JP2630314B2 - Liquid crystal device - Google Patents

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 device which are 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 device with high connection reliability.

[0004]

The liquid crystal device of the present invention has a small
At least one side should have a terminal for connecting to an external circuit.
LCD panel substrate with protrusion and LSI chip mounted
And a terminal part for electrical contact with the terminal extraction part and a front part.
A dummy pattern formed outside the terminal portion;
The terminal portion and the dummy pattern and the terminal extraction portion
An anisotropic conductive film is interposed between the
Electrical connection between the terminal portion and the terminal extraction portion.
Liquid crystal device having a flexible printed circuit board
The flexible printed circuit board is entirely
The liquid crystal panel substrate is disposed on the liquid crystal panel substrate,
The flexible printed circuit board and the anisotropic
Of the terminal portion and the terminal take-out portion via the conductive film
A liquid crystal device, characterized in that the liquid crystal device is electrically connected.

[0005]

[0006]

FIG. 1 is a diagram showing a basic configuration of the present invention. This embodiment will be described with reference to the drawings. FIG. 1 is a view from the FPC base film side, and FIG. 2 is a cross-sectional view thereof. 1 is liquid
Lead out terminals of the LCD panel, 2 anisotropic conductive film, the 3 base film, 4 is valid connection terminal, 5 is 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 showing the state of crimping in FIGS. 7 and 2.
FIG. 1 is a diagram for explaining the effect of the present invention.
FIG. 3 is a diagram showing a state in which thermocompression bonding is performed by a 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 terminal 5a,
If 5b and 5c are present, the outer both ends of the internal effective connection terminal can be connected in the same manner as the central portion, and the crimping property 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.

FIG . 5 shows an LSI chip using the configuration shown in FIGS.
Connected to the FPC with an An-Sn eutectic etc.
4 and the liquid crystal panel terminal take-out part 1
It is a structure in which electrical connection is made via
It is.

FIG . 6 shows an embodiment of the present invention.
FIG. 3 is a diagram showing an embodiment in which is further mounted at a high density. LSI chip
FPC base film 3 equipped with
Are arranged so as to fit within the terminal extraction section 1 and are anisotropically conductive.
It is connected to the terminal extraction unit 1 via the membrane 2. 3,
4 and 5 are the same as in the first embodiment, and 3 is FP
C base film, 4 is an effective connection terminal, 5 is a dummy terminal
It is. FIG. 1 shows the liquid crystal device of this embodiment as in the first embodiment.
FIG. 3 is a view seen from above the FPC base film 3,
2 is a cross-sectional view thereof, and FIG. 3 is an effect at the time of crimping in this embodiment.
FIG. In this embodiment, FIGS.
As can be seen, the dummy terminal 5 is located outside the effective connection terminal 4.
Is provided.

In the mounting structure shown in FIGS.
By the dummy terminal 5 provided outside the connection terminal 4,
The connection between the substrate and the FPC base film is reinforced. Many
In the case of a liquid crystal device with terminals and multiple chips,
The connection is stabilized by the method described in Example 1 or 2.
Thereby, the yield can be improved in a power-wise manner.

[0013]

According to the present invention, in addition to the conductive pattern, a dummy pattern which does not contribute to the electrical connection between the panel terminal and the terminal of the flexible printed board is arranged outside the conductive pattern on the flexible printed board. As a result, disconnection due to stress or the like at the outer end of the terminal portion can be prevented, and a liquid crystal device having an electrical connection structure with high connection reliability can be obtained. In particular, in the mounting structure according to the present invention, stable electrical connection can be obtained despite high-density mounting in which multiple terminals are formed on both the input side and the output side. Furthermore, flexible printed circuit boards are
The board and the flexible printed circuit are placed in the terminal
Pressure bonding with a printed circuit board at multiple locations via an anisotropic conductive film.
For example, the input side of the liquid crystal drive circuit element
Terminals corresponding to both terminals and output terminals are formed
Including flexible printed circuit boards and circuit elements for driving liquid crystal
Conductive patterns for both input and output terminals
High-density mounting for electrical connection with the substrate on which
It can be performed very stably.

[0014]

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration 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 according to 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 diagram showing a reference example of the present invention.

FIG. 6 is a diagram showing an 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

Claims (1)

(57) [Claims] At least one surface is connected to an external circuit.
A liquid crystal panel substrate having a terminal extracting portion for mounting the same and an LSI chip , and electrically contacting the terminal extracting portion
Terminal formed on the outer side of the terminal portion
A terminal pattern and the dummy pattern
Anisotropic conductive film is interposed between the terminal and the terminal extraction portion,
The terminal portion and the terminal extraction portion via the anisotropic conductive film
Flexible printed circuit board with electrical connection to
When, a liquid crystal device having the flexible printed circuit board in its entirety the liquid path
The liquid crystal panel substrate and the frame.
The anisotropic conductive film at a plurality of locations
Electrical connection between the terminal portion and the terminal extraction portion through
A liquid crystal device characterized by being made.