JP2001264787A - Wiring of display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a bent part to the utmost, namely, to provide a structure intended for the purpose of eliminating the bent part. SOLUTION: An electrode terminal 15 and a COF board 14 are connected through an ACF. Wiring consisting of copper foil is applied to the surface of the COF board 14 and the electrode terminal 15 facing each other. The copper foil and the electrode terminal are positioned, and then are connected by the ACF. One end of the COF is made coincide with the outer side end of the electrode terminal 15 provided near the outermost peripheral part of a glass substrate 11, or is disposed inside, namely, to the glass substrate side slightly. Besides, a mountain polygonal line 18 acting as a power bending to the down side is provided. The glass substrate 11 and COF are maintained in nearly parallel by means of this mountain polygonal line 18.

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 chip-on-film (hereinafter referred to as COF) with a flexible insulating film.
) Of the display device using the technology.

[0002]

2. Description of the Related Art In a conventional display device wiring, COF is connected to an electrode provided in a peripheral portion of the display device using COF,
When it was desired to guide the other end of the COF in another direction (in the opposite direction), the COF was fixed to the electrode and then used by inverting the COF by 180 degrees. This is because the thickness of the glass serving as the substrate of the display device was large, and there was little problem in minimizing the size even if the glass was inverted by 180 degrees. That is, there was no need to bend at a curvature smaller than the thickness of the glass.

[0003] However, when the cross section of the COF is bent, when the cross section is observed, elongation occurs on the outside of the neutral surface which does not expand or shrink, and shrinkage occurs on the inside. At this time, if gold is used as the conductor thin film used for COF,
There are few problems because it is rich in ductility and malleability. In the case of copper and aluminum, embrittlement due to work hardening is caused particularly by elongation on the outside, and cracks occur.

A conventional example will be described with reference to FIG. 3 which is a sectional view of a liquid crystal display device. In the liquid crystal display device, liquid crystal is sealed between two glass plates 1 and 2, and an electric field is applied by spaced electrodes to perform display. For this purpose, a COF substrate 4 on which a driver IC 3 is arranged is provided. The terminal electrode 5 is disposed on the periphery of the glass plate 1, and the terminal electrode 5 and the COF substrate 4
Is an electrical connection and a physical fixation with an anisotropic conductive film (hereinafter referred to as ACF).

[0005] If the product does not have the problem of the size and the size of the display device in general, the COF 4 is usually used after being stretched horizontally after being connected to the terminal electrode 5. . However, a specific structure that satisfies the requirement of small size was devised, as shown in the figure, by bending toward the glass substrate, providing a bent portion 6 having a curvature radius as small as possible, and straddling over the glass. The connector was extended to the opposite side of the electrode, and a connector 7 was provided at the end of the COF so that signals could be exchanged.

As a result, the planar spread is reduced to about half and the size is reduced.
Usually, the COF substrate 4 is made of polyimide or the like having a thickness of about 25 μm as a base material. A copper foil having a thickness of 15 μm is provided on the substrate having a thickness of 25 μm, and is selectively etched to obtain a COF substrate having desired circuits and functions. Practically, a process of preparing a copper foil, applying polyimide thereon, integrating it, and then selectively etching is applied.

[0007] Under the above conditions, the bent portion 6 is 0.75
If it is a semicircle having a height of mm, it can be processed as a bent portion.

Particularly, in a portable telephone, the thickness is 0.75 mm, and the projection amount from the glass substrate is 0.37 mm.
5 mm has been taken up as a problem and it has become a trend that requires further reduction.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the size of a bent portion as much as possible. That is, a structure intended to eliminate a bent portion is provided.

According to the present invention, a length of a protruding portion from a glass substrate is reduced. That is, the present invention provides a structure capable of extremely shortening the amount of protrusion from the glass substrate in the horizontal direction of 0.375 mm and the amount of protrusion in the thickness direction of 0.75 mm.

[0011]

According to the present invention, there is provided a display device having a display area formed of a transparent insulator, comprising: a terminal electrode provided on a peripheral portion of a substrate; A wiring of a display device, comprising: a flexible insulating film whose end is disposed near an outermost peripheral portion of the substrate and which is connected to the display area.

Further, according to the present invention, in the wiring of the display device, the flexible insulating film has a connector portion in a peripheral portion different from an end portion connected to the terminal electrode.

Further, a display device having a circuit formed by selectively leaving a conductive thin film on one main surface of the flexible insulating film opposed to the substrate of the display device formed of the transparent insulator according to the present invention. In the wiring.

[0014]

FIG. 1 is a perspective view for explaining the whole of the present invention, and FIG. 2 is a cross-sectional view as viewed from the direction of an arrow shown in FIG. 1A. A display device in which the present invention is applied to a liquid crystal display device will be described. The display device according to the present invention performs a desired display by applying a controlled electric field between electrodes spaced apart from each other by sealing liquid crystal between the glass substrates 11 and 12.

The liquid crystal display device is a display device that is within the scope of the present invention, whether it is a simple matrix or is controlled by an active TFT. Also, self-luminous EL light-emitting display devices are naturally within the scope of the present invention. TFT formed by low-temperature polysilicon and high-temperature polysilicon
The present invention is applicable to a display device controlled by a liquid crystal display, a glass substrate as a substrate, and a plastic substrate. In short, the present invention includes any display device and features a wiring structure.

The glass substrate 11 of the display device according to the present invention,
The liquid crystal is sealed between the electrodes 12, and an electric field is applied by a transparent conductive thin film provided on the opposite main surface of the glass substrate. The driver IC 13 provided on the COF board 14 gives the controlled signal.

A terminal electrode 15 is provided from the glass substrate to transfer the signal. Naturally, it is connected to the inside and outside of the glass substrate and has a desired function.

The electrode terminals 15 and the COF substrate 14 are connected via an anisotropic conductive film (hereinafter referred to as ACF). CO
Wirings made of a conductive thin film such as copper foil are provided on opposing surfaces of the F substrate 14 and the electrode terminals 15, and these wirings and the electrode terminals are connected so as to exhibit a desired function. The copper foil and the electrode terminals are aligned and connected by an ACF.

According to the present invention, as shown in FIG. 1 and FIG. 2, the electrode terminal 15 is provided near the outermost peripheral portion of the glass substrate 11 so as to coincide with or slightly inside the electrode terminal 15, that is, disposed on the glass substrate side. , COF are provided. That is, one feature is that the COF does not protrude from the glass substrate.

Since the wiring portion is disposed on the surface of the COF facing the glass substrate as described above, the driver I
C is located on this surface. That is, as shown, it is located below the COF. The connector section 17 extends to the opposite side from the position where the terminal electrode to which the COF is fixed is arranged.

Further, the COF comes into contact with the glass substrate 12 due to the hardness of the material. That is, the lightly hits the upper glass substrate 11. Due to this phenomenon, there is no particular disadvantage after the completion of the assembly, but during the operation, the whole body has a thickness. In order to prevent this, in the case of FIG. 1, a mountain fold line 18 is provided which serves as a force to bend downward. The fold line 18 allows the glass substrate 11 and the COF to be kept parallel.

Here, the mountain fold according to the present invention, as shown in the drawings, is a mountain fold line that is not sharply creased but is gently bent round and downward to maintain that state. In the case of a COF having a conductive thin film formed of a sufficiently thick copper foil, there is little fear of disconnection, so that there is little problem even if the mountain fold line is clarified.

In another embodiment of the present invention, the position of the connector is taken into account. The location of the connector gives more freedom to the design.

The purpose of the present invention is to reduce the size. As an example, in FIG. 1, the connector section 17 is provided on the COF substrate 14 at a peripheral portion opposite to the end portion connected to the terminal electrode 15. The figures show glass substrates 11 and 12
Although it protrudes further outward, this is often good, but if it is inconvenient, the connector part 17 is
In other words, it is easy to dispose so as not to protrude from 1 and 12, in other words, to shorten it inside.

It is also important to arrange the terminal electrode 15 shown in FIG. 1 on the left and right with respect to the line connecting the connector section 17 extending to the opposite side. That is, it is a feature of the present invention that the connector portion 17 can be disposed on a side different from the side on which the terminal electrode 15 is disposed. As described above, even if the terminal electrodes are not taken out from one side or taken out from two sides, according to the present invention, there is an advantage that the connector portion can be provided on different sides.

As described in the embodiment of the present invention,
The conductive thin film made of copper foil is provided on at least one surface of the COF, and is provided on a surface facing the substrate of the display device. A circuit using a conductive thin film is formed on this surface. Accordingly, the electric components used for controlling the display device, such as the driver IC, are located between the COF and the display device.
F serves as a cover to prevent unintentional scratches and other damage.

[0027]

According to the present invention, the COF is connected from the inside of the glass substrate of the terminal electrode to a position which does not exceed the outermost peripheral end of the terminal electrode. Since it is not necessary to bend into a semicircle, the bent portion of 0.375 mm shown in the section of the prior art does not protrude from the substrate at all. That is, the effect of the smaller size is obtained.

Further, only COF equivalent to 0.025 mm exists on the electrode terminal. On the other hand, when folded into a semicircular shape as described in the related art, the value is 0.1 mm.
There is a height of 75 mm. That is, as far as this electrode terminal is concerned,
This means that the thickness can be reduced to 0.725 mm.

Further, since the surface of the COF substrate on which the copper foil is present is reversed, the height of the driver IC chip is set to 0.
In contrast, even if the thickness is 65 mm, the space required is 1.4 mm above the electrode terminal. On the other hand, in the present invention, the smaller the thickness of the glass substrate is, the smaller the required space is. Compare by case. Conventionally, since the thickness of the glass substrate (0.4 mm) is lower than the height of the bent portion, the calculation for one sheet is out of the calculation. , Driver I
C is 0.65 mm, for a total of 1.8 mm. On the other hand, in the present invention, two glasses (0.8 mm), a driver IC (0.6 mm), and a COF thickness of 0.025 are used.
mm for a total thickness of 1.475 mm.

Comparing the above three items when the length and width of the larger glass is 30 mm, the volume is 80.9%, the area (upper surface) is 98.8%, and the area (cross section) is 81.9%. And the effect of the present invention on the art is great.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining the present invention.

FIG. 2 is a cross-sectional view illustrating the present invention.

FIG. 3 is a cross-sectional view illustrating a conventional example.

Claims (3)

[Claims] 1. A terminal electrode provided on a peripheral portion of a substrate of a display device having a display region formed of a transparent insulator, and a terminal electrode in a direction outside the substrate and near an outermost peripheral portion of the substrate. A wiring for a display device, comprising a flexible insulating film whose end is disposed and connected to the display area. 2. The wiring of the display device according to claim 1, wherein the flexible insulating film has a connector portion at a peripheral portion different from an end portion connected to the terminal electrode. 3. A circuit formed by selectively leaving a conductive thin film on one main surface of the flexible insulating film facing the substrate of the display device made of the transparent insulator. The wiring of the display device according to claim 1.