JP2008112587A - Flat cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat cable that can make its width smaller. <P>SOLUTION: The flat cable 100, in which a plurality of coaxial cables 10 are arranged in parallel and are integrated with an outer cover 20, has an outermost layer 14 constituting the coaxial cable adhered to the outer cover, and each of the outermost layers, constituting neighboring coaxial cables, contacts one another, or is separated from one another by a very narrow gap. As a result, an arrangement pitch can be smaller, since the neighboring coaxial cables are contacting with one another, without outer covers constituting conventional coaxial cables and a width of the flat cable can be made narrower and can be applied for a small cable connector. Moreover, since the outermost layer of the coaxial cable and the outer cover of the flat cable are adhered to each other, peeling off of neighboring coaxial cables near their contacting area can be prevented, even if there is no outer cover that constitutes conventional coaxial cables. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flat cable provided with a coaxial cable for high-speed transmission.

  In general coaxial cables, the inner conductor (center conductor) is covered with an insulator, the outer periphery of the insulator is covered with an outer conductor (shield layer), and the outer periphery of the outer conductor is covered with an outer covering (sheath). It is the structure covered with. Then, a plurality of coaxial cables having such a configuration are arranged in parallel and fixed with a laminate sheet to form a flat cable (see Patent Document 1), or a plurality of coaxial cables are arranged in parallel and the outer covering is fused. Therefore, a flat cable has been proposed (see Patent Document 2). In addition, in the conventional flat cable, a web portion, a so-called bond portion is formed between the coaxial cables for fixing with a laminate sheet, and the center-to-center distance between the coaxial cables is large.

JP 2000-322943 A Japanese Unexamined Patent Publication No. 2000-1000026

  In recent years, for example, in the personal computer market, high-density and high-speed transmission as general-purpose buses has become widespread, and the need for external I / O is increasing for the purpose of function expansion by external units, and flat cables that support high-speed transmission are desired. Has been. However, since the number of coaxial cables arranged in this flat cable increases, the arrangement pitch becomes larger due to the addition of the thickness of the web portion and the outer sheath when the conventional flat cable described above is used. The distance between the centers (hereinafter referred to as “cable width”) increases. For this reason, there exists a problem that it cannot respond to a small cable connector.

  This invention is made | formed in view of the above subjects, The objective is to provide the flat cable which can make a cable width small.

  In order to achieve the above object, in the flat cable of the present invention, in the flat cable in which a plurality of coaxial cables are arranged in parallel and the jacket is integrated, the outermost layer constituting the coaxial cable is bonded to the jacket. And the outermost layers constituting the adjacent coaxial cables are in contact with each other or very slightly separated from each other. As a result, the adjacent coaxial cables are in contact with each other without the outer sheath that constitutes the conventional coaxial cable, so the arrangement pitch can be reduced. It can be made to correspond. Furthermore, since the outermost layer of each coaxial cable and the jacket of the flat cable are bonded, even if the adjacent coaxial cable does not have an outer sheath constituting the conventional coaxial cable, the contact portion of the adjacent coaxial cable It is possible to prevent peeling from the outer cover in the vicinity.

  The coaxial cable includes a center conductor, an insulator formed around the center conductor, a shield layer formed on the outer periphery of the insulator, and an adhesive layer formed on the outer periphery of the shield layer. It is a feature. Thereby, since the coaxial cable is not provided with the outer coating | cover which comprises the conventional coaxial cable, a flat cable with a small cable width can be manufactured. The adhesive layer includes at least an insulator layer and a fusion bond layer. Thus, the shield layer can be protected on the insulator layer side and can be adhered to the outer cover on the fusion layer side. The adhesive layer is formed in a tape shape, and the insulator layer side is spirally wound around the outer periphery of the shield layer. Thereby, since the shield layer can be prevented from being separated, the electrical characteristics of the flat cable can be improved. Further, the jacket is characterized in that it is integrated with the coaxial cable by extrusion molding. As a result, the outermost layer constituting the coaxial cable and the outer jacket can be bonded at the same time as the outer jacket of the flat cable is molded, so that the manufacturing process can be simplified and the manufacturing efficiency can be improved.

  Hereinafter, embodiments of the flat cable according to the present invention will be described. The embodiments described below do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Absent.

  FIG. 1 is a plan view showing an embodiment of a flat cable according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA. In this flat cable 100, a plurality of coaxial cables 10 are arranged in parallel and an outer jacket 20 made of an insulating material is integrated. In the coaxial cable 10, a dielectric layer 12 made of an insulating material is formed around a central conductor 11 made by twisting one conductor or a plurality of conductors, and a plurality of conductor layers are formed on the outer periphery of the dielectric layer 12. A horizontally wound shield layer (which may be a braided layer) 13 is formed by horizontally winding a conductor, and an adhesive layer (fusion layer) 14 which is a characteristic part of the present invention is formed on the outer periphery of the shield layer 13. It is configured. The adhesive layer 14 constitutes the outermost layer of the coaxial cable 10 and has a function of adhering to the jacket 20. The plurality of coaxial cables 10 are arranged in parallel so that the outer peripheral portions of the outermost layers 14 constituting the adjacent coaxial cables 10 are in contact with each other in the axial direction or very slightly separated from each other. It is covered with the cover 20 and integrated.

  For example, polyvinyl chloride (hereinafter referred to as “PVC”) is used as the material of the jacket 20. The material of the center conductor 11 is, for example, silver-plated annealed copper wire, and the material of the dielectric layer 12 is, for example, a tetrafluoroethylene / hexafluoropropylene copolymer (hereinafter referred to as “FEP”). Fluorine resin is used, and the material of the shield layer 13 is, for example, tin-plated annealed copper wire. The material of the adhesive layer 14 is, for example, a polyethylene terephthalate (hereinafter referred to as “PET”) and PVC laminate (hereinafter referred to as “AlPET”) bonded to aluminum via an adhesive.

  As this AlPET, for example, a tape-shaped product in which an aluminum foil having a thickness of 10 μm, a PET having a thickness of 12 μm, and a PVC having a thickness of 2 μm to 3 μm are laminated is used. Then, the aluminum foil is wound spirally so as to face the shield layer 13 side. The aluminum foil has a function of covering and protecting the shield layer 13, PET functions as a reinforcement layer, and PVC functions as a fusion layer that is heat-sealed with the jacket 20. And since it is wound helically, the shield layer 13 can be prevented from being broken and the electrical characteristics of the flat cable 100 can be improved. Instead of AlPET, a laminate having a two-layer structure of PET having a thickness of 4 μm and PVC having a thickness of 4 μm (hereinafter referred to as “PET body”) may be used, and polyethylene terephthalate (hereinafter referred to as “PET”) may be used instead of PVC. , "PE") may be used. Furthermore, any material other than PVC or PE can be used as a material for the fusion layer as long as it can be fused.

  According to the flat cable 100 having such a configuration, the coaxial cable 10 of the present embodiment does not have an external coating as in the case of the conventional coaxial cable. Therefore, the adjacent coaxial cables 10 are extremely thinner than the external coating. The layers 14 are in contact with each other. For this reason, since the arrangement pitch P of the coaxial cable 10 is substantially the same as the diameter of the coaxial cable 10, it can be made smaller than the arrangement pitch of the conventional coaxial cable, and the cable width (the coaxial cables 10 on both sides of the flat cable 100 can be reduced. The center-to-center distance (B) can be reduced to accommodate a small cable connector.

  Further, since the adjacent coaxial cables of the conventional flat cable are integrated with each other through the outer sheath, the outer sheath and the inner portion thereof are not peeled off. However, the flat cable 100 of the present embodiment is not peeled off. Since the adjacent coaxial cables 10 are integrated in a state where there is no jacket 20, there is a risk of peeling from the jacket 20 near the contact portion of the adjacent coaxial cables 10. However, since the adhesive layer 14 is formed on the outermost layer of the coaxial cable 10 to increase the adhesive force with the jacket 20, it is possible to prevent peeling of the adjacent coaxial cable 10 from the jacket 20 in the vicinity of the contact portion. it can.

Next, examples of the present invention will be described.
[Example 1]
First, a conductor layer made of a silver-plated annealed copper wire having a diameter of 160 μm is used as a central conductor 11A, and a dielectric layer 12A made of FEP is formed on the outer periphery thereof so that the outer diameter is 470 μm. The outer periphery of the dielectric layer 12A A cable was prepared in which a side-winding shield layer 13A was formed by winding 21 conductor wires made of tin-plated annealed copper wire into a side winding so that the diameter was 630 μm. Then, the reel around which the cable is wound and the reel around which the tape-like AlPET having a thickness of 24 μm is wound are set on a tape wrapper, and the AlPET is spirally wound around the outer periphery of the shield layer 13A to form the adhesive layer 14A. A coaxial cable 10A was manufactured.

Next, 62 reels around which the coaxial cable 10A is wound are prepared and set side by side in a flat cable molding machine, and the adhesive layer 14A of the adjacent coaxial cable 10A contacts in the axial direction in the molding die. The tip of the coaxial cable 10A was pulled out from each reel and set so as to be slightly separated from each other. Then, the inside of the molding die is heated to pull out all the coaxial cables 10A at the same time, and PVC is extruded into the molding die from the upper and lower sides of the cable row to constitute the adhesive layer 14A of the all coaxial cables 10A. The layers are heat-sealed with the outer cover 20A, and the outer cover 20A having a thickness of 1.3 mm (d shown in FIG. 2) and a width of 44.7 mm (L shown in FIG. 2) is formed around the entire coaxial cable 10A. A flat cable 100A having a cable width B of 42.7 mm was manufactured.
[Example 2]
First, a conductor layer made of silver-plated annealed copper wire having a diameter of 160 μm is used as a central conductor 11B, and a dielectric layer 12B made of FEP is formed on the outer periphery thereof so as to have an outer diameter of 460 μm, and an outer periphery of the dielectric layer 12B is formed on the outer periphery. A cable was prepared in which a braided shield layer 13B was formed by knitting a conductor wire made of tin-plated annealed copper wire with a number of 16 and a number of 3 so that the diameter was 680 μm. Then, the reel around which this cable is wound and the reel around which 8 μm thick tape-like PET is wound are set on a tape wrapper, and PET is spirally wound around the outer periphery of the shield layer 13B to form the adhesive layer 14B. The coaxial cable 10B was manufactured. Next, the above-described flat cable 100A is molded in the same manner, and the fusion layer constituting the adhesive layer 14B of the entire coaxial cable 10B is heat-sealed with the jacket 20B, and 1. A flat cable 100B having a cable width B of 42.7 mm was manufactured by forming a jacket 20 having a thickness of 3 mm (d shown in FIG. 2) and a width of 44.7 mm (L shown in FIG. 2).

  The arrangement pitch P of the coaxial cables 10A and 10B of each of the flat cables 100A and 100B is 700 μm, and the arrangement pitch of the coaxial cables of the flat cable manufactured using 62 conventional coaxial cables is 1200 μm (the width of the web portion is, for example, 500 μm). The size of the cable connector can be significantly smaller than that of a small cable connector.

  As described above, according to the flat cable 100 of the present embodiment, the outermost layer constituting the coaxial cable 10 is bonded to the outer cover 20 as the outermost layer constituting the coaxial cable 10 and the outermost layer constituting the adjacent coaxial cable 10. The adjacent coaxial cables 10 are in contact with each other without the outer coating of the conventional coaxial cable, and the arrangement pitch P of the coaxial cables 10 can be reduced. In addition, the cable width B of the flat cable 100 can be reduced to correspond to a small cable connector. Furthermore, since the adhesive layer 14 that is the outermost layer of each coaxial cable 10 and the outer jacket 20 of the flat cable 100 are bonded, the adjacent coaxial cables 10 do not have an outer sheath that constitutes a conventional coaxial cable. In addition, it is possible to prevent separation from the outer cover 20 in the vicinity of the contact portion of the adjacent coaxial cables 10.

  The scope of the present invention is not limited to the above-described embodiments and examples, and can be applied to various other embodiments as long as they do not contradict the description of the claims. For example, as long as the coaxial cable 10 has the adhesive layer 14 formed on the outermost layer, the other configuration, material, number, etc. are not particularly limited. The material of the outer cover 20 is not particularly limited as long as it can be bonded to the adhesive layer 14. Moreover, it is applicable as a simple electric wire instead of the coaxial cable 10.

  The flat cable according to the present invention is applicable not only to a personal computer but also to all electronic devices.

It is a top view which shows embodiment of the flat cable which concerns on this invention. It is the sectional view on the AA line of the flat cable of FIG.

Explanation of symbols

  10, 10A, 10B coaxial cable, 11, 11A, 11B center conductor, 12, 12A, 12B dielectric layer, 13, 13A, 13B shield layer, 14, 14A, 14B adhesive layer, 20, 20A, 20B jacket, 100 , 100A, 100B Flat cable

Claims (5)

In a flat cable in which a plurality of coaxial cables are arranged in parallel and the jacket is integrated,
The outermost layer constituting the coaxial cable is adhered to the jacket, and the outermost layers constituting the adjacent coaxial cables are in contact with each other or are slightly separated from each other. And flat cable. The coaxial cable includes a center conductor, an insulator formed around the center conductor, a shield layer formed on the outer periphery of the insulator, and an adhesive layer formed on the outer periphery of the shield layer. The flat cable according to claim 1. The flat cable according to claim 2, wherein the adhesive layer includes at least an insulator layer and a fusion bond layer. The flat cable according to claim 3, wherein the adhesive layer is formed in a tape shape, and the insulator layer side is spirally wound around an outer periphery of the shield layer. The flat cable according to any one of claims 1 to 4, wherein the jacket is integrated with the coaxial cable by extrusion molding.

Images