JP4676864B2 - Circuit structure using flexible wiring board - Google Patents

Description

  The present invention relates to a circuit structure that uses a plurality of flexible wiring boards (FPCs) to reduce electromagnetic interference.

  Generally, electromagnetic induction noise (noise) is generated because a magnetic field is generated when a current flows through a wire, and a voltage is induced in other nearby wires. The closer the distance between the wire that is the source of the magnetic field and the wire where the voltage is induced, the longer the parallel distance is, the larger the current is and the more the change is, the more the voltage is induced. . In order to prevent this, if the distance between the electric wire that is the source of the magnetic field and the electric wire that induces the voltage is set far away, it will be less affected by the magnetic field. Since it is difficult to realize when wires are bundled, twisted pair wires are used as a noise countermeasure. Twisted pair wires have a structure in which a pair of wires are twisted so that the directions of currents induced in the wires by an external magnetic field can be offset in opposite directions across the crossing portion. The radiation field can be canceled by using the pair of electric wires so that the flowing directions are opposite to each other, and a noise reduction effect can be obtained.

  Recently, a flexible wiring board (FPC) is used instead of a wire harness in which electric wires are bundled to reduce the thickness and weight. In particular, in automobiles, there is a very high need for weight reduction by FPC in order to improve fuel efficiency as part of environmental measures. In addition, taking advantage of the fact that electronic components can be mounted on FPCs, electronic units that were previously delivered separately from wire harnesses are delivered to FPCs (functional components integrated into FPCs). The need for modularization is increasing. Application of FPC to a module has many merits. However, a wire harness that bundles wires may use twisted pair wires for wiring such as speakers and sensors to prevent noise. It is difficult to produce a twisted pair with a twisting machine like an electric wire, and there is a disadvantage that it causes an increase in cost. For example, when FPC is applied to a door module, the speaker wiring is often a twisted pair wire, and it has been difficult to replace all the electric wires in the door with FPC. As a result, there is a problem that a cost reduction effect cannot be obtained due to a mixture of electric wires and FPCs in one module.

  As an example in which the concept of twisted pair wire in an electric wire is applied to FPC, as shown in FIG. 17, the shape of the signal wiring FPC 100 and the shape of the reference potential wiring FPC 101 are mirror-symmetrical, and each wiring portion 100A. , 101A is formed in a zigzag shape, and correspondingly, the shape of the FPCs 100, 101 is also formed in a zigzag shape by repeating triangular peaks and triangular valleys, and a twisted pair structure is realized by twisting the FPCs 100, 101 together. (See Patent Document 1).

  As a pseudo twisted pair structure by another FPC, as shown in FIG. 18, a plurality of wiring patterns (in the drawing, surface wiring in the drawing) are formed on the surface side of the FPC 102 having a double-sided structure. ) 102A and a plurality of wiring patterns 102B (upper surface wiring in the drawing) 102B crossing the front surface wiring pattern 102A and rising to the right are formed on the back surface side. And 102B are connected to each other by a via hole 104 to realize a pseudo twisted pair structure (see Patent Document 1).

As another pseudo twisted pair structure by FPC, as shown in FIG. 19, circuits (flat conductors) 107 and 108 printed on the base films 105 and 106 meander in a wave shape, and one flat conductor 107 and the other The flat conductor 108 is formed by forming a region surrounded by one flat conductor 107 and the other flat conductor 108 between two intersecting points when viewed from a direction orthogonal to the surface direction of the base films 105 and 106. It is known (see Patent Document 2). According to such a pseudo twisted pair structure by FPC, when a magnetic flux in a direction crossing the surface direction of the base films 105 and 106 is generated, in one flat conductor 107, from the intersection with the other flat conductor 108, the next Inductive voltages in opposite directions are generated in one area reaching the intersection and in the next section adjacent to this area, and they cancel each other out. In addition, when reverse currents flow through the two flat conductors 107 and 108, reverse magnetic fluxes are generated in two adjacent regions in the direction intersecting with the surfaces of the flat conductors 107 and 108, respectively. By canceling each other, the radiation magnetic field formed in the direction intersecting with the surfaces of the flat conductors 107 and 108 formed outside by the current is suppressed.
JP 2001-60746 A (3rd and 4th pages, FIGS. 1 and 2) Japanese Patent No. 3047572 (second page, FIG. 1)

  The conventional twisted example shown in FIG. 17 (FIG. 2 of Patent Document 1) has noise resistance equivalent to that of a twisted-pair electric wire, but in terms of the manufacturing process, two long electric wires such as a twisted-pair electric wire are prepared. Since the twisted machine cannot be used after being cut to the required length, the cost of close-up processing has increased significantly. In addition, the structure of two FPCs twisted together is one of the major advantages of FPC, and it is impossible to batch manufacture multiple wires to one FPC, which can be manufactured individually and combined with other FPCs. There is a disadvantage that it must be assembled, and this also causes a large cost increase, and at the same time, it is combined with another FPC, so that the thickness of the FPC becomes thick and the flexibility is impaired. . Further, in the conventional example shown in FIG. 18 (FIG. 1 of Patent Document 1), in addition to the cost increase due to the use of the multilayer FPC, the processing cost is greatly increased by connecting the wiring on the front and back surfaces via via holes. It was up to. Further, since the connection is made through the via hole, there is a problem that the bending resistance which is a characteristic of the FPC is impaired. For example, if the via hole connection part is bent excessively, the via hole connection part cracks, and in the worst case, there is a problem that it becomes a disconnection state, and it is difficult to apply to a movable bending part such as an automobile door. there were. Further, in the conventional example shown in FIG. 19 (FIG. 1 of Patent Document 2), since only two FPCs are stacked, manufacturing is simple, but against a magnetic field applied in a direction perpendicular to the plane of the FPC. Has noise resistance due to the principle of twisted pair wires (intersection of wiring), but there is no crossing of wiring in this direction against a magnetic field applied in a direction perpendicular to this direction (direction parallel to the surface). However, since the principle of twisted-pair wire does not hold because it becomes a mere parallel wiring, the strongest directivity in the effect of reducing electromagnetic induction noise compared to twisted-pair wire is the biggest drawback. It was difficult to apply to the use that was routed so as to surround the whole.

  Therefore, the present invention provides an FPC that has noise resistance equivalent to that of a twisted-pair electric wire, can be easily manufactured without twisting, and realizes the high flexibility characteristic of the FPC, while simultaneously reducing the cost. An object is to provide a circuit structure used.

In order to achieve the above object, the present invention provides a circuit structure using a pair of flexible wiring boards (FPCs) in which a corrugated wiring pattern in which peaks and valleys are repeated on one side of a base film. At least two or more wiring patterns are formed in each of the first FPC and the second FPC , and an opening is provided so as to surround the valley or peak near at least every other valley or peak of the wiring pattern of the first FPC. And at least every other crest or trough of the wiring pattern of the second FPC and close to the crest or trough corresponding to the trough or crest of the first FPC. Forming an opening to surround
Ridges or valleys when viewed from a direction orthogonal to the insertion to the plane direction in the valleys or crests near the opening of the wiring pattern of the first 1FPC respective wiring of the wiring pattern of openings forming positions of the first 2FPC A portion that is surrounded by one wiring pattern and the other wiring pattern between two points where the patterns intersect each other, and where one wiring pattern and the other wiring pattern intersect when viewed from a direction parallel to the plane direction It is comprised without twisting so that it may have.

In addition to the above configuration , the present invention may be configured such that the opening has a slit shape surrounding a peak or trough of a corrugated wiring pattern. Moreover, you may form the conducting wire different from a corrugated wiring pattern in the single side | surface of the said base film. Furthermore, the number of the wiring patterns intersecting with each other when viewed from the direction orthogonal to the surface direction and intersecting with each other when viewed from the direction parallel to the surface direction may be plural to plural instead of one to one. Further, at least one end of each of the first FPC and the second FPC is formed in a corrugated shape that matches the wiring pattern, and an opening is not formed in the corrugated wiring pattern near the end, You may insert the peak part and trough part of a wiring pattern in the other party's opening part.

According to the present invention, in a circuit structure using a pair of flexible wiring boards (FPC) in which a corrugated wiring pattern in which peaks and valleys repeat on one side of a base film, the pair of first FPC and second FPC Forming at least two or more of the wiring patterns, and forming an opening so as to surround the valley or peak near at least every other valley or peak of the wiring pattern of the first FPC, At least every other crest or trough of the wiring pattern of the second FPC, and an opening is formed so as to surround the crest or trough near the crest or trough corresponding to the trough or crest of the first FPC. part was formed, the surface side by inserting the crest or trough portion of the wiring pattern of openings forming positions of the first 2FPC the valleys or crests near the opening of the wiring pattern of the first 1FPC A region surrounded by one wiring pattern and the other wiring pattern is formed between two points where the wiring patterns of each waveform shape intersect with each other when viewed from the direction orthogonal to each other, and the surface direction of the first FPC and the second FPC Both directions applied in the direction perpendicular to the surface of the base film and the direction parallel to the surface because it is configured without twisting so that it has a portion where one wiring pattern and the other wiring pattern intersect when viewed from the parallel direction Since the noise reduction effect can be obtained with respect to the magnetic field, the twist-pair electric wire and the noise resistance performance equivalent to that of the conventional example of FIGS. 17 and 18, the noise resistance performance higher than that of the conventional example of FIG. It can be configured without twisting while using FPC. For example, it is only necessary to fit the ends of a pair of FPCs, and it can be easily manufactured. The number of processing steps is much less, thereby reducing the cost as compared with. Further, the bending resistance is not impaired while taking advantage of the thinness that is characteristic of FPC. As described above, since it is possible to simultaneously ensure the noise resistance performance and the high flexibility, it can be applied to a use or a movable bending portion that is arranged so as to surround the entire vehicle like an automobile. Furthermore, since it is configured without twisting, it can be manufactured more easily than twisted ones, and at the same time, the cost can be reduced.

In addition, a plurality of twisted pair-like ones can be easily manufactured. That is, since the intersecting portion is not limited to each end portion of the pair of FPCs, a plurality of twisted pair structure-like wiring patterns can be collectively manufactured with only a pair of FPCs, and two or more FPCs having two sheets are stacked. This eliminates the need to combine them, so that it is possible to further reduce the thickness and ensure high flexibility, and at the same time, greatly reduce the cost.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

  In the first embodiment shown in FIG. 1, the first FPC 1 and the second FPC 2 are each formed with one corrugated wiring pattern 11, 21 on one side of each base film 10, 20, and both end portions thereof. (Upper and lower end portions in the drawing) are also formed in a corrugated shape corresponding to these wiring patterns 11 and 21. Here, the waveform shapes of the wiring patterns 11 and 21 are formed such that trapezoidal peaks 11A and 21A and valleys 11B and 21B repeat. The crest portion 11A of the wiring pattern 11 of the first FPC 1 and the trough portion 21B of the wiring pattern 21 of the second FPC 2 face each other, and the end portions of the corrugated shapes of the first FPC 1 and the second FPC 2 that face each other are fitted to each other. Let As a result, a region surrounded by one wiring pattern 11 and the other wiring pattern 21 is formed between two points where the wiring patterns 11 and 21 intersect each other when viewed from the direction orthogonal to the plane direction of the first FPC 1 and the second FPC 2. To do. At the same time, one wiring pattern 11 and the other wiring pattern 21 intersect with each other when viewed from a direction parallel to the surface direction of the first FPC 1 and the second FPC 2. As shown in the plan view of FIG. 2 and the arrow A direction, the first FPC 1 and the first FPC 1 are arranged so that the wiring patterns 11 and 21 intersect when viewed from the direction orthogonal to the surface direction and from the direction parallel to the surface direction. The two waveform-shaped ends of the 2FPC 2 are fitted together. In the plan view of FIG. 2, the upper and lower sides of the wiring patterns 11 and 21 are exchanged at each intersection, and the upper and lower sides of the wiring patterns 11 and 21 are also shown at each intersection in the arrow A view (side view) in FIG. Are configured to be interchanged. When attention is paid only to the wiring pattern 11 of the first FPC 1 in the plan view of FIG. 2, this pattern is a repetition of the back, back, front, and front at every two intersecting portions, but the back, back, back, back, It may be a configuration in which the front and the back are switched every four places of the table, the table, the table, and the table, or more. For example, when used in a part that requires the highest noise resistance performance in the vehicle (engine room, etc.), wiring with a waveform shape that satisfies the noise resistance performance by switching the front and back every two places Designed to patterns 11 and 21 (adjusting the pitch between peaks and troughs) and used in areas where the required level of noise resistance is relatively low, the front and back every 4 locations or more It is possible to provide a product with the best cost performance by using a configuration in which is replaced. Thus, the fitting method can be freely changed according to the required degree of noise resistance performance. Note that the opposite end portions of the first FPC 1 and the second FPC 2 that are not fitted to each other need not be formed in a corrugated shape. Further, the shape of the peaks and valleys may be a triangular mountain and a triangular valley similar to the conventional example, or a shape meandering in a wave shape.

  In the embodiment shown in FIGS. 1 and 2 and the embodiment to be described later, a conductor layer, an adhesive layer, and a coverlay to be the wiring patterns 11 and 21 are formed on the base films 10 and 20 as in an ordinary FPC. It is a laminated one.

  In the first embodiment shown in FIGS. 1 and 2, the first FPC 1 and the second FPC 2 can be twisted together to form a twisted pair structure as in the conventional FIG. 17, or simply overlapped as in FIG. However, it has a noise resistance equivalent to that of the twisted one shown in FIG. 17, can be easily manufactured, and has a high degree of flexibility. In order to be applied to applications and movable bends, the wiring pattern 11, rather than a configuration that is simply twisted together (difficult to work, difficult to ensure bending resistance), or a configuration that only overlaps (inferior noise resistance) A configuration (twisted pair structure-like circuit) that fits 21 so as to intersect even when viewed from a direction orthogonal to the surface direction or from a direction parallel to the surface direction is excellent.

  3 and 4 show the second embodiment, and are opposite to the ends of the first FPC 1 and the second FPC 2 that are fitted to each other (the lower end in the first FPC 1 and the upper end in the second FPC 2 in FIG. 3). The end portions (the upper end portion in the first FPC 1 in FIG. 3 and the lower end portion in the second FPC 2 in FIG. 3) are not formed into a corrugated shape, but are straightened, and the opposite end portions are extended to extend the base films 10 and 20. The first FPC1 and the second FPC2 are increased in mechanical strength to improve the tearing strength and to improve the handleability during processing by suppressing torsion. Also in the second embodiment, each of the first FPC 1 and the second FPC 2 has a waveform shape so that the wiring patterns 11 and 21 intersect both when viewed from the direction orthogonal to the plane direction and when viewed from the direction parallel to the plane direction. Fit the ends together.

  The third embodiment shown in FIGS. 5 and 6 includes three linear conductors 12 and 22 in addition to the corrugated wiring patterns 11 and 21 in which the peaks 11A and 21A and the valleys 11B and 21B repeat. The formed first FPC1 and second FPC2 are shown. Here, the conducting wires 12 and 22 are circuits that are not similar to a so-called twisted pair structure that intersects two circuits (wiring patterns), and are not necessarily linear circuits. The same applies to conductive wires in other embodiments described later. In this example as well, as in the second embodiment, the width of the base films 10 and 20 is increased, and the other conductors 12 and 22 are collectively manufactured at the time of manufacturing the FPC in the increased portions. . In addition, the respective end portions that face each other are formed in a corrugated shape that matches the wiring patterns 11 and 21. In this example, the conductors 12 and 22 can be arranged in an arbitrary number other than where the wiring patterns 11 and 21 similar to one twisted pair structure are formed, and a large number of wirings (circuits) are collectively manufactured on two FPCs. In addition, since it is not necessary to combine two or more FPCs in a stack, it is possible to further reduce the thickness and ensure high flexibility, and at the same time, greatly reduce the cost. A combination of a twisted pair structure-like circuit and a conductive line circuit is also possible in the following embodiments, and any combination is possible as necessary.

  The fourth embodiment shown in FIGS. 7 and 8 shows an example in which two sets of wiring patterns 11 and 21 each having the waveform shape shown in the first embodiment are formed. The wiring pattern 11 is a set of two wiring patterns 11x and 11y, and the wiring pattern 21 is also a set of two wiring patterns 21x and 21y. In this example, the wiring patterns 11 and 21 formed on each of the FPCs 1 and 2 are set as two sets, but may be set as three sets or more. In the first embodiment, the wiring patterns 11 and 21 (one pair) intersect each other and the combination to be fitted is set to one-to-one. There can be more than one. In the case of an electric wire, a twisted pair wire (a total of four wires) twisted together with a set of two wires is similar in thickness to the one-to-one combination with only two FPCs ( (Ensuring high flexibility) and the same processing time (cost reduction), it can be easily manufactured just by fitting without twisting. The wiring pattern 11 in the third embodiment shown in FIG. 5 is formed in the wiring patterns 11x and 11y as in this example, and the wiring pattern 21 in the third embodiment is formed in the wiring patterns 21x and 21y in this example. You can also

  The fifth embodiment shown in FIGS. 9 and 10 is a pair of flexible wirings in which corrugated wiring patterns 11 and 11 ′, 21 and 21 ′ are formed on one surface of the base films 10 and 20 so that the peaks and valleys repeat. In a circuit structure using a substrate (FPC), at least two or more of the wiring patterns 11 and 11 ′, 21 and 21 ′ are formed on the pair of first FPC 1 and second FPC 2, respectively, and the wiring patterns 11 and 11 of the first FPC 1 are formed. ′, The opening 5 is formed at a predetermined location in the vicinity, and the opening 5 is also formed at a predetermined location in the vicinity of the wiring patterns 21, 21 ′ of the second FPC 2. 21 ′ peak portions or trough portions are inserted into the openings 5 near the valley portions or peak portions of the wiring patterns 11 and 11 ′ of the first FPC 1 so that each arrangement is seen from the direction perpendicular to the plane direction. A region surrounded by one wiring pattern 11, 11 ′ and the other wiring pattern 21, 21 ′ is formed between two points where the line patterns 11, 21, 11 ′ and 21 ′ intersect each other, and parallel to the surface direction. When viewed from the right direction, one wiring pattern 11, 11 ′ and the other wiring pattern 21, 21 ′ are configured without twisting so as to have a crossing portion. More specifically, two (or more) wiring patterns 11, 11 ′, 21, 21 ′ are formed on the two rectangular base films 10 and 20, and the wiring of the first FPC 1 is formed. Of the valleys 11B and 11'B of the patterns 11 and 11 ', an opening 5 is formed so as to surround the valleys near at least every other valley 11B and 11'B. Further, at least every other crest portion 21A, 21'A of the wiring patterns 21, 21 'of the second FPC 2, and crest portions 21A, 21 corresponding to the trough portions 11B, 11'B in which the opening 5 is formed. An opening 5 is formed in the vicinity of 'A so as to surround the peaks 21A, 21'A. Then, the peak portions 21A and 21'A of the opening portion 5 formation portion of the second FPC 2 are inserted into the opening portions 5 near the valley portions 11B and 11'B of the first FPC 1 so as to protrude from the back side of the first FPC 1 to the front side, Fit the ridges 11A, 11'A and 21A, 21'A and the valleys 11B, 11'B, 21B, 21'B of the wiring patterns 11, 11 'and 21, 21' of the first FPC1 and the second FPC2 The wiring patterns 11 and 21 and 11 ′ and 21 ′ are configured to intersect both when viewed from the direction orthogonal to the surface direction and when viewed from the direction parallel to the surface direction. In FIG. 10, the first FPC 1 is located on the front side and the second FPC 2 is located on the back side. It can also be inserted from the front side to the back side. In the example shown in the figure, the formation of the opening 5 is present in each valley or mountain of the corrugated wiring patterns 11, 11 ′, 21, 21 ′, is present, is present, is present, is not present, Yes, yes, no, no ... or yes, yes, yes, no, no, no ..., and more repeated patterns. Moreover, although the case where at least every other opening 5 is formed (including yes, yes, no, no ... including the above repeated patterns) has been described, for example, it continues to the valley or peak of each wiring pattern Then, the opening 5 may be formed repeatedly, and the other mountain or valley may be inserted only into the necessary opening 5. Further, the opening 5 may be formed not at the valley of the first FPC 1 but at the peak, and at the valley of the second FPC 2 instead of the peak. In this case, the peak portion of the first FPC 1 is inserted into the opening 5 in the valley portion of the second FPC 2. In this example, a plurality of twisted pair structure-like circuits can be easily manufactured, not just a single twisted pair structure-like circuit. That is, since the intersecting and overlapping portions are not limited to the end portions of the two FPCs, a plurality of twisted pair structure-like wiring patterns can be collectively manufactured with only two FPCs. Since it is no longer necessary to combine the sheets, it is possible to further reduce the thickness and ensure high flexibility, and at the same time, greatly reduce the cost.

  Although the said opening part 5 and the opening part 5 in the following embodiment were formed in slit shape, if it functions as an insertion port into which the other party's specific site | part is inserted, it will not be limited to slit shape.

  In the sixth embodiment shown in FIGS. 11 and 12, two conductive wires 12 are formed between the wiring patterns 11 and 11 ′ of the fifth embodiment shown in FIGS. 9 and 10, and between the wiring patterns 21 and 21 ′. The thing which formed the two conducting wires 22 is shown. The locations where the conductive wires 12 and 22 are formed are not limited to the locations and the number shown. In this example, a circuit similar to a plurality of twisted pair structures and a circuit composed of a plurality of conductors 12 and 22 can be arranged at an arbitrary position and in an arbitrary number with only two FPCs. In addition to further reducing the thickness and ensuring high flexibility, the cost can be greatly reduced, and the degree of freedom in circuit layout design is greatly improved.

  In the seventh embodiment shown in FIG. 13 and FIG. 14, each of the waveform-shaped wiring patterns 11, 11 ′ and 21, 21 ′ intersects one-to-one (11 and 21) (11 ′ and 21 ′). Instead, they are crossed in a relationship of 2 to 2 (11x, 11y and 21x, 21y) (11'x, 11'y and 21'x, 21'y). As mentioned above, in the case of the electric wire, it is similar to the twisted pair wire (four in total) twisted by a set of two wires, but this is only two FPCs, With the same thinness (ensure high flexibility) and the same processing time (cost reduction) as in the case of a one-to-one combination, it can be easily manufactured simply by fitting together without twisting. Note that the number of wirings that intersect each other may be two-to-two or more than two-to-two. The conductive wires 12 and 22 may be formed between the wiring patterns 11 and 11 'and between the wiring patterns 21 and 21', respectively. For example, when the conductive wires 12 and 22 shown in FIG. 11 are formed, the wiring patterns 11 and 11 ′ in the sixth embodiment are formed into the wiring patterns 11x, 11y, 11′x, and 11′y as in this example. The wiring patterns 21 and 21 ′ of the sixth embodiment may be formed into the wiring patterns 21x, 21y, 21′x, and 21′y.

  In the eighth embodiment shown in FIGS. 15 and 16, two corrugated wiring patterns 11, 11 ′ are formed on the first FPC 1, and two corrugated wiring patterns 21, 21 ′ are also formed on the second FPC 2. Show things. Also, one end of each of the first FPC 1 and the second FPC 2 (the lower end in the first FPC 1 in the drawing and the upper end in the second FPC 2) is formed in a corrugated shape that matches the wiring patterns 11 and 21, and is opposite The side end (upper end in the first FPC1 in the drawing and lower end in the second FPC2) is formed in a straight line. The opposite end may also have a corrugated shape. An opening 5 is formed so as to surround this trough portion 11'B in the vicinity of at least every other trough portion 11'B of the wiring pattern 11 ', and a crest portion 21'A of the wiring pattern 21' of the second FPC 2 (at least Openings 5 are formed so as to surround the ridges 21′A near the ridges 21′A corresponding to the valleys 11′B of the first FPC 1. The opening 5 is not formed in the wiring patterns 11 and 21 on the side close to the corrugated shape formed at one end of each of the first FPC 1 and the second FPC 2. In the illustrated example, the peak portion 21A of the second FPC 2 is inserted into the opening portion 5 near the valley portion 11′B of the first FPC 1 so as to protrude from the back side of the first FPC 1 to the front side, and the valley portion 11B of the first FPC 1 is inserted into the second FPC 2 The second FPC 2 was inserted into the opening 5 near the peak portion 21'A so as to protrude from the front side to the back side. Contrary to the example shown in the figure, when the second FPC 2 is on the front side and the first FPC 1 is on the back side, the valley portion 11B of the first FPC 1 is placed in the opening 5 near the peak portion 21'A of the second FPC 2, and from the back side of the second FPC 2. While inserting so that it may come out to the front side, it inserts in the opening 5 near trough part 11'B of 1st FPC1 so that it may come out from the front side of 1st FPC1 to the back side. In this example, by forming the end portion into a corrugated shape that matches the wiring pattern, the workability of insertion into the opening 5 is improved compared to the case where both ends are linear. In the eighth embodiment, the same conductors 12 and 22 can be formed between a plurality of wiring patterns formed on one FPC.

  In the above-described eighth embodiment, three or more waveform patterns can be formed on two FPCs. That is, a third or more wiring pattern (not shown) is formed on the first FPC 1 in addition to the wiring patterns 11 and 11 ′, and a third or more wiring pattern (not shown) is formed on the second FPC 2 in addition to the wiring patterns 21 and 21 ′. (Not shown). In this case, wiring patterns (indicated by reference numerals 11 and 21 in FIG. 15) formed near the end portions formed in the waveform shape of the FPC (the lower end portion of the first FPC 1 and the upper end portion of the second FPC in FIG. 15). Wiring patterns other than (wiring pattern) form an opening 5 as shown in FIGS. 9 and 10, and an opening 5 formed in one FPC of two FPCs has a peak formed in the other FPC. A part may be inserted. In this example, in addition to the smoothness of the work of inserting the opening at the end of the corrugated shape, there is also the above-mentioned merit of collectively manufacturing a large number of wirings (circuits similar to a plurality of twisted pair structures). Even in the case where three or more wiring patterns are formed in this way, the same conductors 12 and 22 can be formed between the respective wiring patterns.

  Next, the result of comparing the prior art with the present invention shown in FIGS. 1 and 2 is shown. Conventional Example 1 is shown in FIG. 17 (FIG. 2 of Patent Document 1), twisted together, Conventional Example 2 is shown in FIG. 18 (FIG. 1 of Patent Document 1), Conventional Example 3 Is a superposition only shown in FIG. 19 (FIG. 1 of Patent Document 3). The results are as shown in Table 1 below. In Table 1, “◎” means that it is greatly superior, “◯” means that it is excellent, “Δ” means that it is inferior, and “×” means that it is very inferior.

The top view before the assembly | attachment of 1st Embodiment. The top view of the state which fitted FIG. 1, and A direction arrow line view (side view). The top view before the assembly | attachment of 2nd Embodiment. The top view of the state which fitted FIG. The top view before the assembly | attachment of 3rd Embodiment. The top view of the state which fitted FIG. The top view before the assembly | attachment of 4th Embodiment. The top view of the state which fitted FIG. The top view before the assembly | attachment of 5th Embodiment. The top view of the state which fitted FIG. The top view before the assembly | attachment of 6th Embodiment. The top view of the state which fitted FIG. The top view before the assembly | attachment of 7th Embodiment. The top view of the state which fitted FIG. The top view before the assembly | attachment of 8th Embodiment. The top view of the state which fitted FIG. The top view which shows a prior art example. The top view which shows another prior art example. The perspective view which shows another prior art example.

Explanation of symbols

1 First FPC
2 Second FPC
10, 20 Base film 11, 21 Wiring pattern 11A, 21A Mountain part 11B, 21B Valley part

Claims (5)

In a circuit structure using a pair of flexible wiring boards (FPCs) in which a corrugated wiring pattern in which peaks and valleys repeat on one side of a base film is formed,
Forming at least two wiring patterns on each of the pair of first FPC and second FPC ;
An opening is formed so as to surround the valley or peak near at least every other valley or peak of the wiring pattern of the first FPC, and at least every other peak of the wiring pattern of the second FPC. Forming an opening so as to surround the peak or valley near the peak or valley corresponding to the valley or peak of the first FPC,
Ridges or valleys when viewed from a direction orthogonal to the insertion to the plane direction in the valleys or crests near the opening of the wiring pattern of the first 1FPC respective wiring of the wiring pattern of openings forming positions of the first 2FPC A portion that is surrounded by one wiring pattern and the other wiring pattern between two points where the patterns intersect each other, and where one wiring pattern and the other wiring pattern intersect when viewed from a direction parallel to the plane direction A circuit structure using a flexible wiring board, characterized in that it is configured without twisting so as to have. The opening, the circuit structure using a flexible wiring board according to claim 1, characterized in that the slit surrounding the crests or troughs of the wiring pattern of the wave shape. The circuit structure using the flexible wiring board according to claim 1, wherein a conductive wire separate from the corrugated wiring pattern is formed on one side of the base film . 4. The number of the wiring patterns intersecting each other when viewed from a direction perpendicular to the surface direction and intersecting when viewed from a direction parallel to the surface direction is not one-to-one but a plurality of pairs. A circuit structure using the flexible wiring board according to any one of the above. At least one end portion of each of the first FPC and the second FPC is formed in a corrugated shape matching the wiring pattern, and the opening portion is not formed in the corrugated wiring pattern near the end portion. 5. The circuit structure using the flexible wiring board according to claim 1 , wherein the peak portion and the valley portion are inserted into the opening of the other party .

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