIGS. 1 to 4 according to the first embodiment are denoted by the same reference numerals.

The wiring terminal 21 is basically composed of the metal wiring film 5 and the protective insulating film 6.
Is provided with a rectangular through hole 6c, that is, by removing the protective insulating film 6 in the through hole 6c,
The metal wiring film 5 is exposed to form a terminal connection portion 23a. On the both sides of the terminal connection portion 23a, two U-shaped grooves 24 are formed independently so as to surround the terminal connection portion 23a in the left-right direction in the drawing.

As a result, it is possible to increase the distance (the creeping distance) from the interface between the anisotropic conductive film 4 and the protective insulating film 6 until the moisture that has entered reaches the terminal connecting portion 23a. Therefore, it is possible to delay the time until the corrosion occurs in the terminal connection portion 23a due to the infiltrated water. Further, both sleeve portions 23A of the terminal connection portion 23a near the groove portion 24 and substantially surrounded by the groove portion 24.
Corrodes relatively quickly, the generated electrons move,
The central portion of the terminal connection portion 23a can be subjected to cathodic protection.

In the example of the third embodiment, FIG.
As can be understood from the cross-sectional view shown in FIG. 1, a part of the protective insulating film 6 is intentionally inserted into the groove 24.
Therefore, it is possible to effectively prevent the metal wiring film 5 located around the terminal connection portion 23a from being eroded, as compared with the case where the protective insulating film is not inserted into the groove. Also,
With this configuration, it is possible to further increase the distance (creepage distance) until the intruded moisture reaches the terminal connection portion 23a.

In the example of the third embodiment, the groove 2
As is easily understood from FIG. 11, the cross-sectional shape of 4 is rectangular (concave) as an example. However, the cross-sectional shape of the groove is not particularly limited as long as the creepage distance can be extended, and may be V-shaped, trapezoidal, or semi-circular. The cross-sectional area of the groove 24 is not particularly limited. However, if the area occupied by the groove 24 is excessively large in order to increase the corrosion life, the terminal connection area and the current path tend to be relatively small. . Therefore, it is preferable to appropriately change the shape of the groove 24 in accordance with the corrosion resistance and resistance value of the metal material used for the wiring terminal. Also, the number and arrangement of the grooves 24 are not particularly limited, but by arranging a plurality of grooves in parallel, the creepage distance before reaching the terminal connection portion 23a can be further increased. The configuration of such a groove is also preferable. Further, also in the wiring terminal of the third embodiment,
As in the first and second embodiments, since metal corrosion can be more effectively suppressed, the metal wiring film 5 is easily corroded, but easy to form, has low resistance, and It is preferable to use a metal that is less likely to cause environmental problems, for example, Mo or Al.

Next, the wiring terminal 2 in the third embodiment
The formation method (steps (E) to (H)) of No. 1 will be briefly described. The order of the steps (G) and (H) is not limited, and the step (G) may be performed before the step (H), or the steps (H) and (H) may be performed because the number of steps can be reduced. It is also preferable to perform (G) simultaneously.

(E) A patterned metal wiring film 5 having holes at the positions corresponding to the grooves is provided on the substrate 2 by a combination of sputtering, photolithography and the like via a predetermined mask pattern. In the example of the third embodiment,
As shown in FIG. 10, the planar shape of the metal wiring film 5 is substantially square. As can be understood from FIGS. 10 and 11, holes at positions corresponding to the grooves are formed in the terminal connection portions 23a.
Are provided so as to be opposed to each other. In addition, the holes are independently formed as U-shaped planes so as to surround the terminal connection portion 23a in the left-right direction.

(F) Next, a protective insulating film 6 such as a CVD nitride film is uniformly and entirely formed on the patterned metal wiring film 5. Therefore, the metal wiring film 5 is entirely covered with the protective insulating film 6 in a state where the protective insulating film 6 enters the holes corresponding to the grooves.

(G) A portion corresponding to the terminal connection portion 23 a in the coated protective insulating film 6 is removed by a mechanical or chemical method, and an external drive circuit is electrically connected via the anisotropic conductive film 4. Is formed to expose the metal wiring film 5 as a base. In the example of the third embodiment, the planar shape of the connection hole 6c is substantially a planar rectangular shape, and overlaps a part of the groove 24.

(H) Similar to the terminal connecting portion 23a, the groove 2
Part or all of the protective insulating film 6 that has entered the trench 4 is removed by a mechanical or chemical method to form a groove 24. In the example of the third embodiment, as shown in FIG. 11, only a part of the protective insulating film 6 that has entered the groove 24 is removed. Therefore, as compared with the case where the terminal connection portion 23a is completely removed, it is possible to effectively prevent the metal wiring film 5 located around the terminal connection portion 23a from spreading, and the invading moisture reaches the terminal connection portion 23a. It is also possible to further increase the distance (creepage distance) before the movement. By forming the wiring terminal 21 of the third embodiment in this manner,
Wiring terminals having excellent corrosion resistance can be obtained by reducing the number of forming steps as compared with conventional wiring methods.
Display defects and the like due to wiring pattern defects can be reduced.

(4) Fourth and Fifth Embodiments In the first and second embodiments, the case where the air-exposed portion is formed is described. In the third embodiment, the case where the groove is formed is described. As a fourth embodiment,
It is also preferable to form the exposed portion and the groove portion on the wiring terminal. This point will be briefly described with reference to FIG. The wiring terminal 33 shown in FIG.
In the drawing, two flat groove portions 34 are provided on the left side of the terminal connection portion, and are provided on both sides of the terminal connection portion. Therefore, the cathodic protection effect in the first embodiment and the corrosion delay effect in the third embodiment as described above can be synergistically obtained.

Further, as a fifth embodiment which is a modification of the fourth embodiment, it is preferable to form a groove 44 and a plurality of exposed portions 43b to 43d in the wiring terminal 43 as shown in FIG. In this way, the cathodic protection effect in the first embodiment and the corrosion delay effect in the third embodiment can be synergistically obtained, and furthermore, the corrosiveness of the metal wiring film 5 is controlled to facilitate corrosion. Even when a metal having a property is used, the tendency to excessively corrode the metal wiring film 5 can be reduced.

In addition, in the case of manufacturing a matrix type liquid crystal display device, the pixel electrode is formed of a transparent conductive film (ITO). It is also preferable to form an ITO film on the terminal connection part at the same time. In this way, the terminal connection
By forming the O film, it is possible to further extend the corrosion life of the metal wiring film in the terminal connection portion. Also,
Since the formation is performed simultaneously with the formation of the pixel electrodes, there is no problem such as an increase in the number of steps.

[0060]

As described above, according to the present invention,
By providing a through hole in the protective insulating film on the wiring terminal to form an exposed part to the atmosphere, the metal wiring film in the exposed part corrodes preferentially over the terminal connection part, and this corrosion reaction occurs. The transferred electrons move to the terminal connection portion, and the terminal connection portion can be efficiently subjected to cathodic protection. Therefore, since the corrosion of the metal wiring film at the terminal connection portion can be suppressed, a metal material that is easily corroded but has a small resistance value and is easy to form, such as Mo or Al, is used as the terminal material. be able to. Therefore, by using such a wiring terminal in a matrix type liquid crystal display device, it is possible to effectively prevent image quality deterioration, display defects, and the like.

Further, even when the metal wiring film is formed as a single layer or a thin film, the metal corrosion at the terminal connection portion can be effectively suppressed. Over-etching, under-cut, and the like do not occur, and display defects due to defective wiring patterns are reduced, thereby preventing a reduction in yield. Further, since the manufacturing is easy, the number of steps for forming the terminals and the time can be reduced, and the cost can be reduced.

In addition, when the wiring structure is a single layer or a thin film, it is possible to relax the restrictions on the metal material to be used and the manufacturing process, and it is also possible to obtain an advantage that the degree of freedom in design can be increased. .

[Brief description of the drawings]

FIG. 1 is a plan view showing a structure of a wiring terminal according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a sectional view taken along line BB in FIG.

FIG. 4 is a sectional view taken along line CC in FIG.

FIG. 5 is a plan view showing a structure of a wiring terminal according to a second embodiment of the present invention.

6 is a sectional view taken along line AA in FIG.

FIG. 7 is a sectional view taken along the line BB in FIG. 5;

8 is a sectional view taken along the line CC in FIG.

FIG. 9 is a sectional view taken along the line DD in FIG. 5;

FIG. 10 is a plan view illustrating a structure of a wiring terminal according to a third embodiment of the present invention.

11 is a sectional view taken along line AA in FIG.

FIG. 12 is a sectional view taken along line BB in FIG. 10;

13 is a sectional view taken along the line CC in FIG.

FIG. 14 is a plan view showing a structure of a wiring terminal according to a fourth embodiment of the present invention.

FIG. 15 is a plan view showing a structure of a wiring terminal according to a fifth embodiment of the present invention.

FIG. 16 is a plan view showing a structure of a wiring terminal provided in a conventional matrix liquid crystal display device.

FIG. 17 is an enlarged plan view showing a portion b in FIG. 16 in an enlarged manner.

18 is a sectional view taken along line AA in FIG.

19 is a sectional view taken along the line BB in FIG.

[Explanation of symbols]

1,11,21,33,43,106 Wiring terminal 2,104 Substrate 3a, 13a, 23a, 105 Terminal connection part 3b, 13b-13d, 33a, 43b-43d Atmospheric exposure part 4,110 Anisotropic conductive film 5 , 103 Metal wiring film 6, 107 Protective insulating film 6a, 6c Connection hole 6b Through hole 24, 34, 44 Groove (concave groove)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-251169 (JP, A) JP-A-7-72508 (JP, A) JP-A-61-17126 (JP, A) JP-A-6-126 18909 (JP, A) JP-A-7-191341 (JP, A) JP-A-11-133452 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1345

Claims (11)

(57) [Claims] In a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, a protective insulating film is provided on the metal wiring film, and an anisotropic film is formed on a part of the protective insulating film. a connecting hole for electrically connecting the external drive circuit via sexual conductive film, preferentially
Wiring terminals, characterized in that the atmospheric exposure portion in which a part of the wiring terminal for cathodic protection by corrosion was exposed are formed respectively. 2. The wiring terminal according to claim 1, wherein the air exposure portion is formed on both sides or any one side of the connection hole. 3. The method according to claim 1, wherein at least one metal selected from a metal group consisting of Al (aluminum), Cu (copper), Mo (molybdenum) and W (tungsten) is exposed to the atmosphere-exposed portion. The wiring terminal according to claim 1. 4. A wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, wherein a protective insulating film is provided on the metal wiring film, and a part of the protective insulating film is anisotropically formed. A connection hole for electrically connecting an external drive circuit via a conductive conductive film, and a groove formed on both sides or any one side of the connection hole. . 5. The wiring terminal according to claim 4, wherein the groove has a planar rectangular shape. 6. A wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, wherein a protective insulating film is provided on the metal wiring film, and a part of the protective insulating film is anisotropically formed. A connection hole for electrically connecting an external drive circuit via the conductive film, and an air-exposed portion where a part of the wiring terminal is exposed, and both sides or one side of the connection hole A wiring terminal, wherein a groove is formed in the wiring terminal. 7. The semiconductor device according to claim 1, wherein the wiring terminal is a scanning line and / or a signal line.
7. The wiring terminal according to any one of 6. 8. At least a part of the metal wiring film is made of A
l (aluminum), Cu (copper), Mo (molybdenum)
The wiring terminal according to any one of claims 1 to 7, wherein the wiring terminal is made of at least one metal selected from a metal group consisting of W and tungsten (W). 9. A method for forming a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, comprising the following steps (A) to (D). (A) Step of forming a metal wiring film. (B) a step of covering the surface of the metal wiring film with a protective insulating film. (C) a step of forming a connection hole for electrically connecting an external drive circuit through an anisotropic conductive film in a part of the protective insulating film by removing a part of the protective insulating film. (D) By removing a part of the protective insulating film, a part of the protective insulating film is preferentially corroded to perform cathodic protection.
Forming an exposed part in the atmosphere exposing a part of the metal wiring film. 10. A method for forming a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, comprising the following steps (E) to (H). (E) a step of forming a metal wiring film having holes at positions corresponding to the grooves. (F) a step of covering the surface of the metal wiring film with a protective insulating film. (G) a step of forming a connection hole for electrically connecting an external drive circuit through a part of the anisotropic conductive film by removing a part of the protective insulating film; (H) a step of forming a groove by removing a part of the protective insulating film. 11. A method for forming a wiring terminal comprising a metal wiring film provided in a matrix type liquid crystal display device, comprising the following steps (I) to (M). (I) A step of forming a metal wiring film having a hole at a position corresponding to the groove. (J) a step of covering the surface of the metal wiring film with a protective insulating film. (K) a step of forming a connection hole for electrically connecting an external drive circuit through a part of the anisotropic conductive film by removing a part of the protective insulating film. (L) forming a part of the protective insulating film to be exposed to the atmosphere, in which a part of the wiring terminal is exposed, by removing a part of the protective insulating film; (M) a step of forming a groove by removing a part of the protective insulating film;