JPH10117049A - Liquid crystal apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent disconnection, due to a stress to obtain a highly reliable FPC(flexible printed circuit board) and a liquid crystal display unit by arranging a dummy pattern which does not contribute to electrical connection between a terminal section of a substrate and a terminal section of a flexible printed circuit board to the external side of the terminal. SOLUTION: A liquid crystal apparatus is formed of a liquid crystal panel terminal leading section 1, an anisotropic conductive film 2, a base film 3 and an effective connection terminal 4. Both external end sections of the effective connection terminal 4 are provided with a dummy terminal 5, which is a reinforcing member which does not contribute to electrical connection. When a dummy terminal 5 is provided as explained above, even if a shearing stress is generated due to the difference of thermal expansion coefficient of the base film 3 and liquid crystal panel terminal leading section 1, a load is applied to the dummy terminals 5 at both ends but is not loaded on the internal effective connection terminal 4. Moreover, the dummy terminal 5 is formed of the same material as the effective connection terminal 4 to realize reinforcement without increase of the process. Moreover, effects of stresses due to difference of material can be minimized.

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 the thermal expansion coefficient between the base film of the FPC and, for example, a glass substrate, the outermost end of the FPC is 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 according to the present invention is characterized in that reinforcing members 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 for connecting the reinforcing member to an external circuit of the liquid crystal panel are electrically connected through an anisotropic conductive film. It is characterized by the following.

[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. . In addition, the outer end portions of the effective connection terminal portion can be connected in the same manner as the center portion, have a uniform connection strength, and have the effect of increasing crimp uniformity over the entire effective connection terminal portion. I have.

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 17, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

[Title of the Invention] Liquid crystal device

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction contents]

[0004]

According to the liquid crystal device of the present invention, both terminals of a substrate having terminals and a flexible printed circuit having terminals connected to an LSI chip are opposed to each other to form an anisotropic conductive film. A liquid crystal display device electrically connected via a terminal, wherein a dummy pattern that does not contribute to the electrical connection between the terminal portion of the substrate and the terminal portion of the flexible printed board is provided outside the terminal portion of the flexible printed board. It is characterized by being arranged. Further, a liquid crystal device comprising a substrate having a terminal portion and a flexible printed circuit having a terminal portion to which an LSI chip is connected, wherein both terminal portions are opposed to each other and electrically connected via an anisotropic conductive film, A plurality of dummy patterns not contributing to the electrical connection between the terminal portion of the substrate and the terminal portion of the flexible printed board are arranged outside the terminal portion of the flexible printed board.

[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, disconnection due to stress or the like at the outer end of the terminal portion can be prevented, and a liquid crystal device having high connection reliability can be obtained. In addition, the outer end portions of the terminal portion can be connected in the same manner as the center portion, so that the terminal portion has a uniform connection strength, and has the effect of increasing the uniformity of crimping over the entire surface of the terminal portion. Further, since a plurality of dummy patterns are provided outside the terminal portion, the most easily peelable, even when the outermost dummy pattern is peeled, by bonding the other dummy pattern and the substrate,
The strength of the electrical connection between the terminal portion of the board and the terminal portion of the flexible printed board can be maintained.

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: