JPH1073838A - Flexible circuit board and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to fulfill the function with only one side of the signal lines on a substrate side and to use the inexpensive substrate by forming an output terminal on one side and forming input terminals on the same plane on two sides intersecting with one side. SOLUTION: The liquid crystal display device formed by using COFs arranged with the input terminals perpendicular to the output and is arranged with the respective input terminals in parallel and, therefore, the input terminals are made parallel with B to G of signal lines 5. The substrate 8 to be connected is the one-side substrate not requiring vertical conduction by through-holes. The B to G of the signal lines 5 and the input terminals a to h of the COFs are connected by soldering, etc. The liquid crystal display device 7 and the input terminals 1 are connected by anisotropic conductive adhesives, etc. The substrate 8 is merely necessitated to be formed with patterns on the one surface alone by constituting the liquid crystal display device in such a manner and, therefore, the production is easy and the shortening of the stage is made possible. The cost of the liquid crystal display element is consequently reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible circuit board used for a liquid crystal display.

[0002]

2. Description of the Related Art A flexible circuit board (hereinafter abbreviated as COF) used for a conventional liquid crystal display device or the like has an LSI chip for driving a liquid crystal display element mounted thereon, and has input terminals a to h as shown in FIG. Are arranged in parallel with the output terminal 1 so that vertical conduction by the through hole 6 is achieved.
The input terminals a to h and the signal lines B to G were connected using the layer substrate.

FIG. 5 is a schematic view of FIG. 4, showing a state in which the liquid crystal display device is developed.
And COF 4 are folded on the back side of the liquid crystal display element 7 and Z and Z are connected by soldering or the like.

[0004]

However, in the above-mentioned prior art, the input terminals 2a to 2h of the COF 4 are arranged in parallel with the signal lines B to G, so that the terminals a to h and the signal line 5B are connected.
When G is connected, a two-layer substrate is required which is vertically conductive by the through hole 6 in order to avoid orthogonality with other signal lines. Therefore, there is a problem that a liquid crystal display device using such a two-layer substrate is expensive. Accordingly, the present invention is to solve such a problem, and an object of the present invention is to provide a flexible circuit board which does not require a two-layer board and an inexpensive and highly reliable liquid crystal display device.

[0005]

In the flexible circuit board of the present invention, an LSI chip is mounted substantially at the center, and an output terminal having a wiring connected to the LSI chip is formed on one side. An input terminal having a wiring connected to the LSI chip is formed on the same image of two sides crossing one side.

A liquid crystal display device according to the present invention has a liquid crystal display element and an output terminal electrically connected to an end of the liquid crystal display element formed on one side and two sides intersecting the one side on the same plane. A plurality of flexible circuit boards having input terminals formed thereon, and a board having a plurality of signal lines for electrically connecting between the flexible circuit boards arranged in parallel formed on only one surface. The flexible circuit board and the board are arranged so as to overlap with each other, and an end of the liquid crystal display element and the output terminal are arranged to face each other and are electrically connected.

[0007]

FIG. 1 is a wiring diagram of a COF 4 according to an embodiment of the present invention, wherein a to h of input terminals 2 are arranged perpendicular to an output terminal 1 and each input terminal is arranged in parallel. ing. It is each C that a and h of the input terminal 2 are located on the same line. This is for cascade connection of F4. In the case where the cascade connection is not performed, the input terminals can be collectively arranged in one of the left and right directions.

FIG. 2 is a detailed view of the liquid crystal display device using the COF. The input terminals are arranged perpendicular to the output and each input terminal is arranged in parallel. On the other hand, the substrate 8 to be connected in parallel is a single-sided substrate that does not require vertical conduction by through holes. Signal line 5
Are connected to the input terminals a to h of the COF by soldering or the like. The liquid crystal display element 7 and the output terminal 1 are connected with an anisotropic conductive adhesive or the like.

FIG. 3 is a schematic view of FIG. 2, showing a state in which the liquid crystal display device is developed.
The substrate 8 and the COFs 4 are folded on the back side of the liquid crystal display element 7, and Z and Z 'are connected by soldering or the like.

With the above-described configuration, the substrate 8
Since it is sufficient to form a pattern on only one side, manufacturing is easy and the process can be shortened. As a result, the cost of the liquid crystal display device was reduced.

An LSI chip 3 mounted on the COF 4
Comes to a position on the substrate 8, so that it is supported by the substrate 8 even in the step of bending the COF 4 to complete the liquid crystal display element, and has the effect of preventing failure due to bending and impact on the LSI chip 3. ing.

Further, since the connection between the COF 4 and the substrate 8 is made on two opposing sides of one COF, the connection is strong.

[0013]

As described above, according to the present invention, in particular, a plurality of flexible terminals in which an output terminal is formed on one side and an input terminal is formed on the same surface of two sides crossing the one side. Since the circuit board is used, it is possible to oppose the signal line formed on the board in the same direction, so that the signal line on the board side has only one side and an inexpensive board can be used. Furthermore, since the flexible circuit board and the board are arranged so as to overlap with each other, there is an effect that the mounting area is reduced.

Further, the connection between the COF and the substrate becomes strong, and a highly reliable liquid crystal display device can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a flexible circuit board of the present invention.

FIG. 2 is an enlarged view of a main part of the liquid crystal display device of the present invention.

FIG. 3 is a schematic diagram of a liquid crystal display device of the present invention.

FIG. 4 is an enlarged view of a main part of a conventional liquid crystal display device.

FIG. 5 is a schematic diagram of a conventional liquid crystal display device.

[Explanation of symbols]

 1 output terminal 2 input terminal 3 LSI chip 4 COF

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[Procedure amendment]

[Submission date] May 22, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

A flexible circuit board according to the present invention is a flexible circuit board on which an LSI chip is mounted, comprising: an output terminal formed on one side of the flexible board; and two sides intersecting the one side. And an input terminal connected to a signal line formed on a substrate, wherein the input terminal corresponds to each of the input terminals of the signal lines. And are arranged so as to intersect only with. Further, in the liquid crystal display device of the present invention, a liquid crystal display element and an output terminal electrically connected to an end of the liquid crystal display element are formed on one side and formed on the same surface of two sides crossing the one side. A flexible circuit board on which input terminals are formed, and a board on which a plurality of signal lines for electrically connecting between the flexible circuit boards arranged in parallel are formed only on one surface, The input terminal intersects only with the signal line corresponding to each of the input terminals among the signal lines. Further, an end of the liquid crystal display element and the output terminal are arranged to face each other and are electrically connected via an anisotropic conductive adhesive. Further, the input terminal formed on the same surface of the two sides and the signal line are arranged to face each other and are electrically connected by soldering.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

[0013]

As described above, the present invention uses a plurality of flexible circuit boards in which output terminals are formed on one side and input terminals are formed on the same plane on two sides intersecting the one side. Since the input terminal intersects only with the signal line corresponding to each input terminal among the signal lines formed on the substrate, the signal lines formed on the substrate can be opposed in the same direction, Since signal wiring only needs to be provided on one side of the substrate, a two-layer substrate is not required, and an inexpensive substrate can be used. Further, a plurality of flexible circuit boards in which the output terminal is formed on one side and the input terminal is formed on the same surface of two sides crossing the one side,
Since it can be arranged so as to overlap with the substrate, the mounting area can be reduced. Further, since the connection between the flexible substrate and the substrate can be performed on two opposite sides of the flexible substrate, the connection becomes strong.

Claims (4)

[Claims] An LSI chip is mounted at a substantially central part, and an output terminal having a wiring connected to the LSI chip is formed on one side, and the output terminal is provided on the same surface of a side crossing the one side. A flexible circuit board comprising an input terminal having a wiring connected to an LSI chip. 2. A liquid crystal display element, and an output terminal electrically connected to an end of the liquid crystal display element is formed on one side, and an input terminal is formed on the same plane on two sides intersecting the one side. Having a plurality of flexible circuit boards, and a board in which a plurality of signal lines for electrically connecting between the flexible circuit boards arranged in parallel are formed only on one surface,
The flexible circuit board and the board are arranged so as to overlap with each other, and an end of the liquid crystal display element and the output terminal are arranged facing each other and electrically connected to each other, and on the same surface of the two sides. A liquid crystal display device, wherein the input terminal formed on the liquid crystal display and the signal line are arranged to face each other and are electrically connected to each other. 3. The liquid crystal display device according to claim 2, wherein an end of said liquid crystal display element and said output terminal are arranged to face each other and are electrically connected via an anisotropic conductive adhesive. Liquid crystal display. 4. The liquid crystal display according to claim 2, wherein said input terminal and said signal line formed on the same surface of said two sides are arranged to face each other and are electrically connected by soldering. apparatus.