Multi-core cable, method for manufacturing same, and electronic device using the multi-core cable

Abstract

The multi-core cable includes a cable main body portion and a cable terminal processing portion, the cable terminal processing portion includes terminal portions of at least three of the plurality of ultra-thin cables, the terminal portions of the ultra-thin cables are exposed out of the terminal portion of the conductor, and a support plate having a first side and a second side opposite to the first side. A plurality of grooves extending in a direction from the first side to the second side are formed in at least an upper surface of the support plate, a terminal portion of the conductor includes a first region that is a region overlapping the support plate and a second region that is a region not overlapping the support plate, and in the first region, the second region is a region not overlapping the support plate. At least a part of the terminal portion of the conductor is located in the groove of the support plate, a part or all of the conductor located in the groove of the support plate has a flat portion substantially parallel to the upper surface of the support plate, and the terminal portion of at least two conductors located in the same cross section among the conductors located in the groove of the support plate has a flat portion substantially parallel to the upper surface of the support plate. The radius r of the conductor in the cable main body portion and the width A of the flat portion of the conductor satisfy the relationship r < A (formula (1)).

Description

Technical Field

[0001] The present invention relates to a multi-core cable including a plurality of ultra-fine insulated cables or ultra-fine coaxial cables, a method for manufacturing the same, and an electronic device using the multi-core cable. Background Art

[0002] In order to cope with the development of high-density wiring of substrates as these devices become smaller and more precise, insulated cables or coaxial cables used in measuring devices, communication devices, medical probe cables, micro-machines, etc., are required to have very fine outer diameters recently. In response to such requirements, for example, coaxial cables are manufactured by manufacturing ultra-fine coaxial cables with an outer diameter of 0.16 mm or 0.10 mm, and ultra-fine multi-core cables such as round cables formed by twisting multiple ultra-fine cables or flat cables formed by arranging multiple ultra-fine cables side by side are used.

[0003] When such a multi-core cable is connected to a cable connection pad of a printed circuit board arranged at a narrow pitch, for example, the connection conductor must be extremely thin, and the work of arranging and connecting the conductors one by one requires precision and accuracy. Therefore, the thinner the cable, the more troublesome the connection work is, and the more skilled the skills are required. In addition, in terms of the quality of the connection, there are technical problems such as poor connection and low quality stability.

[0004] Japanese Patent Laid-Open No. 2002-95129 discloses the following method: when electrically connecting the center conductor of an ultrafine coaxial cable to a connection portion provided on a substrate, a heat radiation transmitting member having an arrangement groove is used to arrange the center conductor, and an electrode portion fixed to the substrate is pressed to provide heat radiation through the heat radiation transmitting member with grooves. Thus, the cables can be connected uniformly. However, when the arranged center conductor and the electrode portion of the substrate are uniformly joined, the connection strength and contact area may sometimes vary.

[0005] In addition, Japanese Patent Laid-Open No. 2003-143728 discloses the following connection method: a coaxial cable is arranged in an arrangement groove of a base and fixed as an integral body, and as the base is polished, a central conductor and an outer conductor are exposed on the same plane, and a conductor circuit pattern member is fixed thereon. Although this connection method can be expected to simplify the manufacturing process, since the terminal portion of the central conductor is polished, there is a possibility of disconnection of the central conductor and adverse effects on electrical characteristics such as resistance value caused by volume loss of the conductor.

[0006] Japanese Patent Laid-Open No. 2010-118318 discloses a technique for electrically connecting the center conductor of a coaxial cable arranged on a flexible insulating sheet to an electrode portion of a printed circuit board. The center conductor arranged on the flexible insulating sheet is electrically connected to the electrode portion by using a conductive adhesive and heating it with a laser or the like. In this technique, the effect of arranging the center conductor is achieved by the adhesive arranged on the flexible insulating sheet. In this method, it is difficult to stabilize the position of the center conductor relative to the electrode portion of the substrate, and the contact between the conductive particles between the center conductor and the electrode is limited, and sometimes the contact area of ​​the connection is deviated. Prior art literature Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2002-95129 Patent Document 2: Japanese Patent Application Publication No. 2003-143728 Patent Document 3: Japanese Patent Application Publication No. 2010-118318 Summary of the invention Technical problem to be solved by the invention

[0008] The present invention is made to solve the above-mentioned problems, and its technical problem is to provide a multi-core cable that can be connected by a simple method and has excellent stability and reliability of electrical connection when ultra-fine cables are arranged at narrow intervals and electrically connected to electrode parts, etc. Technical solutions to technical problems

[0009] In order to solve the above technical problems, the structure described in the claims can be adopted. For example, according to one embodiment of the present invention, a multi-core cable includes a plurality of ultra-fine cables, the ultra-fine cables have conductors and insulators located on the periphery of the conductors, the multi-core cable includes a cable main body and a cable terminal processing part, the cable terminal processing part includes the terminal parts of at least three of the plurality of ultra-fine cables and a support plate, the terminal parts of the ultra-fine cables expose the terminal parts of the conductors, the support plate has a first side and a second side opposite to the first side, and at least the upper surface of the support plate has a plurality of grooves extending from the first side to the second side, the conductors The terminal portion includes a first region which overlaps with the support plate, and a second region which does not overlap with the support plate. In the first region, at least a portion of the terminal portion of the conductor is located in the groove of the support plate, and a portion or all of the conductor located in the groove of the support plate has a flat portion which is substantially parallel to the upper surface of the support plate. For two or more conductors located in the groove of the support plate and which are in the same cross section, the radius r of the conductor in the cable body and the width A of the flat portion of the conductor satisfy the relationship r<A (Formula (1)).

[0010] By adopting the above structure, in particular, by using a support plate having grooves formed on the surface, the terminal parts of the conductors can be easily arranged at a narrow pitch. By arranging the conductors on the support plate, they can be connected to the electrode parts in a unified manner. In addition, part or all of the conductors located in the grooves of the support plate have a flat portion that is substantially parallel to the upper surface of the support plate, so that the stability of the electrical connection to the electrode parts can be easily achieved.

[0011] In the multi-core cable of the present invention, the cross-sectional shape of the conductor in the groove of the support plate is preferably such that the ratio (D2 / D1) of the maximum width D2 of the conductor in the direction parallel to the flat portion of the conductor to the maximum height D1 of the conductor in the direction perpendicular to the flat portion of the conductor satisfies 1.0<(D2 / D1)<2.0. It is possible to ensure a sufficient area of ​​the flat portion of the conductor facing the substrate for electrical connection to the electrode portion while ensuring a gap between the conductors.

[0012] The terminal ends of the conductors may be arranged side by side in the first region overlapping the support plate. The conductors may be spaced apart from each other by 0.04 mm to 1.0 mm.

[0013] In the present invention, the outer diameter of the conductor in the cable body can be 0.01 mm to 0.15 mm. In the present invention, a cable with a conductor outer diameter of 0.01 mm to 0.1 mm can achieve a higher effect, and when the conductor outer diameter is 0.01 to 0.05 mm, the effect is particularly easy to achieve.

[0014] The difference (absolute value) between the cross-sectional area of ​​the conductor in the cable body and the cross-sectional area of ​​the conductor in the groove of the support plate at the terminal portion of the conductor is preferably within 10.0% of the cross-sectional area of ​​the conductor in the cable body, and more preferably within 5.0%. Even near the connection portion between the electrode portion and the conductor, the influence on the electrical characteristics can be suppressed by minimizing the change in the cross-sectional area of ​​the conductor.

[0015] The cross-sectional area of ​​the groove of the support plate is preferably less than 97% of the cross-sectional area of ​​the conductor located in the groove of the support plate. In addition, the cross-sectional area of ​​the groove of the support plate is more preferably 40% to 97% of the cross-sectional area of ​​the conductor located in the groove of the support plate, and further preferably 50% to 95%. In the case where the cross-sectional area of ​​the groove formed in the support plate is smaller than the cross-sectional area of ​​the conductor, the conductor located in the groove of the support plate is stably in a state of protruding from the upper surface of the support plate even when pressed from above. When the flat portion of the conductor located in the groove of the support plate is in a state of protruding from the upper surface of the support plate, when the multi-core cable of the present invention is electrically connected to the electrode portion via the anisotropic conductive film, it is easy to concentrate pressure on the joint portion between the electrode portion and the conductor, and it is easy to achieve stability and reliability of the electrical connection.

[0016] In addition, when the grooves of the support plate are arranged side by side, the spacing of the grooves of the support plate can be 0.04mm~1.0mm. The spacing of the grooves of the support plate is equivalent to the spacing of the conductors of the multi-core cable connection part. In order to obtain the effect of miniaturization around the connection part between the substrate and the multi-core cable, the spacing of the grooves can be 0.05mm~1.0mm, or 0.04mm~0.5mm, or 0.04mm~0.4mm. The configuration of the grooves of the support plate can be determined according to the arrangement of the electrode parts to be connected to the multi-core cable, and the spacing of the grooves arranged side by side can be uniform or uneven. In addition, in addition to being arranged side by side, the grooves of the support plate can also be arranged radially extending from the first side of the plate to the second side, or grooves that are not only extended in a straight line but also curved in the direction from the first side of the plate to the second side.

[0017] The support plate is preferably made of an insulating material, or may be made of a material having a suitable hardness.

[0018] The multi-core cable of the present invention can electrically connect the conductor located in the groove of the support plate and the electrode part on the connection substrate via an anisotropic conductive film. The connection via the anisotropic conductive film eliminates the occurrence of short circuit failures caused by solder adhering to the adjacent conductor or electrode part near the connection part, and has a high effect on improving the reliability of the electrical connection. In addition, in the multi-core cable of the present invention, the conductor located in the groove of the support plate protrudes from the upper surface of the support plate relative to the flat part of the substrate. In the case of being electrically connected to the electrode part via the anisotropic conductive film, it is easy to concentrate on the joint part of the electrode part and the conductor to apply pressure, and it is easy to uniformly connect the conductors integrated by the support plate. In addition, it is easy to capture conductive particles between the electrode part and the flat part of the conductor, which is effective in achieving a connection with high stability and reliability.

[0019] Furthermore, an electronic device according to the present invention includes any one of the multi-core cables described above.

[0020] In addition, the manufacturing method of the multi-core cable involved in the present invention is characterized in that it comprises: a process of preparing a plurality of extremely fine cables, the extremely fine cables including a conductor and an insulator located on the periphery of the conductor; a process of removing the insulator at the terminal portion of the plurality of extremely fine cables to expose the conductor; a process of preparing a support plate, the support plate having a first side and a second side opposite to the first side, and having a plurality of grooves extending from the first side to the second side formed on at least the upper surface; a process of arranging the conductor exposed by removing the insulator in the groove formed in the support plate; and a process of pressing the conductor arranged in the groove from above the support plate so that it is engaged with the groove of the support plate, and forming a flat portion on the conductor arranged in the groove that is roughly parallel to the upper surface of the support plate. Effects of the Invention

[0021] The multi-core cable of the present invention can connect an extremely fine insulated cable or an extremely fine coaxial cable to electrodes arranged at a narrow pitch. The multi-core cable of the present invention has a structure that can achieve electrical connection with excellent stability and reliability in a simple method, and is effective in manufacturing electronic equipment with stable electrical characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram showing an example of a multi-core cable according to the present invention. Figure 2 This is a schematic diagram of a cross section of a terminal portion of an example of an ultra-fine insulated cable. Figure 3 This is a schematic diagram of a cross section of a terminal portion of an example of an ultra-thin coaxial cable. Figure 4 This is a diagram showing the vicinity of a terminal portion of an example of a cable. Figure 5 is a schematic diagram of an example of a support plate used in the present invention. Figure 6 This is a diagram showing an example of a cross section of a support plate. Figure 7 It is a diagram showing a state where conductors are arranged on a support plate. Figure 8 It is a schematic cross-sectional view showing a state where conductors are arranged on a support plate. Fig. 9 It is a schematic cross-sectional view showing a state where conductors are arranged on a support plate. Fig.10 This is a partially enlarged schematic cross-sectional view showing a state where conductors are arranged on a support plate. Fig.11 This is a diagram for explaining an example of the cross-sectional shape of the conductor on the support plate. Fig.12It is a diagram for explaining another example of the cross-sectional shape of the conductor on the support plate. Fig.13 It is a diagram for explaining another example of the cross-sectional shape of the conductor on the support plate. Fig.14 It is a diagram for explaining the cross-sectional area of ​​the groove of the support plate. Fig.15 It is a diagram showing another example of the support plate. Fig.16 This is a schematic diagram of the cable terminal processing area when connected to the electrode part. Fig.17 This is a schematic cross-sectional view of the cable terminal processing portion when connected to the electrode portion. Fig.18 This is a schematic cross-sectional view of the cable terminal processing portion when connected to the electrode portion. DETAILED DESCRIPTION

[0023] The structure of a multicore cable according to an embodiment of the present invention is described below with reference to the drawings. The embodiment described below is not intended to limit the claims of the present invention, and the combination of features described in the embodiment is not necessarily all necessary for the solution of the invention.

[0024] Figure 1 1 is a diagram for explaining the structure of a multi-core cable according to an embodiment of the present invention. The multi-core cable 1 can be roughly divided into a cable main body portion M and a cable terminal processing portion K. Figure 1 The cable terminal processing part K and the cable terminal processing part K of the cable main body M are shown. A plurality of ultra-fine cables 10 are arranged side by side in a plane near the cable terminal processing part K. In the cable terminal processing part K, the insulator of the terminal part of the ultra-fine cable 10 is removed by a specified length, and a part of the terminal part of the exposed conductor 100 is located in the groove 210 of the support plate 20. The terminal part of the conductor 100 includes a first area C1, an area overlapping with the support plate 20, and a second area C2, an area not overlapping with the support plate 20. The length of the second area C2 can also be made as close to 0 as possible as needed. Figure 1 In the example, 8 ultrafine cables 10 are arranged side by side, but the number of ultrafine cables 10 arranged side by side can be about 3 to 100, and the number required for arrangement and connection can be sufficient. In addition, the cable body M (the area other than the terminal processing part K) can be a cable with a circular cross-section formed by twisting multiple ultrafine cables 10, or a cable with a flat cross-section formed by arranging multiple ultrafine cables 10. In addition, the multi-core cable of the present invention can also be a multi-core cable including multiple support plates 20.

[0025] The ultra-fine cable 10 includes a conductor and an insulator located on the periphery of the conductor. It can be an ultra-fine insulated cable composed of a conductor and an insulator, or an ultra-fine coaxial cable that also includes a shielded conductor on the periphery of the insulator. The cables constituting the multi-core cable of the present invention can be composed of only ultra-fine insulated cables or only ultra-fine coaxial cables, or can be composed of a combination of ultra-fine insulated cables and ultra-fine coaxial cables. In addition, the cables constituting the multi-core cable of the present invention can also be a cable in which long strips such as uncoated wires or pipes other than ultra-fine insulated cables or ultra-fine coaxial cables are mixed and configured together with ultra-fine cables. Figure 2 and Figure 3 1 is a schematic diagram showing a cross section of a terminal portion of an example of an ultrafine cable 10 constituting the multi-core cable according to the present invention. Figure 2 This is an example of an ultrafine insulated cable 110 , and shows a cable in which an insulator 112 is coated on the outer periphery of a conductor 111 having an outer diameter of 0.01 mm to 0.15 mm. Figure 3 This is an example of an ultra-fine coaxial cable 120, which shows an ultra-fine cable in which an insulator 122 is covered on the outer periphery of a conductor 121 with an outer diameter of 0.01mm to 0.15mm, a shielded conductor 123 formed by horizontally winding a shielded wire is arranged on the outer periphery of the insulator 122, and a sleeve 124 is added to the outer side. The conductors 111, 121 and the shielded conductor 123 can be made of wires commonly used as conductors, and as materials, for example, wires made of copper, silver, aluminum, steel, various alloys, etc. can be used. This kind of wire is usually mostly made of wires coated with a plating layer such as silver or tin on the surface, for example, silver-plated copper alloy wire can be used. The conductors 111 and 121 can be either single wires or twisted wires, or can be arranged in parallel without being twisted.

[0026] The cable terminal processing part K of the multi-core cable of the present invention is described in detail below. The multi-core cable of the present invention may be a cable whose main body has a circular cross section or a cable whose main body has a flat cross section, but the cables are preferably arranged flat in the cable terminal processing part K. In addition, a plurality of cables having a circular cross section or a plurality of cables having a flat cross section may be used to form the cable terminal processing part K having a single support plate.

[0027] Figure 4 This is a diagram showing the vicinity of the terminal portion of an example of a cable. It shows the state before the conductor is arranged on the support plate at the terminal portion of the cable. At the terminal portion of the cable, the insulators of the ultrafine cables 10 arranged side by side are removed by a predetermined length to expose the conductors 100 at each terminal portion. At least a part of the terminal portion of the exposed conductor 100 is arranged in the groove of the support plate.

[0028] Figure 5: is a schematic diagram of an example of the support plate 20. The support plate 20 is formed of an insulating material, for example, a thin plate-like material with a thickness of 0.02mm to 0.20mm can be used. Depending on the hardness of the material, a thickness of 0.03mm to 0.10mm can be appropriately used. As an insulating material, a material with heat resistance is suitable. For example, polyimide resin (PI), polyamide-imide resin (PAI), polyetheretherketone resin (PEEK), polyphenylene sulfide resin (PPS), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. can be used, but are not limited to this. In addition, as a material of the support plate 200, it is preferred to have an appropriate hardness. In the case of pressing the conductor arranged in the groove 210 of the support plate 20 from above the support plate 20, the conductor 100 is easily embedded in the groove 210, so that it is easy to maintain the state in which at least a part of the terminal portion of the conductor 100 is arranged in the groove 210 of the support plate 20 before the multi-core cable is connected to the electrode portion, etc. In addition, it is easy to uniformly apply pressure to a plurality of conductors, which is advantageous for stable connection.

[0029] Figure 5 2 is a diagram showing the upper surface of the support plate 20 when the support plate 20 is viewed from above. The support plate 20 has a first side 201 and a second side 202 opposite to the first side 201. A plurality of grooves 210 extending from the first side 201 to the second side 202 are formed on the upper surface of the support plate 20. The grooves 210 are formed in a shape and interval corresponding to the arrangement of the electrode portion, etc., for connecting the multi-core cable, and the conductors 100 with the terminal portions of the ultrafine cables 10 exposed are arranged in the grooves 210.

[0030] Figure 6 is a diagram showing an example of a cross section of the support plate 20, Figure 5 A1-A1 section view. Grooves 210 are formed on the upper surface of the support plate 20 at predetermined intervals P, and the open side of the groove becomes the surface opposite to the electrode portion when connected to the electrode portion. The interval P of the grooves 210 of the support plate refers to the distance between the center of the width of the opening of the groove and the center of the width of the opening of the adjacent groove, and the interval P of the grooves 210 can be, for example, 0.04mm to 1.0mm. In particular, the technology of the present invention can also be applied to the case where the electrode portion to be connected is very fine and high-density, and can be applied to the process of connecting the conductor of the ultra-fine cable 10 to the electrode portion on the substrate at intervals of, for example, 0.10mm or 0.05mm.

[0031] At least a portion of the conductor 100 exposed at the terminal end of the ultrafine cable 10 is disposed in the groove 210 formed in the support plate 20 described above. Figure 7The state in which the conductors 100 at the terminal ends of the ultrafine cables 10 are arranged in the grooves 210 of the support plate 20 is shown. The conductors 100 with the terminal ends of the cables exposed are arranged on the support plate in accordance with the arrangement of the grooves 210 . Figure 8 yes Figure 7 The A2-A2 cross-sectional view shows a state where the conductor 100 is arranged on the groove 210 of the support plate 20. Figure 8 As an example of a method of arranging the conductor of the cable terminal on the support plate, a schematic diagram of the conductor terminal and the support plate 20 is shown when the conductor 100 arranged in the groove 210 is pressed from above the support plate 20 so that the conductor 100 and the groove 210 are fitted. In this method, the material constituting the support plate 20 can be an insulating material having an appropriate height and being elastically deformable, so that the cross-sectional area of ​​the groove 210 is formed smaller than the cross-sectional area of ​​the conductor 100. By arranging the conductor 100 in the groove 210 and pressing it, the support plate and the ultrafine cable can be easily fitted. When it is necessary to fix more firmly, an adhesive layer can be provided in the groove. For example, a thermosetting resin such as epoxy resin or an ultraviolet curing resin can be used as the adhesive.

[0032] Fig. 9 The diagram shows the state of the conductor 100 at the terminal end of the ultrafine cable being fitted onto the support plate 20. Figure 7 A cross-section of the A2-A2 position in FIG. Fig. 9 The upper surface is the upper surface of the support plate 20, and becomes the surface facing the electrode portion. Part or all of the conductor 100 located in the groove 210 of the support plate 20 has a flat portion 101 that is substantially parallel to the upper surface of the support plate 20. The conductor on the surface facing the electrode portion has a flat portion that is substantially parallel to the upper surface of the support plate 20, which makes it easy to ensure that the conductor and the electrode portion are spaced at an equal distance, which is conducive to stable electrical connection.

[0033] Fig.10 Yes Fig. 9 The enlarged view of the vicinity of the conductor 100. The width A of the flat portion 101 of the conductor 100 that is roughly parallel to the upper surface of the support plate 20 preferably has a length greater than the radius r of the conductor in the cable body, and the width A of the flat portion 101 is preferably as long as possible within the scope of the structure that satisfies the present invention. As the outer diameter of the conductor becomes thinner, it becomes increasingly difficult to match the connection position and ensure the connection area with the electrode portion, but having a width of the flat portion greater than the radius r of the conductor is beneficial to the stability of the connection. The flat portion 101 of the conductor 100 that is roughly parallel to the upper surface of the support plate 20 can be formed before the conductor is arranged on the support plate, or it can be formed by deforming the conductor 100 simultaneously when the conductor 100 is fitted into the groove 210 of the support plate. In addition, the flat portion 101 of the conductor 100 that is roughly parallel to the upper surface of the support plate 20 is preferably in the same plane as the upper surface of the support plate or protrudes upward from the upper surface of the support plate. Fig. 9 , the height of each flat portion 101 of the conductor 100 disposed on the upper surface of the support plate 20 can be made to be aligned on the same straight line as the straight line (surface line) S along the upper surface of the support plate or on a straight line (for example, straight line S1) substantially parallel to the surface line S. The term "substantially parallel" in the present invention includes not only completely parallel but also substantially parallel within a certain error range.

[0034] For example, when conductors of different outer diameters are arranged on a support plate, by adjusting the depth and cross-sectional area of ​​the groove 210, the height of the flat portion 101 of each conductor on the support plate can be made to be aligned on the same straight line as the surface line S of the support plate or on a straight line substantially parallel to the surface line S. The flat portion of the conductor is opposite to the connected electrode portion. For example, in the case of connecting the conductor and the electrode portion with solder or conductive paste, since the conductor has a flat portion, the relative position and distance between the electrode portion and the conductor are easily stabilized, and the connection area with the electrode portion can be increased. In addition, when the height of the flat portion 101 of the conductor is located above the upper surface of the support plate, for example, in the case of using an anisotropic conductive film for connection, it is easy to concentrate pressure on the joint portion of the electrode portion and the conductor, which is more effective in achieving a highly stable and reliable connection.

[0035] The cross-sectional area of ​​the conductor of the ultrafine cable electrically connected to the electrode part preferably does not change much from beginning to end. Specifically, the absolute value of the difference between the cross-sectional area of ​​the conductor in the cable body and the cross-sectional area of ​​the conductor in the groove of the support plate at the terminal part of the conductor is preferably within 10.0% of the cross-sectional area of ​​the conductor in the cable body, and more preferably within 5.0%. It is believed that less change in the cross-sectional area of ​​the conductor can suppress the influence on the electrical characteristics.

[0036] Fig.11 1 is a diagram illustrating an example of the cross-sectional shape of the conductor 100 on the support plate. The cross-sectional shape of the conductor 100 located in the groove of the support plate can be formed so that the maximum height D1 of the conductor in the direction perpendicular to the flat portion of the conductor and the maximum width D2 of the conductor in the direction parallel to the flat portion 101 of the conductor satisfy the relationship D1<D2. In addition, the ratio (D2 / D1) of the maximum width D2 of the conductor in the direction parallel to the flat portion of the conductor (hereinafter, sometimes referred to as the maximum width D2 of the conductor) and the maximum height D1 of the conductor in the direction perpendicular to the flat portion of the conductor (hereinafter, sometimes referred to as the maximum height D1 of the conductor) can be greater than 1.0 and less than 2. D2 / D1 can also be greater than 1.0 and less than 1.8. When the ratio of D1 to D2 is within this range, it is easy to achieve a structure that is conducive to connection and a distance between conductors that are simultaneously ensured.

[0037] Fig.12 and Fig.13is another example of a cross-sectional shape of the conductor 100 located in the slot of the support plate. Fig.12 As shown in FIG. 1 , the cross section of the conductor 100 located in the groove of the support plate may be formed in a shape in which the upper portion is expanded in a flange shape. In the case of this shape, the maximum width D2 of the conductor is measured by removing the flange-shaped portion or the special shape portion such as the protrusion. Fig.12 The shape shown is advantageous in that it is easy to ensure the length A of the flat portion when the conductor becomes extremely thin and it is difficult to ensure the length A of the flat portion of the connecting side of the conductor. Fig.13 As shown, depending on the shape of the slot, a shape in which the maximum height D1 of the conductor is larger than the maximum width D2 of the conductor may be adopted.

[0038] The size relationship between the conductor located in the groove of the support plate and the groove of the support plate is preferably such that the cross-sectional area of ​​the groove of the support plate is set smaller than the cross-sectional area of ​​the conductor located in the groove of the support plate. The cross-sectional area of ​​the groove 210 formed on the support plate is preferably less than 97% of the cross-sectional area of ​​the conductor 100 located in the groove of the support plate. In addition, the cross-sectional area of ​​the groove formed on the support plate is more preferably 40% to 95% of the cross-sectional area of ​​the conductor located in the groove of the support plate. When the cross-sectional area of ​​the groove of the support plate is smaller than 40% of the cross-sectional area of ​​the conductor, it is sometimes necessary to use an adhesive in the groove or make the groove a special shape, etc. Fig.14 As shown, the cross-sectional area of ​​the groove 210 can be measured by, for example, photographing a cross section (cross section) cut perpendicular to the long side direction of the groove of the support plate using a digital microscope or the like to obtain an image. The area enclosed by the surface line S of the upper surface of the support plate 210 and the line 211 of the inner surface of the groove 210 of the support plate (for example Fig.14 The shaded portion of the groove 210 is the cross-sectional area of ​​the groove 210. When the groove 210 contains an insulating material such as an adhesive that is different from the main material of the board 200, the cross-sectional area occupied by the material is not included in the cross-sectional area of ​​the groove 210.

[0039] Fig.15 In the above description, an example is shown in which the cross-sectional shape of the groove 210 of the support plate 20 is a trapezoidal shape, but the shape of the groove 210 is not particularly limited as long as it is a shape that can easily accommodate the conductor. For example, it can be Fig.15 a) V-shaped groove 210a, Fig.15 b) the semicircular groove 210b shown, or Fig.15 c) Square grooves 210 c shown in FIG. 1 and 10 b. When the conductors 100 are arranged at a narrow pitch, the ratio of the width to the depth of the grooves 210 (width / depth) is preferably less than 2.

[0040] The multi-core cable of the present invention can be connected not only by solder or conductive paste but also by an anisotropic conductive film. The anisotropic conductive film is a film formed into a film by dispersing conductive particles such as fine metal particles in a thermosetting resin matrix. When the film is sandwiched between the conductor and the electrode and heated and pressure is applied, the conductive particles dispersed in the film are brought together and electrically connected by contact with each other. In the portion where no pressure is applied in the film, the insulator around the conductive particles is maintained, so it has the property of being able to maintain insulation between the lateral electrodes. Fig.16 This is a schematic diagram of the vicinity of the cable terminal processing part when the conductor located in the groove of the support plate and the connected electrode part are electrically connected via the anisotropic conductive film. The conductor 100 of the terminal part of the ultra-fine cable 10 arranged side by side is embedded in the groove of the support plate 20, and the anisotropic conductive film 300 is laminated on the support plate 20 and the conductor 100. By laminating the anisotropic conductive film 300 on the support plate 20 and the conductor 100, it is also expected to prevent the conductor 100 from being separated from the groove of the support plate 20. Since the ultra-fine cable can be transported in a state of being integrated with the support plate, it can be transported in a state of being connected to the electrode part only by heating and pressurizing the anisotropic conductive film.

[0041] Fig.17 and Fig.18 Yes means Fig.16 A cross-sectional view of a cable terminal processing portion of an example is shown Fig.16 Schematic diagram of the A3-A3 section. Fig.17 In the embodiment, an anisotropic conductive film 300 is arranged on the upper part of the support plate 20 and the conductor 100. In the multi-core cable of the present invention, if a support plate corresponding to the arrangement of the electrode portion of the substrate is used, the support plate on which the conductor is arranged can be directly connected to the electrode portion of the substrate using the anisotropic conductive film. If the support plate of the present invention can be formed very thin and the anisotropic conductive film uses a light-transmitting film, the position of the electrode pad can be confirmed through the support plate and the anisotropic conductive film. Fig.18In the embodiment of the present invention, after the surface of the support plate 20 and the conductor 100 on which the anisotropic conductive film is disposed is pasted correspondingly to the electrode portion 400 of the substrate 40, the electrode portion 400 and the conductor 100 are electrically connected by heating and pressurizing between the support plate 20 and the electrode portion 400. In the multi-core cable of the present invention, part or all of the conductor in the groove of the support plate at the cable terminal processing part has a flat portion substantially parallel to the upper surface of the support plate, and the conductive particles contained in the anisotropic conductive film are easily retained between the flat portion of the conductor and the convex portion of the electrode portion, and it is easy to achieve the formation of a conductive path by retaining a sufficient amount of conductive particles for electrical connection. In particular, when the flat portion of the conductor is in a state of protruding upward from the upper surface of the support plate, it is easy to concentrate pressure on the connection portion between the electrode portion and the conductor, and the stability and reliability of the electrical connection are excellent.

[0042] The structure of the multi-core cable of the present invention has been described so far, and the multi-core cable of the present invention is manufactured by the following steps. The steps described below are not limited to the order described. <Process of preparing ultra-thin cables> As the ultrafine cable, an ultrafine insulated cable and / or an ultrafine coaxial cable are prepared. The cable body is often a cable having a circular cross section formed by twisting a plurality of ultrafine cables, or a cable having a flat cross section formed by arranging a plurality of ultrafine cables. <Conductor exposure process> The insulators at the terminal parts of the prepared plurality of very fine cables are removed to expose the conductors. When using very fine coaxial cables, the sheath, shield conductor, and insulator are removed from the outer circumference of the cable in order to expose the conductors. <Steps for preparing the support plate> A support plate is prepared, which has a first side and a second side opposite to the first side, and a plurality of grooves extending from the first side to the second side are formed at least on the upper surface. A film is prepared as a material of the support plate, and the grooves are formed by laser processing or the like. <Step of placing conductor on support plate> The conductor exposed by removing the insulator is arranged in a groove formed in the prepared support plate. <Step of fitting the conductor into the groove of the support plate> The conductor arranged in the groove of the support plate is pressed from above the support plate to be fitted into the groove of the support plate. In addition, a flat portion substantially parallel to the upper surface of the support plate is formed on the conductor arranged in the groove of the support plate.

[0043] The multi-core cable of the present invention can be connected to fine electrodes arranged at a high density, and has excellent electrical connection stability and reliability. Since it also has a good effect on miniaturization of the periphery of the substrate connection portion, an electronic device including any of the cables of the present invention can be used as an electronic device in fields requiring miniaturization or high precision, such as medical imaging devices, micromachines, measuring devices, and communication devices. Example

[0044] (Determination of conductor cross-sectional shape) The cross-sectional shape of the conductor in the groove of the support plate of the cable terminal processing part is measured by cutting in a manner that the shape of the measurement part is maintained to produce a cross section. For example, if the vicinity of the measurement part is wrapped with a curable resin or the like and cut, the shape can be maintained to produce a cross section. The cross section is measured using a digital microscope or the like. The measurement position is set to the vicinity of the center in the length direction of the first area where the terminal of the conductor overlaps the support plate, assuming that the conductor is stably fixed on the support plate. The measurement is performed on all the conductors or more than 20 conductors arranged on the support plate. <Width A of the flat portion of the conductor> On the cross section of the conductor, draw a straight line that passes through the flat part of each conductor and is roughly parallel to the upper surface of the support plate, and measure the length of the flat part in the direction along the straight line. The length is the width A of the flat part of the conductor. For each conductor, compare the width A of the flat part of the conductor with the radius r of the conductor of the cable body. In one support plate, when more than 50% of the measured conductors satisfy the relationship r<A, the multi-core cable is deemed to satisfy the relationship r<A between the radius r of the conductor in the cable body and the width A of the flat part of the conductor. <Maximum conductor height D1> The contour line of the conductor cross section is confirmed and measured. The distance from the flat part of the conductor to the point on the contour line with the longest distance in the direction perpendicular to the flat part of the conductor is measured as the maximum height D1 of the conductor. <Maximum width D2 of conductor in a direction parallel to the flat portion> In the direction parallel to the flat portion of the conductor, the maximum width of the conductor's profile is set to the maximum width D2 of the conductor. Fig.12 or Fig.13In the case where the connecting side of the conductor described in the specification has a special shape portion such as a flange or a protrusion, when measuring the maximum width D2 of the conductor, such a special shape portion is not measured, but the normal shape portion is measured. For each conductor, the maximum height D1 of the conductor and the maximum width D2 of the conductor are compared. When more than 50% of the measured conductors satisfy the relationship D1<D2, the multi-core cable is deemed to satisfy the relationship D1<D2 for the maximum height D1 of the conductor and the maximum width D2 of the conductor in the direction parallel to the flat portion of the conductor. In addition, when more than 50% of the measured conductors satisfy the relationship 1.0<(D2 / D1)<2.0, the multi-core cable is deemed to satisfy the relationship 1.0<(D2 / D1)<2.0 for the ratio (D2 / D1) of the maximum width D2 of the conductor in the direction parallel to the flat portion of the conductor to the maximum height D1 of the conductor. <Cross-sectional area of ​​the groove of the support plate> The cross-sectional area of ​​the groove of the support plate can be measured at the same time as the cross-sectional shape of the conductor is measured. Fig.14 As described in , the area enclosed by the straight line S along the upper surface of the support plate and the contour line of the inner surface of the groove of the support plate is the cross-sectional area of ​​the groove. When the interior of the groove contains an insulating material such as an adhesive that is different from the material of the support plate body, the contour line of the material is treated as the contour line of the groove, and the area occupied by the material is excluded from the cross-sectional area of ​​the groove. Compare the cross-sectional area of ​​each groove and the conductor corresponding to the groove. When more than 50% of the measured combinations of grooves and conductors satisfy that the cross-sectional area of ​​the groove is less than 97% of the cross-sectional area of ​​the conductor, the multi-core cable is deemed to have a groove cross-sectional area of ​​less than 97% of the cross-sectional area of ​​the conductor in the cable connection. In addition, when more than 50% of the measured combinations of grooves and conductors satisfy that the cross-sectional area of ​​the groove is 40% to 97% of the cross-sectional area of ​​the conductor, the multi-core cable is deemed to have a groove cross-sectional area of ​​40% to 97% of the cross-sectional area of ​​the conductor in the cable connection. <Pitch P of the grooves of the support plate> The spacing P of the grooves of the support plate can be measured at the same time as the measurement of the cross-sectional shape of the conductor. The distance between the width center of the opening of the groove on the straight line S along the upper surface of the support plate and the width center of the opening of the adjacent groove is the spacing P of the grooves of the support plate. When 50% or more of the measured spacing P of the grooves is within the predetermined range, the spacing of the grooves formed in the support plate of the multi-core cable is deemed to be within the predetermined range.

[0045] Example 1 An insulated cable was made by covering the outer circumference of a conductor with an outer diameter of 0.040 mm with an insulator made of PFA, and 12 such cables were arranged side by side. The front end was a 3.0 mm strip and the terminal end of the conductor was exposed. A polyimide film with a width of 1.5 mm, a length of 0.5 mm, and a thickness of 50 μm was prepared as the material of the support plate, and the interval P of the groove was set to 0.1 mm, and the grooves were formed by laser processing. The exposed terminal parts of the conductors are placed in the grooves of the processed support plate, and arranged in accordance with the arrangement of the grooves. The conductors arranged on the support plate are pressed from above the support plate using a small punching machine, so that the conductors fit into the grooves and a flat part is formed on the conductors. In this way, a multi-core cable including a support plate is obtained. The cable terminal processing part of the obtained multi-core cable is wrapped with a curing resin, and the cross section is made by vertically cutting along the long side direction near the center of the length direction of the first area where the terminal part of the conductor overlaps with the support plate. Various measurements are made on the terminal processing part of the multi-core cable. The results of the measurement are: the radius r of the conductor in the cable body is 0.02mm, the width A of the flat part of the conductor is 0.034mm~0.038mm, the maximum height D1 of the conductor is 0.022~0.024mm, the maximum width D2 of the conductor is 0.038mm~0.040mm, and D2 / D1 is 1.58~1.7. The cross-sectional area of ​​the groove is 70% of the cross-sectional area of ​​the conductor in the cable connection part, and the difference (absolute value) between the cross-sectional area of ​​the conductor in the cable body and the cross-sectional area of ​​the conductor in the cable connection part is within 0.5% of the cross-sectional area of ​​the conductor in the cable body. Example 2 The cables were prepared in the same manner as in Example 1 except that the outer diameter of the conductor of Example 1 was changed to 0.030 mm, arranged side by side and their front ends were formed into strips. In the same manner as in Example 1, a polyimide film was prepared, and the width and depth of the grooves were changed according to the outer diameter of the conductor, the cross-sectional area of ​​the grooves was adjusted, and a support plate with a groove spacing P of 0.1 mm was prepared. Using the prepared support plate, a multi-core cable including the support plate was prepared in the same steps as in Example 1. The terminal processing portion of the obtained multi-core cable was wrapped with a curing resin, and a cross section was prepared by cutting it perpendicular to the long side direction near the center of the length direction of the first area where the terminal portion of the conductor overlapped with the support plate. Various measurements were performed on the terminal processing portion of the multi-core cable. The results of the measurement are as follows: the radius r of the conductor in the cable body is 0.015 mm, the width A of the flat portion of the conductor is 0.025 mm to 0.029 mm, the maximum height D1 of the conductor is 0.016 to 0.017 mm, the maximum width D2 of the conductor is 0.030 mm to 0.031 mm, and D2 / D1 is 1.76 to 1.92. The cross-sectional area of ​​the groove is 50% of the cross-sectional area of ​​the conductor in the cable connection part, and the difference (absolute value) between the cross-sectional area of ​​the conductor in the cable body and the cross-sectional area of ​​the conductor in the cable connection part is within 0.5% of the cross-sectional area of ​​the conductor in the cable body. Example 3 The cables are prepared in the same manner as in Example 1 except that the outer diameter of the conductor of Example 1 is changed to 0.025 mm, arranged side by side and the front ends thereof are formed into strips. In the same manner as in Example 1, a polyimide film is prepared, the width and depth of the grooves are changed according to the outer diameter of the conductor, the cross-sectional area of ​​the grooves is adjusted, and a support plate with a groove spacing P of 0.05 mm is prepared. Using the prepared support plate, a multi-core cable including the support plate is prepared in the same steps as in Example 1. The cable connection portion of the obtained multi-core cable is wrapped with a curing resin, and the cable is cut perpendicularly to the long side direction near the center of the length direction of the first area where the terminal portion of the conductor overlaps with the support plate to prepare a cross section. Various measurements are performed on the terminal processing portion of the multi-core cable. The results of the measurement are as follows: the radius r of the conductor in the cable body is 0.0125 mm, the width A of the flat portion of the conductor is 0.0214 mm to 0.0231 mm, the maximum height D1 of the conductor is 0.0243 mm to 0.0247 mm, the maximum width D2 of the conductor is 0.0265 mm to 0.0269 mm, and D2 / D1 is 1.07 to 1.11. The cross-sectional area of ​​the groove is 87% of the cross-sectional area of ​​the conductor in the cable connection part, and the difference (absolute value) between the cross-sectional area of ​​the conductor in the cable body and the cross-sectional area of ​​the conductor in the cable connection part is within 0.5% of the cross-sectional area of ​​the conductor in the cable body.

[0046] An anisotropic conductive film is placed on the support plate and the conductor of the multi-core cable obtained in Example 1, heated to about 80°C, and laminated on the support plate. The anisotropic conductive sheet uses a film with an epoxy resin as the matrix and conductive particles plated with nickel dispersed in the resin particles. The conductors arranged on the support plate with the anisotropic conductive film sandwiched therebetween are arranged corresponding to the electrode parts of the substrate, and the support plate and the substrate are electrically connected by applying heat and pressure of about 200°C from top to bottom. All the conductors arranged on the support plate can be uniformly connected to the accurate position. The cable length was set to 1000 mm, and the resistance value of each electrically connected circuit was measured. As a result, the multi-core cable obtained in Example 1 could obtain a stable resistance value within the range of ±0.1Ω of the measured value of the conductor resistance. In addition, the holding strength of the conductor of the support plate is high, and no conductor was found to be separated from the groove of the support plate during operation and transportation.

[0047] Comparative Example 1 As in Example 1, prepare cables, arrange them side by side and form their front ends into strips. As in Example 1, prepare a polyimide film and make a support plate. Place the exposed terminal portions of the conductors in the grooves of the processed support plate and arrange them in accordance with the arrangement of the grooves. Instead of pressing with a small punch, place an anisotropic conductive film on top of the support plate and the conductor, heat it to about 80°C, and laminate it on the support plate. The anisotropic conductive sheet uses the same conductive sheet as in Example 1. The conductors arranged on the support plate with the anisotropic conductive film sandwiched between them are arranged corresponding to the electrode portions of the substrate, and heat and pressure of about 200°C are applied to the support plate and the substrate from top to bottom to electrically connect them. The cable length was set to 1000 mm, and the resistance values ​​of the electrically connected circuits were measured in the same manner as in Example 1. The results were as follows: in the multi-core cable obtained in Reference Example 1, the maximum and minimum resistance values ​​of each circuit had a difference of 41.2Ω, and the deviation of the resistance value was large.

[0048] The reason why the resistance value is unstable in the multi-core cable of Comparative Example 1 is that the connection area between the conductor and the electrode portion becomes very small in the ultra-thin cable, so in the sample of Comparative Example 1 without a flat portion of the conductor, the curved surface of the conductor cannot accurately capture the electrode portion when the conductor and the electrode portion are joined. In contrast, the multi-core cable of the embodiment can obtain a stable resistance value, confirming that the stability and reliability of the electrical connection are excellent.

[0049] The multi-core cable of the present invention can be connected to fine electrode parts on a substrate arranged at a high density, and the stability and reliability of the electrical connection are excellent. In addition, the connection operation between the electrode part and the conductor is simple, and it is also effective in miniaturizing the periphery of the substrate connection part. The multi-core cable of the present invention can be applied to fields requiring miniaturization or high precision of the device, such as medical probe cables or micromachines, measuring devices, and communication devices. Description of symbols

[0050] 1 multi-core cable, 10 ultra-fine cable, 100 conductor, 110 ultra-fine insulated cable, 120 ultra-fine coaxial cable, 20 support plate, 200 plate, 210 groove, 300 anisotropic conductive film, 40 substrate, 400 electrode part.

Claims

1. A multi-core cable comprising a plurality of ultra-fine cables, wherein the ultra-fine cables have a conductor and an insulator located on the periphery of the conductor, wherein the multi-core cable is characterized in that: The multi-core cable comprises a cable main body and a cable terminal processing part. The cable terminal processing part includes the terminal parts of at least three of the plurality of ultra-thin cables and a support plate. The terminal end of the ultrafine cable exposes the terminal end of the conductor. The support plate has a first side and a second side opposite to the first side, The support plate has a plurality of grooves extending from the first side toward the second side on at least the upper surface thereof. The terminal portion of the conductor includes a first region that overlaps with the support plate and a second region that does not overlap with the support plate. In the first region, at least a portion of the terminal end of the conductor is located in the groove of the support plate, A part or all of the conductors located in the grooves of the support plate have a flat portion substantially parallel to the upper surface of the support plate, For two or more conductors in the same cross section among the conductors located in the groove of the support plate, the radius r of the conductor in the cable body and the width A of the flat portion of the conductor have a relationship as expressed by formula (1): r＜A····(1)。 2. The multi-core cable according to claim 1, characterized in that: In the cross-sectional shape of the conductor located in the groove of the support plate, the ratio (D2 / D1) of the maximum width D2 of the conductor in a direction parallel to the flat portion of the conductor to the maximum height D1 of the conductor in a direction perpendicular to the flat portion of the conductor is 1.0<(D2 / D1)<2.

0.

3. The multi-core cable according to claim 1, characterized in that: The terminal ends of the conductors are arranged side by side at least in the first region.

4. The multi-core cable according to claim 1, characterized in that: The outer diameter of the conductor in the cable body is 0.01 mm to 0.15 mm.

5. The multi-core cable according to claim 1, characterized in that: A difference between a cross-sectional area of ​​the conductor in the cable body and a cross-sectional area of ​​the conductor at a terminal portion of the conductor in the groove of the support plate is within 10.0% of a cross-sectional area of ​​the conductor in the cable body.

6. The multi-core cable according to claim 1, characterized in that: The cross-sectional area of ​​the groove of the support plate is 40% to 97% of the cross-sectional area of ​​the conductor located in the groove of the support plate.

7. The multi-core cable according to claim 1, characterized in that: The interval between the grooves of the support plate is 0.04 mm to 1.0 mm.

8. The multi-core cable according to claim 1, characterized in that: The support plate is made of insulating material.

9. The multi-core cable according to claim 1, characterized in that: The conductor located in the groove of the support plate and the electrode portion on the connection substrate are electrically connected via an anisotropic conductive film.

10. An electronic device, characterized in that: A multi-core cable comprising any one of claims 1 to 9.

11. A method for manufacturing a multi-core cable, used for manufacturing a multi-core cable, characterized in that: have: A step of preparing a plurality of ultrafine cables, the ultrafine cables comprising a conductor and an insulator located on the periphery of the conductor; a step of removing insulators from terminal portions of a plurality of the ultrafine cables to expose the conductors; A step of preparing a support plate, the support plate having a first side and a second side opposite to the first side, and having a plurality of grooves extending from the first side toward the second side formed on at least an upper surface; a step of placing the conductor exposed by removing the insulator in the groove formed in the support plate; as well as The step of pressing the conductor arranged in the groove from above the support plate so as to fit into the groove of the support plate, and forming a flat portion substantially parallel to the upper surface of the support plate on the conductor arranged in the groove.

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