JPH10319876A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve display quality by providing a convex part on a flexible film a wiring corresponding to a transparent electrode on a substrate on this convex part through an anisotrophy conduction film. SOLUTION: A flexible film 60 of a ruggedness end part shape is provided on a substrate 20 on which a semiconductor device 30 is provided through an anisotrophy conduction film. In this case, the semiconductor device 30 is placed in a concave part of the flexible film 60, a convex part and a concave part are provided on the substrate 20. In this liquid crystal display device 10, a driving signal for driving the semiconductor device 30 is supplied to a transparent electrode 40 provided on the substrate 20 of the liquid crystal device 10 through a wiring 70 of the flexible film 60 from the outside. And cascade wirings 50 consisting of transparent electrodes 40 are provided among the semiconductor devices 30, convex parts of the flexible film 60 are placed among the semiconductor devices 30, wirings 70 provided on a convex part of the flexible film 60 are constituted so as to overlap the transparent electrode 40 on the substrate 20.

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 used as a display of an information device such as a TV or a computer.
G) A structure of a liquid crystal display device in which a semiconductor chip is mounted by a method and a flexible film is provided.

[0002]

2. Description of the Related Art A conventional technique in which a flexible film is provided on a glass substrate of a liquid crystal display device on which a semiconductor device is mounted by COG via an anisotropic conductive film will be described with reference to FIGS. explain.

FIG. 4 is a front view showing a case where a flexible film is provided on a substrate having a plurality of semiconductor devices, and wiring provided on the flexible film is used as cascade wiring between the semiconductor devices.

FIG. 5 is a front view showing that a flexible film is provided on a substrate having a plurality of semiconductor devices, and cascade wiring between the semiconductor devices is provided on the substrate.

FIG. 6 is a front view showing that a flexible film having an uneven shape is provided on a substrate having a plurality of semiconductor devices, and transparent electrodes and wiring of the flexible film are provided as cascade wiring between the semiconductor devices. FIG.

First, the operation of the liquid crystal display device shown in FIG. 4 will be described. A flexible film 60 is provided on the substrate 20 of the liquid crystal display device 10, and a driving signal is supplied from the wiring 70 of the flexible film 60 to the semiconductor device 30 via the transparent electrodes 40 provided on the substrate 20.

A plurality of semiconductor devices 3 to which drive signals have been supplied
Numeral 0 supplies an output signal to the liquid crystal display device 10, and in order to synchronize the signals output from the semiconductor devices 30, a cascade wiring 50 is provided between the semiconductor devices 30 to exchange a synchronization signal.

[0008] In the liquid crystal display device 10 shown in FIG.
The cascade wiring 50 composed of the transparent electrode 40 is provided on the substrate 20 between 0. The synchronization signal takes a path from the semiconductor device 30 to the adjacent semiconductor device 30 via the cascade wiring 50.

The cascade wiring 50 shown in FIG. 5 passes from the semiconductor device 30 through the transparent electrode 40 of the liquid crystal display device 10 to the wiring 70 of the flexible film 60, and passes through the transparent electrode 40 of the substrate 20 to the adjacent semiconductor. Take a route to the device 30.

The liquid crystal display device 10 shown in FIG. 6 is provided, for example, around a region to be a pixel on which a glass substrate is bonded by a method described in Japanese Patent Application Laid-Open No. 8-146449.
This is a conventional example in which a frame width of a substrate on which a semiconductor chip is mounted is reduced, and a convex portion of a flexible film 60 is provided between semiconductor devices 30. According to Japanese Patent Application Laid-Open No. 8-146449, the cascade wiring 50 between the semiconductor devices 30 passes through the wiring 70 of the flexible film 60 from the semiconductor device 30 via the transparent electrode 40 of the substrate 20, and
A path leading to the adjacent semiconductor device 30 via the zero transparent electrode 40 is taken.

[0011]

The transparent electrode used in the liquid crystal display device uses an oxide of indium and tin (hereinafter referred to as ITO). Although ITO has both transparency and conductivity, ITO is an oxide. For this reason, it has the property that the wiring resistance is higher than that of metal.

In the liquid crystal display device 10 shown in FIG. 4 in which only the transparent electrode 40 is provided as the cascade wiring 52, the number of connection points is only two. However, since the wiring resistance of the transparent electrode 40 is high, the connection resistance of the wiring circuit is high. Rises. As a result, the waveform of the synchronizing signal is rounded, which is not preferable for image display.

In particular, as the driving frequency increases and the synchronizing signal frequency increases, the deterioration of image quality due to the resistance value of the cascade wiring increases.

Although the cascade wiring 52 shown in FIG. 4 has a high wiring resistance, it is necessary to make the wiring width large. However, the nature of the transparent electrode limits the reduction of the resistance value. For example, even when a transparent electrode having a sheet resistance of 8Ω is used and a transparent electrode wiring having a width of 1 mm is provided in a shortest straight line between 10 mm between semiconductor devices, the resistance will be about 80Ω.

If the wiring width cannot be increased, the transparent electrode 40
It is technically possible to lower the resistance by forming a metal wiring thereon by a plating means, a vacuum evaporation method, or a sputtering method, but this is not preferable because it increases the manufacturing cost of the liquid crystal display device.

In the configuration of the liquid crystal display device 10 described with reference to FIG. 5, the cascade wiring 54 for obtaining a synchronization signal between the semiconductor devices 30 is connected to the transparent electrode 40 through the flexible film 6.
It has a path that passes through the transparent electrode 40 via the zero wiring 70. Therefore, there are four connection points in the path between the semiconductor devices 30, and because of an increase in contact resistance at the connection points and redundancy of the wiring circuit, the waveform of the synchronization signal is rounded, which is not preferable in image display.

In the configuration of the liquid crystal display device 10 described with reference to FIG. 6, the cascade wiring 54 for obtaining a synchronization signal between the semiconductor devices 30 is connected from the transparent electrode 40 to the wiring 70 of the flexible film 60 similarly to FIG. Through the transparent electrode 40. Although the redundancy of the wiring circuit is avoided, the connection width of each wiring must be narrowed in order to have four connection points in the path between the semiconductor devices and to concentrate the wiring only on the convex portion of the flexible film. And the contact resistance at the connection point and the connection resistance of the wiring circuit increase, causing the waveform of the synchronization signal to become rounded.
Not desirable on display.

The object of the present invention is to reduce the wiring resistance of the cascade wiring to improve the display quality, and to obtain the effect of reducing the frame width of the liquid crystal display device. I do. In particular, it is an object of the present invention to effectively reduce the wiring resistance of the cascade wiring in a simple matrix type liquid crystal display device.

[0019]

In order to achieve the above object, the liquid crystal display of the present invention employs the following structure.

In the liquid crystal display device of the present invention, a plurality of transparent electrode groups provided on the substrate, a plurality of semiconductor devices connected to the transparent electrodes and provided on the substrate, a cascade wiring connecting the semiconductor devices, A flexible film connected to a transparent electrode via a conductive film and having a wiring provided on a substrate, wherein the end portion of the flexible film is uneven, and the convex portion is a liquid crystal display device. Is located between the semiconductor devices provided in the flexible film via the anisotropic conductive film, and the wiring provided in the concave and convex portions of the flexible film is electrically connected to the transparent electrode via the anisotropic conductive film. A wiring corresponding to the cascade-connected transparent electrode and a wiring for supplying a drive signal to the semiconductor device are provided on the convex portion of the flexible film, and a drive signal for the semiconductor device is supplied to the concave portion of the flexible film. Wiring provided And wherein the door.

In the liquid crystal display device of the present invention, a plurality of transparent electrode groups provided on the substrate, a plurality of semiconductor devices connected to the transparent electrodes and provided on the substrate, a cascade wiring connecting the semiconductor devices, A flexible film connected to a transparent electrode via a conductive film and having a wiring provided on a substrate, wherein the flexible film has an uneven end portion, and a convex portion of the flexible film. The portion is located between the semiconductor devices provided in the liquid crystal display device via an anisotropic conductive film, and the wiring corresponding to the transparent electrode cascaded to the convex portion of the flexible film and the drive signal to the semiconductor device are provided. And a wiring to be supplied.

[Operation] In the liquid crystal display device of the present invention, the cascade wiring provided on the convex portion of the flexible film and the cascade transparent electrode wiring provided between the semiconductor devices are connected via the anisotropic conductive film.

According to the above configuration, the cascade wiring of the flexible film is overlapped on the cascade wiring of the transparent electrodes while keeping the frame width of the liquid crystal display device, so that the wiring resistance can be reduced and the operation stability of the synchronization signal can be reduced. Is improved, and even if the clock frequency increases, waveform rounding can be suppressed, and deterioration of image quality can be prevented.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device according to a preferred embodiment for carrying out the present invention will be described below with reference to the drawings.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of a liquid crystal display device 10 having a semiconductor device 30 provided with a flexible film 60, and FIG. 2 is an enlarged view of a portion where the flexible film 60 and the substrate 20 of FIG. FIG. 3 is a sectional view taken along the line AA shown in FIG.

The flexible film 60 shown in FIGS. 1 and 2
Only the wiring corresponding to the transparent electrode 40 is shown in the wiring 70 of FIG.

[Description of Liquid Crystal Display Device: FIGS. 1, 2 and 3] First, a liquid crystal display device 10 according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, a substrate 20 on which a semiconductor device 30 is provided is provided with a flexible film 6 having concave and convex end portions.
0 is provided via an anisotropic conductive film 80 (not shown for easy viewing). Flexible film 60
The semiconductor device 30 is provided in the concave portion, and the convex portion and the concave portion are provided on the substrate 20.

A driving signal for driving the semiconductor device 30 is supplied from outside to the transparent electrode 40 provided on the substrate 20 of the liquid crystal display device 10 through the wiring 70 of the flexible film 60.

As shown in FIG. 2, a cascade wiring 50 composed of a transparent electrode 40 is provided between the semiconductor devices 30, and the convex portion of the flexible film 60 is located between the semiconductor devices 30. The wiring 70 provided on the convex portion is configured to overlap the transparent electrode 40 on the substrate 20.

FIG. 3 is a sectional view taken along the line AA of FIG. 2. In the cascade wiring 50, a wiring 70 is provided on the transparent electrode 40 via an anisotropic conductive film 80. Anisotropic conductive film 8
The cascade wiring 50 and the wiring 70 are electrically connected by the conductive beads 100 dispersed in the
0 lowers the resistance.

By reducing the resistance of the cascade wiring 50,
Since the synchronization signal between the semiconductor devices 30 can operate stably, the effect of preventing the image quality from being deteriorated even when the clock frequency of the synchronization signal increases can be obtained.

The cascade wiring 50 shown in FIGS. 1 and 2
Is desirably provided linearly at the shortest distance between the semiconductor devices 30 as shown in the figure.

Although the width of the cascade wiring 50 is shown as a small width for ease of explanation, it is naturally desirable to make the width as wide as possible in terms of design in order to reduce wiring resistance.

The flexible film is made of polyimide, polyethylene, polyethylene terephthalate, or polyester. The thickness of the flexible film is 1
One having a size of 2.5 μm to 100 μm is used.

A wiring 70 made of copper is provided on the flexible film, and gold (Au), platinum (Pt), silver (Ag), palladium (Pd), ,
Nickel (Ni) is formed.

The cascade wiring 54 composed of the wiring 50 of the flexible film 60 and the transparent electrode 40 is also provided in the conventional example described in JP-A-8-146449, which is characterized in that the frame width is reduced. Thus, similarly, the wiring resistance of the cascade wiring 54 can be reduced, the synchronization signal can be prevented from deteriorating, and the image quality can be prevented from deteriorating.

When only the protrusions of the flexible film are used for electrical connection, the wiring concentrates on the protrusions, so that it is difficult to increase the width of the cascade wiring. For this reason, the wiring resistance of the cascade wiring can be reduced particularly effectively by backing the cascade wiring with the wiring of the flexible film with the anisotropic conductive film.

[0039]

As apparent from the above description, according to the liquid crystal display device of the present invention, the flexible film is provided with the convex portion,
By providing the wiring 70 corresponding to the transparent electrode 40 on the substrate 20 via the anisotropic conductive film on the projection, the wiring resistance of the cascade wiring can be reduced. The reduction in cascade wiring prevents signal deterioration for synchronizing between semiconductor devices, so that image quality does not deteriorate.

By providing the flexible film with the projections, the bonding area of the flexible film can be increased, so that the connection width of the flexible film shown in FIG.
% Is obtained.

In the liquid crystal display device according to the embodiment described in JP-A-8-146449, in which only the protrusions of the flexible film are provided on the substrate, wiring corresponding to the cascade wiring is provided on the protrusions of the flexible film. By providing and connecting with an anisotropic conductive film, the wiring resistance of the cascade wiring can be reduced, and similarly, the deterioration of image quality can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a structure of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view illustrating a structure of a liquid crystal display device according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a structure of a liquid crystal display device according to an embodiment of the present invention.

FIG. 4 is a plan view illustrating a structure of a liquid crystal display device according to the related art.

FIG. 5 is a plan view showing a structure of a liquid crystal display device according to the related art.

FIG. 6 is a plan view showing a structure of a liquid crystal display device according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Liquid crystal display device 20 Substrate 30 Semiconductor device 40 Transparent electrode 50 Cascade wiring 60 Flexible film 70 Wiring 80 Anisotropic conductive film 90 Connection width 100 Conductive beads

Claims (2)

[Claims] 1. A plurality of transparent electrode groups provided on a substrate, a plurality of semiconductor devices connected to the transparent electrode and provided on the substrate, cascade wiring connecting the semiconductor devices, and a transparent electrode via an anisotropic conductive film. A liquid crystal display device comprising: a flexible film connected to a flexible film having wiring provided on a substrate, wherein the flexible film has a concave and a convex portion having an uneven end portion; and a convex portion of the flexible film. Is located between the semiconductor devices provided in the liquid crystal display device via the anisotropic conductive film, and the wiring provided in the concave portion and the convex portion of the flexible film is a transparent electrode and an electrically anisotropic conductive film. And a wiring corresponding to the cascade connection transparent electrode and a wiring for supplying a drive signal to the semiconductor device are provided on the convex portion of the flexible film, and the driving of the semiconductor device is provided on the concave portion of the flexible film. Wiring to supply signals A liquid crystal display device characterized by the following. A plurality of transparent electrode groups provided on the substrate, a plurality of semiconductor devices connected to the transparent electrodes and provided on the substrate, cascade wiring connecting the semiconductor devices, and a transparent electrode via an anisotropic conductive film. A liquid crystal display device comprising: a flexible film connected to a flexible film having wiring provided on a substrate, wherein the flexible film has a concave and a convex portion having an uneven end portion; and a convex portion of the flexible film. Is located between the semiconductor devices provided in the liquid crystal display device via an anisotropic conductive film, and supplies a wiring corresponding to a transparent electrode cascaded to the convex portion of the flexible film and a drive signal to the semiconductor device. A liquid crystal display device comprising: