JPH11177198A - Flexible wiring board - Google Patents

Abstract

(57) [Problem] To provide a flexible wiring board capable of increasing the bonding strength and thereby improving the connection reliability. A substrate 10 using a flexible insulating sheet is provided.
And a plurality of conductive patterns 11 printed and wired in parallel on the substrate, and a connection terminal portion 12 provided at an end of the conductive pattern. In the present invention, the terminal portion is divided into a plurality of fingers 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible wiring board having an improved bonding strength at a connection portion.

[0002]

2. Description of the Related Art A flexible wiring board in which a plurality of conductive patterns are printed and printed in parallel on a flexible insulating sheet substrate is used for transmitting and receiving a large number of signal lines between devices or circuit units. A connection terminal portion is formed at an end of the conductive pattern of this type of flexible wiring board, and this terminal portion is connected to a normal printed wiring board or another flexible wiring board.

FIG. 3 is a plan view when connecting flexible wiring boards. One insulating sheet substrate 1
In the case 0, a plurality of conductive patterns 11 are formed on the upper surface, and the end 12 of the pattern 11 is a connection terminal. The other insulating sheet substrate 20 has a plurality of conductive patterns 21 formed on the lower surface thereof.
One end 22 is a connection terminal.

The conductive patterns 11 and 12 on the substrates 10 and 20
1 have the same arrangement form, and when these are overlapped as shown in FIG. 4A, the terminal portions 12 and 22 are opposed to each other. Therefore, as shown in FIG. 4 (B), a conductive adhesive, for example, an anisotropic conductive film (ACF) 30 is interposed between the two terminal portions 12 and 22 so as to press-contact with each other so that the two portions have conductivity. Glue to

[0005]

The connection terminals 12, 22 of the conductive patterns 11, 21 described above have a small area because they are equal to the width of the conductive patterns 11, 21. For this reason, the adhesive strength by the adhesive 30 is weak, and it is easy to peel off. In particular, the connection portions 12 and 22 that are closer to the side in the arrangement direction of the conductive patterns 11 and 21 are most easily peeled off, which impairs the reliability of connection of the flexible wiring board.

An object of the present invention is to provide a flexible wiring board capable of improving the bonding strength and consequently improving the connection reliability by devising the shape or arrangement of the connection terminal portion at the end of the conductive pattern. It is an object.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide a substrate using a flexible insulating sheet, a plurality of conductive patterns printed in parallel on the substrate, and an end of the conductive pattern. And a connection terminal portion provided on the portion, and the terminal portion can be attained by a flexible wiring board divided into a plurality of fingers.

If the connection terminal portion of one conductive pattern is divided into a plurality of portions, even if some of the terminal portions of this conductive pattern become defective due to poor adhesion and the connection becomes unstable, the remaining terminal portions may be used. Since the connection state is reliably maintained, the connection stability of the flexible wiring board is improved.

According to one embodiment of the present invention, the terminal portions on both sides in the arrangement direction of the plurality of conductive patterns are:
The number of divisions is larger than that of the terminal portion at the center in the arrangement direction. This enhances the adhesive strength of both sides, which are particularly easily peeled.

According to another embodiment of the present invention, a dummy pattern that is not connected to the conductive pattern is formed between adjacent patterns of the plurality of conductive patterns or outside both sides in the arrangement direction. This prevents a connection failure due to a work error.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments shown in the drawings. FIG. 1 is a plan view of a flexible wiring board showing one embodiment of the present invention.
In this figure, one of the insulating sheet substrates 10 has a plurality of conductive patterns 11 formed on an upper surface thereof, and ends 12 of the patterns 11 are connection terminals. The other insulating sheet substrate 20 has a plurality of conductive patterns 21 formed on the lower surface thereof.
Reference numeral 2 denotes a connection terminal.

The flexible wiring board of the present invention has a finger shape in which the connection terminals 12, 22 of the conductive patterns 11, 21 are divided into a plurality of fingers 13, 23. In the illustrated example, the terminal portions 12 and 22 at the center are divided so as to have two fingers 13 and 23, whereas the terminal portions 12 and 22 at both sides are divided into three portions having a larger number of divisions. Fingers 13,23
Is divided into

The flexible wiring board of the present invention shown in FIG. 1 is connected in the same manner as described with reference to FIG. In this case, in the present invention, since the connection portions 12 and 22 of one conductive pattern 11 and 21 are divided into at least two fingers 13 and 23, even if the connection of one finger is unstable,
The connection is secured by the remaining fingers. In particular, since the number of fingers 13 and 23 at the side of the substrate is larger than that at the center, the reliability of the connection is improved and the adhesive strength of the connection at the side of the substrate which is easily peeled is increased.

FIG. 2 is a plan view of a flexible wiring board showing another embodiment of the present invention. In the flexible wiring board shown in this example, a dummy pattern 14 that is not connected to the conductive pattern 11 is provided between adjacent patterns of the connecting part 12 of the conductive pattern 11 and between the adjacent parts of the board.
It is formed to have the same length as that.

The use of this dummy pattern 14 is based on the other flexible wiring board (not shown) (corresponding to 20 described above).
When both substrates are connected to the conductive pattern 11
Of the dummy pattern 1
4 provides an advantage that the connection stability is ensured because the adhesive area is supplemented.

[0016]

As described above, according to the present invention, the shape or arrangement of the connection terminal at the end of the conductive pattern is devised, so that the bonding strength of the connection is high and the reliability of the connection is improved. Flexible wiring board can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a flexible wiring board according to an embodiment of the present invention.

FIG. 2 is a plan view of a flexible wiring board according to another embodiment of the present invention.

FIG. 3 is a plan view of a conventional flexible wiring board.

FIG. 4 is a plan view and a side view showing a connection state of a conventional flexible wiring board.

[Explanation of symbols]

 10, 20 Insulating sheet substrate 11, 12 Conductive pattern 12, 22 Connection terminal part 13, 23 Divided finger 14 Dummy pattern

Claims (3)

[Claims] 1. A substrate using a flexible insulating sheet, a plurality of conductive patterns printed and wired in parallel on the substrate, and a connection terminal portion provided at an end of the conductive pattern. A flexible wiring board, wherein the terminal portion is divided into a plurality of fingers. 2. The flexible wiring board according to claim 1, wherein the terminal portions on both sides in the arrangement direction of the plurality of conductive patterns have a larger number of divisions than the terminal portions in the center portion in the arrangement direction. 3. A dummy pattern that is not connected to the conductive pattern is formed between adjacent patterns of the plurality of conductive patterns or outside of both sides in the arrangement direction. 2. Flexible board.