JP3671536B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly, to a liquid crystal display device having a structure in which a transparent electrode is provided on a color filter.
[0002]
[Prior art]
When color display is enabled in a liquid crystal display device, the most common method is to form a color filter on the inner surface of one of the two substrates sandwiching the liquid crystal layer. There are various methods for forming this color filter. Among them, the method of applying a colored resist and forming a pattern by photolithography is excellent in that the colored layer can be formed with high accuracy.
[0003]
7 and 8 show an inner surface structure of a counter substrate constituting a liquid crystal display device having a conventional color filter. The color filter 11 formed on the surface of the counter substrate 10 is sequentially coated, exposed, and developed using a colored resist containing three color pigments of red (R), green (G), and blue (B). As a result, a colored layer of three colors having a shape corresponding to the pixel region is formed. Further, a black matrix layer for light shielding is formed at the boundary between the colored layers. The black matrix layer may be composed of a resist containing a black pigment, may be composed of a metal layer, or may be composed of laminated colored layers having different tones.
[0004]
A protective film 12 made of a transparent acrylic resin is formed on the surface of the color filter 11, and the color filter 11 is protected by the protective film 12.
[0005]
On the surface of the protective film 12, transparent electrodes 13 made of ITO (indium tin oxide) are formed in a stripe shape. The transparent electrode 13 includes an electrode portion 13a formed in a linear stripe shape in the display region on the protective film 12, and a lead line portion 13b connected to the electrode portion 13a and led out from the display region. The terminal portion 13c formed at the distal end portion of the lead wire portion 13b is integrally formed.
[0006]
The plurality of terminal portions 13c formed on the surface of the counter substrate 10 are arranged in parallel at a predetermined pitch depending on the application, such as being connected to an external flexible wiring board or directly connected to an IC chip. A lead wire portion 13b extends from the electrode portion 13a toward the terminal portion 13c.
[0007]
[Problems to be solved by the invention]
However, the liquid crystal display device having the conventional color filter has the following problems.
[0008]
First, when the transparent electrode 13 is formed on the protective film 12 as described above, since the transparent electrode 13 is also formed on the outer edge portion 12a of the protective film 12, the transparent electrode 13 is formed on the outer edge portion 12a. A space may be formed between the portion 13d of the transparent electrode 13 and the outer edge portion 12a due to a wraparound failure during film formation. In particular, the outer edge portion 12a of the protective film 21 is generally reversely tapered with respect to the substrate surface as shown in FIG. 2 (the side surface formed on the outer edge portion is facing downward). A large space is generated between the transparent electrode 13 and the transparent electrode 13.
[0009]
Further, since the transparent electrode 13 is formed on the protective film 12, the ITO film formation temperature is limited by the heat-resistant temperature of the protective film 12, and the transparent electrode 13 that is sufficiently dense and high in strength cannot be formed. . For example, the heat resistance temperature of the protective film 12 is usually 240 ° C. at most, but a film forming temperature of about 300 to 350 ° C. is necessary to form the high-quality transparent electrode 13. Therefore, the transparent electrode 13 having the above structure must be formed at a low temperature, so that the film quality is weak and the etching rate is high.
[0010]
Furthermore, the residue of the protective film 12 formed at the time of patterning is left on the outer side of the outer edge portion 12a of the protective film 12, or the transpiration material at the time of sputtering is reattached, and is formed thereon. Adhesion between the transparent electrode 13 and the base is not sufficient.
[0011]
Due to the above reasons, an under-etching phenomenon is likely to occur between the portion 13d of the transparent electrode 13 and the outer edge portion 12a of the protective film 12 during patterning of the transparent electrode 13, and in particular, the lead line portion 13b. Although the portion where the outer edge 12a intersects with the obtuse angle θ is good, the etching solution easily enters the portion 13d from the portion with the acute angle φ, and a V-shaped notch-like etching mark is generated. Has the problem of causing wiring breaks.
[0012]
In order to solve the above problems, a method of forming the protective film 12 on the entire surface of the substrate 10 may be considered, but in this case, a flexible substrate is attached to the external terminal portion or an IC chip is mounted. If a defect is found and removed from the substrate or IC chip after the operation, the terminal portion 13c is peeled off from the protective film 12.
[0013]
Therefore, the present invention solves the above problems, and the problem is that in the case of forming a transparent electrode on the protective film of the color filter as described above in a liquid crystal display device, The object is to realize a novel structure and manufacturing method capable of preventing wiring disconnection due to etching.
[0014]
[Means for Solving the Problems]
Measure taken by the present invention to solve the above problems is configured to obtain a desired display state by disposing a liquid crystal layer between two substrates, the coercive Mamorumaku and a transparent electrode on one of the substrate sequentially stacking made by, the transparent electrode is provided with the lead wire portion drawn to the external terminal portion in the form that is not the region of the protective film of the upper substrate from the portion located on the protective film on the substrate In the liquid crystal display device, the transparent electrode is bent from a portion on the protective film toward the external terminal portion, and is formed on the first bent portion and the protective film in a region where the protective film is not formed. A second bent portion, wherein the first bent portion is provided on one side surface of the transparent electrode, the second bent portion is provided on the other side surface of the transparent electrode, and an outer edge portion of the protective film. intersection angle between the side surface of the first bent portion of the transparent electrode and is Becomes square, characterized in that the crossing angle between the side surface of the second bent portion of the transparent electrode and the outer edge of the protective film is configured to be obtuse.
[0015]
According to this means, by configuring the crossing angle between the outer edge of the protective film and the transparent electrode to be substantially right angle or obtuse, the intrusion of the etching solution is suppressed at the crossing portion, the wiring in the transparent electrode is broken, An increase in wiring resistance can be prevented.
[0016]
In addition, the intersection part with the outer edge part of a protective film may be a leader line part of a transparent electrode, or parts other than a leader line part.
[0017]
Here, it is preferable that the outer edge portion of the protective film is formed to have a forward taper with respect to the substrate surface.
[0018]
According to this means, since the outer edge portion is formed so as to be forward tapered with respect to the substrate surface, a gap is formed between the transparent electrode deposited on the outer edge portion, and adhesion is improved. Since it can prevent that it falls, the obstacle of a transparent electrode can further be reduced.
[0019]
Further, both side surfaces of the transparent electrode are configured to be substantially orthogonal to the outer edge portion of the protective film, and the lead-out line portion is in a direction in which the external terminal portion exists outside the outer edge portion of the protective film. It is preferable to constitute so as to extend.
[0020]
According to this means, by limiting the extending position of the leader line portion to the outside of the outer edge portion of the protective film, the cross shape of the transparent electrode on the outer edge portion can be formed into a desired shape, and the extension of the leader line portion can be formed. The direction can be designed arbitrarily.
[0021]
Further, a liquid crystal layer is disposed between two substrates to obtain a desired display state, and a protective film and a transparent electrode are sequentially stacked on one of the substrates, and the transparent electrode is formed on the substrate. In the liquid crystal display device having a lead line portion led out from a portion on the protective film to an external terminal portion in a region where the protective film is not formed on the substrate, the transparent electrode is formed on the protective film. It is preferable that the outer edge portion is formed so as to be narrowed toward the outside, and the intersection angle between the outer edge portion of the protective film and both side surfaces of the transparent electrode is an obtuse angle .
[0022]
According to this means, since the crossing angle between the both side surfaces of the transparent electrode and the outer edge portion can be formed to be an obtuse angle, the obstacle of the transparent electrode can be further reduced.
[0023]
In addition, a liquid crystal layer is disposed between two substrates to obtain a desired display state, and a protective film and a transparent electrode are sequentially stacked on one of the substrates, and the transparent electrode is formed on the substrate. In the liquid crystal display device including a lead line portion led out from a portion on the protective film to an external terminal portion in a region where the protective film is not formed on the substrate, the transparent electrode is the protective film Bending toward the external terminal portion from an upper portion, and the crossing angle between the outer edge portion of the protective film and both side surfaces of the transparent electrode is a right angle or an obtuse angle so that the crossing angle is obtained. to the transparent electrode before Symbol protective film may be formed a protrusion protruding toward the direction of bending.
[0024]
According to this means, by matching the shape of the outer edge portion of the protective film so as to obtain the above-described crossing angle, the degree of freedom of the pattern shape of the leader line portion is increased, and the wiring pattern can be arbitrarily designed. Become.
[0025]
Further configured between two substrates so as to obtain a desired display state by disposing a liquid crystal layer made by sequentially stacking a coercive Mamorumaku and a transparent electrode on one of the substrate, the transparent electrode, the substrate In the method of manufacturing a liquid crystal display device having a lead line portion led out from a portion on the protective film to an external terminal portion in a region where the protective film is not formed on the substrate, the transparent electrode A first bent portion in a region where the protective film is not formed and a second bent portion on the protective film, bent from the portion on the protective film toward the external terminal portion, The first bent portion is provided on one side surface of the transparent electrode, the second bent portion is provided on the other side surface of the transparent electrode, and the outer edge portion of the protective film and the first bent portion of the transparent electrode are provided. The crossing angle with the side surface on the part side becomes a right angle, and the outside of the protective film As the crossing angle between the side surface of the second bent portion side parts and the transparent electrode is an obtuse angle, and is characterized in that the patterning of the transparent electrode.
[0026]
Here, it is preferable to adjust the formation conditions of the protective film to form the outer edge of the protective film in a forward taper with respect to the substrate surface.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of a liquid crystal display device and a manufacturing method thereof according to the present invention will be described with reference to the accompanying drawings.
[0028]
1 and 2 are an enlarged plan view and a cross-sectional view showing a part of a counter substrate of the liquid crystal display device according to the present embodiment. A color filter 21 is formed on the surface of the counter substrate 20, a protective film 22 made of ITO is formed thereon, and a transparent electrode 23 is further formed thereon. The transparent electrode 23 is comprised from the electrode part 23a, the leader line part 23b, and the terminal part 23c like the past.
[0029]
In this embodiment, the electrode portion 23a of the transparent electrode 23 is formed so as to extend to the outside of the outer edge portion 22a of the protective film 22, and the outer edge portion 22a of the protective film 22 and the electrode portion 23a are orthogonal to each other. ing. As a result, the crossing angles θ and φ between the both side surfaces of the electrode portion 23a and the outer edge portion 22a are both substantially perpendicular.
[0030]
In the present embodiment, the protective film 22 is formed of a photocurable resin such as polyacrylate or epoxy resin, or a thermosetting resin. When the protective film 22 is formed of polyacrylate, it is applied by spin coating or the like, then pre-baked at about 80 to 110 ° C. and exposed to predetermined ultraviolet light, and then 0.1 to 1 of potassium hydroxide. Develop with 0 wt% aqueous solution. Then, it forms by performing a post-baking at the temperature of 180-220 degreeC.
[0031]
Here, the surface shape of the outer edge portion 22a of the protective film 22 has a forward taper with respect to the substrate surface in order to allow the transparent electrode 23 to be formed on the surface without any gap and to improve the adhesion with the transparent electrode 23. In other words, it is preferable that the angle ψ between the substrate surface and the surface of the outer edge portion shown in FIG. 2 is an obtuse angle.
[0032]
The outer edge portion 22a can be forward tapered with respect to the substrate surface by setting the formation conditions of the protective film 22a. In order to increase the angle ψ, the temperature of the pre-bake is lowered (for example, the temperature is set to 80 ° C.) and the development processing is weakened (for example, the concentration of potassium hydroxide is set to 0.1 to 0.5 wt%). .)do it.
[0033]
In the above-described embodiment, the width of the electrode portion 23a of the transparent electrode 23 shown in FIG. 1 is about 200 to 300 μm, and the lead wire portion 23b and the terminal portion 23c have a smaller width. The wide portion of the transparent electrode 23 needs to be secured to some extent before and after the outer edge portion 22a of the protective film 22, and the distance l from directly above the outer edge portion 22a to the end portion of the electrode portion 23a shown in FIG. It is preferable to secure about 50 μm.
[0034]
According to the present embodiment, since the crossing angles θ and φ with the outer edge portion 22a of the protective film 22 on both side surfaces of the transparent electrode 23 are both substantially perpendicular, there is little erosion when the transparent electrode 23a is etched, etc. It is possible to prevent wiring breakage and wiring resistance increase due to under-etching.
[0035]
In particular, since the outer edge portion 22a of the protective film 22 is formed in a forward taper, the adherence to the outer edge portion 22a of the transparent electrode 23 is improved, and a gap is formed between them or the adhesion is reduced. In other words, under-etching of the transparent electrode 23 on the outer edge 22a can be suppressed.
[0036]
FIG. 3 shows a planar shape of the transparent electrode 23 in another embodiment. In the transparent electrode 23, an extension portion 23 d formed between the electrode portion 23 a and the lead wire portion 23 b is formed above the outer edge portion 22 a of the protective film 22. The extended portion 23d is formed as a linear portion wider than the leader line portion 23b, and includes a side surface orthogonal to the outer edge portion 22a of the protective film 22.
[0037]
The extension 23d is the same as the above embodiment in that the wiring breakage caused by the etching can be prevented. Regardless of the width of the electrode portion 23a and the lead-out portion 23b, the extension portion 23d is formed to have a width sufficient to prevent wiring breakage due to etching and an increase in resistance value that hinders liquid crystal driving. be able to.
[0038]
FIG. 4 shows the main part of a further different embodiment. In this structure, the electrode portion 23a of the transparent electrode 23 and the lead wire portion 23b are directly connected, but the bent portion 23e between the side surface of the electrode portion 23a and the side surface of the lead wire portion 23b is formed on the protective film 22. The bent portion 23f on the opposite side surface is disposed outside the outer edge portion 22a on the inner side of the outer edge portion 22a.
[0039]
As a result, the crossing angle θ between the side surface of the transparent electrode 23 and the outer edge portion 22a is an obtuse angle, and the crossing angle φ is substantially a right angle. Therefore, on any side surface of the transparent electrode 23, wiring breakage and wiring resistance increase due to under-etching during etching are suppressed.
[0040]
FIG. 5 shows a planar shape of the transparent electrode 23 in another embodiment. In this embodiment, the side surface portions 23g and 23h formed obliquely in the direction in which the width decreases from the electrode portion 23a toward the lead wire portion 23b between the electrode portion 23a and the lead wire portion 23b of the transparent electrode 23. Is provided. Due to the side portions 23g and 23h, the transparent electrode 23 has a narrowed shape on the outer edge portion 22a. As a result, the crossing angles θ and φ formed between the transparent electrode 23 and the outer edge portion 22a of the protective film 22 are Both are obtuse.
[0041]
As a result, the disconnection of wiring at the intersection with the outer edge portion 22a in the transparent electrode 23 and the increase in wiring resistance are further suppressed.
[0042]
FIG. 6 shows the planar shapes of the protective film 22 and the transparent electrode 23 in still another embodiment. In this embodiment, the transparent electrode 23 is substantially the same as the conventional planar shape, but a protruding portion 22b formed in accordance with the lead wire portion 23b is formed on the outer edge portion 22a of the protective film 22. The projecting portion 22b is deformed so that the extending direction of the outer edge portion 22a is substantially orthogonal to the side surface of the leader line portion 23b. As a result, the crossing angles θ and φ are substantially perpendicular, and the same effect as in the above-described embodiment can be obtained.
[0043]
Similar to the method shown in FIG. 6, by changing the outer edge shape of the protective film 22, it is possible to appropriately obtain the same effect as the structure shown in FIG. In this case, if the outer edge shape of the protective film 22 is curved in the protruding direction at the intersections with both side surfaces of the transparent electrode 23, both the intersection angles θ and φ can be set to obtuse angles.
[0044]
【The invention's effect】
As described above, the present invention has the following effects.
[0045]
According to the present invention , the crossing angle between the outer edge portion of the protective film and the transparent electrode is configured to be substantially a right angle or an obtuse angle. An increase in wiring resistance can be prevented.
[0046]
According to the present invention , since the outer edge portion is formed so as to be forward tapered with respect to the substrate surface, a gap is formed between the outer edge portion and the transparent electrode deposited on the outer edge portion, or adhesion is improved. Since it can prevent that it falls, the obstacle of a transparent electrode can further be reduced.
[0047]
According to the present invention , by limiting the position where the leader line portion extends to the outside of the outer edge portion of the protective film, the cross shape of the transparent electrode on the outer edge portion can be formed into a desired shape, and the extension of the leader line portion can be achieved. The direction can be designed arbitrarily.
[0048]
According to the present invention , since the crossing angle between the both side surfaces and the outer edge of the transparent electrode can be formed to be an obtuse angle, the obstacle of the transparent electrode can be further reduced.
[0049]
According to the present invention , by matching the shape of the outer edge portion of the protective film so as to obtain the above-described crossing angle, the degree of freedom in the pattern shape of the leader line portion is increased, and the wiring pattern can be arbitrarily designed. Become.
[Brief description of the drawings]
FIG. 1 is an enlarged plan view showing a planar structure on a counter substrate of an embodiment of a liquid crystal display device according to the present invention.
FIG. 2 is an enlarged cross-sectional view showing a cross-sectional structure on the counter substrate of the embodiment.
FIG. 3 is an enlarged plan view showing a planar structure of a transparent electrode in a different embodiment.
FIG. 4 is an enlarged plan view showing a planar structure of a transparent electrode in still another embodiment.
FIG. 5 is an enlarged plan view showing a planar structure of a transparent electrode in another embodiment.
FIG. 6 is an enlarged plan view showing a planar structure of a transparent electrode and a protective film in still another embodiment.
FIG. 7 is an enlarged plan view showing a part of a planar structure of a counter substrate in a conventional liquid crystal display device.
FIG. 8 is an enlarged cross-sectional view showing a partial cross-sectional structure of a counter substrate in a conventional liquid crystal display device.
[Explanation of symbols]
20 Counter substrate 21 Color filter 22 Protective film 22a Outer edge portion 23 Transparent electrode 23a Electrode portion 23b Lead wire portion 23c Terminal portion θ, φ Crossing angle

Claims (6)

Between the two substrates by placing the liquid crystal layer is configured to obtain a desired display state, made by sequentially laminating the coercive Mamorumaku and a transparent electrode on one of the substrate, the transparent electrode, on the substrate In a liquid crystal display device comprising a leader line portion led out from a portion on the protective film to an external terminal portion in a region where the protective film is not formed on the substrate ,
The transparent electrode is bent from a portion on the protective film toward the external terminal portion, and a first bent portion in a region where the protective film is not formed and a second bent portion on the protective film, Have
The first bent portion is provided on one side surface of the transparent electrode, and the second bent portion is provided on the other side surface of the transparent electrode,
The intersection angle between the outer edge portion of the protective film and the side surface of the transparent electrode on the first bent portion side is a right angle, and the intersection angle between the outer edge portion of the protective film and the side surface of the transparent electrode on the second bent portion side. A liquid crystal display device characterized by having an obtuse angle.   2. The liquid crystal display device according to claim 1, wherein an outer edge portion of the protective film is formed to have a forward taper with respect to the substrate surface. A liquid crystal layer is disposed between two substrates to obtain a desired display state, and a protective film and a transparent electrode are sequentially stacked on one of the substrates, and the transparent electrode is formed on the substrate. In a liquid crystal display device comprising a leader line portion led out from a portion on the protective film to an external terminal portion in a region where the protective film on the substrate is not formed,
Forming the transparent electrode so as to squeeze outward on the outer edge of the protective film ;
A liquid crystal display device , wherein an intersection angle between an outer edge portion of the protective film and both side surfaces of the transparent electrode is an obtuse angle . A liquid crystal layer is disposed between two substrates to obtain a desired display state, and a protective film and a transparent electrode are sequentially stacked on one of the substrates, and the transparent electrode is formed on the substrate. In a liquid crystal display device comprising a leader line portion led out from a portion on the protective film to an external terminal portion in a region where the protective film on the substrate is not formed,
The transparent electrode is bent from the portion on the protective film toward the external terminal portion,
The crossing angle between the outer edge of the protective film and both side surfaces of the transparent electrode is configured to be a right angle or an obtuse angle,
The way crossing angle is obtained, a liquid crystal display device in which the transparent electrode before Symbol protective film is characterized in that a projecting portion is formed protruding toward the direction of bending. Between the two substrates by placing the liquid crystal layer is configured to obtain a desired display state, made by sequentially laminating the coercive Mamorumaku and a transparent electrode on one of the substrate, the transparent electrode, on the substrate In a method of manufacturing a liquid crystal display device including a lead line portion led out from a portion on the protective film to an external terminal portion in a region where the protective film is not formed on the substrate ,
The transparent electrode is bent from a portion on the protective film toward the external terminal portion, and a first bent portion in a region where the protective film is not formed and a second bent portion on the protective film, The first bent portion is provided on one side surface of the transparent electrode, the second bent portion is provided on the other side surface of the transparent electrode, and an outer edge portion of the protective film and the transparent electrode The transparent electrode is formed so that the intersection angle with the side surface on the first bent portion side is a right angle, and the intersection angle between the outer edge portion of the protective film and the side surface on the second bent portion side of the transparent electrode is an obtuse angle. A method of manufacturing a liquid crystal display device, wherein a pattern is formed.   6. The method for manufacturing a liquid crystal display device according to claim 5, wherein the formation condition of the protective film is adjusted to form an outer edge portion of the protective film in a forward taper with respect to the substrate surface.

Images