JP2845219B2 - Electrical connection structure and liquid crystal device - Google Patents

Description

BACKGROUND OF THE INVENTION [0001] [Technical Field of the Invention The present invention is an outer connecting terminal groups
Dummy patterns that do not contribute to the electrical connection
Flexible printed circuit board and conductive pattern
Electrical connection to a substrate made of glass or other material
Regarding the structure. More specifically, the substrate and another substrate
Liquid crystal device with liquid crystal cell formed with plates facing each other
You. 2. Description of the Related Art Conventionally, a group of connection terminals of an FPC has been formed so as to face a terminal extraction portion for connection to an external circuit of a liquid crystal panel, and has been electrically connected. [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 maximum is required. There is a drawback that the connection terminal at the outer end 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] An electrical connection structure according to the present invention comprises a substrate having a terminal portion and a flexible printed circuit board having the terminal portion, both terminals being opposed to each other via an anisotropic conductive film. And 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 circuit board. It is characterized in that a plurality of each are arranged on the outside and opposed to the substrate via the anisotropic conductive film. The liquid crystal device of the present invention is a liquid crystal device in which both terminals of a substrate having a terminal portion and a flexible printed circuit board having a terminal portion 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 portions of the substrate and the terminal portions of the flexible printed board are respectively arranged outside both of the terminal portions on the flexible printed board, and the anisotropic conductive film is provided. Characterized in that it is opposed to the substrate via 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. DETAILED 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 a theoretical plane, it is considered that both ends and the center are the same. However, when the heater head 6 becomes concave due to thermal deformation, it is connected to an 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. 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 an electrical connection structure with high connection reliability can be obtained. A liquid crystal device with high connection reliability using the connection structure 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. Furthermore, since a plurality of dummy patterns are provided at both ends of the terminal portion, even when the outermost dummy pattern which is most easily peeled is peeled off, the other dummy pattern and the substrate are bonded to each other so that the terminal portion of the substrate can be removed. The strength of the electrical connection with the terminals of the flexible printed circuit board can be maintained. 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 seen from a base film side of the present invention. 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 Codes] 1. LCD panel terminal extraction section 2. Anisotropic conductive film Base film4. Effective connection terminal 5. Dummy terminal 6. Heater head7. Resist material8. LSI chip

Claims (1)

(57) [Claims] A substrate having a terminal portion, an electrical connection structure in which both terminal portions of the flexible printed circuit board having the terminal portion are opposed to each other and electrically connected via an anisotropic conductive film, and the terminal portion of the substrate A plurality of dummy patterns not contributing to the electrical connection with the terminal portion of the flexible printed board are respectively arranged outside both of the terminal portions on the flexible printed board, and the dummy pattern faces the substrate via the anisotropic conductive film. An electrical connection structure characterized by being performed. 2. A liquid crystal device comprising a substrate having a terminal portion and a flexible printed circuit board having a terminal portion, 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 with the terminals of the printed circuit board are respectively arranged outside both of the terminals on the flexible printed circuit board, and are opposed to the substrate via the anisotropic conductive film. A liquid crystal device.