Preparation device and preparation method of active cable and inner shielding layer made of indium tin oxide

Abstract

The invention belongs to the technical field of active cables, and particularly relates to an active cable made of indium tin oxide, an inner shielding layer preparation device and a preparation method thereof.The active cable comprises an inner conductor, inner shielding layers, an insulating layer, an outer shielding layer set and a sheath layer, the inner conductor comprises two wires arranged in parallel, each wire is sleeved with one inner shielding layer, and the insulating layer is arranged in the outer shielding layer set; the inner shielding layers are made of indium tin oxide, the insulating layer is arranged outside the two inner shielding layers in a sleeving mode, and the insulating layer is sequentially wrapped with the outer shielding layer set and the sheath layer outwards. The electric field of the active cable in the transmission process is enhanced through the indium tin oxide of the inner shielding layers, and therefore the effective transmission distance of the active cable is increased; meanwhile, by means of the excellent heat insulation property of the micron-sized indium tin oxide film, it can be guaranteed that the use performance of the active cable can be stably guaranteed at the extreme temperature, the vacuum evaporation method is used, the film forming method is simple, the purity and compactness of the film are high, the film structure and performance are unique, and the processing method can be used for large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of active cables, and in particular relates to an active cable made of indium tin oxide, a preparation device for an inner shielding layer and a preparation method thereof. Background Art

[0002] Active cables are cables that integrate active components such as amplifiers and filters to achieve special functions. Compared with ordinary passive cables, active cables can provide signal amplification, filtering and other capabilities to enhance the transmission performance of electrical signals. Active cables are widely used in signal transmission in telecommunications, radio and television, military, aerospace and other fields.

[0003] AEC active cables are released by the HiWire Alliance. The HiWire AEC specification defines the standards for basic electrical and mechanical specifications. The faster the maximum transmission rate of the active cable, the shorter the transmission distance limit. Generally, the length of active cables is within 10m. Active cables require external power supply to power the electronic circuits, which increases the power consumption of the system. As the transmission distance increases, the power consumption will continue to increase, which also limits the transmission distance. With the development and application of the communications field, the industry has put forward further requirements for the transmission distance and environmental resistance of active cables. Summary of the invention

[0004] In view of this, in order to solve the problems existing in the prior art, the purpose of the present invention is to provide an active cable made of indium tin oxide, a preparation device for an inner shielding layer and a preparation method thereof, which has the advantages of enhancing the electric field of the active cable during the transmission process, thereby increasing the effective transmission distance of the active cable, and being able to maintain a good use effect under extreme temperature conditions.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] An active cable made of indium tin oxide, comprising: an inner conductor, an inner shielding layer, an insulating layer, an outer shielding layer group and a sheath layer, wherein the insulating layer is outwardly covered with the outer shielding layer group and the sheath layer in sequence, the inner conductor comprises two parallel wires, each of the wires is sheathed with an inner shielding layer to form a conductor structure, the inner shielding layer is made of indium tin oxide, and the two conductor structures are embedded in the insulating layer.

[0007] The specific technical effect is: through the indium tin oxide of the inner shielding layer, the electric field of the active cable during the transmission process is enhanced, thereby increasing the effective transmission distance of the active cable. At the same time, the excellent thermal insulation of the micron-level indium tin oxide film can ensure that the active cable can stably maintain its performance under extreme temperatures. The active cable with an inner shielding layer made of indium tin oxide can be used in chassis distribution connections and external field wiring layouts.

[0008] Furthermore, the outer shielding layer group includes an outer shielding layer and a wire pair shielding layer which are sequentially sleeved from the inside to the outside, the outer shielding layer is made of copper, and the wire pair shielding layer is made of tinned copper mesh.

[0009] The specific technical effect is: using a tightly woven tinned copper mesh outside the outer shielding layer can prevent external electromagnetic wave interference.

[0010] Furthermore, it also includes a drain wire, which is made of tinned copper wire and is inserted into the outer shielding layer and located between the two conductors.

[0011] Furthermore, the thickness of the outer shielding layer ranges from 0.10 mm to 0.30 mm, the outer diameter of the wire of the tinned copper mesh ranges from 0.10 mm to 0.20 mm, and the weaving density of the tinned copper mesh is not less than 85%.

[0012] Furthermore, the conductor is made of copper wire with a diameter of 0.506 mm to 0.510 mm.

[0013] Furthermore, the insulating layer is made of PVC material, and the thickness of the insulating layer ranges from 0.30 mm to 0.35 mm.

[0014] Furthermore, the sheath layer is made of polyperfluoroethylene propylene copolymer, and the thickness of the sheath layer ranges from 0.33 mm to 0.68 mm.

[0015] A preparation device for preparing the inner shielding layer described in any one of the above items, comprising a shell, a vacuum chamber formed in the shell, a tin oxide crucible for evaporating tin oxide and an indium oxide crucible for evaporating indium oxide provided at the bottom of the vacuum chamber, the tin oxide crucible and the indium oxide crucible being arranged in parallel, a movable baffle that can move up and down is provided above the tin oxide crucible and the indium oxide crucible, a first through hole for the indium oxide vapor to flow through and a second through hole for the tin oxide vapor to flow through are provided on the movable baffle, and a rotating shaft clamp for placing the inner conductor is provided on both sides of the upper end of the shell.

[0016] The specific technical effect is: indium oxide is used as the basic framework of the material to establish a stable crystal structure and basic electronic properties, and tin oxide is doped to improve the electrical conductivity of the material. Since the surface of indium tin oxide has abundant chemical bonds, it is conducive to combining with the interface of metal and other media, so no complicated chemical process is required for treatment. Therefore, through the design of the vacuum chamber, indium oxide crucibles and tin oxide crucibles are set in the vacuum chamber to use vacuum evaporation. Compared with other physical vapor deposition methods, this method has the advantages of simple film formation method, high film purity and density, unique film structure and performance, etc., and can evaporate a variety of different substances at the same time, which is suitable for the evaporation of mixed indium tin oxide films.

[0017] Furthermore, mounting holes are respectively provided on both sides of the upper end of the shell, each of the mounting holes is arranged opposite to one of the rotating shaft clamps, and a sealing ring is arranged in each of the mounting holes.

[0018] The specific technical effect is: the sealing performance of the vacuum chamber is ensured by setting a sealing ring.

[0019] A preparation method, using a preparation device as described in any one of the above to prepare the inner shielding layer as described in any one of the above, wherein the method comprises the following steps:

[0020] Step S1, cleaning and polishing, using deionized water to clean and polish the selected inner conductor;

[0021] Step S2, placing the inner conductor processed in step S1 into the vacuum chamber, and installing the two ends of the inner conductor in the rotating shaft clamp through the sealing rings in the mounting holes respectively, and the rotating shaft clamp can drive the inner conductor to rotate 180°;

[0022] Step S3, loading tin oxide into a tin oxide crucible, loading indium oxide into an indium oxide crucible, connecting the tin oxide crucible and the indium oxide crucible to an external power supply, and controlling the evaporation rates of the tin oxide crucible and the indium oxide crucible respectively;

[0023] Step S4, performing vacuum evaporation operation, turning on the external power supply, and controlling the proportion of indium oxide and tin oxide in the inner shielding layer of indium tin oxide according to the evaporation temperature and steam flow in the tin oxide crucible and the indium oxide crucible and the position of the movable baffle, respectively, and the thickness of the inner shielding layer ranges from 0.5um to 1um;

[0024] Step S5, after the vacuum evaporation process of step S4 is completed, the external power supply is turned off, and when the air pressure in the vacuum chamber is close to that in the outside, the vacuum chamber is opened to turn the inner conductor 180 degrees by means of the rotating shaft clamp;

[0025] Step S6, repeating steps S4 and S5, so that both sides of the inner conductor can be plated with indium tin oxide, thereby forming an inner shielding layer;

[0026] Step S7, cutting and sampling the inner shielding layer obtained in step S6, performing physical characterization by scanning electron microscopy, and measuring the thickness of the indium tin oxide film layer. If the thickness requirement is met, subsequent processing operations of the insulating layer, the outer shielding layer group and the sheath layer can be performed.

[0027] The beneficial effects of the present invention are:

[0028] (1) The indium tin oxide shielding layer of the active cable can effectively enhance the local electric field of the active cable during the transmission process, effectively ensure the strength of the active cable transmission, thereby being able to transmit electromagnetic signals over a longer distance and provide a good thermal insulation environment, which can meet the layout efficiency and functional requirements of the corresponding equipment and has good economic benefits and social value;

[0029] (2) Using a tightly woven tinned round copper mesh as the outer shielding layer can prevent external electromagnetic interference;

[0030] (3) In the preparation method of indium tin oxide active cable, since the surface of indium tin oxide has abundant chemical bonds, it is conducive to combining with the interface of metal and other media, so no complicated chemical process is required for treatment. Therefore, vacuum evaporation is used here. Compared with other physical vapor deposition methods, this method has the advantages of simple film formation method, high film purity and density, unique film structure and performance, etc., and can evaporate a variety of different substances at the same time, which is suitable for the evaporation of mixed indium tin oxide film. By virtue of the advantages of this material in metal contact and interface engineering, a processing method that can be mass-produced is proposed.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 It is a schematic structural diagram of the preparation device of the present invention;

[0034] Figure 2 It is a schematic diagram of the longitudinal cross-section structure of the active cable of the present invention;

[0035] Figure 3 It is a schematic diagram of the cross-sectional structure of the active cable of the present invention.

[0036] In the figure:

[0037] 1. Inner conductor; 2. Inner shielding layer; 3. Insulating layer; 4. Outer shielding layer group; 41. Outer shielding layer; 42. Line pair shielding layer; 5. Sheath layer; 6. Drain wire; 7. Shell; 8. Vacuum chamber; 9. Tin oxide crucible; 10. Indium oxide crucible; 11. Moving baffle; 12. First through hole; 13. Second through hole; 14. Rotating shaft clamp. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] like Figures 1 to 3 As shown, an active cable made of indium tin oxide includes: an inner conductor 1, an inner shielding layer 2, an insulating layer 3, an outer shielding layer group 4 and a sheath layer 5, the insulating layer 3 is sleeved on the outside of the two inner shielding layers 2, and the insulating layer 3 is sequentially covered with the outer shielding layer group 4 and the sheath layer 5 outward, the inner conductor 1 includes two parallel wires, each of which is sleeved with an inner shielding layer 2 to form a conductor structure, the inner shielding layer 2 is made of indium tin oxide, and the two conductor structures are embedded in the insulating layer 3.

[0040] It should be noted here that: the indium tin oxide of the inner shielding layer 2 is used to enhance the electric field of the active cable during transmission, thereby increasing the effective transmission distance of the active cable. At the same time, the excellent thermal insulation of the micron-level indium tin oxide film can ensure that the active cable can stably maintain its performance under extreme temperatures. The active cable with the inner shielding layer 2 made of indium tin oxide can be used in the fields of chassis distribution connection and external field wiring layout; the indium tin oxide film of the active cable is a degenerate semiconductor, and its carrier concentration measured in a laboratory environment reaches 10 20 cm -3 . In the case of an external electric field, the indium tin oxide film layer will be polarized. After the polarization is stable, it can generate a certain electric field and achieve a good electric field enhancement effect. At the same time, the carriers of this degenerate semiconductor basically do not change with temperature. Its electronic properties depend on electron mobility, and the electron mobility of indium tin oxide is determined by the material itself. Therefore, the indium tin oxide layer can well isolate the influence of temperature.

[0041] The outer shielding layer group 4 comprises an outer shielding layer 41 and a wire pair shielding layer 42 which are sequentially sleeved from the inside to the outside. The outer shielding layer 41 is made of copper, and the wire pair shielding layer 42 is made of tinned copper mesh.

[0042] It should be noted here that the use of a tightly woven tinned copper mesh outside the outer shielding layer 41 can prevent external electromagnetic wave interference.

[0043] The device further comprises a drain wire 6 which is made of tinned copper wire. The drain wire 6 is inserted into the outer shielding layer 41 and is located between the two conductors.

[0044] The thickness of the outer shielding layer 41 ranges from 0.10 mm to 0.30 mm, the outer diameter of the wire of the tinned copper mesh ranges from 0.10 mm to 0.20 mm, and the weaving density of the tinned copper mesh is not less than 85%.

[0045] The conductor is made of copper wire with a diameter of 0.506mm to 0.510mm.

[0046] The insulating layer 3 is made of PVC material, and the thickness of the insulating layer 3 is in the range of 0.30 mm to 0.35 mm.

[0047] The sheath layer 5 is made of polyperfluoroethylene propylene copolymer, and the thickness of the sheath layer 5 is in the range of 0.33 mm to 0.68 mm.

[0048] A preparation device, used for preparing the inner shielding layer 2 of any one of the above items, comprising a shell 7, a vacuum chamber 8 is formed in the shell 7, a tin oxide crucible 9 for evaporating tin oxide and an indium oxide crucible 10 for evaporating indium oxide are arranged at the bottom of the vacuum chamber 8, the tin oxide crucible 9 and the indium oxide crucible 10 are arranged in parallel, a movable baffle 11 that can move up and down is arranged above the tin oxide crucible 9 and the indium oxide crucible 10, a first through hole 12 for indium oxide vapor to flow through and a second through hole 13 for tin oxide vapor to flow through are opened on the movable baffle 11, and a rotating shaft clamp 14 for placing the inner conductor 1 is respectively arranged on both sides of the upper end of the shell 7.

[0049] It should be noted here that indium oxide serves as the basic framework of the material to establish a stable crystal structure and basic electronic properties, and tin oxide is doped to improve the electrical conductivity of the material. Since the surface of indium tin oxide has abundant chemical bonds, it is conducive to combining with the interface of metal and other media, so no complicated chemical process is required for treatment. Therefore, through the design of the vacuum chamber 8, an indium oxide crucible 10 and a tin oxide crucible 9 are set in the vacuum chamber 8 to use a vacuum evaporation method. Compared with other physical vapor deposition methods, this method has the advantages of simple film forming method, high film purity and density, unique film structure and performance, etc., and can evaporate a variety of different substances at the same time, which is suitable for the evaporation of mixed indium tin oxide films.

[0050] Mounting holes are respectively provided on both sides of the upper end of the housing 7 , each mounting hole is arranged opposite to a rotating shaft clamp 14 , and a sealing ring is arranged in each mounting hole.

[0051] It should be noted here that the sealing performance of the vacuum chamber 8 is ensured by providing a sealing ring.

[0052] A preparation method, using a preparation device as described above to prepare the inner shielding layer 2 of any one of the above, wherein the method comprises the following steps:

[0053] Step S1, cleaning and polishing, using deionized water to clean and polish the selected inner conductor 1;

[0054] Step S2, placing the inner conductor 1 processed in step S1 into the vacuum chamber 8, and installing the two ends of the inner conductor 1 into the rotating shaft clamp 14 through the sealing rings in the mounting holes respectively, and the rotating shaft clamp 14 can drive the inner conductor 1 to rotate 180°;

[0055] Step S3, tin oxide is loaded into the tin oxide crucible 9, and indium oxide is loaded into the indium oxide crucible 10, and both the tin oxide crucible 9 and the indium oxide crucible 10 are connected to an external power supply, and the evaporation rates of the tin oxide crucible 9 and the indium oxide crucible 10 are controlled to reach 1:9 respectively, so as to meet the composition requirements for forming an indium tin oxide film layer;

[0056] Step S4, perform vacuum evaporation operation, turn on the external power supply, the air pressure environment in the vacuum chamber 8 is about 1*10-4Pa, and the evaporation temperature is controlled according to the tin oxide crucible 9 and the indium oxide crucible 10, for example, the evaporation temperature in the tin oxide crucible 9 can be set at 1900°C, and the evaporation temperature in the indium oxide crucible 10 is set at about 2100°C. Considering the uniform deposition and the mean free path of the particles, the height of the movable baffle 11 from the tin oxide crucible 9 and the indium oxide crucible 10 is guaranteed to be about 40cm. The proportion of indium oxide and tin oxide in the inner shielding layer 2 of indium tin oxide is controlled by the steam flow and the position of the movable baffle 11, and the thickness range of the inner shielding layer 2 is 0.5um~1um;

[0057] Step S5, after the vacuum evaporation process of step S4 is completed, the external power supply is turned off, and when the air pressure of the vacuum chamber 8 is close to that of the outside, the vacuum chamber 8 is opened to turn the inner conductor 1 180° through the rotating shaft clamp 14;

[0058] Step S6, repeating step S4 and step S5, so that both sides of the inner conductor 1 can be plated with indium tin oxide, thereby forming an inner shielding layer 2;

[0059] Step S7, cutting and sampling the inner shielding layer 2 obtained in step S6, performing physical characterization by scanning electron microscopy, and measuring the thickness of the indium tin oxide film layer. If the thickness requirement is met, subsequent processing operations of the insulating layer 3, the outer shielding layer group 4, the drain wire 6 and the sheath layer 5 can be performed.

[0060] The processing steps of the subsequent insulating layer 3, the outer shielding layer group 4 and the sheath layer 5 after the inner shielding layer 2 is prepared in the present invention are as follows:

[0061] Processing of the insulating layer 3: Polyvinyl chloride (PVC) is a non-crystalline material, and is in a viscous flow state during insulation processing. At this time, the temperature of PVC is only 160℃~180℃, while the melting temperature of indium tin oxide is thousands of degrees and its surface chemical bonds and metal bonding are excellent, so there is no need to worry that the indium tin oxide film will be damaged during the production of the insulating layer 3. The thickness of the insulating layer 3 attached to the outside of the inner shielding layer 2 should be less than 0.35mm.

[0062] Processing of the outer shielding layer 41: Copper plating is performed on the outside of the PVC insulating layer 3. The outer shielding layer 41 is manufactured by plastic electroplating, and the thickness of the electroplated copper is controlled within 0.36 mm.

[0063] Processing of drain wire 6: The drain wire 6 is made of tinned copper wire with excellent performance. Tinned copper wire can prevent the generation of verdigris. In addition, its material is soft and has good conductivity. Tinned copper wire has a long service life under weak current conditions. A tinned copper wire is set in the middle of the copper outer shielding layer 41 along the direction of conductor transmission extension as the drain wire 6. The drain wire 6 is located between the two conductors;

[0064] The production process of tinned copper wire is as follows: select copper wire with a diameter of 0.3mm to 0.5mm and a smooth and round surface; then anneal it, and the annealing temperature is set at about 500°C; the annealed copper wire is cleaned in an environment with a pH value of about 1.2 to ensure the adhesion of the tin layer and the copper wire; then put the copper wire into a tin furnace for calcination, cool it after tinning; then add guide shaft oil to prevent the generation of tin ash; finally, pull the tinned copper wire to a drain wire 6 with a diameter of 0.3mm to 0.5mm.

[0065] Processing of the wire pair shielding layer 42: A wire pair shielding layer 42 is arranged outside the drain wire 6. The material used for the wire pair shielding layer 42 is the same as that of the drain wire 6, which is a tightly woven and stretched tinned round copper mesh. The outer diameter of the tinned copper mesh is in the range of 0.10mm to 0.20mm, and the weaving density of the tinned copper mesh is not less than 85%.

[0066] Processing of the sheath layer 5: A sheath layer 5 is arranged outside the line shielding layer 42. The sheath layer 5 is made of polyperfluoroethylene propylene copolymer (FEP) extruded outside the braided layer of the tinned round copper mesh to improve the high temperature resistance of the cable. The thickness of the sheath layer 5 ranges from 0.33mm to 0.68mm.

[0067] In summary, the beneficial effects of the present invention are:

[0068] (1) The indium tin oxide shielding layer of the active cable can effectively enhance the local electric field of the active cable during the transmission process, effectively ensure the strength of the active cable transmission, thereby being able to transmit electromagnetic signals over a longer distance and provide a good thermal insulation environment, which can meet the layout efficiency and functional requirements of the corresponding equipment and has good economic benefits and social value;

[0069] (2) Using the tightly woven tinned round copper mesh of the outer shielding layer 41 can prevent external electromagnetic wave interference;

[0070] (3) In the preparation method of indium tin oxide active cable, since the surface of indium tin oxide has abundant chemical bonds, it is conducive to combining with the interface of metal and other media, so no complicated chemical process is required for treatment. Therefore, vacuum evaporation is used here. Compared with other physical vapor deposition methods, this method has the advantages of simple film formation method, high film purity and density, unique film structure and performance, etc., and can evaporate a variety of different substances at the same time, which is suitable for the evaporation of mixed indium tin oxide film. By virtue of the advantages of this material in metal contact and interface engineering, a processing method that can be mass-produced is proposed.

[0071] The various devices selected in this application are all universal standard parts or parts known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0072] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0074] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An active cable made of indium tin oxide, characterized in that: include: An inner conductor (1), an inner shielding layer (2), an insulating layer (3), an outer shielding layer group (4) and a sheath layer (5), wherein the insulating layer (3) is outwardly covered with the outer shielding layer group (4) and the sheath layer (5) in sequence, the inner conductor (1) comprises two parallel wires, each of which is sheathed with an inner shielding layer (2) to form a conductor structure, the inner shielding layer (2) is made of indium tin oxide, and the two conductor structures are embedded in the insulating layer (3).

2. An active cable made of indium tin oxide as claimed in claim 1, characterized in that: The outer shielding layer group (4) comprises an outer shielding layer (41) and a line pair shielding layer (42) which are sequentially sleeved from the inside to the outside, the outer shielding layer (41) is made of copper material, and the line pair shielding layer (42) is made of tinned copper mesh braiding.

3. An active cable made of indium tin oxide as claimed in claim 2, characterized in that: It also includes a drain wire (6), which is made of tinned copper wire. The drain wire (6) is inserted into the outer shielding layer (41) and is located between the two conductive wires.

4. An active cable made of indium tin oxide as claimed in claim 2, characterized in that: The thickness of the outer shielding layer (41) ranges from 0.10 mm to 0.30 mm, the outer diameter of the wire of the tinned copper mesh ranges from 0.10 mm to 0.20 mm, and the weaving density of the tinned copper mesh is not less than 85%.

5. An active cable made of indium tin oxide as claimed in claim 1, characterized in that: The conductor is a copper wire with a diameter of 0.506 mm to 0.510 mm.

6. An active cable made of indium tin oxide as claimed in claim 1, characterized in that: The insulating layer (3) is made of PVC material, and the thickness of the insulating layer (3) ranges from 0.30 mm to 0.35 mm.

7. An active cable made of indium tin oxide as claimed in claim 1, characterized in that: The sheath layer (5) is made of polyperfluoroethylene propylene copolymer, and the thickness of the sheath layer (5) ranges from 0.33 mm to 0.68 mm.

8. A preparation device for preparing the inner shielding layer (2) as claimed in any one of claims 1 to 7, characterized in that: The invention comprises a shell (7), wherein a vacuum chamber (8) is formed in the shell (7), a tin oxide crucible (9) for evaporating tin oxide and an indium oxide crucible (10) for evaporating indium oxide are arranged at the bottom of the vacuum chamber (8), the tin oxide crucible (9) and the indium oxide crucible (10) are arranged in parallel, a movable baffle (11) which can move up and down is arranged above the tin oxide crucible (9) and the indium oxide crucible (10), a first through hole (12) for the indium oxide vapor to flow through and a second through hole (13) for the tin oxide vapor to flow through are opened on the movable baffle (11), and a rotating shaft clamp (14) for placing the inner conductor (1) is respectively arranged on both sides of the upper end of the shell (7).

9. A preparation device as claimed in claim 8, characterized in that: Mounting holes are respectively provided on both sides of the upper end of the housing (7), each of the mounting holes is arranged directly opposite to a rotating shaft clamp (14), and a sealing ring is arranged in each of the mounting holes.

10. A preparation method, using a preparation device as claimed in any one of claims 8 to 9 to prepare the inner shielding layer (2) as claimed in any one of claims 1 to 7, characterized in that: The steps include: Step S1, cleaning and polishing, using deionized water to clean and polish the selected inner conductor (1); Step S2, placing the inner conductor (1) processed in step S1 into a vacuum chamber (8), and installing the two ends of the inner conductor (1) into the rotating shaft clamp (14) through the sealing rings in the mounting holes respectively, and the rotating shaft clamp (14) can drive the inner conductor (1) to rotate 180 degrees; Step S3, loading tin oxide into a tin oxide crucible (9), loading indium oxide into an indium oxide crucible (10), connecting the tin oxide crucible (9) and the indium oxide crucible (10) to an external power supply, and controlling the evaporation rates of the tin oxide crucible (9) and the indium oxide crucible (10), respectively; Step S4, performing a vacuum evaporation operation, turning on an external power supply, and controlling the proportion of indium oxide and tin oxide in the inner shielding layer (2) of indium tin oxide according to the evaporation temperature and steam flow in the tin oxide crucible (9) and the indium oxide crucible (10) and the position of the movable baffle (11), wherein the thickness of the inner shielding layer (2) is in the range of 0.5 um to 1 um; Step S5, after the vacuum evaporation process of step S4 is completed, the external power supply is turned off, and when the air pressure of the vacuum chamber (8) is close to that of the outside, the vacuum chamber (8) is opened and the inner conductor (1) is turned 180° by the rotating shaft clamp (14); Step S6, repeating steps S4 and S5, so that both sides of the inner conductor (1) can be plated with indium tin oxide, thereby forming an inner shielding layer (2); Step S7, cutting and sampling the inner shielding layer (2) obtained in step S6, performing physical characterization by scanning electron microscopy, and measuring the thickness of the indium tin oxide film layer. If the thickness requirement is met, subsequent processing operations of the insulating layer (3), the outer shielding layer group (4) and the sheath layer (5) can be performed.

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