JP2581711Y2 - Liquid crystal display - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device in which a liquid crystal display element and a printed circuit board on which a liquid crystal driving circuit is mounted are connected by a flexible printed circuit (FPC).

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 10, a plurality of terminals (for example, 150 or more) provided at the ends of a printed circuit board 1 on which a liquid crystal driving circuit is mounted and a liquid crystal display element 2 are provided. In a liquid crystal display device in which each line of the portion is connected by thermo-compression bonding (heat sealing), there is a problem that when one FPC 3 is used, misalignment is likely to occur and a defective rate increases. That is, since the alignment is performed at one edge of the terminal portion of the FPC 3, elongation or bending occurs due to a temperature change in the working environment, a temperature change during thermocompression bonding, or a variation in the operation (one edge). (The position shift of (2) becomes a large shift at the other edge.), There is a problem that a connection failure easily occurs.

[0003] In order to solve the above-mentioned problem, it is common to connect two FPCs 3a and 3b as shown in FIG.

[0004]

[Problems to be solved by the invention] However, FIG.
As shown in (2), when two FPCs 3a and 3b are used for connection, it is necessary to perform positioning and thermocompression operations twice each, resulting in a problem that the number of operation steps increases and the assembly cost increases. In addition, FP which can be taken from full size FPC
There is a problem that the number of C3a and 3b is reduced and the material cost is increased. Furthermore, it is necessary to provide alignment regions at both ends of each FPC 3a, 3b.
(Necessary for four places), and there is a problem that the panel size of the liquid crystal display element 2 increases accordingly. If the terminal is narrowed by the alignment area,
The terminal pitch is reduced, which causes operational problems.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a liquid crystal display device which can reduce assembly costs and material costs and can be downsized. It is in.

[0006]

According to a first aspect of the present invention, there is provided a liquid crystal display device including a printed circuit board on which a liquid crystal driving circuit is mounted.
In addition, in a liquid crystal display device in which each line of the terminal portion of the FPC 3 is connected by thermocompression bonding to a large number of terminals provided at the end of the liquid crystal display element 2, an alignment mark 5 is provided at the center of the terminal portion. It is a thing.

According to a second aspect of the present invention, each of the terminals of the FPC 3 is connected by thermo-compression to a large number of terminals arranged in rows at the ends of the printed circuit board 1 on which the liquid crystal drive circuit is mounted and the liquid crystal display element 2. In the liquid crystal display device described above, a slit 6 for positioning is provided at the center of the terminal portion.

[0008]

The present invention is constructed as described above, and is positioned at the center of the terminal portion of the FPC 3 which is thermocompression-bonded to a large number of terminals of the printed circuit board 1 on which the liquid crystal drive circuit is mounted and the liquid crystal display element 2. Mark 5 or slit 6 is provided, and by performing alignment at the center of the terminal portion, the extension caused by the temperature change can be distributed to both sides, and the displacement at both ends can be reduced by half. . Therefore, even when the connection is performed by one FPC 3, the connection failure due to the displacement can be reduced.
The assembly cost and material cost can be reduced, and the size can be reduced.

[0009]

1 to 4 show one embodiment of the present invention, in which a printed circuit board 1 on which a liquid crystal driving circuit is mounted and a large number of terminals provided at the ends of a liquid crystal display element 2 are provided with FPCs 3.
In a liquid crystal display device in which the respective wires 4 of the terminal portion are connected by thermocompression bonding, a positioning mark 5 is provided at the center of the terminal portion. Here, the FPC 3 electrically connects the liquid crystal display element 2 and the printed circuit board 1 disposed on the back of the liquid crystal display element 2, and has a fine pitch (0.
3 mm or less) is used. The width of the U-shaped mark 5 is substantially the same as the pitch t, and a small-diameter dot 5a is provided at the center of the bottom. In the figure, reference numeral 8 denotes a bezel for protecting and fixing the liquid crystal display element 2.

In the present embodiment, a positioning mark 5 is provided at the center of the terminal of the FPC 3. In the case of thermocompression connection, first, the terminal 5 is formed by the dot 5a of the mark 5. Then, as shown in FIG. 6, the soldering iron 7 performs temporary press-bonding of the mark 5 portion. At this time, the positioning operation is performed using the microscope 9, and the central portion is positioned based on the positioning mark 5, and the positioning is performed using two or three lines 4 at both ends of the FPC 3. The central part is melted with a soldering iron 7 to perform temporary compression bonding. By performing the alignment in this way, the extension caused by the temperature change can be distributed to both sides, and the displacement at both ends can be reduced by half.

If the wires 4 of the FPC 3 are thermocompression-bonded to the terminals in this temporarily crimped state, connection failures due to misalignment can be reduced, and assembly costs can be reduced. Further, since the connection can be performed by one FPC 3, the yield of the partial cut can be improved and the material cost can be reduced as compared with the conventional example using two FPCs 3a and 3b. Further, since there are two alignment regions, the panel size of the liquid crystal display element 2 can be reduced.

FIG. 6 to FIG. 8 show another embodiment. In the same liquid crystal display device as the above embodiment, an FPC is used.
3, a slit 6 for positioning is provided at the center of the terminal portion. Here, the slit width t of the slit 6 is 1
mm or more (minimum dimension of Thomson die-cutting), and the slit length is about 1/4 of the width 1 of the FPC 3.

In the present embodiment, the alignment is performed at the center of the terminal portion by the alignment slit 6 at the center of the terminal portion of the FPC 3. Material costs can be reduced, and miniaturization can be achieved. In addition, FPC3
Are divided into right and left by the slits 6, and the extension due to the temperature change can be regarded as equivalent to the case where two FPCs 3 are used.

FIG. 9 shows another embodiment, in which a slit 6 is provided only in a terminal portion on the side of the printed circuit board 1 where the step of the crimping portion is large and a positional deviation is likely to occur.

[0015]

According to the present invention, as described above, the position of the printed circuit board 1 on which the liquid crystal drive circuit is mounted and the center of the terminal portion of the FPC 3 which is thermocompression-bonded to a large number of terminals of the liquid crystal display element 2 are provided. Since the mark 5 or the slit 6 is provided, and the alignment at the center of the terminal portion is performed, the extension caused by the temperature change can be distributed to both sides, and the displacement at both ends can be reduced by half. One F
Even when the connection is performed by the PC 3, the connection failure due to the displacement can be reduced, the assembly cost and the material cost can be reduced, and the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view of one embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a front view of a main part of the above.

FIG. 5 is an explanatory diagram showing a connection operation according to the first embodiment.

FIG. 6 is a front view of another embodiment.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

FIG. 8 is a front view of a main part of the above.

FIG. 9 is a front view of a main part of still another embodiment.

FIG. 10 is a front view of a conventional example.

FIG. 11 is a front view of another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Liquid crystal display element 3 FPC 4 line 5 Mark 6 Slit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/1345

Claims (2)

(57) [Scope of request for utility model registration] 1. A liquid crystal display device comprising: a printed circuit board on which a liquid crystal driving circuit is mounted; and a plurality of terminals provided at an end of the liquid crystal display element, each of the terminals of the flexible printed circuit board being connected by thermocompression bonding. A liquid crystal display device, wherein a detecting means for positioning is provided at a central portion of the terminal portion. 2. A printed circuit board on which a liquid crystal drive circuit is mounted, and a plurality of terminals arranged in a line at an end of the liquid crystal display element, each wire of a terminal portion of the flexible printed circuit board being connected by thermocompression bonding. 3. The liquid crystal display device according to claim 1, wherein a positioning mark or a slit is provided in a central portion of said terminal portion.