A superconducting semi-rigid coaxial cable connection method

Abstract

The present invention relates to the technical field of semi-rigid coaxial cables, and in particular to a superconducting semi-rigid coaxial cable connection method, comprising: pre-treating the semi-rigid coaxial cable; adding an electroplating layer on the surface of the semi-rigid coaxial cable after the pre-treatment; cleaning, drying and welding with a connector after electroplating; wherein, before welding, respectively determining the heat conduction efficiency of each structural layer of the semi-rigid coaxial cable per unit length; determining the welding temperature according to the heat conduction efficiency and the melting point of the welding material, and determining the welding time according to the diameter of the semi-rigid coaxial cable and the thickness of the electroplating layer; welding the semi-rigid coaxial cable and the connector according to the welding temperature and the welding time; in the welding process, determining the welding stress according to the temperature data during welding and the thermal expansion coefficient of the electroplating layer, and determining the adjustment method of the welding time and / or the welding temperature according to the welding stress. The present invention can improve the welding quality.

Description

Technical Field

[0001] The invention relates to the technical field of semi-rigid coaxial cables, and in particular to a superconducting semi-rigid coaxial cable connection method. Background Art

[0002] Superconducting alloy materials refer to superconducting materials that are formed by fusing two or more metal elements and have superconductivity. Superconducting alloy materials have the characteristic of zero resistance in the superconducting state, which means that current can flow through the material without loss. And superconducting alloy materials can maintain the superconducting state at higher currents. These characteristics make superconducting alloy materials widely used in the field of superconducting cables.

[0003] Superconducting alloy materials are often used as inner and outer conductor materials for ultra-low temperature coaxial cables in quantum computer systems. When niobium-titanium alloy is used as the inner and outer conductor materials of coaxial cables, the niobium-titanium alloy material has poor weldability and does not adhere to tin during welding and heating. Therefore, it is impossible to weld connectors to niobium-titanium alloy coaxial cables. If other methods such as crimping connectors are used, the signal transmission effect is poor. If glue is used for bonding, the bonding strength of the glue cannot be guaranteed because the working environment temperature is close to absolute zero.

[0004] Therefore, how to process superconducting semi-rigid cables to make them easy to weld is an issue that needs to be solved urgently. Summary of the invention

[0005] To this end, the present invention provides a superconducting semi-rigid coaxial cable connection method to overcome the problem of poor weldability of the semi-rigid coaxial cable using niobium-titanium alloy materials as inner and outer conductor layers in the prior art.

[0006] To achieve the above object, the present invention provides a superconducting semi-rigid coaxial cable connection method, comprising:

[0007] Step S1, cleaning, decontamination and activation pretreatment of the surface of the outer conductor layer of the semi-rigid coaxial cable;

[0008] Step S2, adding an electroplating layer of a preset thickness on the surface of the outer conductor layer of the pretreated semi-rigid coaxial cable;

[0009] Step S3, cleaning and drying the electroplated semi-rigid coaxial cable, and then welding it to the connector;

[0010] Wherein, step S3 comprises:

[0011] Step S31, before welding, respectively determining the heat conduction efficiency per unit length of each structural layer of the semi-rigid coaxial cable;

[0012] Step S32, determining the welding temperature according to the heat conduction efficiency and the melting point of the welding material, and determining the welding time according to the thermal conductivity of the electroplating layer;

[0013] Step S33, welding the semi-rigid coaxial cable and the connector according to the welding temperature and welding time;

[0014] Step S34, during the welding process, determining welding stress according to temperature data during welding at several time points and the thermal expansion coefficient of the electroplating layer, and determining a method for adjusting the welding time and / or welding temperature according to the welding stress;

[0015] Step S35, after welding is completed, the resistivity is determined according to the resistance value of the semi-rigid coaxial cable, and the adjustment method of the thickness of the electroplating layer is determined according to the comparison result of the resistivity and the standard resistivity.

[0016] Furthermore, in step S31, it includes:

[0017] Determine the thermal conductivity of each structural layer of the semi-rigid coaxial cable;

[0018] Determine the cross-sectional diameter of each structural layer of the semi-rigid coaxial cable respectively;

[0019] Determine the cross-sectional area of ​​each structural layer according to the cross-sectional diameter;

[0020] The heat transfer efficiency is determined based on the heat transfer coefficient and the cross-sectional area.

[0021] Furthermore, in step S32, the heat conduction efficiency is compared with a preset heat conduction efficiency, and the welding temperature is determined according to the comparison result and the melting point of the welding material.

[0022] Further, including:

[0023] If the heat conduction efficiency is less than the preset heat conduction efficiency, determining the welding temperature according to the melting point of the welding material and the preset first temperature;

[0024] If the heat conduction efficiency is greater than the preset heat conduction efficiency, determining the welding temperature according to the melting point of the welding material and the preset second temperature;

[0025] Wherein, the preset first temperature is greater than the preset second temperature.

[0026] Furthermore, in step S32, it includes:

[0027] The welding time is determined according to a preset welding current, a preset welding voltage and the thermal conductivity of the electroplating layer.

[0028] Furthermore, in step S34, it includes:

[0029] Determine the temperature difference at adjacent time points according to the temperature data at a plurality of time points;

[0030] The welding stress at adjacent time points is determined according to the temperature difference and the thermal expansion coefficient.

[0031] Furthermore, a comprehensive welding stress is determined according to the welding stresses at adjacent time points, the comprehensive welding stress is compared with a preset welding stress, and a method for adjusting the welding temperature and / or welding time is determined according to the comparison result.

[0032] Furthermore, the comprehensive welding stress is compared with a preset welding stress. If the comprehensive welding stress is greater than the preset welding stress, the welding temperature is reduced and / or the welding time is shortened.

[0033] Furthermore, an adjusted welding temperature is determined according to the comprehensive welding stress, the preset welding stress and the welding temperature.

[0034] Furthermore, the adjusted welding time is determined according to the comprehensive welding stress, the preset welding stress and the welding time.

[0035] Further, in step S35, if the resistivity is greater than the standard resistivity, the thickness of the electroplating layer is increased, and the thickness of the electroplating layer is determined according to the difference between the resistivity and the standard resistivity, the empirical coefficient, and the preset thickness of the electroplating layer.

[0036] Compared with the prior art, the beneficial effect of the present invention is that, by pre-treating the semi-rigid coaxial cable and adding a preset thickness of the electroplating layer, the welding performance of difficult-to-weld materials such as niobium-titanium alloy is effectively improved, the welding quality of the cable and the connector is guaranteed, and the effective transmission of the semi-rigid coaxial cable signal is ensured. At the same time, by accurately controlling the welding temperature and welding time, the welding process is further optimized, the welding stress is reduced, and the welding quality is improved.

[0037] Furthermore, before welding, the present invention determines the thermal conduction efficiency of each structural layer of the semi-rigid coaxial cable per unit length, and flexibly adjusts the welding temperature according to the comparison result of the thermal conduction efficiency and the preset thermal conduction efficiency, so as to further ensure the welding quality of the cable and the connector and ensure the effective transmission of the semi-rigid coaxial cable signal.

[0038] Furthermore, the present invention determines a comprehensive welding stress based on the welding stress at adjacent time points, compares the comprehensive welding stress with the preset welding stress, and determines an adjustment method for the welding temperature and / or welding time based on the comparison result, thereby further ensuring the welding quality of the cable and the connector and ensuring effective transmission of the semi-rigid coaxial cable signal.

[0039] Furthermore, the present invention determines the adjustment amount of welding temperature and welding time according to the comparison result of the comprehensive welding stress and the preset welding stress, so as to balance the problem of excessive welding stress in the welding process, thereby reducing the influence of welding stress on the welding effect, achieving effective control of welding stress, further ensuring the welding quality of the cable and the connector, and ensuring the effective transmission of semi-rigid coaxial cable signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a superconducting semi-rigid coaxial cable connection method according to an embodiment of the present invention;

[0041] Figure 2 A flow chart for determining a method for adjusting welding time and / or welding temperature according to an embodiment of the present invention;

[0042] Figure 3 A flow chart for determining heat transfer efficiency according to an embodiment of the present invention;

[0043] Figure 4 This is a decision diagram for adjusting welding temperature and / or welding time according to a comparison result between comprehensive welding stress and preset welding stress according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0045] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0046] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0047] In addition, it should be noted that in the description 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] See also Figure 1-2 As shown, Figure 1 A flow chart of a superconducting semi-rigid coaxial cable connection method according to an embodiment of the present invention; Figure 2 A flow chart for determining a method for adjusting welding time and / or welding temperature according to an embodiment of the present invention; specifically, it includes:

[0049] Step S1, cleaning, decontamination and activation pretreatment of the surface of the outer conductor layer of the semi-rigid coaxial cable;

[0050] Step S2, adding an electroplating layer of a preset thickness on the surface of the outer conductor layer of the pretreated semi-rigid coaxial cable;

[0051] Step S3, cleaning and drying the electroplated semi-rigid coaxial cable, and then welding it to the connector;

[0052] Wherein, step S3 comprises:

[0053] Step S31, before welding, respectively determining the heat conduction efficiency per unit length of each structural layer of the semi-rigid coaxial cable;

[0054] Step S32, determining the welding temperature according to the heat conduction efficiency and the melting point of the welding material, and determining the welding time according to the thermal conductivity of the electroplating layer;

[0055] Step S33, welding the semi-rigid coaxial cable and the connector according to the welding temperature and welding time;

[0056] Step S34, during the welding process, determining welding stress according to temperature data during welding at several time points and the thermal expansion coefficient of the electroplating layer, and determining a method for adjusting the welding time and / or welding temperature according to the welding stress;

[0057] Step S35, after welding is completed, the resistivity is determined according to the resistance value of the semi-rigid coaxial cable, and the adjustment method of the thickness of the electroplating layer is determined according to the comparison result of the resistivity and the standard resistivity.

[0058] It is understandable that the structure of a semi-rigid coaxial cable usually includes three layers, including an inner conductor layer, an insulating layer, and an outer conductor layer arranged from the inside to the outside. The outer conductor of the semi-rigid coaxial cable has good weldability and can be easily welded to the connector. However, if the outer conductor layer is made of niobium-titanium alloy material, the weldability becomes poor, and tin does not stick during welding heating, so it is impossible to weld the connector to the niobium-titanium alloy semi-rigid coaxial cable. Therefore, an electroplating layer is provided on the outer conductor layer of the semi-rigid coaxial cable to improve the welding performance through the electroplating layer. And the welding time and welding temperature are determined during the welding process to improve the welding quality.

[0059] In a specific embodiment, the inner conductor layer in the internal structure of the semi-rigid coaxial cable is a niobium-titanium alloy round wire inner conductor layer, the insulating layer is a solid PTFE (polytetrafluoroethylene) insulating layer, and the outer conductor layer is a seamless niobium-titanium alloy tube. In view of the fact that gold has complete oxidation resistance and can completely prevent oxidation of the surface of the cable's outer conductor, gold is selected as the electroplating layer to ensure the welding quality between the cable and the connector. At the same time, in view of the radio frequency signal transmission characteristics of the semi-rigid coaxial cable, the signal is only transmitted in the space between the outer surface of the inner conductor and the inner surface of the outer conductor. The electroplating layer (gold-plated layer) is the outermost layer of the outer conductor and will not affect the actual signal transmission of the semi-rigid coaxial cable. And the preset thickness of the electroplating layer has a value range of 0.085 μm ~0.16 μm Preferably, the preset thickness ranges from 0.1 μm ~0.15 μm . The gold-plated layer is extremely thin, and the heat conduction to the semi-rigid coaxial cable in an ultra-low temperature environment can be ignored. The interval duration of the several time points ranges from 3 minutes to 7 minutes. Preferably, the interval duration of the several time points is 5 minutes. In practice, the preset thickness of the electroplated layer, the range of values ​​of the several time points and the preferred value can be determined according to the actual situation, and no specific limitation is made here, and no further description is given.

[0060] In a specific embodiment, the resistivity is the product of the resistance value of the semi-rigid coaxial cable and the ratio of the conductive cross-sectional area to the cable length. The standard resistivity is a reference value or an industry standard value provided by the cable manufacturer. In implementation, the standard resistivity can be determined based on actual conditions. No specific limitation is made here and no further details are given.

[0061] The present invention pre-treats the semi-rigid coaxial cable and adds a preset thickness of the electroplating layer, which effectively improves the welding performance of difficult-to-weld materials such as niobium-titanium alloy, ensures the welding quality of the cable and the connector, and ensures the effective transmission of the semi-rigid coaxial cable signal. At the same time, by accurately controlling the welding temperature and welding time, the welding process is further optimized, the welding stress is reduced, and the welding quality is improved.

[0062] See also Figure 3 As shown, Figure 3 This is a flow chart of determining heat conduction efficiency according to an embodiment of the present invention. Specifically, in step S31, it includes:

[0063] Step S311, respectively determining the thermal conductivity of each structural layer of the semi-rigid coaxial cable;

[0064] Step S312, respectively determining the cross-sectional diameter of each structural layer of the semi-rigid coaxial cable;

[0065] Step S313, determining the cross-sectional area of ​​each structural layer according to the cross-sectional diameter;

[0066] Step S314: determining the heat conduction efficiency according to the heat conduction coefficient and the cross-sectional area.

[0067] In a specific embodiment, the thermal conductivity coefficient of the inner conductor layer is the thermal conductivity coefficient of the niobium-titanium alloy, the thermal conductivity coefficient of the insulating layer is the thermal conductivity coefficient of PTFE (polytetrafluoroethylene), the thermal conductivity coefficient of the outer conductor layer is the thermal conductivity coefficient of the niobium-titanium alloy, and the thermal conductivity coefficient of the electroplating layer is the thermal conductivity coefficient of gold. At the same time, since the cross-section of the semi-rigid coaxial cable is circular, the circular area formula is used to calculate the cross-sectional area of ​​each structural layer, so the cross-sectional area of ​​the inner conductor is determined according to the cross-sectional diameter of the inner conductor. The insulating layer is wrapped around the inner conductor layer, so the cross-sectional area of ​​the insulating layer is determined according to the cross-sectional diameter of the insulating layer and the cross-sectional diameter of the inner conductor; the outer conductor layer is wrapped around the insulating layer, so the cross-sectional area of ​​the outer conductor layer is determined according to the cross-sectional diameter of the insulating layer and the cross-sectional diameter of the outer conductor layer; the electroplating layer is wrapped around the outer conductor layer, so the cross-sectional area of ​​the electroplating layer is determined according to the cross-sectional diameter of the outer conductor layer and the cross-sectional diameter of the semi-rigid coaxial cable after electroplating. The cross-sectional area of ​​each structural layer is multiplied and summed by the thermal conductivity coefficient of each corresponding structural layer to obtain the thermal conduction efficiency. In implementation, the heat conduction efficiency may be determined according to actual conditions, and is not specifically limited here and will not be elaborated on.

[0068] Specifically, in step S32, the heat conduction efficiency is compared with a preset heat conduction efficiency, and the welding temperature is determined according to the comparison result and the melting point of the welding material.

[0069] Specifically, if the heat conduction efficiency is less than a preset heat conduction efficiency, the welding temperature is determined according to the melting point of the welding material and a preset first temperature;

[0070] If the heat conduction efficiency is greater than the preset heat conduction efficiency, determining the welding temperature according to the melting point of the welding material and the preset second temperature;

[0071] Wherein, the preset first temperature is greater than the preset second temperature.

[0072] It is understandable that if the heat conduction efficiency is less than the preset heat conduction efficiency, selecting a lower welding temperature may not allow the welding material to be fully melted, and it is not possible to ensure that the solder penetrates well into the welding joint. In this case, selecting a relatively high welding temperature can ensure the welding quality. If the heat conduction efficiency is greater than the preset heat conduction efficiency, selecting a higher welding temperature may cause excessive heat to accumulate in the welding area. In this case, selecting a lower welding temperature can ensure the welding quality. Therefore, the preset first temperature is greater than the preset second temperature.

[0073] In a specific embodiment, the preset heat conduction efficiency is the average of several heat conduction efficiencies of qualified welding joints in several historical operations of welding semi-rigid coaxial cables and connectors. The melting point of the electroplating layer, that is, the melting point of gold, is 1063.69℃~1069.74℃. The welding temperature must be ensured to be lower than the melting point of the electroplating layer to avoid melting of the electroplating layer during welding. In practice, semi-rigid coaxial cables and connectors are usually welded using solder, which has good conductivity and plasticity, and can ensure the quality and reliability of the welded joints. The melting point of solder is generally around 183℃~217℃. In actual welding operations, the welding temperature is usually higher than the melting point of solder to ensure that the solder can be fully melted and penetrate into the welded joint. Therefore, when soldering is used, if the heat conduction efficiency is less than the preset heat conduction efficiency, the preset first temperature is the product of the amplification factor and the melting point temperature of the solder, the absolute value of the difference between the heat conduction efficiency and the preset heat conduction efficiency is the first difference, and the amplification factor is the sum of the first difference and the preset heat conduction efficiency ratio and 1. The preset second temperature is the product of the reduction factor and the melting point of the solder, the absolute value of the difference between the heat conduction efficiency and the preset heat conduction efficiency is the second difference, and the reduction factor is the difference between 1 and the ratio of the second difference to the preset heat conduction efficiency. In implementation, the value range and preferred value of the preset heat conduction efficiency, the preset first temperature and the preset second temperature can be determined according to actual conditions, and are not specifically limited here and will not be repeated.

[0074] Before welding, the present invention determines the heat conduction efficiency of each structural layer of the semi-rigid coaxial cable per unit length, and flexibly adjusts the welding temperature according to the comparison result of the heat conduction efficiency and the preset heat conduction efficiency, so as to further ensure the welding quality of the cable and the connector and ensure the effective transmission of the semi-rigid coaxial cable signal.

[0075] Specifically, in step S32, it includes:

[0076] The welding time is determined according to a preset welding current, a preset welding voltage and the thermal conductivity of the electroplating layer.

[0077] It is understandable that the two parameters of preset welding current and preset welding voltage are important control factors in the welding process. The welding current determines the amount of electricity passing through the welding material during welding, while the welding voltage affects the stability and efficiency of the current during the welding process. In addition, different electroplating materials may have different thermal conductivities, which will affect the transfer and distribution of heat during welding. The preset welding current, preset welding voltage, and thermal conductivity of the electroplating layer jointly affect the generation, transfer and distribution of heat, thereby determining the time required for the welding process. Therefore, when performing welding operations, it is necessary to comprehensively consider the preset welding current, preset welding voltage, and thermal conductivity of the electroplating layer to determine the appropriate welding time to ensure the efficiency, stability and high quality of the welding process, and avoid loose welding due to too short welding time, and damage to welding materials or other quality problems due to too long welding time.

[0078] In a specific embodiment, the thermal conductivity of the electroplating layer is the thermal conductivity of gold, the preset welding current is in the range of 30A to 100A, preferably, the preset welding current is 40A, and the preset welding voltage is in the range of 15V to 25V, preferably, the preset welding voltage is 20V. In implementation, the ranges and preferred values ​​of the preset welding depth, preset welding current, and preset welding voltage can be determined according to actual conditions, and are not specifically limited here, nor will they be described in detail.

[0079] In a specific embodiment, the welding time is the ratio of welding energy to the product of a preset welding voltage and a preset welding current, and the welding energy is the total energy of heat input during the welding process. The welding time can be determined according to actual conditions, and is not specifically limited here and will not be repeated.

[0080] Specifically, in step S34, it includes:

[0081] Determine the temperature difference at adjacent time points according to the temperature data at a plurality of time points;

[0082] The welding stress at adjacent time points is determined according to the temperature difference and the thermal expansion coefficient.

[0083] It is understandable that during the welding process, temperature data at several time points will be recorded. These data reflect the temperature changes during the welding process. The temperature difference is determined by comparing the temperature data at adjacent time points as the basis for subsequent calculation of welding stress. Welding stress is the internal force generated by temperature changes and thermal expansion or contraction of materials during welding. By controlling the welding stress generated during welding, welding deformation can be reduced and welding quality and reliability can be improved.

[0084] In a specific embodiment, the thermal expansion coefficient of the electroplating layer is the thermal expansion coefficient of gold, the welding stress is the product of the thermal expansion coefficient of gold, the elastic modulus of the semi-rigid coaxial cable and the temperature difference, the elastic modulus is the ratio of the welding stress to the welding strain of the semi-rigid coaxial cable within the elastic deformation range, and the elastic modulus represents the ability of the semi-rigid coaxial cable to resist deformation when subjected to welding stress. In implementation, the welding stress can be determined according to actual conditions, such as adjustment according to specific welding conditions, material properties and process requirements, etc., which is not specifically limited here and will not be repeated.

[0085] See also Figure 4 As shown, Figure 4 The present invention is a judgment diagram for adjusting the welding temperature and / or welding time according to the comparison result between the comprehensive welding stress and the preset welding stress. Specifically, the comprehensive welding stress is determined according to the welding stress at adjacent time points, the comprehensive welding stress is compared with the preset welding stress, and the adjustment method of the welding temperature and / or welding time is determined according to the comparison result.

[0086] In a specific embodiment, the comprehensive welding stress is the average of the sum of the welding stresses at several adjacent time points, and the preset welding stress can be the average of several welding stresses with qualified welding joint quality in several welding processes of semi-rigid coaxial cables and connectors. In implementation, the value range and preferred value of the comprehensive welding stress and the preset welding stress can be determined according to actual conditions, and are not specifically limited here and will not be repeated.

[0087] The present invention determines a comprehensive welding stress according to the welding stress at adjacent time points, compares the comprehensive welding stress with a preset welding stress, and determines an adjustment method for the welding temperature and / or welding time according to the comparison result, thereby further ensuring the welding quality of the cable and the connector and ensuring effective transmission of the semi-rigid coaxial cable signal.

[0088] Specifically, the comprehensive welding stress is compared with the preset welding stress. If the comprehensive welding stress is greater than the preset welding stress, the welding temperature is reduced and / or the welding time is shortened.

[0089] It can be understood that the preset welding stress is used to determine whether the welding stress is too high in the current welding process. If the comprehensive welding stress is greater than the preset welding stress, it means that the welding stress is too high in the current welding process, which may have an adverse effect on welding. Therefore, the welding temperature is lowered to reduce thermal expansion and contraction during welding, or the welding time is shortened to reduce the welding impact range and intensity.

[0090] Specifically, the adjusted welding temperature is determined according to the comprehensive welding stress, the preset welding stress and the welding temperature.

[0091] In a specific embodiment, the adjusted welding temperature is the product of the ratio of the preset welding stress to the comprehensive welding stress and the welding temperature. In implementation, the adjusted welding temperature can be determined according to actual conditions, including considering various variables in the welding process (such as ambient temperature, humidity, pretreatment of welding materials, etc.) and post-welding detection and evaluation results, etc., which are not specifically limited here and will not be elaborated.

[0092] Specifically, the adjusted welding time is determined according to the comprehensive welding stress, the preset welding stress and the welding time.

[0093] In a specific embodiment, the adjusted welding time is the product of the ratio of the preset welding stress to the comprehensive welding stress and the welding time. In implementation, the adjusted welding time can be determined according to actual conditions, such as according to the characteristics of the welding material, welding size, stability of the welding equipment, temperature and humidity of the welding environment, etc., which is not specifically limited here and will not be elaborated.

[0094] The present invention determines the adjusted welding temperature and welding time according to the comparison result of the comprehensive welding stress and the preset welding stress, so as to balance the problem of excessive welding stress in the welding process, thereby reducing the influence of welding stress on the welding effect, achieving effective control of welding stress, further ensuring the welding quality of the cable and the connector, and ensuring the effective transmission of the semi-rigid coaxial cable signal.

[0095] Specifically, if the resistivity is greater than the standard resistivity, the thickness of the electroplating layer is increased, and the thickness of the electroplating layer is determined according to the difference between the resistivity and the standard resistivity, an empirical coefficient, and a preset thickness of the electroplating layer.

[0096] It is understandable that resistivity is an indicator to measure the conductive performance of semi-rigid cables, indicating the resistance of semi-rigid cables per unit length and unit cross-sectional area to current. The standard resistivity is used to evaluate whether the conductive performance of semi-rigid cables meets the requirements. If the resistivity is greater than the standard resistivity, it means that the conductive performance of the cable is poor, and the thickness of the electroplating layer may need to be increased to improve the conductivity. Therefore, the thickness of the electroplating layer is determined by comprehensively considering the resistivity difference, the empirical coefficient and the preset thickness. Among them, the difference between the resistivity and the standard resistivity reflects the degree of deviation of the conductive performance of the electroplating layer from the standard requirements. The greater the difference, the greater the thickness of the electroplating layer that may need to be increased. The empirical coefficient is a value derived from practical experience, which comprehensively considers the influence of various factors in the electroplating process (such as the concentration, temperature, current density, etc. of the electroplating solution) on the thickness of the electroplating layer. The thickness of the electroplating layer is adjusted and determined to improve the conductive performance of the electroplating layer.

[0097] In a specific embodiment, if the resistivity is greater than the standard resistivity, the thickness of the electroplating layer is increased, and the added value of the electroplating layer is the product of the empirical coefficient, the initial electroplating layer thickness and the difference and the standard resistivity ratio. The initial electroplating layer thickness is a preset thickness, and the empirical coefficient is determined according to the specific electroplating process and the electroplating solution formula. The empirical coefficient reflects the sensitivity of the electroplating layer thickness to the resistivity change. The electroplating layer thickness is the sum of the initial electroplating layer thickness and the electroplating layer added value. In implementation, the value range and preferred value of the cable layer thickness can be determined according to actual conditions. No specific limitation is made here and it will not be repeated.

[0098] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A superconducting semi-rigid coaxial cable connection method, characterized in that: include: Step S1, cleaning, decontamination and activation pretreatment are performed on the surface of the outer conductor layer of the semi-rigid coaxial cable, wherein the structure of the semi-rigid coaxial cable comprises an inner conductor layer, an insulating layer and an outer conductor layer arranged in sequence from the inside to the outside, the inner conductor layer is a niobium-titanium alloy round wire inner conductor layer, the insulating layer is a solid PTFE (polytetrafluoroethylene) insulating layer, and the outer conductor layer is a seamless niobium-titanium alloy tube; Step S2, adding an electroplating layer of a preset thickness on the surface of the outer conductor layer of the pretreated semi-rigid coaxial cable; Step S3, cleaning and drying the electroplated semi-rigid coaxial cable, and then welding it to the connector, which includes: Step S31, before welding, respectively determining the heat conduction efficiency per unit length of each structural layer of the semi-rigid coaxial cable; Step S32, determining the welding temperature according to the heat conduction efficiency and the melting point of the welding material, and determining the welding time according to the thermal conductivity of the electroplating layer, wherein the welding temperature is determined according to the comparison result of the heat conduction efficiency and the preset heat conduction efficiency and the melting point of the welding material, including: If the heat conduction efficiency is less than the preset heat conduction efficiency, the welding temperature is determined according to the melting point of the welding material and the preset first temperature, the preset first temperature is the product of the amplification factor and the melting point temperature of the solder, the absolute value of the difference between the heat conduction efficiency and the preset heat conduction efficiency is the first difference, and the amplification factor is the sum of the first difference and the ratio of the preset heat conduction efficiency and 1; If the heat conduction efficiency is greater than the preset heat conduction efficiency, the welding temperature is determined according to the melting point of the welding material and the preset second temperature, the preset second temperature is the product of the reduction factor and the melting point temperature of the solder, the absolute value of the difference between the heat conduction efficiency and the preset heat conduction efficiency is the second difference, and the reduction factor is the difference between 1 and the ratio of the second difference to the preset heat conduction efficiency; The preset first temperature is greater than the preset second temperature, and the preset heat conduction efficiency is an average of several heat conduction efficiencies of qualified welding joints in several historical operations of welding semi-rigid coaxial cables and connectors; Step S33, welding the semi-rigid coaxial cable and the connector according to the welding temperature and welding time; Step S34, during the welding process, determining welding stress according to temperature data during welding at several time points and the thermal expansion coefficient of the electroplating layer, and determining a method for adjusting the welding time and / or welding temperature according to the welding stress; Step S35, after welding is completed, the resistivity is determined according to the resistance value of the semi-rigid coaxial cable, and the adjustment method of the electroplating layer thickness is determined according to the comparison result between the resistivity and the standard resistivity.

2. The superconducting semi-rigid coaxial cable connection method according to claim 1, characterized in that: In step S31, it includes: Determine the thermal conductivity of each structural layer of the semi-rigid coaxial cable; Determine the cross-sectional diameter of each structural layer of the semi-rigid coaxial cable respectively; Determine the cross-sectional area of ​​each structural layer according to the cross-sectional diameter; The heat transfer efficiency is determined based on the heat transfer coefficient and the cross-sectional area.

3. The superconducting semi-rigid coaxial cable connection method according to claim 1, characterized in that: In step S32, The welding time is determined according to a preset welding current, a preset welding voltage and the thermal conductivity of the electroplating layer.

4. The superconducting semi-rigid coaxial cable connection method according to claim 1, characterized in that: In step S34, Determine the temperature difference at adjacent time points according to the temperature data at a plurality of time points; Determining welding stress at adjacent time points according to the temperature difference and the thermal expansion coefficient; The comprehensive welding stress is determined according to the welding stress at adjacent time points, the comprehensive welding stress is compared with the preset welding stress, and the adjustment method of the welding temperature and / or welding time is determined according to the comparison result.

5. The superconducting semi-rigid coaxial cable connection method according to claim 4, characterized in that: The comprehensive welding stress is compared with the preset welding stress. If the comprehensive welding stress is greater than the preset welding stress, the welding temperature is reduced and / or the welding time is shortened.

6. The superconducting semi-rigid coaxial cable connection method according to claim 5, characterized in that: The adjusted welding temperature is determined according to the comprehensive welding stress, the preset welding stress and the welding temperature.

7. The superconducting semi-rigid coaxial cable connection method according to claim 6, characterized in that: include: The adjusted welding time is determined according to the comprehensive welding stress, the preset welding stress and the welding time.

8. The superconducting semi-rigid coaxial cable connection method according to claim 1, characterized in that: In step S35, if the resistivity is greater than the standard resistivity, the thickness of the electroplating layer is increased, and the thickness of the electroplating layer is determined according to the difference between the resistivity and the standard resistivity, the empirical coefficient, and the preset thickness of the electroplating layer.

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