An integrated differential signal transmission unit's data transmission cable with a common ground

Abstract

The present invention discloses a data transmission cable with a common ground for an integrated differential signal transmission unit, comprising: a plurality of groups of differential signal transmission units arranged according to a set combination and bonded with transparent insulating heat-melt Mylar and single-sided conductive aluminum foil Mylar; and a plurality of ground wires; the differential signal transmission unit includes heat-melt copper foil Mylar and a pair of differential signal lines wrapped by the heat-melt copper foil Mylar, wherein two conductors of the pair of differential signal lines are injection-molded in the same insulator; the outer side of the heat-melt copper foil Mylar is the conductive side, which is bonded to the conductive side of the single-sided conductive aluminum foil Mylar; the ground wires are connected by being bonded to the conductive side of the single-sided conductive aluminum foil Mylar. The data transmission cable with a common ground for an integrated differential signal transmission unit provided by the present invention improves the data transmission bandwidth and the manufacturing precision of the signal transmission unit, enables the wire arrangement to have a higher density, and simultaneously solves the problems of large wire arrangement thickness and difficult bending.

Description

Technical Field

[0001] The present invention relates to the technical field of data transmission cables, and particularly to a data transmission cable with a common ground for an integrated differential signal transmission unit. Background Art

[0002] Currently, there are mainly the following three common data transmission cables: The first is to laminate two upper and lower aluminum foil mylars to wrap a group of differential signal transmission units, and the aluminum foil mylar is used as a reference layer to connect to the ground wire and ground; the second is to wrap a group of differential signal wires together with the ground wire with an aluminum foil mylar as a group of differential signal transmission units, and the ground wire is on one side of the center line connecting the two conductors and not in the same plane; the third is to wrap a group of differential signal wires together with two ground wires with an aluminum foil mylar as a group of differential signal transmission units, and the ground wires are on the left and right sides of the center line connecting the two conductors and in the same plane; the fourth is that two signal transmission conductors are integrally formed, wrapped with a layer of copper foil shielding, then a layer of aluminum foil mylar, and the outermost layer is a heat-melting plastic sheath.

[0003] However, each of these four solutions has its own drawbacks: In the first solution, the two aluminum foil mylars are laminated together and close to the left and right insulating places, unable to fit tightly, resulting in impedance changes at this place and affecting the integrity of signal transmission; in the second solution, after peeling off the aluminum foil and insulation, the position of the ground wire must be manually adjusted before it can be welded to the pad, and a ground wire grounding pad must be assigned to each pair to make it work properly, affecting production efficiency and quality; in the third solution: the total width of the wire harness is too large and the density is low; and manual adjustment is required during welding, with low processing efficiency; winding the ground wire and the transmission unit in the same plane results in an unstable structure, prone to twisting and deformation, thus affecting consistency and causing changes in characteristic impedance, affecting the integrity of signal transmission. In the fourth solution, the subsequent ground wire processing process is complex and costly; and the overall thickness of the wire harness is large, not conducive to bending and shaping, affecting data transmission accuracy. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides a data transmission cable with a common ground for an integrated differential signal transmission unit, which improves the data transmission bandwidth and the manufacturing accuracy of the signal transmission unit, makes the wire harness have a higher density, and at the same time solves the problems of large wire harness thickness and difficult bending.

[0005] To achieve the above object, the present invention provides a data transmission cable with a common ground for an integrated differential signal transmission unit, comprising:

[0006] A plurality of groups of differential signal transmission units and a plurality of ground wires arranged according to a set combination and laminated with a transparent insulating heat-melting mylar and a single-sided conductive aluminum foil mylar;

[0007] The differential signal transmission unit includes a heat-melt copper foil mylar and a pair of differential signal lines wrapped by the heat-melt copper foil mylar. Among them, the two conductors of the pair of differential signal lines are injection-molded in the same insulator;

[0008] The outer side of the heat-melt copper foil mylar is the conductive side, which is attached to the conductive side of the single-sided conductive aluminum foil mylar; the ground wire is connected by attaching to the conductive side of the single-sided conductive aluminum foil mylar.

[0009] In one embodiment, the insulating side material of the single-sided conductive aluminum foil mylar is insulating plastic mylar, and the conductive side material is aluminum-based conductive metal foil.

[0010] In one embodiment, the outer side of the heat-melt copper foil mylar is the conductive side, which is attached to the conductive side of the single-sided conductive aluminum foil mylar, including:

[0011] The conductive side of the heat-melt copper foil mylar is directly attached to the conductive side of the single-sided conductive aluminum foil mylar, or attached through conductive hot melt adhesive.

[0012] In one embodiment, the ground wire is connected by attaching to the conductive side of the single-sided conductive aluminum foil mylar, including:

[0013] The ground wire is connected to the conductive side of the single-sided conductive aluminum foil mylar by direct attachment or by attachment through conductive hot melt adhesive.

[0014] In one embodiment, the heat-melt copper foil mylar is wrapped on the outer surface of the insulator. Specifically, the inner layer of the heat-melt copper foil mylar tightly wraps the outer surface of the insulator in a winding or longitudinal wrapping manner by heat melting.

[0015] In one embodiment, the material of the transparent insulating heat-melt mylar is polyester resin.

[0016] In one embodiment, the material of the insulating layer is any one of polyethylene, polypropylene, polytetrafluoroethylene, and perfluoroethylene-propylene copolymer.

[0017] In one embodiment, the materials of the conductor and the ground wire are any one of silver-plated copper, tin-plated copper, and bare copper.

[0018] In one embodiment, the sizes of the conductor and the ground wire are any one of 22 American wire gauge to 36 American wire gauge.

[0019] Compared with the prior art, the high-speed data transmission cable with a common ground for the integrated differential signal transmission unit provided by the embodiments of the present invention has at least the following beneficial effects:

[0020] 1) The method of integrally forming two conductors of differential signals is adopted, which improves the accuracy of the relative position of the two conductors; the design of the relative position of the two conductors is more flexible, and the spacing does not have to be limited to the sum of twice the outer radius of insulation; during subsequent production testing and twisting and bending during use, the design structure can be better maintained without causing changes in electrical performance parameters.

[0021] 2) The method of independently shielding each group of differential signal transmission units is adopted, which avoids the disadvantage of the change in characteristic impedance caused by the opening of the paste gap that may occur in the method of directly laminating two metal foils, and improves the data transmission bandwidth.

[0022] 3) Compared with other solutions that separately shield differential signal transmission units, this solution cancels the ground wire inside the unit and connects the ground wire to the ground through aluminum foil. The advantage is that the structure inside the unit is simpler and more compact, and when multiple units are arranged side by side, the total width is smaller; at the same time, canceling the ground wires inside these units makes it more convenient to strip wires and weld during subsequent cable assembly production, improving production efficiency and quality.

[0023] 4) One of the outermost layers adopts a single-sided aluminum foil method, which reduces costs, reduces the thickness of the cable, and makes the cable softer.

[0024] 5) The difference in the appearance of the outermost two layers of film makes it convenient to identify the direction during subsequent assembly, and it is easy to trace the order of each unit group inside the cable when bending and wiring. Description of the Drawings

[0025] Figure 1 is a cross-sectional schematic diagram of a data transmission cable with a common ground for a group of integrated differential signal transmission units provided by an embodiment of the present invention;

[0026] Figure 2 is a structural schematic diagram of a data transmission cable with a common ground for integrated differential signal transmission units provided by an embodiment of the present invention;

[0027] Figure 3 is a cross-sectional schematic diagram of a data transmission cable with a common ground for integrated differential signal transmission units provided by an embodiment of the present invention;

[0028] Figure 4 is a cross-sectional schematic diagram of a data transmission cable with a common ground for integrated differential signal transmission units provided by an embodiment of the present invention;

[0029] Figure 5 is a cross-sectional schematic diagram of a data transmission cable with a common ground for integrated differential signal transmission units provided by an embodiment of the present invention;

[0030] Figure 6It is a cross-sectional schematic diagram of a data transmission cable with a common ground for an integrated differential signal transmission unit provided by an embodiment of the present invention;

[0031] Figure 7 It is a cross-sectional schematic diagram of a data transmission cable with a common ground for an integrated differential signal transmission unit provided by an embodiment of the present invention.

[0032] Main components and symbol descriptions:

[0033] Data transmission cable 100, ground wire 10, heat-melt copper foil mylar 20, conductor 301, insulating layer 302, transparent insulating heat-melt mylar 40, single-sided conductive aluminum foil mylar 50, differential signal transmission unit 60 Specific embodiments

[0034] The following combines the accompanying drawings and embodiments to further describe in detail the specific embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0035] The present invention provides a data transmission cable with a common ground for an integrated differential signal transmission unit, including:

[0036] A number of differential signal transmission units and a number of ground wires arranged according to a set combination and bonded with a transparent insulating heat-melt mylar and a single-sided conductive aluminum foil mylar;

[0037] The differential signal transmission unit includes a heat-melt copper foil mylar and a pair of differential signal lines wrapped by the heat-melt copper foil mylar, wherein the two conductors of the pair of differential signal lines are injection-molded in the same insulator;

[0038] The outer side of the heat-melt copper foil mylar is the conductive side, which is bonded to the conductive side of the single-sided conductive aluminum foil mylar; the ground wire is connected by being bonded to the conductive side of the single-sided conductive aluminum foil mylar.

[0039] In this embodiment, it should be noted that a pair of differential signal lines wrapped by a heat-melt copper foil mylar form a set of differential signal transmission units. The heat-melt copper foil mylar, also known as copper foil mylar polyester tape, has a golden yellow appearance, uniform color, and no odor. It utilizes the high tensile strength and electrical properties of biaxially stretched polyester materials to provide the coating and insulation for the internal structure of the cable, and is suitable for the insulation of composite wires with multi-strand structures such as signal transmission lines and control lines, as well as other wires. In this embodiment, through a transparent insulating heat-melt mylar and a single-sided conductive aluminum foil mylar, the ground wire and the differential signal transmission units are arranged in a certain combination and then bonded together. The copper foil layer serves as the reference plane for the differential signal lines and is electrically connected to the single-sided conductive aluminum foil mylar, and the ground wire is also electrically connected to the single-sided conductive aluminum foil mylar, thereby realizing the grounding of the reference plane of the differential signal unit. In addition, by using a single-sided aluminum foil on one outermost layer, the cost is reduced, the thickness of the wire arrangement is reduced, and the wire arrangement becomes softer; by using a transparent heat-melt mylar on the other outermost layer, the natural color of the copper foil mylar can be seen from the outside, making the appearance better-looking and more technological. And due to the different appearances of the outermost two layers of the film, it is convenient to identify the direction during subsequent assembly, and it is easy to trace the order of each unit group in the wire arrangement when bending and wiring.

[0040] Among them, it should be noted that the two conductors of the pair of differential signal lines are injection-molded in the same insulator; that is, there is no air layer in the differential signal lines wrapped by the heat-melt copper foil mylar, and it is a solid structure.

[0041] In a certain embodiment, the insulating side material of the single-sided conductive aluminum foil mylar is insulating plastic mylar, and the conductive side material is aluminum-based conductive metal foil.

[0042] In this embodiment, the single-sided conductive aluminum foil mylar has single-sided conductivity, and the conductive side material is aluminum-based conductive metal foil. This material is a thin and continuous metal foil, which is usually also used as the conductor of the circuit board and has good ductility; the insulating plastic mylar is a kind of mylar sheet, and the appearance of the mylar sheet has various color classifications such as milky white, black, natural color, and transparent color. There are various materials for mylar sheets, such as PET mylar sheets, PVC mylar sheets, PC mylar sheets, fireproof mylar sheets, etc.

[0043] Common applications are divided into: insulating type, buffering type, wear-resistant type, sealing type, and appearance decoration type mylar. Here, insulating plastic mylar is used.

[0044] In a certain embodiment, the outer side of the heat-melt copper foil mylar is the conductive side, which is bonded to the conductive side of the single-sided conductive aluminum foil mylar, including:

[0045] The conductive side of the heat-melt copper foil mylar is directly bonded to the conductive side of the single-sided conductive aluminum foil mylar, or bonded through conductive hot melt adhesive.

[0046] In this embodiment, the hot-melt copper foil Mylar is a single-sided conductive Mylar. Its conductive side is directly adhered to the conductive side of the single-sided conductive aluminum foil Mylar, or adhered through a conductive hot melt adhesive. The hot melt adhesive has characteristics such as no peculiar smell and high melting point, so it performs excellently in terms of environmental protection and washing resistance. At the same time, the hot melt adhesive web has good air permeability, and products with high air permeability requirements can use the hot melt adhesive web as raw material. Adhering with a hot melt adhesive has the following advantages: 1) Fast bonding speed, convenient for continuous and automated high-speed operation, and low cost; 2) No solvent pollution and non-flammable; 3) No drying process is required, and the bonding process is simple; 4) The product itself is solid, convenient for packaging, transportation, storage, small floor area, and convenient for storage; 5) Has good bonding strength and flexibility; 6) Can bond a wide range of objects, both bonding and sealing; 6) Good gloss and gloss retention, good shielding property. Of course, adhering with a hot melt adhesive also has corresponding disadvantages. For example: Limited performance, insufficient heat resistance, low bonding strength, poor chemical resistance; Special hot melt equipment needs to be equipped for construction, such as a hot melt adhesive machine and a hot melt adhesive gun; The bonding will be affected by climate and seasons. Therefore, in order to avoid this disadvantage, a direct adhesion method can be used.

[0047] In one embodiment, the ground wire is connected by adhering to the conductive side of the single-sided conductive aluminum foil Mylar, including:

[0048] The ground wire is connected to the conductive side of the single-sided conductive aluminum foil Mylar by direct adhesion or by adhesion with a conductive hot melt adhesive.

[0049] In one embodiment, the hot-melt copper foil Mylar is wrapped on the outer surface of the insulator. Specifically: The inner layer of the hot-melt copper foil Mylar tightly wraps the outer surface of the insulator in a winding or longitudinal wrapping manner by hot melt.

[0050] In this embodiment, the hot melt method is generally used for hot melt connection. The principle of hot melt connection is to closely attach the mating surfaces of two PE pipes to a heating tool to heat their flat end faces until they are melted. After removing the heating tool, tightly press the two melted end faces together and maintain them under pressure until the joint cools, so that the two sections of pipes are connected into a whole.

[0051] Among them, a perfect ratio must be achieved among the wire diameter of the composite insulation winding wire, the width and thickness of the winding film, the overlap rate, the winding pitch, and the winding angle during winding. At the same time, the stretching of the film must be considered in the structural design. Longitudinal wrapping is a method of wrapping tape, that is, dragging a layer of tape along the advancing direction of the semi-finished product during extrusion to achieve the effect of isolating the outer sheath.

[0052] In one embodiment, the material of the transparent insulating hot-melt Mylar is polyester resin. This material has the following characteristics: It has good mechanical properties, and its impact strength is 3-5 times that of other films. It has good folding resistance, is resistant to oil, fat, dilute acids, dilute alkalis, and most solvents; it has excellent high and low temperature resistance, can be used for a long time within the temperature range of 120 °C, can withstand a short-term high temperature of 150 °C, and can withstand a low temperature of -70 °C. Moreover, its mechanical properties are little affected by high and low temperatures; it has low gas and water vapor permeability, and has excellent gas, water, oil, and odor barrier properties; it has high transparency, can block ultraviolet rays, and has good gloss; it is non-toxic, odorless, has good hygienic safety, and can be directly used for food packaging. Polyester resin is the most important variety in thermoplastic polyesters.

[0053] In one embodiment, the material of the insulating layer is any one of polyethylene, polypropylene, polytetrafluoroethylene, and perfluoroethylene-propylene copolymer.

[0054] In this embodiment, it should be noted that in actual applications, the most commonly used is perfluoroethylene-propylene copolymer; also known as FEP, it can be applied to flexible plastics. Its tensile strength, wear resistance, and creep resistance are lower than those of many engineering plastics. It is chemically inert and has a low dielectric constant in a wide temperature and frequency range. This material does not ignite and can prevent the spread of flames. It has excellent wear resistance and a low coefficient of friction. This material can be made into granular products for extrusion and molding, used as powders for fluidized beds and electrostatic coating, and can also be made into an aqueous dispersion. The semi-finished products include film plates. Its main uses are for making the inner lining of pipes and chemical equipment, the surface layer of rollers, and various wires and cables, such as aircraft hook-up wires, pressurized cables, alarm cables, flat cables, and well logging cables for oil wells. FEP films are also commonly used as thin coatings for solar collectors; polytetrafluoroethylene is transparent to opaque, easy to bend, and elastic; while polyethylene is semi-transparent to transparent, hard, and can be made into transparent films; in terms of characteristics, polytetrafluoroethylene can be widely used in various places that require resistance to acids, alkalis, and organic solvents. It is not toxic to the human body itself, but one of the raw materials used in the production process, PFOA, is considered potentially carcinogenic. It can work at a temperature of +250 °C to -180 °C for a long time. Except for molten sodium metal and liquid fluorine, it can withstand all chemical substances. Its high temperature resistance and small coefficient of friction not only play a lubricating role but also make it an ideal coating for non-stick pans and the inner layer of water pipes. Polyethylene is a thermoplastic resin obtained by polymerizing ethylene. It has excellent low temperature resistance (the lowest service temperature can reach -70 °C to -100 °C). It has good chemical stability and can withstand the erosion of various acids and alkalis (except for oxidizing acids). It is insoluble in common solvents at room temperature, has little water absorption, and has excellent electrical insulation properties. However, polyethylene is very sensitive to environmental stress (chemical and mechanical actions), has poor heat aging resistance, and the properties of polyethylene vary depending on the variety, mainly depending on the molecular structure and density.

[0055] In one embodiment of the present invention, the material of the conductor and the ground wire is any one of silver-plated copper, tin-plated copper, and bare copper. Copper will undergo an oxidation reaction in the air, generating copper green, which will greatly weaken the electrical conductivity of the cable. Therefore, some manufacturers use tin-plated, nickel-plated, or high-end silver-plated copper wires to make cables. Tin-plated copper wires have better electrical conductivity than bare copper, and of course, the cost is also higher than that of bare copper. Moreover, for some welding projects, tin-plated ones are more convenient for welding. Therefore, tin-plated copper is commonly used as the conductor now.

[0056] In one embodiment of the present invention, the sizes of the conductor and the ground wire are any one of 22 American Wire Gauge (AWG) to 36 AWG. AWG is an abbreviation and a standard for differentiating wire diameters, also known as Brown & Sharpe wire gauge. The value in front of AWG (such as 24 AWG, 26 AWG) represents the number of holes that the wire has to pass through before forming the final diameter. The larger the value, the higher the grade of the holes that the wire passes through, and the smaller the wire diameter. Thick wires have better physical strength and lower resistance, but the thicker the wire, the more copper is required to make the cable, which will result in a heavier, more difficult-to-install, and more expensive cable. The challenge in cable design is to use wires with the smallest possible diameter (to reduce cost and installation complexity) while ensuring the maximum capacity of the wire under the necessary voltage and frequency.

[0057] Please refer to Figure 2 and Figure 3 , one embodiment of the present invention provides a data transmission cable with a common ground for an integrated differential signal transmission unit. Figure 2 which is the overall structure diagram of the cable, Figure 3 and

[0058] Please refer to Figure 4 and Figure 5 , one embodiment of the present invention provides a cross-sectional view of a data transmission cable with a common ground for an integrated differential signal transmission unit. The cable is composed of 12 groups of differential signal transmission units and 6 ground wires. The middle part can be conveniently cut, facilitating splitting it into two in practical applications. The cross-sectional view of the cable after splitting into two is as shown in Figure 5 .

[0059] Please refer to Figure 6 , one embodiment of the present invention provides a cross-sectional view of a data transmission cable with a common ground for an integrated differential signal transmission unit. The cable is composed of 12 groups of differential signal transmission units and 7 ground wires.

[0060] Please refer to Figure 7 , a cross-sectional view of a data transmission cable with a common ground for an integrated differential signal transmission unit according to an embodiment of the present invention. The cable is composed of 6 groups of differential signal transmission units and 4 ground wires.

[0061] It should be noted that in actual applications, several groups of differential signal transmission units and several ground wires are bonded with transparent insulating heat-melt Mylar and single-sided conductive aluminum foil Mylar; the rules for arranging combinations can be set according to specific needs. The above-disclosed are only the preferred embodiments of the present invention, and of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. An integrated differential signal transmission unit's data transmission cable sharing a common ground, characterized in that, Including: A number of differential signal transmission units arranged according to a set combination and bonded with transparent insulating heat-melt Mylar and single-sided conductive aluminum foil Mylar, and a number of ground wires; The differential signal transmission unit includes heat-melt copper foil Mylar and a pair of differential signal lines wrapped by the heat-melt copper foil Mylar. Among them, the two conductors of the pair of differential signal lines are injection-molded in the same insulator; The heat-melt copper foil Mylar is wrapped on the outer surface of the insulator. The specific wrapping method is: the inner layer of the heat-melt copper foil Mylar tightly wraps the outer surface of the insulator in a winding or longitudinal wrapping manner by heat-melting; There is no air layer inside the wrapping of the heat-melt copper foil Mylar, and it is a solid structure; The material of the insulator is any one of polyethylene, polypropylene, polytetrafluoroethylene and perfluoroethylene-propylene copolymer; The outer side of the heat-melt copper foil Mylar is the conductive side, which is bonded to the conductive side of the single-sided conductive aluminum foil Mylar; the ground wire is connected by bonding to the conductive side of the single-sided conductive aluminum foil Mylar.

2. The data transmission cable with a common ground for the integrated differential signal transmission unit according to claim 1, characterized in that The insulating side material of the single-sided conductive aluminum foil Mylar is insulating plastic Mylar, and the conductive side material is aluminum-based conductive metal foil.

3. The data transmission cable with a common ground for the integrated differential signal transmission unit according to claim 1, wherein, The outer side of the heat-melt copper foil Mylar is the conductive side, which is bonded to the conductive side of the single-sided conductive aluminum foil Mylar, including: The conductive side of the heat-melt copper foil Mylar is directly bonded to the conductive side of the single-sided conductive aluminum foil Mylar, or bonded through conductive hot melt adhesive.

4. The data transmission cable with a common ground for the integrated differential signal transmission unit according to claim 1, characterized in that, The ground wire is connected by bonding to the conductive side of the single-sided conductive aluminum foil Mylar, including: The ground wire is connected to the conductive side of the single-sided conductive aluminum foil Mylar by direct bonding or by bonding through conductive hot melt adhesive.

5. The data transmission cable with a common ground for the integrated differential signal transmission unit according to claim 1, wherein The material of the transparent insulating heat-melt Mylar is polyester resin.

6. The data transmission cable with a common ground for the integrated differential signal transmission unit according to claim 1, wherein The materials of the conductor and the ground wire are any one of silver-plated copper, tin-plated copper and bare copper.

7. The data transmission cable with a common ground for the integrated differential signal transmission unit according to claim 1, wherein The sizes of the conductor and the ground wire are any one of 22 American wire gauge to 36 American wire gauge.

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