JP2002204042A - Flexible printed circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible printed circuit for improving noise resistance by a simple structural change of a wiring pattern and a film sheet. SOLUTION: The flexible printed circuit 1 comprises a base film 11 made of PET or the like, and a wiring pattern 12 formed on the film 11 and made of a copper foil or the like. One region 11a and another region 11b of the film 11 are bent symmetrically with respect to a boundary line L and used. At least a part of the first and second wiring patterns 12a and 12b are formed in a wave shape, and formed so as to have a phase difference P of 180 deg. from each other when the film 11 is folded at the line L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flexible printed circuit such as an FPC (flexible printed circuit) harness.

[0002]

2. Description of the Related Art Flexible printed circuits are usually PE
It is formed by forming a wiring pattern such as copper foil on a film sheet such as T. (1) Thinner, (2) Lighter, (3) Component mounting possible,
It has such advantages.

[0003]

When used in a speaker or a sensor, noise countermeasures are required. However, in the case of a flexible printed circuit, countermeasures such as a twisted pair wire like a wire harness are difficult due to the structure thereof. is there. For example, when applying FPC to a door module,
In many cases, the speaker wiring is a twisted pair wire, and it has been difficult to replace all the wires in the door with the FPC. As a result, the electric wire and FP in one module
There is a problem in that the cost reduction effect cannot be obtained due to the coexistence of C.

The present invention has been made in view of the above problems, and has as its object to provide a flexible printed circuit having improved noise resistance by a simple structure change of a wiring pattern and a film sheet.

[0005]

A flexible printed circuit according to the present invention includes a base film and a wiring pattern formed on the base film, and a boundary between one region and the other region of the base film. A flexible printed circuit used by being symmetrically bent at a line, wherein at least a part of the wiring pattern is a first wiring pattern having a wavy shape formed in one region and the first wiring pattern.
And a second wiring pattern formed at a position facing the first wiring pattern in the other area when bent at the boundary line, the second wiring pattern being formed in the same wave shape as that of the first wiring pattern. The wave shape of the wiring pattern and the wave shape of the second wiring pattern are formed so as to have a phase difference of 180 degrees when bent at the boundary line.

According to the flexible printed circuit of the present invention, since a pseudo twisted pair is formed by using a corrugated wiring pattern having a phase difference of 180 degrees formed by at least one pair, it is possible to reduce electromagnetic induction noise. Noise resistance can be improved. Further, if the present invention is applied to a place where a twisted pair wire is used, it is not necessary to mix an electric wire and a flexible printed circuit, thereby realizing cost reduction.

In another flexible printed circuit according to the present invention, the corrugated first and second wiring patterns are arranged near an edge of the base film. And the edge of the other region is formed in a contour along the first and second wiring patterns formed in the wavy shape, and the edge of the one and the other region facing each other when folded is formed. It is characterized in that it further comprises an engagement portion which is engaged alternately with the engagement.

[0008] Still another flexible printed circuit according to the present invention includes an upper flexible printed circuit having an upper base film, an upper wiring pattern formed on the upper base film, a lower base film, and a lower base film. A lower flexible printed circuit having a lower wiring pattern formed on a side base film and a lower flexible printed circuit, wherein at least a part of the upper and lower wiring patterns is An upper corrugated wiring pattern having a corrugated shape formed on a base film, and formed in the same corrugated shape as the upper corrugated wiring pattern, and the upper corrugations of the lower base film when the upper and lower flexible printed circuits are overlapped. A lower waveform wiring pattern formed at a position facing the wiring pattern. The wave shape of the upper waveform wiring pattern and the wave shape of the lower waveform wiring pattern are formed so as to have a phase difference of 180 degrees when the upper and lower flexible printed circuits are overlapped. I do.

Still another flexible printed circuit according to the present invention is a flexible printed circuit comprising a base film, and upper and lower wiring patterns formed on the upper and lower sides of the base film. At least a part of the upper surface side and the lower surface side wiring pattern is formed in a wavy upper surface side waveform wiring pattern formed on the upper surface side of the base film, and formed in the same wave shape as the upper surface side waveform wiring pattern, The upper surface side waveform wiring pattern of the base film and the lower side waveform wiring pattern formed at a position facing each other with the base film interposed therebetween, and the wave shape of the upper side waveform wiring pattern and the lower side waveform wiring pattern The wave shape is characterized in that it is formed so as to have a phase difference of 180 degrees.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to the present invention will be described below with reference to the accompanying drawings. In FIG.
FIG. 2 is a plan view showing a main part of the flexible printed circuit 1 according to the first embodiment of the present invention, and FIG. 2 shows a usage state of the circuit. The flexible printed circuit 1 according to the present embodiment has P
ET or other base film 11 and this base film 1
1 and a wiring pattern 12 made of a copper foil or the like formed on the substrate 1. As shown in FIG. 2, the circuit includes one region 11a of the base film 11 and another region 1a.
It is used by being symmetrically bent at the boundary line L with 1b. At least a part of the wiring pattern 12 (in this example, the first and second wiring patterns 12a and 12b located on both side ends)
Are formed in a wavy shape while the other wiring patterns 12 are in a straight shape. That is, the first wiring pattern 12a is formed in one region 11a, and the second wiring pattern 12b is formed in the same wave shape as the first wiring pattern 12a. It is formed at a position facing the first wiring pattern 12a in the other area 11b when bent. Waveform of first wiring pattern 12a and second wiring pattern 12b
Is formed so as to have a phase difference P of 180 degrees when the base film 11 is bent at the boundary line L.

According to the flexible printed circuit of the present invention, a pseudo twisted pair line is formed by overlapping at least one pair of the wave-shaped wiring patterns 12a and 12b having a phase difference of 180 degrees. Therefore, noise resistance against electromagnetic induction noise can be improved. Further, if the present invention is applied to a place where a twisted pair wire is used, it is not necessary to mix an electric wire and a flexible printed circuit, thereby realizing cost reduction.

FIG. 3 is a plan view showing a main part of a flexible printed circuit 2 according to a second embodiment of the present invention, and FIG.
Fig. 2 shows the usage state of the circuit. This embodiment is an application of the above-described first embodiment. This embodiment differs from the above-described first embodiment in the shape of the edge of the base film 21.
Also in the flexible printed circuit 2 according to the present embodiment,
First and second wiring patterns 2 formed in a wavy shape
The reference numerals 2a and 22b are disposed near the edges of the base film 21 on the opposite side of the boundary line L between the one and other regions 21a and 21b, respectively. However, the edges of the one and other regions 21a and 21b of the base film 21 are formed in a wavy contour along the first and second wiring patterns 22a and 22b. In addition, when the base film 21 is bent at the boundary L, the one and the other regions 21 which are opposed to each other.
Further, engaging portions 23a and 23b are provided which engage the edges of the a and 21b alternately. This engaging part 2
In this example, one and the other regions 21a, 2b of the base film 21 formed in, for example, a corrugated shape.
1b is a cut groove formed at the edge of FIG.

According to the present embodiment, the shape of the edges of the one and other regions 21a and 21b of the base film 21 is corrugated in accordance with the wiring pattern formed in a waveform, and the shape of the one and the other regions 21a and 21b is reduced. When bent and used at the boundary L, the edges of the first and second regions 21a and 21b are alternately meshed and engaged with each other, so that the extending direction of the corrugated wiring patterns 22a and 22b is based on the base. Since the film 21 is twisted without being limited to the plane, the noise resistance against electromagnetic induction noise can be further improved.

FIG. 5 is a perspective view showing a main part of a flexible printed circuit 3 according to a third embodiment of the present invention, and FIG.
Fig. 2 shows the usage state of the circuit. The flexible printed circuit 3 according to the third embodiment of the present invention includes an upper flexible printed circuit 3a having an upper base film 31a, an upper wiring pattern 32a formed on the upper base film 31a, and a lower base. A film 31b;
The lower flexible printed circuit 3b having the lower wiring pattern 32b formed on the lower base film 31b is used in an overlapping manner. At least a part of these upper and lower wiring patterns 32a and 32b are formed in the same waveform as the upper waveform wiring pattern 32a 'and the upper waveform wiring pattern 32a' formed in a waveform on the upper base film 31a. As shown in FIG. 6, when the upper and lower flexible printed circuits 3a and 3b are overlapped, the upper waveform wiring pattern 32 of the lower base film 31b is formed.
This is a lower waveform wiring pattern 32b 'formed at a position facing a'. These upper waveform wiring patterns 32a '
Are formed such that the upper flexible printed circuit 3a and the lower flexible printed circuit 3b have a phase difference P of 180 degrees when the upper flexible printed circuit 3a and the lower flexible printed circuit 3b are overlapped.

FIG. 7 is a perspective view of a main part of a flexible printed circuit 4 according to a fourth embodiment of the present invention. Flexible printed circuit 4 according to a fourth embodiment of the present invention
Is a base film 41, and upper surface side wiring patterns 42a formed on the upper surface side and the lower surface side of the base film 41.
And a lower wiring pattern 42b. At least a part of the upper and lower wiring patterns 42a and 42b has a corrugated upper waveform wiring pattern 42a 'formed on the upper surface of the base film 41 and the same corrugation as the upper waveform wiring pattern 42a'. The lower-side corrugated wiring pattern 42b 'formed at a position facing the upper-side corrugated wiring pattern 42a' of the base film 41 with the base film 41 interposed therebetween. The wave shape of the upper surface side waveform wiring pattern 42a 'and the wave shape of the lower surface side waveform wiring pattern 42b' are formed so as to have a phase difference P of 180 degrees. It is desirable that the corrugated wiring pattern and the other wiring patterns are separated as much as possible in the state of use as in the above embodiment.

[0016]

As described above, according to the flexible printed circuit of the present invention, a pseudo twisted pair is formed by using at least one pair of corrugated wiring patterns having a phase difference of 180 degrees. Therefore, noise resistance against electromagnetic induction noise can be improved. Further, if the present invention is applied to a place where a twisted pair wire is used, it is not necessary to mix an electric wire and a flexible printed circuit, thereby realizing cost reduction.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a flexible printed circuit according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a use state of the flexible printed circuit according to the first embodiment of the present invention.

FIG. 3 is a plan view showing a main part of a flexible printed circuit according to a second embodiment of the present invention.

FIG. 4 is a perspective view showing a use state of a flexible printed circuit according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a main part of a flexible printed circuit according to a third embodiment of the present invention.

FIG. 6 is a perspective view showing a use state of a flexible printed circuit according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing a main part of a flexible printed circuit according to a fourth embodiment of the present invention.

[Explanation of symbols]

1, 2, 3, 3a, 3b, 4 ... flexible printed circuit, 12, 12a, 12b, 22, 22a, 22b, 3
2a, 32b, 32a ', 32b', 42a, 42b,
42a ', 42b' ... wiring pattern, 23a, 23b ...
Engaging part, L: boundary line, P: phase difference.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Ken Hasegawa 1440 Mutsuzaki, Sakura City, Chiba Prefecture Fujikura Sakura Works F-term (reference) 5E338 AA12 BB54 CC01 CD17 EE13

Claims (4)

[Claims] 1. A flexible printed circuit comprising a base film and a wiring pattern formed on the base film, wherein the flexible film is used by being symmetrically bent at a boundary between one region and the other region of the base film. And at least a part of the wiring pattern has a first wiring pattern having a wavy shape formed in one region, and a first wiring pattern having the same waveform as the first wiring pattern. A second wiring pattern formed at a position opposite to the first wiring pattern in the other area, wherein the wave shape of the first wiring pattern and the wave shape of the second wiring pattern are 180 when folded at the boundary
A flexible printed circuit formed so as to have a phase difference of degrees. 2. The first and second wiring patterns formed in a wavy shape are arranged near an edge of the base film, and edges of one and other regions of the base film are Engagement members that are formed to have contours along the first and second wiring patterns formed in the wavy shape, and that, when bent, oppose edges of the one and other regions that are alternately engaged and engaged. The flexible printed circuit according to claim 1, further comprising a joining portion. 3. An upper flexible printed circuit including an upper base film, an upper wiring pattern formed on the upper base film, a lower base film, and a lower side formed on the lower base film. A flexible printed circuit used by superimposing a lower flexible printed circuit provided with a wiring pattern, wherein at least a part of the upper and lower wiring patterns has a corrugated shape formed on the upper base film. An upper waveform wiring pattern, formed in the same wave shape as the upper waveform wiring pattern, and formed at a position facing the upper waveform wiring pattern on the lower base film when the upper and lower flexible printed circuits are overlapped. A lower waveform wiring pattern, wherein the upper waveform wiring pattern has a wave shape and the lower waveform wiring pattern. The wave pattern of the line pattern is a flexible printed circuit characterized by being formed so as to have a phase difference of 180 degrees when the upper and lower flexible printed circuits are overlapped. 4. A flexible printed circuit comprising a base film, and upper and lower wiring patterns formed on the upper and lower surfaces of the base film, wherein the upper and lower wiring patterns are provided. At least a part of the upper surface side waveform wiring pattern formed on the upper surface side of the base film and the same waveform shape as the upper surface side waveform wiring pattern, and the upper surface side waveform wiring pattern of the base film And a lower surface side waveform wiring pattern formed at a position facing the base film via the base film. The wave shape of the upper surface side waveform wiring pattern and the wave shape of the lower surface side waveform wiring pattern have a phase difference of 180 degrees. A flexible printed circuit characterized by being formed to have.