JPH1152394A - Liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a curing defect of a UV curing resin seal in the overlap part of the extraction wiring, sealing part and CF black of a TFT liquid crystal display device. SOLUTION: The extraction wiring of the TFT substrate 1 in the position corresponding to the overlap part of the extraction wiring and the sealing part 3 is formed of a transparent electrode. As a result, the TFT liquid crystal display device which eliminates the curing defect of the photosetting resin seal caused thus far by the overlapping part consisting of a light shielding material by making it possible to effectively irradiate the photosetting resin seal with UV light 9 and has practicable strength is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly to a liquid crystal display device having a seal portion between two substrates.
The present invention relates to a liquid crystal display device for improving V-curing and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 7 is a schematic sectional view of a peripheral portion of a conventional active matrix type liquid crystal display device using thin film transistors. TFT substrate 1 having metal wiring 5 and CF
It has a structure in which a CF substrate 2 having a black 4 is joined by a seal portion 3. The disadvantage of this structure is that the seal 3
When a photo-curable resin is used, the UV light 9 necessary for curing the resin is blocked by the CF black 4 and the metal wiring 5, causing poor curing of the seal under the wiring pattern. That is, a reliability problem such as a leak occurs.

[0003] The reason is that in actual products, CF
While the gap between the black 4 and the metal wiring 5 is about 5 μm, the line width of the metal wiring 5 is about 50 μm, and the UV light incident from the gap is significantly attenuated before reaching the center of the wiring pattern. Because.

As an improvement in this respect, Japanese Patent Laid-Open Publication No.
In No. 019, the panel is inserted between the UV light source and the light reflecting member so that the UV light is applied from both the front and back surfaces of the panel.
A V irradiation device is shown. Also, JP-A-8-87020
Discloses a UV irradiator in which a light scattering member is provided on the UV light source side to irradiate light obliquely to CF black so that light is also applied to a shadow portion. In Japanese Patent Application Laid-Open No. 5-192933, minute solid particles for reflecting or refracting irradiation light are mixed and dispersed in a photocurable resin in advance.
A photocurable resin that is exposed to V light has been proposed.

[0005]

However, in the above-mentioned prior art, the method proposed in Japanese Patent Application Laid-Open No. 8-87019 discloses a method in which an adhesive is sandwiched between two glass substrates in advance to form an integrated work. On the other hand, the UV light transmitted from the CF black side and transmitted through the work is reflected by the light reflecting member, and the reflected UV light is applied from the TFT substrate side. Even if the CF black can be avoided,
Since there is no effect on light shielding by the metal wiring pattern existing on the T substrate, the photocurable resin under the wiring pattern is not cured.

In the method proposed in Japanese Patent Application Laid-Open No. 8-87020, a light diffusing member is arranged near the above-mentioned work on the CF black side, and the CF black is obliquely exposed to UV light to form a shadow. However, as described above, light obliquely incident from a gap of 5 μm significantly attenuates, so that the photocurable resin under the wiring pattern hardens to a practical strength. I can't get it.

The method proposed in Japanese Patent Application Laid-Open No. HEI 5-192933 discloses a method of dispersing minute solid particles for reflecting or refracting irradiation light in an ultraviolet curable resin to reach a portion hardly exposed to ultraviolet light. However, as for liquid crystal display devices with narrow frontage and long depth, photo-curable resins with large attenuation also can harden to practical strength. Absent.

An object of the present invention is to provide a TFT having a metal wiring
In a liquid crystal display device, the problem that a sealant using a photocurable resin caused poor curing due to insufficient light intensity between a metal wiring and a CF black matrix was solved, and practical reliability was maintained. To provide products.

[0009]

According to the present invention, a first substrate on which a pixel matrix is formed and a second substrate on which a color filter is formed are bonded to each other by using a sealing material at a peripheral portion thereof. In a liquid crystal display device in which liquid crystal is sealed therein, the wiring portion of the portion where the wire drawn to the electrode terminal arranged on the periphery of the first substrate and the seal portion overlap is transparent. UV light can be effectively irradiated to the photocurable resin seal as a conductive film.

The wiring other than the overlap portion may be made of metal so that a voltage drop due to wiring resistance is minimized, and the wiring other than the overlap portion is formed of two layers of metal and a transparent electrode film. The voltage drop may be minimized.

According to the present invention, a hole or a slit is formed in the wiring in the overlap portion so that UV light can be applied to the photocurable resin seal. A transparent electrode film may be formed on the holes or slits to minimize the voltage drop.

Further, according to the present invention, in forming a wiring by a photolithographic method, a step of removing a metal also in a portion overlapping with a seal portion, a step of forming a transparent conductive film, a step of forming a wiring and a photolithographic method. Forming a transparent conductive film on the overlapped portion, thereby obtaining a liquid crystal display device manufacturing method.

Further, according to the present invention, the first substrate on which the pixel matrix is formed and the second substrate on which the color filter is formed are bonded by using a sealant at the peripheral portion thereof. In the method of manufacturing a liquid crystal display device by enclosing liquid crystal therein, the first portion corresponding to a portion where a wire led out to an electrode terminal arranged at a peripheral portion of the first substrate and a portion of the seal overlap. A liquid crystal display device is provided in which a window for light transmission is formed in the black matrix portion of the second substrate so that UV light can be effectively irradiated to the photocurable resin seal.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a peripheral portion of the liquid crystal display device according to the first embodiment of the present invention. In the same figure, the portion facing the seal portion 3 shielded from light by the CF black 4 formed on the CF substrate 2 is patterned so that the metal wiring 5 formed on the TFT substrate 1 does not overlap, and is formed simultaneously. In this case, an ITO (transparent conductive film, indium tin oxide) wiring 6 is connected between the terminal extraction side metal wiring 10 and the UV light 9 penetrates the ITO wiring 6 to reach the seal portion 3. .

Here, the region connecting the metal wiring 10 and the metal wiring 5 on the terminal lead-out side only with the ITO wiring 6 is the ITO wiring.
In order to suppress a decrease in drive voltage due to the electric resistance of the wiring 6, it is desirable to set a minimum necessary portion including the entire width of the seal portion 3. A structure in which only the ITO wiring 6 is formed without forming the wiring 10 is also possible.

FIG. 2 is a plan view thereof. Here, TFT
The figure which looked directly from the board | substrate 1 side is shown. Here, C of CF substrate 2
The F black 4 overlaps the seal portion 3 and cannot expose the seal portion 3 to UV light from the back side of the drawing, that is, from the CF side. On the other hand, on the TFT substrate side, between the metal wiring 5 and the terminal take-out side metal wiring 10, an ITO wiring 6 is formed so as to have no obstacle when applying UV light to the seal portion 3.

FIGS. 3A to 3D are views showing a wiring forming step in the present invention. First, as shown in FIG.
A metal film 31 is formed on the FT substrate 1. Next, the metal film 31 is patterned as shown in FIG. At this time, a portion overlapping with the seal portion 3 is previously opened.
Next, an ITO film 32 is formed as shown in FIG.

Finally, the ITO film is patterned to form an ITO wiring 6 as shown in FIG. In this example, ITO
Although the wiring 6 is formed on the entire surface of the metal electrode 5 and the terminal extraction side electrode 10, the ITO wiring may be formed so as to connect at least the metal electrode 5 and the terminal extraction side electrode 10. The above steps can be realized in a normal TFT element formation flow, and the steps of the present invention can be realized only by forming a photomask.

FIG. 4 is a plan view showing a second embodiment of the present invention. In this embodiment, a slit 7 is provided at a portion where the seal portion 3 and the metal wiring 5 overlap each other, and oblique UV light incident from the outer end of the wiring and the slit 7 is applied to the metal indicated by the line width 8. The structure is such that the ultraviolet curable resin of the seal portion 3 between the wiring and the CF black 4 reaches the resin by multiple reflection or the like.

This embodiment aims at alleviating the voltage drop caused by the electric resistance at the ITO junction generated in the first embodiment.
It is desirable to form the TO in the same manner as in the first embodiment. In the second embodiment, the slit 7
The width of the wire and the dimension of the line width 8 are determined by the electric resistance and U
This should be determined in consideration of the V light arrival level. However, in the second embodiment, the curing strength of the sealant is in principle inferior to that of the first embodiment, so that the first embodiment is superior under normal driving conditions. In addition, since the patterning failure of the slit portion is likely to occur with dimensional accuracy, the first embodiment is better in terms of yield. In this embodiment, the case where a slit is provided in the metal wiring is shown, but a round or square hole may be provided instead of the slit.

Next, a third embodiment of the present invention will be described. FIG. 5 is a sectional view thereof. In this embodiment, C
Seal part and TFT for F side black matrix
A window that transmits UV light is provided in a portion overlapping with the wiring on the substrate side (hereinafter, referred to as a “BM window”).

As shown in FIG. 5, a BM window 11 is provided at a portion where the seal portion 3 of the CF black 4 and the metal wiring 5 overlap, and oblique UV light incident from the outer end of the wiring and the BM window 11 is provided. Reach the ultraviolet curing resin of the seal portion 3 by multiple reflection or the like.

FIG. 6 is a plan view thereof. In this case, TF
The wiring pattern on the T-substrate side may be the same as the conventional one, and there is no need to consider the voltage drop. However, it is necessary to irradiate UV light from both the front and back of the element. Alignment accuracy is required.

[0024]

The effect of the present invention described above is that the ultraviolet curable resin seal in the portion sandwiched between the lead wiring of the TFT substrate and the CF black matrix of the CF substrate can be cured with practical strength. The reason is that a conductive material that transmits ultraviolet light is used in a portion where the lead wiring and the seal overlap, or a hole or a slit is provided in the wiring portion, or a CF black matrix in a portion where the lead wiring and the seal overlap is formed. This is because a pattern serving as a window that transmits ultraviolet light is provided in the overlapping portion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a plan view showing the first embodiment of the present invention.

FIGS. 3A to 3D are perspective views showing a manufacturing process according to the first embodiment of the present invention.

FIGS. 4 (a) and 4 (b) are a plan view and a partially enlarged view of a slit showing a second embodiment of the present invention.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

FIG. 6 is a sectional view showing a third embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 TFT substrate 2 CF substrate 3 Seal part 4 CF black 5 Metal wiring 6 ITO wiring 7 Slit 8 Line width 9 UV light 10 Terminal extraction side metal wiring 11 BM window

Claims (7)

[Claims] A first substrate on which a pixel matrix is formed and a second substrate on which a color filter is formed;
In a liquid crystal display device in which the peripheral portion is bonded using a sealant and liquid crystal is sealed therein, wiring drawn to an electrode terminal arranged in the peripheral portion of the first substrate, the sealing portion, A liquid crystal display device, wherein a transparent conductive film is used for a portion of the wiring where the wire overlaps. 2. The liquid crystal display device according to claim 1, wherein the wiring other than the overlap portion is made of metal. 3. The liquid crystal display device according to claim 1, wherein the wiring other than the overlap portion is a two-layered structure including a metal and a transparent electrode film. 4. A first substrate on which a pixel matrix is formed and a second substrate on which a color filter is formed are bonded to each other using a sealant at a peripheral portion thereof, and liquid crystal is sealed therein. In the liquid crystal display device, a hole or a slit is formed in a wiring portion of a portion where a wire drawn to an electrode terminal arranged in a peripheral portion of the first substrate and the seal portion overlap. Liquid crystal display device. 5. The liquid crystal display device according to claim 4, wherein a transparent electrode film is formed on the hole or the slit. 6. A first substrate on which a pixel matrix is formed and a second substrate on which a color filter is formed,
In a method of manufacturing a liquid crystal display device in which a peripheral portion thereof is bonded using a sealant and a liquid crystal is sealed therein, a metal film for wiring is formed on the first substrate, and a wiring is formed by a photolithographic method. In doing so, the method includes a step of removing a metal also in a portion overlapping the seal portion, a step of forming a transparent conductive film, and a step of forming a transparent conductive film on the wiring and the overlap portion by a photolithographic method. A method for manufacturing a liquid crystal display device, comprising: 7. A first substrate on which a pixel matrix is formed and a second substrate on which a color filter is formed,
In a liquid crystal display device in which liquid crystal is sealed in a liquid crystal display device in which a liquid crystal is sealed in the liquid crystal display device, a wiring drawn to an electrode terminal disposed in a peripheral portion of the first substrate and a portion of the seal are attached. A liquid crystal display device, wherein a window for light transmission is formed in a black matrix portion of the second substrate corresponding to a portion where the first and second substrates overlap.