JPH09326538A - Flexible printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality flexible printed wiring board which is high in quality, stable in electrical connectability, and used for electrically wiring AV.OA equipments by a method wherein the overlapped part of a second pattern is kept thick enough. SOLUTION: The edges 10A and 10B of a first pattern 10 which second patterns 11 overlap are tapered in a printing direction of the second pattern 11, and the second patterns 11 are formed by printing overlapping with the edges 10A and 10B of the first pattern 10, whereby the second pattern 11 can be kept thick enough even on the tapered parts 10D and 10F, so that a flexible printed wiring board can be protected against cracking and pattern disconnection even if an external force is applied when it is mounted on an electronic equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed wiring board used for electrical wiring of AV / OA equipment.

[0002]

2. Description of the Related Art In recent years, AV, OA devices and the like have tended to be light, thin, short and small, and can be freely bent and placed in a gap inside a set, and use of a flexible printed wiring board capable of electrically connecting wiring boards and the like. The number of wirings having a narrow pitch is also increasing as the number of wirings increases.

In the conventional flexible printed wiring board, a flexible and soft wiring conductive pattern is laid around in order to ensure electric continuity at the time of bending, and a connector fitting portion or a resistance which requires pattern hardness is used. As shown in the perspective view of FIG. 5A and the cross-sectional view of FIG. 5B, the print resistance portion to which the component is added has a first pattern 2 having various functions such as high hardness or high resistance on the insulating film 1. Was formed by printing, and the second patterns 3 to be wiring conductive patterns were formed by printing so as to overlap the end portions 2A and 2B of the first pattern 2.

[0004]

However, since the ends 2A and 2B of the first pattern 2 are generally vertical to the printing direction, there are slight steps, and ink is applied at these steps. When the conditions suddenly change and the overlapping portion 3A of the second pattern 3 is formed by printing, the root portion 3B is completely imprinted with the printing ink, but the edge portion 3C is thin and partially discontinuous. In the root portion 3E of the other overlapping portion 3D, the imprinting state of the printing ink is insufficient, and cracks or pattern breaks occur in the overlapping portions 3A and 3D due to an external force applied when bending the electronic component such as when it is attached to various electronic devices. It happened.

Further, as the film thickness of the first pattern 2 becomes thicker, the step difference becomes larger, and the overlapping portions 3A and 3A are formed.
The influence on D was also large, and it was difficult to guarantee electrical connectivity.

[0006] On the other hand, the first pattern 2 and the second pattern 3 may be formed by being deviated from each other during the above-mentioned overlay printing, and in order to maintain the insulation between the respective patterns of the narrow pitch wiring pattern, The width of the second pattern 3 needs to be equal to or less than the width of the first pattern 2.

The present invention is intended to solve such a conventional problem, and provides a high-quality flexible printed wiring board with stable electrical connectivity by ensuring the thickness of the overlapping portion of the second pattern. It is intended to be provided.

[0008]

In order to solve the above problems, in the flexible printed wiring board of the present invention, the end portion which is the overlapping portion of the first pattern is inclined with respect to the printing direction of the second pattern. As a shape, the second pattern is formed by printing on it.

Thus, the influence of the end portion of the first pattern can be reduced at the time of printing the second pattern, the thickness of the overlapping portion of the second pattern can be secured, and cracks and pattern breaks can be prevented.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention has a width equal to or less than that of the first pattern formed by printing on the insulating substrate and the first pattern formed by printing on the first pattern. The flexible printed wiring board is formed of the second pattern, and the end of the overlapping portion of the first pattern is inclined with respect to the printing direction of the second pattern. The coating jig hits the tip of the sloping end of the first pattern and rides forward, and the second pattern thickness at the sloping portion of the first pattern is formed by printing including the step difference of the first pattern. It has the effect of being able to.

According to a second aspect of the present invention, in the first aspect of the present invention, the end portion of the overlapping portion of the first pattern has a triangular or arcuate shape, and the end portion has a predetermined distance. On the other hand, it has an effect that it is possible to provide an inclined portion that is approximately doubled.

According to a third aspect of the present invention, in the first aspect of the invention, the end portion of the overlapping portion of the first pattern has a triangular or arcuate recessed shape.
It has the same effect as the invention of claim 2.

According to a fourth aspect of the present invention, in the first aspect of the invention, the front portion of the overlapping portion of the first pattern is a triangular shape in which the front portion is recessed and the rear portion is protruding in the printing direction of the second pattern. Although it has a shape and has the same effect as that of the invention of claim 2, a comparison test of a general flexible printed wiring board in which a carbon resin-based or silver resin-based ink is printed on an insulating film made of polyethylene terephthalate As a result, it has an effect that the best result can be obtained.

According to a fifth aspect of the invention, in the first aspect of the invention, the end portion of the overlapping portion of the first pattern has a linear shape, and especially when the pattern has a narrow width, It has an effect that the end shape of the pattern is easily formed.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. It should be noted that the same parts as those of the conventional configuration are designated by the same reference numerals and the description thereof will be omitted.

(Embodiment 1) FIG. 1 (a) is a perspective view of a flexible printed wiring board according to the same embodiment, and FIG. 1 (b) is a sectional view. In FIG. 1, 1 is the same polyethylene terephthalate as the conventional one. The first pattern 10 is formed by printing on the surface of the insulating film such as
The second pattern 11 is formed by printing on the first pattern 10 and the second pattern 11, respectively.
B has a triangular shape in which the front and rear portions are convex with respect to the printing direction of the second pattern 11.

When the overlapping portion 11A of the second pattern 11 overlapping the first pattern 10 is formed by printing, a printing ink applying jig (not shown) is provided at the tip of the end portion 10A of the first pattern 10. When it reaches the portion 10C, it rides on the end portion 10A and moves forward.
The ink of the second pattern 11 having a thickness including the step difference of the first pattern 10 is applied to the triangular hypotenuse portion 10D of the above, and at the end 10B of the other first pattern 10,
Until the printing ink applying jig moves to the tip portion 10E, the ink of the second pattern 11 is applied to the triangular hypotenuse portion 10F with a thickness including the step difference of the first pattern 10 and the overlapping portion. 11B is formed.

As described above, since the thickness of the overlapping portions 11A and 11B of the second pattern 11 can be secured, the occurrence of cracks and defective pattern cutting is unlikely to occur, and the electrical connectivity can be stabilized.

The vertex angle of the convex triangular shape at the end of the first pattern may be set as necessary, but is set to 90 ° or less in order to stabilize the printability of the first pattern. Is preferred.

In the present embodiment, the first pattern 1
Although the shape of the end portions 10A and 10B of 0 is described as an example of a convex triangular shape, the present invention is not limited to this.
Needless to say, the same effect can be expected with an arc shape.

(Embodiment 2) As shown in FIG. 2, when the end portions 12A and 12B of the first pattern 12 are formed in a triangular shape in which the front and rear portions are concave with respect to the printing direction of the second pattern 13, The overlapping portion 13A of the second pattern 13 having a thickness including the step due to the ink being collected in the concave shape
And 13B are formed, and electrical connectivity can be stabilized.

The triangular concave angle of the end of the first pattern 12 may be set as necessary, but it should be designed to be 90 ° or less in order to stabilize the printability of the first pattern. Is the best, and the same effect can be expected with an arc shape as in the first embodiment.

(Embodiment 3) Even when it is difficult to obtain the expected effect due to the material of the flexible substrate and the characteristics of the printing ink, one end 14A is formed in a concave triangular shape and the other is formed as shown in FIG. It is possible to further stabilize the electrical connectivity between the first pattern 14 and the second pattern 15 by properly using the shape of the end portion 14B of each of them such as a convex triangular shape.

(Embodiment 4) When the width of the first pattern 16 is narrow, the end portions 16A and 16B of the first pattern 16 are slanted with respect to the printing direction of the second pattern 17 as shown in FIG. With such a shape, it is possible to easily form a print, and even if the second pattern 17 is slightly misaligned, the end portions 16A and 16B of the first pattern 16 are slanted straight lines, so that the effect can be absorbed. it can.

[0025]

As described above, according to the present invention, the end portion of the first pattern overlapping the second pattern is inclined with respect to the printing direction of the second pattern, and the second pattern is formed thereon. Since printing is performed, the thickness of the overlapping portion of the second pattern can be ensured, and the advantageous effect that a high-quality flexible printed wiring board having excellent printability and electrical characteristics can be provided is obtained.

[Brief description of drawings]

FIG. 1A is a perspective view of a flexible printed wiring board according to a first embodiment of the present invention, and FIG.

FIG. 2A is a perspective view of a flexible printed wiring board according to a second embodiment of the present invention, and FIG.

FIG. 3 is a perspective view of a flexible printed wiring board according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a flexible printed wiring board according to a fourth embodiment of the present invention.

FIG. 5A is a perspective view of a conventional flexible printed wiring board, and FIG.

[Explanation of symbols]

1 Insulating film 10, 12, 14, 16 First pattern 10A, 10B, 12A, 12B, 14A, 14B, 1
6A, 16B End part 10C, 10E Tip part 10D, 10F Oblique side part 11, 13, 15, 17 Second pattern 11A, 11B, 13A, 13B Superposition part

Front page continuation (72) Inventor O-saki ▼ Tasuku 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Kouji Tanabe, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. An end of an overlapping portion of a first pattern, which comprises a first pattern printed on an insulating substrate and a second pattern having a width equal to or smaller than that of the first pattern formed by printing on the first pattern. A flexible printed wiring board having a shape in which a portion is inclined with respect to the printing direction of the second pattern. 2. The flexible printed wiring board according to claim 1, wherein the end portion of the overlapping portion of the first pattern projects in a triangular shape or an arc shape. 3. The flexible printed wiring board according to claim 1, wherein the end portion of the overlapping portion of the first pattern is depressed in a triangular shape or an arc shape. 4. The flexible printed wiring board according to claim 1, wherein a front portion of the overlapping portion of the first pattern has a depressed triangular shape and a rear portion thereof has a protruding triangular shape with respect to the printing direction of the second pattern. . 5. The flexible printed wiring board according to claim 1, wherein the end portion of the overlapping portion of the first pattern has a linear shape.