JP2002118333A - Noise-proof circuit and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and surely form a noise blocking twisted circuit with two lines on one side of an insulation substrate at a low cost, instead of twisted pair lines. SOLUTION: A plurality of parallel circuit conductors 26, 27 with continuous structures of front and back straight parts 28, 30 to middle inclined parts 29, 31 are formed on one side of an insulation substrate 32. The ends of each straight part locate at both sides of each inclined part insulated by an insulation layer 24 and interconnected through connecting circuit conductors 25 on the insulation layer. Inclined extensions 33, 34 are formed on the ends of the straight parts 28, 30. The insulation substrate 32 uses a flexible flat substrate. A plurality of circuit conductors with continuous structures of front and back straight parts to middle inclined parts are formed on one side of an insulation substrate. The ends of each straight part locate at both sides of each inclined part and may be interconnected through connecting members such as chip jumpers, etc., on one surface of the insulation substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

(Detailed Description of the Invention) The present invention relates to a noise prevention circuit in which the influence of external noise is reduced by forming two twisted circuits instead of twisted pair wires using one surface of an insulating substrate, and the formation thereof It is about the method.

[0002]

2. Description of the Related Art FIGS.
1 shows a conventional noise prevention circuit described in Japanese Patent Publication No. 41-41.

The noise prevention circuit 41 is composed of a plurality of short crank-shaped printed circuit conductors 45 each having front and rear straight portions 43, 43 and an intermediate inclined portion 44 on one surface 42a of one insulating substrate 42. A plurality of printed circuit conductors 48 having the same straight portions 46 and 46 and an inclined portion 47 are arranged on the other surface (back surface) 42b of the insulating substrate 42 symmetrically with respect to the printed circuit conductor 45. The printed circuit conductors 45 and 48 on the front and back are connected at both ends in the longitudinal direction by interlayer connection conductors 49 penetrating in the thickness direction of the insulating substrate 42.

The straight part 43 on the front side and the straight part 46 on the back side
Are located parallel to each other, and the inclined portion 44 on the front surface side and the inclined portion 47 on the rear surface side intersect with being vertically separated. The front and rear straight portions 43, 46 are intermediate inclined portions 44, 47.
It is formed shorter. The interlayer connection conductor 49 connecting the straight portions 43 and 46 on the front and back sides is formed in a substantially conical shape. The printed circuit conductor 45 on the front side is connected to the printed circuit conductor 48 on the back side via the interlayer connection conductor 49, and the printed circuit conductor 48 on the back side is connected to the printed circuit conductor 45 on the front side via the interlayer connection conductor 49. I have.

[0005] The above configuration constitutes a noise prevention wiring board 50 to which the principle of a so-called twisted pair wire (not shown) is applied. The twisted pair wire has a structure in which two insulated wires are twisted, and noise from the surroundings is guided to both wires in the same manner, thereby canceling the noise. One wire is used for signal and the other wire is used for noise ground.

Similarly, the printed circuit conductors 45 and 48 on the front and back and left and right form two independent twisted circuits 51 and 52 via an interlayer connecting conductor 49. For example, one twisted circuit 51 is used for signals, By using the other torsion circuit 52 for noise grounding, the signal circuit 51 can supply a signal current without being affected by external noise, thereby preventing malfunction of electronic components and the like due to noise. Can be.

As a method of forming the noise prevention circuit 41, for example, first, a metal mask is positioned on one surface of a copper foil, and printing and drying of a silver powder-epoxy resin-based conductive paste are repeated a plurality of times. The interlayer connection conductor 49
To form

Next, a copper foil is laminated on the surface on which the interlayer connection conductor 49 is formed via an insulating substrate 42 which is a sheet-like liquid crystal polymer, and the laminate is integrated by applying heat and pressure. By this heat-press drying, a double-sided copper-clad plate is formed in which the front end side of the interlayer connection conductor 49 is pressed into the insulating substrate 42 which is a sheet-like liquid crystal polymer.

Then, in order to form a pre-designed wiring pattern on the double-sided copper foil surface, that is, the printed circuit conductors 45 and 48, unnecessary portions of the copper foil are removed by etching and the etching resist is removed to remove the printed circuit conductors. 4
5, 48 are formed.

[0010]

However, in the above-described conventional noise prevention circuit and the method of forming the same, printed circuit conductors 45 and 48 are provided on both the front and back surfaces of the insulating substrate 42, and the printed circuit conductors 45 and 48 are further provided. Must be connected by the interlayer connection conductor 49, which complicates the structure and the manufacturing process, increases the cost, and reduces the cost of the insulating substrate 42.
The space for arranging electronic components etc. on the top is limited,
There is a problem that the degree of freedom in circuit design is reduced.

SUMMARY OF THE INVENTION In view of the above, the present invention provides a noise prevention circuit and a method of forming the same which are simple in structure, easy to manufacture, low in cost, and capable of providing a large effective space for arranging components on an insulating substrate. The purpose is to provide.

[0012]

In order to achieve the above object, according to the present invention, a plurality of circuit conductors having a straight front part and a middle inclined part are formed in parallel on one surface of an insulating substrate. , The end of each straight part is located on both sides of each slope,
The first noise prevention circuit is characterized in that the end portions of the straight portions are connected to each other by a connecting member (claim 1). It is also effective that the connection member is a chip jumper (claim 2). Also, on the end side of each straight portion,
It is also effective that a wide land portion is formed for the connection member (claim 3). Also, on one surface of the insulating substrate, a plurality of circuit conductors in which a front and rear straight portion and an intermediate inclined portion are continuous are printed and formed in parallel, and the end portions of each straight portion are positioned on both sides of each inclined portion. Then, a method of forming a first noise prevention circuit, wherein the end portions of the straight portions are connected to each other by a connecting member, is also adopted (claim 4). Also,
On one surface of the insulating substrate, a plurality of circuit conductors in which a front and rear straight portion and an intermediate inclined portion are continuous are formed in parallel, and the end portions of each straight portion are positioned on both sides of each inclined portion, and each inclined portion is formed. The second noise prevention circuit is characterized in that the portions are insulated by an insulating layer, and the ends of the straight portions are connected to each other by connection circuit conductors on the insulating layer. 5). It is also effective that an inclined extension portion is formed on the end side of each straight portion, and the inclined extension portions are connected to each other by the connection circuit conductor (claim 6). Also, on one surface of the insulating substrate, a plurality of circuit conductors in which a front and rear straight portion and an intermediate inclined portion are continuous are printed and formed in parallel, and the end portions of each straight portion are positioned on both sides of each inclined portion. A second circuit, wherein each inclined portion is covered with an insulating layer, a connection circuit conductor is printed and formed on the insulating layer, and ends of the straight portions are connected to each other with the connection circuit conductor. (Claim 7). An inclined extension portion is integrally formed on the end side of each straight portion by printing, and each of the inclined portions is exposed from the insulating layer with the same length as the inclined extension portion. It is also effective to connect with a connection circuit conductor (claim 8).
In the noise prevention circuit according to any one of claims 1 to 3 and 5 to 6, it is also effective to use a flexible flat substrate as the insulating substrate (claim 9).

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 and 2 show a first embodiment of a noise prevention circuit and a method of forming the same according to the present invention.

In this noise prevention circuit 1, two torsion circuits 3 and 4 are formed on one surface of an insulating substrate 2 by printing, and an intersection of the two torsion circuits 3 and 4 is connected to one or the other of the torsion circuits 3 and 4. And a conductive chip jumper (connecting member) 7 on the other or one of the twisted circuits 4 and 3 which crosses over the printed circuit conductors 5 and 6 three-dimensionally. Things.

Each of the torsion circuits 3 and 4 comprises a plurality of printed circuit conductors 5 and 6 and a plurality of chip jumpers 7. Each of the printed circuit conductors 5, 6 is a straight part 8, 8, 1 which is separated in the longitudinal direction of the torsion circuit and extends parallel to the left and right.
0, 10 and inwardly inclined portions 9, 11 connecting the front and rear straight portions 8, 8, 10, 10 are formed in a substantially crank shape.

The rear ends of the straight portions 8, 10 on the front side are inclined portions 9,
Following the front end of 11, the rear ends of the inclined portions 9, 11 continue to the front ends of the straight portions 8, 10 on the rear side. The inclination angle of the inclined portions 9 and 11 with respect to the straight portions 8 and 10 is about 45 °, and the length of the inclined portions 9 and 11 is slightly shorter than the length of the straight portions 8 and 10. The straight portions 8, 8, 10, 10 have the same length, and the inclined portions 9, 11 have the same length. "Before and after" in the description
Is for convenience of explanation, and the noise prevention circuit 1
It does not mean before and after the noise preventing circuit board P ₁ was used.

The front and rear straight portions 8 and 10 and the intermediate inclined portions 9 and
The printed circuit conductors 5 and 6 are arranged at equal pitches in the longitudinal direction of the twisted circuit.
6 are mutually connected by a chip jumper 7 arranged in an inclined manner. That is, each printed circuit conductor 5, 6
Front of the front end of the straight portion 8 and 10 are connected to the rear end of the straight portion of the rear side of the chip each print circuit conductors 5 ₂ of the front through the jumper 7, 6 _2, after each printed circuit conductors 5 The rear ends of the straight portions 8 and 10 are connected to the front ends of the front straight portions of the rear printed circuit conductors 5 ₃ and 63 ₃ via a chip jumper 7.

Between the two substantially cranked printed circuit conductors 5 ₂ , 5 (5, 5 ₃ ) before and after the one twisted circuit 3, one substantially cranked printed circuit conductor 6 (6) of the other twisted circuit 4 is connected. ₃ ) are arranged in the same shape. The inclined portion 11 of the other twisted circuit 4 intersects under the chip jumper 7 of the one twisted circuit 3 and is located in a non-contact manner, and the one twisted circuit 4 is located below the chip jumper 7 of the other twisted circuit 4. The three inclined portions 9 intersect and are located in an electrically non-contact manner. FIG.
The chip jumper 7 connecting the printed circuit conductors 6, 63 of the other twisted circuit 4 has a slight gap above the inclined portion 9 of the printed circuit conductor 5 of one twisted circuit ₃ as shown in FIG. are doing.

The chip jumper 7 has electrodes 12 at both ends, an insulating body 13 at an intermediate portion, and a conductive portion (not shown) inserted through the insulating body 13 and connected to the two electrodes 12. ing. The conductive portion is set to have a low electrical resistance similar to that of the printed circuit conductors 5 and 6, and conducts electric signals and noises well. The electrodes 12 on both sides are connected to wide land portions 14 and 15 (FIG. 1) integrally formed at the ends of the straight portions 8 and 10 of the printed circuit conductors 5 and 6 by means of solder 20 or the like.

Each of the land portions 14 and 15 is inclined at the same inclination angle as the inclined portions 9 and 11, and the land portions of the same twisted circuits 3 and 4 (the land portions 14 and the land portion 15) are bordered by the inclined portions 9 and 11. Are located opposite to each other. The slopes 9, 11 of the printed circuit conductors 5, 6 pass under the insulating body 13. Even if the insulating body 13 is
There is no problem even if they are brought into direct contact because insulation is performed.

[0021] If illustrating a circuit configuration in detail, one of the twisting of the first printed circuit conductors 5 of circuit 3 front straight portion 8 of the front through the chip jumper 7 of the second printed circuit conductors 5 ₂ following rear straight portion _82, the first printed circuit third printed circuit conductors 5 ₃ of the front straight portion 8 side of the straight portion 8 of the rear side via the chip jumper 7 after the conductor 5
Continues to ₃ . Here, the first to third are merely for convenience of description, the printed circuit conductors 5,5 _2, 5 ₃ are identical in size, shape and electrical characteristics.

[0022] The first printed circuit conductor 6 of the other twisted circuit 4 is located between the first one of the torsion circuit 3 and the second printed circuit conductors 5,5 _2, the inclined portion 11, a first chip jumpers 7 connecting the second printed circuit conductors 5,5 ₂
Through the lower, following the front straight portion 10 via a second printed circuit conductors 6 chip jumpers 7 to straight portion of the rear side of the _second front, the third printed circuit conductors of the other twisted circuit 4 6 ₃ is located between the first one of the torsion circuit 3 and of the third printed circuit conductors 5,5 _3, the front side of the straight portion 10 ₃ of the first printed circuit conductors 6 via the chip jumper 7 thereof It continues to the straight part 10 on the rear side.

The third printed circuit conductors 6 ₃ of the inclined portion 11
_On top of ₃ is located a chip jumper 7 connecting the first and third printed circuit conductors 5, 53 of one twisted circuit 3. The printed circuit conductor 5 of one twisted circuit 3 is positioned symmetrically with the printed circuit conductor 6 of the other twisted circuit 4. That is, one torsion circuit 3 is located symmetrically with the other torsion circuit 4.

In the above configuration, for example, one of the twist circuits 3
Is used as a signal circuit, and the other torsion circuit 4 is used as a grounding circuit. Noise is canceled by the same principle as that of a twisted pair wire, and external noise is reduced.

The length of the torsion circuits 3 and 4, ie, the number of twists, is determined by the required length of the circuit. For noise reduction, at least two torsion numbers, ie, the first print of one of the torsion circuits 3, is used. A circuit conductor 5 and the other torsion circuit 4
Three chip connecting the first printed circuit conductor 6 inclined portion 11 and the rear of the straight portion 10, and third printed circuit conductors 6 front straight portion 10 ₃ of ₃ and the inclined portion 11 _3, and their Jumper 7 is required.

Hereinafter, a method for manufacturing the noise prevention circuit 1 will be described. For convenience of description, for example, reference numeral 5 _2, 5 ₃
Is code 5, codes 6 ₂ and 6 ₃ are code 6, and codes 8 ₂ and 8
₃ by reference numeral 8, numeral ₁₀₃ is at 10, reference numeral 11 ₃ substitute respectively by the reference numeral 11.

First, one front surface (one surface) of an insulating substrate 2 made of insulating synthetic resin is attached to front and rear elongated straight portions 8,1.
A plurality of substantially crank-shaped circuit conductors 5, 6 each composed of 0 and intermediate slender inclined portions 9, 11 are printed and formed at equal pitches in parallel. The straight portions 8, 10 on the front side of the circuit conductors 5, 6 are arranged at the same pitch on the same straight line, and the straight portions 8, 10 on the rear side are arranged on the straight line parallel to the straight portions 8, 10 at the same pitch. Be placed.

The straight portions 8 and 10 and the inclined portions 9 and 11 have the same width and thickness, and the straight portions 8 and 10 are slightly longer than the inclined portions 9 and 11. A plurality of circuit conductors 5 and 6 serve as printed circuit conductors of one and the other torsion circuits 3 and 4, respectively. The slopes 9, 11 of each printed circuit conductor 5, 6 lie parallel. Straight parts 8,1 on both left and right sides of the inclined parts 9,11
Land portions 14 and 15 at the front and rear ends of 0 are located. The material of the printed circuit conductors 5, 6 is copper foil, conductive paste, or the like.
Wide land portions 14, 15 are provided at the ends of the circuit conductors 5, 6, respectively.
Is formed integrally by printing.

Next, the land portions 14 and 15 of the printed circuit conductors 5 and 6 are connected by the respective chip jumpers 7. That is, the chip jumpers 7 are arranged on the inclined portions 9 and 11 of the printed circuit conductors 5 and 6, and the electrodes 12 at both ends of the chip jumpers 7 are connected to the lands 14 and 15 by solder 20. The inclined portions 9 and 11 and the chip jumper 7 cross three-dimensionally.

In the above two steps (the step of printing the circuit conductors 5 and 6 and the step of soldering the chip jumper 7), the noise prevention circuit 1 is formed simply, reliably and inexpensively. Since the noise prevention circuit 1 can be formed only on one surface (one surface) of the insulating substrate 2, the other surface of the insulating substrate 2 is effectively used as a space for, for example, electronic components and other circuits (not shown). As a result, the degree of freedom in the arrangement position of electronic components and circuits is improved.

It is also possible to use a bus bar (not shown) which is an elongated metal plate in place of the printed circuit conductors 5, 6. Further, a jumper wire can be used instead of the chip jumper 7. Further, a flexible flat substrate can be used as the insulating substrate 2.

FIGS. 3 and 4 show a second embodiment of a noise prevention circuit and a method of forming the same according to the present invention.
In the noise prevention circuit 21, the intersection is formed by the insulating layer 24 and the connection circuit conductor 25 on the insulating layer 24 without using the chip jumper 7 (FIG. 1) at the intersection of the two torsion circuits 22 and 23. It is characterized by the following.

3 (a) to 3 (c) and the corresponding FIGS. 3 (a) to 3 (c) show the method of forming the noise prevention circuit 21 in the order of steps. First, as shown in FIG. A substantially crank-shaped circuit conductor 26 comprising at least front and rear straight portions 28, 28, 30, 30 and intermediate inwardly inclined portions 29, 31;
27 are printed in parallel on one surface of the insulating substrate 32 at an equal pitch. In addition, for convenience of explanation, the reference numerals are different,
The circuit conductors 26 and 27 have the same size and shape, the straight portions 28 and 30 have the same length and width, and the inclined portions 29 and 31 have the same length and width.

Short inclined extensions 33 and 34 are integrally formed at the respective ends of the front and rear straight portions 28 and 30 so as to protrude integrally. Inclined like extension 33 of the rear side of the example one printed circuit conductor 26 is located to face spaced behind the third printed circuit conductors 26 ₃ of the front angled extension 33 _3, both inclined inclined portion 31 of the second printed circuit conductors 27 between Jo extensions 33, 33 ₃ is located. Fig. 4 (a)
As shown in both inclined like extension 33 ₃ inclined portion 31
It is located symmetrically across. The inclination angle of each of the inclined portions 29 and 31 with respect to each of the straight portions 28 and 30 is about 45 °.

Next, as shown by chain lines in FIGS. 3 (b) and 4 (b), an insulating layer (insulating film) 24 is formed on the upper surfaces of the inclined portions 29, 31 of the substantially crank-shaped printed circuit conductors 26, 27. Print and form. The insulating layer 24 is made of, for example, enamel or an insulating synthetic resin material. May be formed an insulating layer 24 in the longitudinal middle portion of the inclined portion 29 and 31, front and rear ends 29a of the inclined portion 29, 31, 31a is allowed to expose a length substantially equal to that of the inclined-like extension 33 ₃ . The width of the insulating layer 24 is shown in FIG.
It is preferable that the width is wide enough to completely cover the inclined portions 29 and 31 in the width direction. Both inclined extensions 33, 33 ₃ may be completely ligated without a gap in the insulating layer 24.

Next, as shown by a solid line in FIGS. 3C and 4C, a connection circuit conductor 25 is printed on the insulating layer 24, and the connection circuit conductor 25 extends the printed circuit conductor 26 in an inclined manner. Parts 33, inclined extension 3 of printed circuit conductor 27
4 are connected to each other. As a result, the connection circuit conductors 25 cross each other three-dimensionally over the inclined portions 29 and 31 via the respective insulating layers 24, and the printed circuit conductors 26 and the printed circuit conductors 27 are connected by the connection circuit conductors 25. Thus, two electrically non-contact torsional circuits 22 and 23 are completed.

The printed circuit conductors 26 and 27 and the connection circuit conductor 25 are formed of a conductive material having a low electric resistance and the same electric characteristics. The noise prevention circuit 21 is constituted by the two twist circuits 22 and 23. At least the noise prevention circuit 21 and the insulating substrate 32 constitute a noise prevention circuit board 35 (FIG. 4C).

Each of the torsion circuits 22 and 23 includes front and rear straight portions 2.
A plurality of printed circuit conductors 26 and 27, which are arranged at substantially equal pitches in a substantially crank shape and include a plurality of printed circuit conductors 26, which are composed of 8, 30 and intermediate inclined portions 29 and 31 and front and rear inclined extensions 33 and 34. The connection circuit conductor 25 connects the inclined extension portions 33 and the inclined extension portions 34 of the printed circuit conductor 27 to each other, and the insulating layer 24 insulates the connection circuit conductor 25 from the inclined portions 29 and 31. . One torsion circuit 22 is arranged symmetrically with the other torsion circuit 23.

The inclined extension 33 on the front side of the first printed circuit conductor 26 of the one twisted circuit 22 is connected to the connection circuit conductor 25.
Is connected to the rear inclined extension 33 ₂ on the front side of the second printed circuit conductor 26 ₂ via the connection circuit conductor 25. It is connected to the front angled extension 33 ₃ of the third printed circuit conductors 26 ₃ of the rear Te. The middle inclined portion 29 of the first printed circuit conductor 26 is covered with the insulating layer 24 and is insulated from the outside.

The inclined extension 34 on the front side of the first printed circuit conductor 27 of the other twisted circuit 23 is connected to the connection circuit conductor 25.
Through following the inclined extension 34 ₂ of the second rear side of the printed circuit conductors 27 ₂ front, the first of the one torsion circuit 22 on the lower side through the insulating layer 24 of the connecting circuit conductor 25 The inclined portions 29 of the printed circuit conductor 26 are located crossing each other.

The middle inclined portion 31 of the first printed circuit conductor 27 of the other twisted circuit 23 is covered and insulated by the insulating layer 24 on the upper side, and the one twisted circuit 2 is placed on the insulating layer 24.
Connection circuit conductor 25 connecting 2 of the first and the third printed circuit conductors 26, 26 ₃ are positioned, an insulating layer beneath the front side of the connection circuit conductor 25 of the first printed circuit conductor 26 of one of the torsion circuit 22 Through 24 is located an intermediate ramp 31 ₂ of the second printed circuit conductor 27 ₂ of the other twisted circuit 23.

The length of the torsional circuits 22, 23, ie, the number of twists, is determined by the required length of the circuit, but for noise reduction at least two torsional numbers, ie, the first print of one of the torsional circuits 22, The circuit conductor 26 and the inclined portion 31 of the first printed circuit conductor 27 of the other twisted circuit 23
And the front straight portion 30 and the second printed circuit conductor 27
And three connection circuit conductor 25 that connects straight portions 30 ₂ of the rear side ₂ and the inclined portion 34 _2, and their respective connection circuit conductors 2
5 is required.

The above three steps (printed circuit conductor 2
The noise prevention circuit 21 is formed simply, reliably, and inexpensively by the printing processes 6 and 27, the insulating process of the inclined portions 29 and 31, and the printing process of the connection circuit conductor 25). Since the noise prevention circuit 21 can be formed only on one surface (one surface) of the insulating substrate 32, the other surface of the insulating substrate 32 is effectively used, for example, as a space for electronic components and other circuits (not shown). As a result, the degree of freedom in the arrangement position of electronic components and circuits is improved.

[0044] Further, since no reference to chip jumper 7 projecting outwardly like the first embodiment (FIG. 1), the overall noise preventing circuit board P ₂ is thinned. In particular, the insulating substrate 32
Even if the flexibility of the flexible flat substrate was used as, without fear of falling or the like of the chip jumpers 7, a noise preventing circuit board P ₂ can be easily bent, noise prevention along the curved shape of the counterpart attachment side it can be assembled to the circuit board P _2. Further, since the chip jumper 7 (FIG. 1) is not used, component costs are reduced and manufacturing costs are reduced.

It is also possible to connect the straight portions 28, 30 directly with the connection circuit conductor 25 without providing the inclined extension portions 33, 34. It is also possible to apply an insulating coating (not shown) on the noise prevention circuits 1 and 21 in each of the above embodiments. The present invention also provides a noise prevention circuit board P ₁ , P ₂ using the above-described noise prevention circuits 1, 21.
The method of forming the noise prevention circuits 1 and 21 is also effective as a method of manufacturing the noise prevention circuit boards P ₁ and P ₂ .

The noise prevention circuits 1 and 21 of the above embodiments
The results of the noise resistance test were confirmed by using the above, and it was confirmed that the noise resistance was improved as compared with the case where the conventional noise prevention circuit was used.

[0047]

As described above, according to the first or fourth aspect of the present invention, the connecting members are three-dimensionally intersected on the inclined portions of the respective circuit conductors, and are electrically non-contact. Since two independent (electrically non-contacting) twisted circuits of each circuit conductor and the connection member are formed using one side of the insulating substrate instead of both sides, it is troublesome to connect the conventional upper and lower circuit conductors. Since the formation work of the interlayer connection conductor is unnecessary, and each circuit conductor is formed on one surface of the insulating substrate, and the connection member is provided,
The operation of forming the circuit conductors is simplified and the structure is simplified, thereby simplifying the process of forming the noise prevention circuit, reducing the cost of forming the noise prevention circuit, and reducing the other surface of the insulating substrate. It can be effectively used as an arrangement surface for electronic components and other circuits, and the degree of freedom in the arrangement and design of electronic components and other circuits is improved.

According to the second aspect of the present invention, by using an existing chip jumper, which is insulated at the periphery and conductive at the inside and has electrodes at both ends, as a connecting member, the inclined portion of the circuit conductor can be reduced. This eliminates the need for the insulating step, and simplifies the operation of forming the noise prevention circuit.

According to the third aspect of the present invention, the connection of the connection member and the chip jumper is facilitated and ensured by the wide land portion, and the reliability of the electrical connection is enhanced.

According to the fifth or seventh aspect of the present invention, the connection circuit conductors intersect three-dimensionally via the insulating layer on the inclined portions of the respective circuit conductors so as to be electrically non-contact. And
Two independent (electrically non-contacting) twisted circuits consisting of each circuit conductor and connection circuit conductor are formed using one side of the insulating substrate instead of both sides, so the conventional upper and lower circuit conductors are connected The troublesome work of forming interlayer connection conductors becomes unnecessary, and since each circuit conductor is formed on one side of the insulating substrate and the connection circuit conductors are formed, the circuit conductor formation work is simplified and the structure is simplified. As a result, the process of forming the noise prevention circuit is simplified, the cost of forming the noise prevention circuit is reduced, and the other surface of the insulating substrate can be effectively used as a mounting surface for electronic components and other circuits. The degree of freedom in arranging electronic components and other circuits and the degree of freedom in design are improved. Further, by connecting each circuit conductor with a connection circuit conductor having the same thickness as the circuit conductor, the noise prevention circuit is reduced in thickness.

According to the invention of claim 6 or claim 8, the inclined extension portion functions as a connection portion for the connection circuit conductor, and the positioning and connection work of the connection circuit conductor is facilitated. Further, the length of the connection circuit conductor can be shortened by the length of the inclined extension portion, and the formation of the connection circuit conductor is facilitated and the cost is reduced.

Further, according to the invention of claim 8, by exposing the inclined portion from the insulating layer with the same length as the inclined extension portion, the exposed length of each circuit conductor becomes the same, and the distance from the surroundings is reduced. The noise is guided to the two twisted circuits in a well-balanced manner, and the noise is accurately canceled.

According to the ninth aspect of the present invention, the noise prevention circuit board including the noise prevention circuit can be easily bent in accordance with the curved shape of the mating mounting portion. In particular, according to the noise prevention circuit board including the noise prevention circuit according to any one of claims 5 to 6, thinning can be further promoted, and it can be easily mounted in a narrow space.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of a noise prevention circuit according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1, showing a noise prevention circuit board including the noise prevention circuit.

FIGS. 3A to 3C are plan views showing a second embodiment of a noise prevention circuit and a method for forming the noise prevention circuit according to the present invention in the order of steps.

4 (a) is a sectional view taken along the line BB of FIG. 3 (a), and FIG. 4 (b)
3C is a sectional view taken along line CC of FIG. 3B, and FIG. 4C is a sectional view taken along line D-C of FIG.
It is D sectional drawing.

FIG. 5 is a plan view showing a conventional noise prevention circuit.

FIG. 6 is a sectional view taken along the line EE of FIG. 5;

[Explanation of symbols]

 1,21 Noise prevention circuit 2,32 Insulating substrate 5,6,26,27 Printed circuit conductive (circuit conductor) 7 Chip jumper (connecting member) 8,10,28,30 Straight portion 9,11,29,31 Inclined portion 14, 15 Land 24 Insulating layer 25 Connection circuit conductor 33, 34 Inclined extension

Claims (9)

[Claims] 1. A plurality of circuit conductors each having a straight front part and a middle inclined part are formed in parallel on one surface of an insulating substrate, and the ends of the straight parts are formed on both sides of each inclined part. Position to,
A noise prevention circuit, wherein the end portions of the straight portions are connected to each other by a connection member. 2. The noise prevention circuit according to claim 1, wherein said connection member is a chip jumper. 3. The noise prevention circuit according to claim 1, wherein a wide land portion for the connection member is formed on an end side of each straight portion. 4. On one surface of an insulating substrate, a plurality of circuit conductors in which a front and rear straight portion and an intermediate inclined portion are continuous are printed in parallel, and ends of each straight portion are formed on both sides of each inclined portion. A method for forming a noise prevention circuit, characterized in that the end portions of the straight portions are connected to each other by a connecting member. 5. On one surface of an insulating substrate, a plurality of circuit conductors in which a front and rear straight portion and an intermediate inclined portion are continuous are formed in parallel, and the end portions of each straight portion are formed on both sides of each inclined portion. Position to,
A noise prevention circuit, wherein each inclined portion is insulated by an insulating layer, and ends of the straight portions are connected to each other by a connection circuit conductor on the insulating layer. 6. The noise prevention circuit according to claim 5, wherein an inclined extension is formed on an end side of each of the straight portions, and the inclined extensions are connected by the connection circuit conductor. . 7. On one surface of an insulating substrate, a plurality of circuit conductors in which a front and rear straight portion and an intermediate inclined portion are continuous are printed and formed in parallel, and ends of the straight portions are formed on both sides of each inclined portion. Side, covering each inclined portion with an insulating layer, printing and forming a connection circuit conductor on the insulating layer, and connecting the end portions of the straight portions to each other with the connection circuit conductor. Of forming a noise prevention circuit. 8. An inclined extension portion is integrally formed on one end of each straight portion by printing, and each of the inclined portions is exposed from the insulating layer with the same length as the inclined extension portion. 8. The method for forming a noise prevention circuit according to claim 7, wherein the extension portions are connected by the connection circuit conductor. 9. The noise prevention circuit according to claim 1, wherein a flexible flat substrate is used as said insulating substrate.