Intermediate components for conductor welding connections, conductor connection structures and connection methods

Abstract

This invention relates to the field of metal conductor welding technology, specifically to an intermediate component for conductor welding connections, a conductor connection structure, and a connection method thereof. The intermediate component connects a first conductor and a second conductor. The intermediate component has a cylindrical body for fitting over the first conductor; the inner surface of the cylindrical body is a bare substrate surface suitable for laser welding, allowing the intermediate component to be laser welded to the first conductor; the cylindrical body has multiple welding through-holes for laser welding the first conductor to the cylindrical body; the cylindrical body has a soldering section adapted to the shape of the second conductor for soldering to the second conductor, and the outer circumferential surface of the soldering section has a first metal plating layer for soldering. This intermediate component, by setting laser welding through-holes and functional partitioning of the inner and outer surfaces, solves the technical problem of reliable connection and easy connector replacement between difficult-to-weld metal conductors (such as niobium and niobium-titanium alloys) and conventional conductors (such as gold-plated connectors).

Description

Technical Field

[0001] This invention relates to the field of metal conductor welding technology, and more specifically to intermediate components for conductor welding connections, conductor connection structures, and connection methods thereof. Background Technology

[0002] In fields such as electronic engineering, cryogenic superconductivity, and radio frequency communications, the quality of the connection between conductors directly determines the overall performance and operational reliability of the equipment. In practical applications, it is often necessary to reliably connect difficult-to-solder metal conductors (defined as the first conductor) to conventional solderable metal conductors (defined as the second conductor). Connecting these dissimilar conductors has always been a technical challenge in the industry.

[0003] Currently, the industry commonly uses physical clamping to achieve this type of connection. For example, the coaxial cable connector disclosed in Chinese Patent Publication No. CN108432052B uses an axially movable shell to compress a clamping member. The front of the clamping member deforms radially inward to press the cable, while its rear expands radially outward to lock it within the connector body, thus achieving mechanical fixation and environmental sealing. Although this mechanical compression clamping structure solves the assembly problem to some extent, it still has several shortcomings:

[0004] First, precisely controlling the clamping force is extremely difficult. Too little force can lead to insufficient connection reliability, causing loosening during equipment vibration or long-term use and disrupting the continuity of signal transmission. Too much force can directly compress and damage the cable's dielectric layer (such as PTFE, glass dielectric, etc.) or the conductor itself, causing degradation of the cable's electrical performance. Moreover, the clamping force will decrease with mechanical vibration, stress relaxation, and other factors, affecting the stability of the long-term connection.

[0005] Secondly, in extreme temperature environments such as low-temperature superconductivity (e.g., the 4K liquid helium temperature range), the thermal expansion coefficients of different materials vary greatly, which may cause the clamping force preset at room temperature to become loose or too tight at low temperatures, resulting in loose connections, deterioration of electrical performance, or even cable damage.

[0006] Most importantly, physical clamping cannot achieve atomic-level metal fusion between the connector and the cable conductor. There are oxide films and microscopic gaps between the contact surfaces, resulting in high and unstable contact resistance. Summary of the Invention

[0007] This invention provides intermediate components for conductor welding connections, conductor connection structures, and connection methods to solve the technical problems of poor reliability and difficulty in replacing the second conductor in existing heterogeneous conductor connections.

[0008] To solve the above problems, the present invention is achieved through the following technical solution:

[0009] On one hand, the present invention provides an intermediate component for conductor welding, used to connect a first conductor and a second conductor. The intermediate component has a cylindrical body for fitting over the first conductor. The inner surface of the cylindrical body is a bare substrate surface suitable for laser welding, for laser welding the intermediate component to the first conductor. The cylindrical body has a plurality of welding through holes on its wall for laser welding the first conductor to the cylindrical body. The cylindrical body has a soldering cylindrical section adapted to the shape of the second conductor, the soldering cylindrical section being soldered to the second conductor, and the outer peripheral surface of the soldering cylindrical section having a first metal plating layer for soldering.

[0010] This intermediate component for conductor welding solves the problem of reliable connection between difficult-to-weld metal conductors (such as niobium and niobium-titanium alloys) and conventional conductors by setting laser welding through holes and functional partitions on the inner and outer surfaces. It is particularly suitable for the transition connection between radio frequency coaxial cables and standard connectors used in low-temperature superconducting quantum computers. Specifically, it has the following outstanding advantages:

[0011] This invention sets the inner surface of the intermediate cylinder as a bare substrate surface suitable for laser welding, and opens multiple through-holes in the circumferential sidewalls of the cylinder. The arrangement of these through-holes ensures a reliable laser metallurgical bond between the cylinder and the first conductor (such as niobium or niobium-titanium alloy). During laser welding, under the protection of an inert gas, a high-energy-density laser beam causes the metal at the bottom edge of the welding through-hole and the surface of the first conductor to partially melt and diffuse into each other, forming an atomically fused metallurgical bond. This generates an alloy, completely eliminating the contact resistance problem caused by the oxide film, significantly improving the conductivity of the contact interface, and overcoming the technical barrier that traditional tin soldering cannot be applied to difficult-to-weld materials (such as niobium and niobium-titanium superconducting materials).

[0012] The outer surface of the soldering cylinder section is coated with a metal layer for soldering, ensuring that the second conductor (such as a copper RF connector) can be uniformly and fully soldered to the intermediate component through conventional soldering processes.

[0013] The intermediate component cylinder employs a surface functional partitioning system of "bare substrate on the inner surface + metal plating on the outer surface," balancing the optimal performance of different welding processes. Maintaining the original metallic state of the inner surface ensures the metallurgical quality of laser welding; the tin-soldering section on the outer surface enhances solderability through plating. This design fully leverages the advantages of both welding processes, achieving a synergistic effect of "high-strength laser welding + high-reliability tin soldering," while also considering connection strength and the ease of disassembly, replacement, and maintenance of the second conductor.

[0014] As a preferred embodiment of the present invention, a second metal plating layer is provided on the wall of the welding through hole. The second metal plating layer is used for soldering to strengthen the soldering connection between the soldering cylinder section and the second conductor.

[0015] As a preferred embodiment of the present invention, the first metal plating layer and the second metal plating layer are plating layers of the same material, wherein the plating layer is a gold plating layer, a silver plating layer or a tin plating layer.

[0016] As a preferred embodiment of the present invention, the outer diameter of the welding through hole is larger than the inner diameter.

[0017] As a more preferred technical solution of the present invention, the welding through hole is one or more of the following: flat-bottomed straight hole, flat-bottomed conical hole, and conical-bottomed hole;

[0018] The flat-bottomed straight hole is composed of an upper cylindrical hole and a lower cylindrical hole arranged coaxially.

[0019] The conical bottom hole is composed of an upper cylindrical hole and a lower conical hole arranged coaxially, or a single conical hole.

[0020] The flat-bottomed conical hole is composed of an upper conical hole and a lower cylindrical hole arranged coaxially.

[0021] By using a welding through-hole design with a small inner diameter and a large outer diameter, a wider incident channel for the laser beam is provided, reducing the requirements for beam collimation accuracy and minimizing energy loss or hole wall ablation caused by off-axis irradiation. The reduced lower aperture concentrates laser energy locally, increasing the energy density per unit volume and promoting rapid melting of the first conductor material (such as niobium or niobium-titanium) to achieve deep metallurgical bonding with the intermediate substrate. This design is particularly suitable for welding materials with high reflectivity or high thermal conductivity, effectively improving laser energy utilization, shortening welding time, reducing the heat-affected zone, and protecting the original properties of the conductor.

[0022] In a preferred embodiment of the present invention, the outer surface of the soldering cylinder section is provided with flow channels for guiding and containing solder. The flow channels include at least one circumferential flow channel and several axial flow channels; the circumferential flow channel extends circumferentially along the intermediate part, and the axial flow channels extend axially along the intermediate part; the circumferential flow channel and the axial flow channels are interconnected.

[0023] The surface of the soldering cylinder section is equipped with dedicated flow channels, serving as directional flow pathways for the solder during the soldering process. When heated and melted, the solder spreads orderly along the flow channels, avoiding the problems of random solder flow, accumulation, or shortage in traditional soldering. This design ensures that the solder is concentrated in the gap between the soldering cylinder section and the second conductor, forming a continuous and dense metallurgical bonding layer.

[0024] As a preferred embodiment of the present invention, the circumferential flow channel intersects with the axial flow channel to divide the outer surface of the soldering cylinder section into several protrusions, and the welding through holes are provided on the several protrusions.

[0025] During the soldering process, driven by the good wettability and surface tension of the molten solder, the molten solder first spreads rapidly along the flow channel, and then penetrates vertically through the welding through-hole to the periphery of the laser welding area on the inner surface of the cylinder and fills the welding through-hole.

[0026] Interconnected circumferential and axial flow channels form a network for solder flow. During soldering heating, molten solder first enters the circumferential flow channels, rapidly and uniformly spreading along the circumference, while simultaneously extending axially through the interconnected axial flow channels, achieving a "ring-like diffusion + axial propulsion" filling pattern. This flow channel network enhances the solder spreading speed and coverage, ensuring uniform filling of the entire solder area in a short time and avoiding localized incomplete soldering or cold solder joint defects.

[0027] Because the flow channel network has excellent flow guiding capabilities, solder can be pre-placed at any axial or circumferential flow channel inlet without precisely aligning all connection points. After melting, the solder will automatically diffuse throughout the entire flow channel network via the connecting path, achieving "single-point feeding and full-area filling".

[0028] After solidification, the solder forms a "mesh metal skeleton" within the circumferential and axial flow channels and the welding through-holes, creating a complex interlocking structure with the outer surface of the solder cylinder section. This structure significantly enhances the shear and peel resistance between the solder and the intermediate component, maintaining the integrity of the connection even under strong vibration or mechanical shock environments, making it suitable for harsh operating conditions such as aerospace and mobile testing equipment.

[0029] As a preferred embodiment of the present invention, the protrusion is further provided with a flow guide groove, which connects the welding through hole with the axial flow channel and / or the circumferential flow channel, and is used to guide the solder to flow into the welding through hole during soldering.

[0030] A guide channel is added between the outer surface flow channel and the through-hole for welding, serving as a dedicated connection channel between the two. This guide channel structurally forms a low-resistance path for transporting molten solder, enhancing the solder's penetration ability in the vertical direction (i.e., the depth direction of the hole). After entering the welding through-hole via the guide channel, the solder can further penetrate into the fusion zone formed by laser welding, strengthening the bond strength between different connection methods and improving the overall performance of the conductor connection structure.

[0031] On the other hand, the present invention also provides a conductor connection structure, including a first conductor, a second conductor, and the aforementioned intermediate component; the cylindrical body of the intermediate component is sleeved on the first conductor, and the inner surface of the cylindrical body is laser-welded to the first conductor through the welding through hole; the second conductor is disposed on the outer peripheral surface of the soldering cylindrical body section, and the soldering cylindrical body section is connected to the second conductor by soldering.

[0032] This connection structure uses an intermediate component as a transition medium, solving the technical challenge of directly soldering difficult-to-weld materials such as niobium and niobium-titanium alloys. Laser welding ensures the metallurgical bonding strength at the first conductor end, while soldering guarantees the process compatibility and connection quality at the second conductor end, thus achieving a reliable connection between two incompatible materials.

[0033] The second conductor (such as an RF connector) is soldered to the soldered cylindrical section of the intermediate component. Compared to mechanical clamping or direct laser welding to the superconducting cable, this method is easier to disassemble and replace. When the connector is damaged or the interface type needs to be upgraded, only the soldered cylindrical section of the intermediate component can be desoldered and resoldered by heating, without replacing the entire expensive superconducting cable, which greatly reduces maintenance costs and time.

[0034] On the other hand, the present invention also provides a connection method for the above-mentioned conductor connection structure, comprising the following steps: sleeve the cylindrical body of the intermediate component onto the first conductor; weld the inner surface of the cylindrical body to the first conductor by laser welding, with the laser beam passing through the welding through hole; place the second conductor on the outer surface of the soldering cylindrical body section, and flow molten solder between the second conductor and the soldering cylindrical body section, the solder quickly filling the flow channel and filling each welding through hole, and finally forming a solder layer to achieve the connection and fixation of the intermediate component and the second conductor.

[0035] By employing a step-by-step connection process of "laser welding first, then soldering," the two welding processes are separated in time and space, avoiding the thermal impact of high-temperature laser welding on the already formed solder joint (preventing remelting, deformation, or cracking of the solder joint), and ensuring the integrity and reliability of the conductor connection structure. The laser beam is precisely guided to the target area through the welding through-hole to achieve micro-area localized heating, with a small heat-affected zone, and will not damage the first conductor body (such as the dielectric layer or core wire of a superconducting cable).

[0036] The beneficial effects are:

[0037] 1. This invention fundamentally solves the technical problem of achieving a low-resistance, high-stability, and high-airtightness connection between a first conductor of difficult-to-weld materials (such as niobium and niobium-titanium alloys) and a conventional solderable second conductor, while also ensuring maintainability, through a cleverly designed intermediate component. This overcomes the inherent defects of traditional physical clamping and direct laser welding. By functionally partitioning the intermediate component, with its inner surface as the laser welding area and its outer surface as the soldering area, the difficult problem of "welding dissimilar materials" is broken down into two mature "welding of the same material" processes. Ultimately, this achieves high reliability between difficult-to-weld materials and conventional conductors, as well as convenient maintenance functions for disassembling and replacing the second conductor.

[0038] 2. The intermediate component is designed as a cylindrical structure, which can be directly fitted onto the outer periphery of the first conductor. The installation and positioning are simple and no complex fixtures are required for processing.

[0039] 3. Multiple through-holes are formed on the circumferential sidewalls of the intermediate component. During laser welding, the laser beam can penetrate the holes, causing the first conductor material to partially melt and flow into the holes. After cooling, the weld joints form a "weld stud" mechanical anchoring structure. This design enables multi-point, omnidirectional welding between the intermediate component and the first conductor, effectively preventing relative rotation or axial slippage and improving the overall structural stability of the connection.

[0040] 4. This invention can be applied to other metal systems that are difficult to solder directly (such as tantalum, zirconium, molybdenum, etc.) by adjusting the intermediate substrate (such as brass, beryllium copper, stainless steel, titanium alloy or niobium alloy), as a universal transition element for connecting dissimilar metals.

[0041] 5. This conductor connection structure achieves a highly reliable connection: the metallurgical bond formed by laser welding at the first conductor end is unaffected by temperature cycling, maintaining stable mechanical strength and conductivity even at a 4K liquid helium temperature, avoiding clamping failure due to differences in the thermal expansion coefficients of the materials. Simultaneously, the solder connection at the second conductor end is also very stable, ensuring long-term reliable operation of the connection structure in harsh environments such as cryogenics and high vacuum. Attached Figure Description

[0042] Figure 1 A three-dimensional structural diagram of an intermediate component for conductor welding;

[0043] Figure 2 for Figure 1 The main view;

[0044] Figure 3 for Figure 2 Cross-sectional view along the AA direction;

[0045] Figure 4 for Figure 2 Cross-sectional view along the BB direction (welded through holes are conical bottom holes and flat bottom straight holes);

[0046] Figure 5 Another preferred embodiment of the intermediate component (the welding through hole is a flat-bottomed straight hole and a flat-bottomed conical hole);

[0047] Figure 6 A schematic diagram of a structure in which an intermediate component is fitted onto the first conductor;

[0048] Figure 7 This is a schematic diagram of the structure after laser welding of the intermediate component and the first conductor.

[0049] Figure 8 This is a schematic diagram of the conductor connection structure in Example 1 (i.e., the intermediate component is welded to the first conductor and the second conductor).

[0050] Figure 9This is a schematic diagram of the coaxial cable connection structure in Example 2 (i.e., the intermediate component is welded to the coaxial cable and connector).

[0051] Explanation of reference numerals in the attached figures:

[0052] 10. Cylinder body; 11. Welding through hole; 111. Conical bottom hole; 112. Flat bottom straight hole; 113. Flat bottom conical hole; 121. Circumferential flow channel; 122. Axial flow channel; 123. Guide groove; 20. Coaxial cable; 21. Inner conductor; 22. Cable dielectric layer; 23. Outer conductor; 30. Connector; 31. First connecting mechanism; 32. Insulating layer; 33. Second connecting mechanism; 34. Tinning hole; 35. Outer shell; 40. Solder layer; 41. Solder joint. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0054] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper", "lower", "inner", "outer", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as a limitation of this application.

[0055] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and are not limited in number; for example, a first object can be one or more.

[0056] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0057] Existing low-temperature superconducting radio frequency coaxial cables often use niobium or niobium-titanium alloys as the inner and outer conductors. However, these materials are difficult to solder using traditional methods, so physical and mechanical clamping methods are currently mainly used to assemble the connector and coaxial cable together.

[0058] However, physical clamping methods present a significant challenge in precisely controlling the clamping force: too little force results in poor reliability, while too much force can damage the cable. In contrast, welding is far more reliable because it ensures the metals of the connector and the inner and outer conductors of the cable are fused, conductive, and continuous, creating a continuous and unobstructed path for signal transmission.

[0059] Compared to clamping and crimping, welding achieves atomic-level fusion, contact, and conductivity between the coaxial cable and the connector. Clamping and crimping only brings the two infinitely close, but cannot achieve atomic-level contact because an oxide film always exists between the contact surfaces. The presence of the oxide film hinders electron attraction and increases contact resistance, affecting signal transmission.

[0060] At a liquid helium temperature of 4K, the clamping mechanical properties of metals assembled at room temperature will change due to the ultra-low temperature, which may even cause metals that are elastic at room temperature to lose their elasticity, thereby causing clamping failure.

[0061] Therefore, it is necessary to invent a technology to achieve a reliable connection between niobium or niobium-titanium metal and the inner and outer conductors of conventional radio frequency coaxial connectors.

[0062] The present invention designs an intermediate component whose inner surface is connected to niobium or niobium-titanium through multi-point laser welding, and whose outer surface is welded to the inner and outer conductors of the connector by soldering.

[0063] The intermediate component is made of brass, beryllium copper, stainless steel, titanium alloy, or niobium alloy as the base material, designed for easy laser welding to the inner and outer conductors of the cable. The intermediate component has multiple laser welding through holes around its perimeter, and the outer surface has solder grooves. Except for the inner surface, which is the original bare base material, all other surfaces are gold-plated to facilitate soldering.

[0064] This intermediate component provides a reliable soldering solution; compared to laser soldering connectors directly to cables, soldered connectors are easier to replace, repair, and inspect. Furthermore, this intermediate component can also be used for soldering transitions of difficult-to-solder conductors.

[0065] The following is in conjunction with the appendix Figure 1 -Appendix Figure 9 The present application provides a detailed description of the intermediate components for conductor welding connections, conductor connection structures, and connection methods provided in this application through specific embodiments and application scenarios.

[0066] Example 1:

[0067] like Figures 1-5 This invention provides an intermediate component for conductor welding, used to connect a first conductor and a second conductor. The intermediate component is a cylindrical structure, fitted over the first conductor. It is made of beryllium copper, a material easily laser-welded, to facilitate laser welding to the first conductor. The cylindrical body 10 has multiple welding through holes 11 on its wall for laser welding between the first conductor and the cylindrical body 10. A soldering section is provided on the outer surface of the cylindrical body 10, used for soldering and fixing to the second conductor. This soldering section has a first metal plating layer. This invention achieves a reliable and easy-to-maintain connection between the first conductor (a difficult-to-weld material) and the second conductor (standard connector 30) by physically and materially isolating the laser welding area (inner surface) from the soldering area (outer surface).

[0068] The bare substrate material of the cylinder 10 must be selected from materials similar to and compatible with the first conductor to ensure optimal laser welding quality with the first conductor. In other embodiments, the cylinder 10 may be made of brass, beryllium copper, stainless steel, titanium alloy, or niobium alloy substrate.

[0069] In some preferred embodiments of the present invention, the inner surface of the cylinder 10 is not entirely a bare substrate, but it is ensured to be a bare substrate on the main contact surface of the laser welding area. For example, there may be a slight extension of the coating at the edge of the welding through hole 11 due to process reasons, but this slight coating will be vaporized or diffused during laser welding and will not have a substantial impact on the quality of the weld body.

[0070] The shape of the soldered cylindrical section matches the shape of the second conductor.

[0071] In this embodiment, the soldering cylinder section is the outer surface of the entire cylinder 10, which is a cylindrical surface; of course, in some other embodiments, the soldering cylinder section can also be an arc-shaped surface, a plane or a partial mating surface, etc. The shape of the soldering cylinder section is intended to achieve the maximum contact area with the second conductor and reliable clamping and positioning, so as to provide the optimal assembly basis for subsequent soldering.

[0072] Therefore, in this embodiment, the first metal coating is applied to the entire outer surface of the cylinder 10.

[0073] In some preferred embodiments of the present invention, a second metal plating layer is provided on the wall of the welded through hole 11. Of course, the second metal plating layer may also be provided only on the upper end of the wall of the welded through hole 11 (i.e., the area near the outer surface of the cylinder 10). The first metal plating layer and the second metal plating layer may be plating layers of the same or similar materials.

[0074] In this embodiment, the plating layer is preferably a gold plating layer because it has excellent solderability and oxidation resistance. In other embodiments, plating layers such as silver plating or tin plating layers, which can provide a good solderable surface, may also be used.

[0075] Multiple through-holes 11 are provided on the side wall of the cylinder 10 at intervals along the circumferential and axial directions. The multiple through-holes 11 are evenly distributed in the circumferential direction and arranged in multiple rows in the axial direction.

[0076] The diameter of the welded through hole 11 near the outer surface is larger than the diameter near the inner surface. In this embodiment, as shown... Figure 4 As shown, the welding through hole 11 is divided into an upper section and a lower section from top to bottom:

[0077] The upper section is a cylindrical hole, and its hole wall is perpendicular to the outer surface of the cylinder 10.

[0078] The lower section is configured in two forms according to requirements: in some of the welded through holes 11, it is a cylindrical hole, forming a flat-bottomed straight hole 112; in the other part of the welded through holes 11, it is a conical hole, forming a conical bottom hole 111.

[0079] This stepped structure, wider at the top and narrower at the bottom, offers multiple benefits during laser welding: First, the larger upper orifice facilitates the entry of the laser beam, reducing beam obstruction; second, the tapered or smaller cylindrical lower section helps to concentrate laser energy, increasing energy density; finally, this structure can accommodate more molten base material formed by the melting of the cylinder 10 and the first conductor during the welding process, resulting in a full and reliable weld point 41. In this embodiment, the tapered bottom hole 111 and the flat-bottomed straight hole 112 are alternately arranged.

[0080] In some embodiments, such as Figure 5 As shown, the welded through hole 11 can also be a stepped hole, with each welded through hole 11 divided into an upper section and a lower section from top to bottom:

[0081] The lower section is a cylindrical hole, and its hole wall is perpendicular to the inner surface of the cylinder 10.

[0082] The upper section is configured in two forms according to requirements: in some welded through holes 11, the upper section is a cylindrical hole, forming a flat-bottomed straight hole 112; in the other part of the welded through holes 11, it is a conical hole, forming a flat-bottomed conical hole 113.

[0083] In some embodiments, the welding through hole 11 may be provided with only one hole type, such as a conical bottom hole 111, a flat bottom straight hole 112, or a flat bottom conical hole 113.

[0084] The welding through hole 11 has three optional hole types: tapered bottom hole 111, flat bottom straight hole 112, and flat bottom tapered hole 113. Among them, the flat bottom straight hole 112 is the simplest to process, but it requires the laser to be incident at a strictly perpendicular angle, and has high requirements for process tolerance; the flat bottom tapered hole 113 provides a larger tolerance for the incident angle of the laser, which is convenient for optimizing the welding process, but its processing complexity is the highest; the tapered bottom hole 111 achieves the best balance between processing complexity and process adaptability. It is easy to process and also provides a certain degree of flexibility in adjusting the laser incident angle.

[0085] In this embodiment, the soldering cylinder section is the entire outer surface of the cylinder 10; therefore, the flow channel on the soldering cylinder section is disposed on the outer surface of the cylinder 10. This flow channel includes:

[0086] Circumferential flow channel 121: One (or more) channels are provided, extending circumferentially around the cylinder 10, serving as the main channel for solder flow.

[0087] Axial flow channels 122: Several such channels are provided, extending axially along the cylinder 10. These axial flow channels 122 are interconnected with the circumferential flow channels 121, conveying solder to both sides.

[0088] The welding through holes 11, axial flow channels 122, and circumferential flow channels 121 are arranged alternately on the outer surface of the cylinder 10. That is, each axial flow channel 122 is located between two adjacent rows of welding through holes 11, and each circumferential flow channel 121 is located between two adjacent welding through holes 11. This layout ensures that the solder can be efficiently and evenly distributed to the area where each welding through hole 11 is located.

[0089] To further optimize the solder flow path and ensure that the solder can accurately fill the welding through-hole 11, guide grooves 123 are provided between the axial flow channel 122 and the welding through-hole 11, and between the circumferential flow channel 121 and the welding through-hole 11. The width of the guide groove 123 is smaller than the width of the axial flow channel 122 and the circumferential flow channel 121. The guide groove 123 accurately guides the solder in the axial flow channel 122 and the circumferential flow channel 121 and injects it into the welding through-hole 11.

[0090] It is understood that the core of this invention lies in solving the problem of reliable connection between conductors using two incompatible welding processes through an intermediate component that combines a laser welding area (inner surface) and a soldering area (outer surface). Therefore, as long as this core idea is applied, the specific shape, size, and material of the intermediate component and conductor can be adjusted according to the actual application scenario, and these modifications should all be considered to fall within the protection scope of this invention.

[0091] Example 2:

[0092] Its main difference from Example 1 is:

[0093] like Figure 6-8 As shown, the present invention also provides a conductor connection structure, including a first conductor, a second conductor, and the aforementioned intermediate component; the cylindrical body 10 of the intermediate component is sleeved on the first conductor, the inner surface of the cylindrical body 10 is laser-welded to the first conductor through a welding through-hole 11, the second conductor is disposed on the outer peripheral surface of the soldering cylindrical body section, and the soldering cylindrical body section is connected to the second conductor by soldering.

[0094] Furthermore, the present invention also provides a connection method for a conductor connection structure, comprising the following steps:

[0095] S1. The intermediate component's cylindrical body 10 is fitted onto the first conductor;

[0096] S2. Laser welding is performed through the welding through-hole 11, so that the laser beam passes through the welding through-hole 11 to fuse the inner surface of the cylinder 10 with the first conductor to form a reliable weld point 41; thus achieving a high-strength, low-resistance metallurgical bond.

[0097] S3. The second conductor is placed on the outer surface of the soldering cylinder section for soldering operation. The molten solder flows into the gap between the second conductor and the soldering cylinder section through the soldering hole 34. Under capillary action, it quickly fills the circumferential flow channel 121 and the axial flow channel 122. Then, it is accurately sucked in through the guide groove 123 and fills each welding through hole 11, finally forming a dense, void-free solder layer 40 with high mechanical strength, realizing a reliable connection and mechanical fixation between the intermediate part and the second conductor.

[0098] By using the welding through-hole 11 of the intermediate component and the flow channel network (i.e., the intersecting axial flow channel 122 and circumferential flow channel 121), the connection quality of both laser welding and soldering processes is optimized, solving the problem of reliable connection between dissimilar conductors.

[0099] Example 3:

[0100] Its main difference from Example 1 is:

[0101] In this embodiment, the first conductor is a coaxial cable 20, and the second conductor is a coaxial cable connector 30.

[0102] like Figure 9 As shown, the present invention provides a coaxial cable connection structure for connecting a low-temperature superconducting coaxial cable 20 and a connector 30. The coaxial cable connection structure includes a coaxial cable 20, a connector 30, and an intermediate component.

[0103] The coaxial cable 20 comprises, from the inside out, an inner conductor 21, a cable dielectric layer 22, and an outer conductor 23. The materials of the inner conductor 21 and the outer conductor 23 are niobium or niobium-titanium alloy.

[0104] The connector 30 includes, from the inside out, a first connecting mechanism 31, an insulating layer 32, a second connecting mechanism 33, and a housing 35.

[0105] The middleware includes a first middleware and a second middleware. The base material of the middleware is niobium alloy or titanium alloy.

[0106] The first intermediate component is disposed between the inner conductor 21 and the first connecting mechanism 31. The inner surface of the first intermediate component is laser-welded to the inner conductor 21, and its outer surface (i.e., the soldered cylindrical section) is soldered to the first connecting mechanism 31.

[0107] The second intermediate component is disposed between the outer conductor 23 and the second connecting mechanism 33. The inner surface of the second intermediate component is laser welded to the outer conductor 23, and its outer surface (i.e., the soldered cylindrical section) is soldered to the second connecting mechanism 33.

[0108] The inner surface (bare substrate) of the intermediate component is laser-welded to the inner conductor 21 or outer conductor 23 of the niobium or niobium-titanium alloy coaxial cable to achieve a high-reliability connection; the outer surface (i.e., the soldered cylindrical section) of the intermediate component is soldered to the gold-plated first connection mechanism 31 or gold-plated second connection mechanism 33 of the standard connector 30 to achieve a perfect connection.

[0109] A connection method for a coaxial cable connection structure includes the following steps:

[0110] S1. The first intermediate component is fitted onto the inner conductor 21 of the coaxial cable 20, and the second intermediate component is fitted onto the outer conductor 23.

[0111] S2. Laser welding is performed through the welding through-hole 11 to fuse the inner surface of the first intermediate part with the inner conductor 21 and the inner surface of the second intermediate part with the outer conductor 23.

[0112] S3. The connector 30 is fitted onto the outer surface of the intermediate component and soldered. Molten solder is filled into the space between the outer surface of the first intermediate component and the first connecting mechanism 31 through the solder filling hole 34. After cooling, a solder layer is formed, thus achieving the welding of the first intermediate component and the first connecting mechanism 31. Molten solder is filled into the space between the outer surface of the second intermediate component and the second connecting mechanism 33 through the solder filling hole 34. After cooling, a solder layer is formed, thus achieving the welding of the second intermediate component and the second connecting mechanism 33. Thus, a reliable connection between the coaxial cable and the connector is completed.

[0113] Of course, the first conductor can also be other metal wires that are difficult to solder, such as tantalum, tungsten, or their alloys. The second conductor can be any standard electrical interface suitable for soldering that needs to be connected to.

Claims

1. An intermediate piece for soldering a conductor, for connecting a first conductor and a second conductor, characterized in that: the intermediate piece has a barrel for sleeving the first conductor; the inner surface of the barrel is a bare substrate surface suitable for laser welding, for laser welding the intermediate piece to the first conductor; a plurality of welding through holes are formed on the barrel wall of the barrel, for laser welding the first conductor and the barrel; the barrel has a solder barrel section for adapting to the shape of the second conductor, the solder barrel section is soldered to the second conductor, and the outer circumferential surface of the solder barrel section is provided with a first metal plating layer for tin soldering; the outer surface of the solder barrel section is provided with a flow channel for guiding and containing solder; the flow channel includes at least one circumferential flow channel and a plurality of axial flow channels, and the circumferential flow channel and the axial flow channel are in communication with each other; the intersection of the circumferential flow channel and the axial flow channel separates the outer surface of the solder barrel section to form a plurality of protrusions, and the welding through holes are arranged on the protrusions; the protrusions are also provided with flow guide grooves, and the flow guide grooves are in communication with the welding through holes and the axial flow channels and / or circumferential flow channels; the welding through holes are provided with a second metal plating layer on the hole wall, and the second metal plating layer is used for tin soldering to strengthen the soldering connection strength between the solder barrel section and the second conductor; the first metal plating layer and the second metal plating layer are plating layers of the same material, and the plating layer is a gold plating layer, a silver plating layer or a tin plating layer; the outer diameter of the welding through hole is larger than the inner diameter of the welding through hole; the welding through hole is one or more of a flat-bottom straight hole, a flat-bottom tapered hole and a tapered-bottom hole; wherein the flat-bottom straight hole is composed of an upper segment cylindrical hole and a lower segment cylindrical hole arranged coaxially; the flat-bottom tapered hole is composed of an upper segment tapered hole and a lower segment cylindrical hole arranged coaxially; the tapered-bottom hole is composed of an upper segment cylindrical hole and a lower segment tapered hole arranged coaxially, or a single segment tapered hole; the intermediate piece of any one of claims 1-5; the barrel of the intermediate piece is sleeved on the first conductor, the inner surface of the barrel is laser welded with the first conductor through the welding through hole; the second conductor is arranged on the outer circumferential surface of the solder barrel section, and the solder barrel section is connected with the second conductor by tin soldering; the steps include: sleeving the barrel of the intermediate piece on the first conductor; laser welding, and melting the inner surface of the barrel and the first conductor through the welding through hole by a laser beam; arranging the second conductor on the outer circumferential surface of the solder barrel section, and flowing the molten solder between the second conductor and the solder barrel section to form a solder layer, so as to realize the connection and fixation of the intermediate piece and the second conductor. ​ ​ ​ ​ ​ ​ 2. The intermediate for conductor bonding as claimed in claim 1, wherein: ​ 3. The interposer for soldering conductors according to claim 2, wherein: ​ 4. The intermediate for conductor bonding as claimed in claim 1, wherein: ​ 5. The intermediate for conductor bonding as claimed in claim 4, wherein: ​ ​ ​ ​ 6. A conductor connecting structure comprising a first conductor and a second conductor; characterized by, ​ 7. A method of connecting a conductor connection structure as defined in claim 6, characterized by ​ ​ ​ ​

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