JPH09121078A - Electrical connection structure and liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wire breakage by assigning a dummy pattern, not concerned with electrical connection, on the outside of a conductor pattern in a flexible substrate, for facing a glass substrate with an anisotropic conductive film. SOLUTION: A plurality of dummy patterns 5, not concerned with electrical connection between a conductive pattern and a flexible printed board, are assigned on both outsides of the flexible print board, respectively, for making face a glass substrate 3 with an anisotropic conductive film 2 in between. When the dummy terminal 5 is provided in this manner, if shearing stress is caused by difference in a thermal expansion coefficient between the base film 3 and a liquid crystal panel terminal taking-out part 1, the load is applied on the dummy terminal 5 on the most outer end, not on an effective connection terminal 4 on the inside. So that wire breakage due to the stress, etc., of the outer both end parts is prevented, so that, a display device with high reliability in connection is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit board (hereinafter abbreviated as "FPC") and a liquid crystal display device used for mounting a high-density, multi-terminal LCD panel.

[0002]

2. Description of the Related Art Conventionally, a group of connection terminals of an FPC is formed so as to face a terminal extraction portion for connection to an external circuit of a liquid crystal panel, and electrical connection is made.

[0003]

In the conventional FPC, all terminals are used as effective connection terminals. Therefore, when a stress is generated due to a difference in thermal expansion coefficient between the base film of the FPC and, for example, a glass substrate, the outermost end of the FPC is not used. There is a drawback that the connection terminal is disconnected and causes a defect immediately. Therefore, an object of the present invention is to prevent disconnection due to stress or the like and obtain an FPC and a liquid crystal display device with high connection reliability.

[0004]

The FPC of the present invention is characterized in that reinforcing members which are not involved in electrical connection are arranged at both outer ends of the connection terminal group.

In the liquid crystal display device of the present invention, the connection terminal group of the FPC and the terminal lead-out portion for connecting the reinforcing member and the external circuit of the liquid crystal panel are electrically connected via the anisotropic conductive film. It is characterized by

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.
FIG. 2 is a cross-sectional view as viewed from the PC base film side. Reference numeral 1 denotes a liquid crystal panel terminal extraction portion, 2 denotes an anisotropic conductive film, 3 denotes a base film, 4 denotes an effective connection terminal, and 5 denotes a dummy terminal.

When the dummy terminals 5 are provided in this manner, even if a shear stress is generated due to a difference in the thermal expansion coefficient between the base film 3 and the liquid crystal panel terminal extraction portion, a load is applied to the outermost dummy terminals 5. No load is applied to the inner effective connection terminal 4. Further, since the dummy terminal as the reinforcing member is made of the same material as the effective connection terminal, the reinforcement can be easily performed without increasing the number of steps. In addition, it has the effect of minimizing the effect of stress due to differences in materials.

FIG. 3 is a view for explaining the effect at the time of pressure bonding, and shows a state in which the pressure bonding is performed by the heater head 6. When the flatness of the heater head 6 is pressed in parallel on the theoretical plane, it is considered that both ends and the center are the same. However, when the heater head 6 is concave due to thermal deformation, it is connected to the end terminal. Stress concentrates and makes electrical stable connection difficult. Even in such a case, the dummy terminals 5a, 5b, 5
If c exists, the internal effective connection terminal 4 can maintain an electrically stable connection. Therefore, the outer ends of the effective connection terminal can be connected in the same manner as the center, and the uniformity of crimping can be increased over the entire surface of the effective connection terminal.

FIG. 4 shows a structure in which a resist material 7 on an FPC has a similar function in place of the dummy terminals 5a, 5b and 5c.

The mounting structure shown in FIG.
The structure is such that the connection is made to the FPC with Sn eutectic or the like, and the effective connection terminal 4 and the terminal extraction portion 1 of the liquid crystal panel are electrically connected via the anisotropic conductive film 2.

The mounting structure shown in FIG. 6 is a method in which the method shown in FIG.
This is a structure in which an FPC on which the I chip 8 is mounted is electrically connected via an anisotropic conductive film.

Since the mounting structure shown in FIGS. 5 and 6 constitutes one product with multiple terminals and multiple chips, the yield is improved by a power by the stable connection of the outer ends of the connection terminals.

[0013]

As described above, by arranging reinforcing members at both outer ends of the connection terminal group of the FPC, disconnection due to stress or the like at the outer both ends is prevented, and a display device with high connection reliability can be obtained. . Further, both outer ends of the effective connection terminal portion can be connected in the same manner as the central portion, and have a uniform connection strength, and have an effect of increasing the pressure bonding uniformity on the entire surface of the effective connection terminal portion. There is.

Therefore, it is possible to reduce defects due to stress caused by a difference in thermal expansion coefficient when the FPC is enlarged and the number of terminals is increased. Further, it is strong against mechanical peeling force, and highly reliable electrical connection is possible.

[Brief description of the drawings]

FIG. 1 is a view of the present invention as viewed from a base film side.

FIG. 2 is a sectional view of an embodiment of the present invention.

FIG. 3 is a pressure-bonding process diagram of the present invention.

FIG. 4 is a diagram in which a dummy terminal 5 of the present invention is replaced with a resist material 7;

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

FIG. 6 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1. LCD panel terminal extraction section 2. 2. Anisotropic conductive film Base film 4. Effective connection terminal 5. Dummy terminal 6. Heater head 7. Resist material 8. LSI chip

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[Procedure amendment]

[Submission date] November 6, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Title: Electrical connection structure and liquid crystal device

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

TECHNICAL FIELD The present invention relates to an outer side of a connecting terminal group.
Dummy patterns not involved in electrical connection at both ends
Arranged flexible printed circuit board and conductive pattern type
Electrical connection with a substrate made of glass or other material
Regarding the structure. More specifically, the substrate and another substrate
The present invention relates to a liquid crystal device in which a plate and a plate face each other to form a liquid crystal cell.
You.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

An electrical connection structure of the present invention
Has a glass substrate having a terminal portion and a conductive pattern.
Anisotropic conductivity by facing the flexible printed circuit board
It is an electrical connection structure that is electrically connected through a film.
The conductive pattern and the flexible printed circuit board.
The dummy pattern that is not involved in the electrical connection with
Both of the conductive patterns in the kisible printed circuit board
A plurality of films are arranged on the outside of each of the
And is opposed to the glass substrate. Ma
Further, the liquid crystal device of the present invention has a predetermined area on at least one surface.
A first substrate on which a conductive pattern is formed, and the first substrate
It is arranged so as to face the area other than the predetermined area of the substrate.
The second substrate is electrically connected to the conductive pattern.
For increasing the adhesive strength between the terminal part for the
A plurality of dummies formed on both outer sides of the terminal portion for
The first substrate having a pattern and having an anisotropic conductive film interposed therebetween.
A flexible printed circuit board electrically connected to the
It is characterized by having.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction contents]

[0013]

As described above, according to the present invention, the end
Prevents disconnection due to stress on the outer edge of the child part, and
A highly reliable electrical connection structure can be obtained. Also, outside the terminals
Both ends can be connected in the same way as the center part.
Has a uniform connection strength and is crimped evenly over the entire surface of the terminal.
It has the effect of increasing unity. Furthermore, the edge
Since a plurality of dummy patterns are provided at both ends of the child part,
The outermost dummy pattern that is most easily peeled off
Even if you do, other dummy patterns and glass substrate
By bonding the
The strength of the electrical connection with the terminals of the lint board can be maintained.
You.

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Claims (4)

[Claims] 1. A flexible printed circuit board, wherein reinforcing members not involved in electrical connection are arranged at both outer ends of a connection terminal group. 2. The flexible printed circuit board according to claim 1, wherein said reinforcing member is made of the same material as said connection terminal. 3. The flexible printed circuit board according to claim 1, wherein said reinforcing member is made of a resist material. 4. A connection terminal group of the flexible printed circuit board according to claim 1, wherein said reinforcing member and a terminal extraction portion for connection to an external circuit of a liquid crystal panel are electrically connected via an anisotropic conductive film. A liquid crystal display device comprising: