A low contact resistance electrical connection interface, terminal, connector and method of making the same

Abstract

The application discloses a low-contact-resistance electric connection interface, a terminal, a connector and a preparation method thereof. The electric connection interface comprises a first conductive part and a second conductive part matched with each other, and a soft elastic conductor module arranged at a contact area of the first conductive part and / or the second conductive part. The soft elastic conductor module comprises an elastic support body and a plurality of flexible conductive elements arranged on the outer surface of the elastic support body. The flexible conductive elements have fixed connection parts electrically connected and fixed with the bearing conductive parts and contact parts exposed outside the elastic support body. In a working connection state, the matched conductive part presses the soft elastic conductor module, so that the elastic support body is elastically deformed, and the plurality of contact parts form a plurality of dispersed electric contact points, electric contact lines or local electric contact surfaces with the matched conductive part, thereby forming a plurality of parallel conductive paths between the first conductive part and the second conductive part.

Description

Technical Field

[0001] This invention relates to the field of electrical connector technology, and in particular to an electrical connection interface for reducing contact resistance and improving contact stability between conductive components, an electrical connection terminal including the interface, a connector, a flexible conductor module, and related manufacturing methods. Background Technology

[0002] Connectors are used to establish detachable, assemblable, or maintainable electrical connections between devices, cables, circuit boards, modules, or conductive structures. Connector terminals are generally divided into two categories: power terminals and signal terminals. Their performance largely depends on the contact resistance after the terminals are mated: the higher the contact resistance, the higher the terminal temperature rise and the worse the allowable current or signal transmission performance.

[0003] For power terminals, contact resistance directly affects temperature rise, rated current, terminal size, material usage, and overall thermal design. Taking the common XT30 power connector as an example, its nominal contact resistance is approximately 700μΩ. With a fixed contact interface size, the rated current is approximately 15A, corresponding to a contact resistance heat generation of approximately 315mW. As a result, many manufacturers of high-power drones, robots, and everyday devices have had to switch to larger-specification power connectors like the XT120 and XT150, which are several times more expensive, ten to twenty times larger and heavier, and offer better heat dissipation. Similar situations exist in the automotive, aircraft, and rocket industries.

[0004] In recent years, the connector industry has proposed various structural improvement schemes, but most of them have failed to achieve a significant reduction in the contact resistance of power terminals. For example, patent CN120033479A (published on May 23, 2025, and under substantive examination at the time of publication) discloses a connector terminal assembly for high current applications: its female terminal is a cylindrical conductor with continuous spiral grooves on its circumferential wall, and the inner diameter of the cylindrical conductor is smaller than the outer diameter of the cylindrical conductor of the male terminal; when the male terminal is inserted, the cylindrical conductor is expanded by the spiral grooves to wrap around the male terminal, improving the contact between the inner circumferential surface of the female terminal and the outer circumferential surface of the male terminal from the traditional line contact to a surface-to-surface contact, thereby reducing the contact resistance and increasing the current carrying capacity without changing the material or increasing the amount of material used. However, this solution still belongs to the improvement of the contact area between rigid metal terminals, and the hardness of the contact surface layer remains unchanged. It is difficult to fundamentally break through the lower limit of contact resistance determined by the hardness of the contact surface layer, and it still has limitations for applications such as through-shaft miniaturization and high-frequency signals that require a significant reduction in contact resistance.

[0005] On the other hand, with the widespread adoption of hollow shaft motors in robots, the industry has generally encountered the problem that "the size of the power connector that meets the contact resistance requirements is much larger than the hollow shaft hole": the terminal size that meets the contact resistance requirements is too large, while the contact resistance of the terminal that meets the size requirements is too large. This forces the entire industry to adopt an assembly method of threading the wires first and then soldering the connectors, which significantly reduces assembly efficiency and makes on-site maintenance difficult. According to analysis, if the contact resistance of the terminal that meets the size requirements can be reduced to about 1 / 30 of the current level, a power connector that can pass through the hollow shaft hole, is pluggable, and is easy to maintain in the field can be obtained.

[0006] On another front, power connectors often use a brass "rod-tube" design, and because they typically employ a full gold-plating process, they are quite long, resulting in high material costs, as seen in the XT30-XT150 series connectors. Further analysis reveals that the contact area of ​​the "rod-tube" is often less than 1 / 20 of its mating area, thus wasting a significant amount of metal and generating unnecessary "conductor resistance," leading to a higher overall connector resistance. This excessive redundancy is intended to ensure tight contact between the "rod-tube" during vibration and insertion / removal, guaranteeing current flow.

[0007] For signal terminals, especially for RF, high-frequency, or high-speed signal connections, contact impedance and its fluctuations affect insertion loss, return loss, noise, and long-term reliability. Currently, high-frequency signal connections often use fuzz button-type structures, whose contact resistance is about 1 / 10 of that of ordinary terminals of the same size, and can be used for signal connections up to about 100GHz. However, fuzz buttons are usually made of imported beryllium copper wire plated with gold, which has problems such as high cost, easy damage, poor resistance to contamination, and high assembly requirements. They are basically only used in the military and aerospace fields and are difficult to use on a large scale in civilian applications. Moreover, as the signal frequency band develops towards terahertz (THz), the contact resistance of fuzz buttons is still relatively large and needs to be further reduced by about an order of magnitude.

[0008] In addition, existing micro-elastic contact components, spring pins and other structures, while improving contact resistance, often have problems such as high manufacturing cost, fragile structure, sensitivity to contamination and surface condition, high assembly requirements or difficulty in large-scale civilian use.

[0009] In summary, existing connectors, due to their relatively high contact resistance (contact impedance), limit the transmission capabilities of high-current and high-frequency signals, and to some extent, also restrict the development of related industries. Furthermore, the need for significant redundancy in design results in high connector material costs, further hindering the development of related industries. Therefore, there is a need for an electrical connection structure that can significantly reduce contact resistance and improve contact stability while maintaining essentially the same or only slightly increasing terminal dimensions, while also considering manufacturing and assembly feasibility, reducing the use of precious metals, and being suitable for civilian application. Summary of the Invention

[0010] The purpose of this invention is to provide a low-contact-resistance electrical connection interface to solve the problems of limited effective contact units and difficulty in further reducing contact resistance and its fluctuation under small-size conditions of existing rigid terminals, while taking into account the feasibility of processing and assembly and civilian application.

[0011] To achieve the above objectives, the present invention provides a low-contact-resistance electrical connection interface, comprising a first conductive element, a second conductive element, and a flexible conductor module that cooperate with each other. The flexible conductor module is disposed in the contact area of ​​the first conductive element and / or the second conductive element. For ease of explanation, the conductive element on which the flexible conductor module is disposed will be referred to as the carrier conductive element, and the conductive element that contacts and cooperates with the flexible conductor module will be referred to as the mating conductive element.

[0012] The flexible conductor module includes an elastic support body and multiple flexible conductive elements disposed on the outer surface of the elastic support body. At least some of the flexible conductive elements have a fixed connection portion that is electrically connected and mechanically fixed to a carrier conductive element, and a contact portion exposed on the outside of the elastic support body. When the first conductive element and the second conductive element are in a plug-in, crimp, fit, or other working connection state, the cooperating conductive element presses the flexible conductor module, causing the elastic support body to elastically deform, and the multiple contact portions and the cooperating conductive element to form multiple dispersed electrical contact points, electrical contact lines, or local electrical contact surfaces, thereby forming multiple parallel conductive paths between the first conductive element and the second conductive element.

[0013] To prevent the conductor material of flexible conductive elements from breaking due to localized tensile stress, repeated bending fatigue, or stress concentration during the insertion, pressing, or bonding of the first and second conductive components, and to consider low resistance, high-frequency surface conductivity, miniaturization, and feasibility of mass production, this invention provides a high-strength composite conductor filament. This composite conductor filament comprises a fiber skeleton and a good conductor layer. The fiber skeleton is composed of high-strength, low-elongation fibers, primarily used to withstand mechanical loads during tension, bending, torsion, or repeated motion of the composite conductor filament. The good conductor layer is fully or partially tightly attached to the outer surface of the fiber skeleton, forming a continuous or quasi-continuous conductive path along the length of the fiber skeleton. Thus, the composite conductor filament simultaneously possesses the tensile and bending resistance provided by the fiber skeleton and the conductivity provided by the good conductor layer.

[0014] Principle of reduced contact resistance To more clearly illustrate the principle of reducing contact resistance in this invention, the following analysis is based on contact resistance theory. According to Holm's contact resistance theory, when two clean metal conductors come into contact under a certain normal pressure, current can only be conducted through a number of microscopic real contact spots (a-spots). The resulting shrinkage resistance (i.e., contact resistance) mainly depends on the resistivity of the contact material, the hardness of the contact surface material, and the normal contact pressure. It can be approximately expressed as the contact resistance being proportional to the material resistivity, increasing with the square root of the contact surface hardness, and decreasing with the square root of the contact normal pressure. Therefore, under the condition of constant contact material resistivity and contact normal pressure, the lower the equivalent hardness of the contact surface material, the easier it is for plastic bonding to occur under the same normal pressure, resulting in a larger real contact area and thus a lower contact resistance.

[0015] The contact surfaces of commonly used power terminals or signal terminals are mostly made of brass plated with nickel, brass, brass plated with silver, or brass plated with gold. Their surface hardness is approximately 80HB, 100HB, 30HB, and 35HB, respectively. The hardness difference is limited, and the corresponding contact resistance only varies within a small range. Therefore, it is difficult to reduce the contact resistance by orders of magnitude simply by replacing the above-mentioned terminal surface plating.

[0016] This invention takes a novel approach: High-strength, highly conductive, relatively independent flexible conductive elements (soft conductor wires) with diameters on the order of approximately 10 μm are tightly disposed on the outer surface of an elastic support body with an equivalent hardness far lower than that of brass (in one exemplary condition, it can be as low as approximately one ten-thousandth the hardness of brass). This creates a flexible, highly conductive contact layer—a soft-elastic conductor module—with extremely low equivalent hardness and composed of numerous parallel micro-conductors at the contact interface of the rigid terminal. When the mating conductive element presses against this contact layer, the elastic support body deforms accordingly, and numerous flexible conductive elements adhere to the surface of the mating conductive element with extremely low equivalent hardness, forming numerous, dispersed, and parallel real micro-contacts. This significantly increases the actual contact area, reduces contact resistance and its fluctuations, and minimizes the impact of single contact point failure on overall conductivity.

[0017] Exemplary technical effects As an example, under the condition that the mating surface is relatively flat gold-plated brass and the contact pressure is equivalent to that of the conventional terminals, the contact resistance between the flexible conductor module and the mating conductive part can be reduced to a fraction of the contact resistance when conventional gold-plated brass terminals are in contact, reaching approximately 1 / 100 in one example. Correspondingly, for power connectors, while maintaining the rated current, the terminal contact interface size can be significantly reduced, to approximately 1 / 10 in one example; or, while keeping the terminal size essentially unchanged, the transmittable power can be significantly increased, to approximately 10 times in one example. For scenarios requiring through-shaft wiring, such as robot joints and hollow shaft motors, a low-contact-resistance power connection structure capable of passing through hollow shaft holes can be obtained when the contact resistance of terminals meeting size requirements is reduced to approximately 1 / 30. For high-frequency or high-speed signal connectors, signal transmission performance can be improved by approximately one order of magnitude due to the significant reduction in contact impedance and its fluctuations. It should be understood that the above values ​​and multiples are merely illustrative examples used to explain the technical effects that the present invention may achieve, and do not constitute a limitation on the scope of protection of the present invention; the actual effect depends on factors such as materials, size, arrangement, normal pressure, mating surface condition and test conditions.

[0018] Overview of Preferred Implementation Methods In one embodiment, the contact area of ​​the carrier conductive element is provided with a groove, guide groove, positioning groove, receiving groove, receiving pit, or limiting groove. At least a portion of the flexible conductor module is disposed within the aforementioned groove or pit. This structure enables mechanical positioning of the flexible conductor module, preventing the flexible conductor module from being carried away by friction during insertion and removal of the first and second conductive elements, and reducing displacement caused by crimping, vibration, or thermal cycling. Simultaneously, when the flexible conductor module is compressed, the flexible conductive element can form bottom-surface contact, side-surface contact, or semi-enclosed contact with the carrier conductive element, thereby shortening the local conductive path, improving the reliability of the fixed connection, and helping to improve the fixing yield of welding or crimping.

[0019] In one embodiment, the flexible conductive element can be a composite conductor wire, a pure conductor wire, a stranded conductor wire, a conductive fiber, a surface-plated conductive wire, a metal flat wire, or a combination thereof. The flexible conductive elements can be arranged approximately parallel to each other along the length of the elastic support, or they can be spirally wound, cross-wrapped, braided, mesh-covered, or form a multi-layered composite structure. At least a portion of the multiple flexible conductive elements can remain independent or only partially overlap each other, so as to form multiple mutually dispersed micro-contact units after being compressed.

[0020] Preferably, the flexible conductive element employs a composite conductor filament, which comprises a fiber skeleton and a highly conductive layer. The fiber skeleton is composed of high-strength, low-elongation fibers, primarily used to withstand mechanical loads on the composite conductor filament during stretching, bending, torsion, or repeated motion. The highly conductive layer is fully or partially tightly attached to the outer surface of the fiber skeleton, forming a continuous or quasi-continuous conductive path along the length of the fiber skeleton. Thus, the composite conductor filament simultaneously possesses the tensile and bending resistance provided by the fiber skeleton and the conductivity provided by the highly conductive layer.

[0021] In a preferred embodiment, the fiber skeleton has a breaking strength greater than 2.5 GPa, an elongation before breaking of less than 5%, and a single filament diameter of less than 100 μm. The fiber skeleton may be aramid fiber, carbon fiber, modified glass fiber, polyimide fiber, liquid crystal polymer fiber, silicon carbide fiber, basalt fiber, alumina fiber, or a combination thereof, satisfying the above strength and elongation requirements.

[0022] In a preferred embodiment, the good conductor layer comprises copper, silver, gold, nickel, aluminum, copper alloys, silver alloys, gold alloys, nickel alloys, silver-plated copper, gold-plated copper, nickel-plated copper, tin-plated copper, or combinations thereof. The bulk resistivity of the good conductor material is not greater than 1.0 × 10⁻⁶. -7 Ω·m, preferably not greater than 7.0 × 10 -8 Ω·m, further preferably not greater than 6.84×10 -8 Ω·m. Depending on the specific application, silver, copper, gold, aluminum or their alloys may be preferred as the low resistivity main conductive layer, and nickel, gold, tin, palladium or other metals may be used as the adhesion enhancement layer or surface protective layer.

[0023] In a preferred embodiment, the elongation at break of the good conductor material at the target operating temperature or equivalent test conditions is greater than 8%, preferably greater than 10%. This configuration prevents the good conductor layer from breaking completely before the fiber skeleton reaches its breaking point, thus allowing the fiber skeleton to effectively perform its tensile load-bearing function. For scenarios requiring high flexibility and high cyclic bending life, the good conductor layer can also employ spiral covering, partitioned covering, corrugated covering, mesh covering, island interconnected covering, or multi-segment overlapping covering to provide strain release space during bending, torsion, or axial micro-elongation.

[0024] In a preferred embodiment, the good conductor layer can be formed by single crystal growth, directional growth, sputtering deposition, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electroless plating, electroplating, melt coating, conductive paste coating, or a combination thereof. To improve adhesion strength, the fiber skeleton surface can be first cleaned, roughened, activated, sensitized, coupled, plasma-treated, or chemically treated before forming the adhesion reinforcement layer, seed layer, and main conductive layer.

[0025] In one embodiment, the elastic support is made of an elastic material that retains its resilience at the target operating temperature, such as silicone rubber, foamed silicone rubber, fluororubber, fluorosilicone rubber, ethylene propylene rubber, polyurethane elastomer, or high-temperature resistant thermoplastic elastomer. Its temperature resistance is preferably not lower than 120°C, and its compression set or creep rate under long-term extrusion conditions or equivalent accelerated testing conditions is preferably not greater than 30%. Furthermore, to reduce the tearing stress on the flexible conductive element caused by the lateral expansion of the elastic support under pressure, the elastic support preferably uses a material or structure with a Poisson's ratio greater than 0.5, such as foamed silicone rubber or an elastomer with irregular cross-sections such as hollow, slotted, or corrugated sections, thereby protecting the flexible conductive element from tearing and extending the contact layer life under repeated pressure.

[0026] Furthermore, in a preferred embodiment, the carrier conductive element or mating conductive element is made of a metal with a long-life elastic structure, such as a "copper-steel composite sheet" with a deformable elastic region. This design ensures that, even when the elastic support undergoes creep, the carrier conductive element and the mating conductive element remain in constant contact, maintaining excellent contact between them.

[0027] Furthermore, since the amount of flexible conductive elements and elastic supports used in a single soft and elastic conductor module is very small, and it can be prepared using conventional, efficient, and low-cost processes such as continuous winding, wrapping, braiding, hot air assisted welding, and hot pressing, this invention can significantly reduce contact resistance without raising the cost of related terminals to an unacceptable level for civilian use, which is conducive to its promotion in civilian fields such as drones, robots, power tools, vehicles, and energy storage.

[0028] Beneficial effects Compared with existing technologies, the present invention has at least the following beneficial effects: First, by forming multiple parallel contact units through multiple flexible conductive elements with low equivalent hardness, the actual contact area is increased under the same contact normal pressure, which can significantly reduce the overall contact resistance and its fluctuations while keeping the terminal size basically unchanged or slightly increased; Second, the elastic support can compensate for changes in contact pressure caused by manufacturing tolerances, insertion tolerances, and thermal cycling, thereby improving long-term contact stability; Third, the positioning groove, receiving groove, and limiting structure are conducive to improving the fixing reliability and fixing yield of the soft elastic conductor module and shortening the local conductive path; Fourth, the elastic support with a preferred Poisson ratio greater than 0.5 can protect the flexible conductive elements from being cracked and improve the contact layer life; Fifth, the structure can adjust the material, size, arrangement, and shape of the elastic support of the flexible conductive elements according to different scenarios such as power connection, high-frequency signal connection, and robot joint through-axis connection, and has a wide range of applications; Sixth, the soft elastic conductor module can be prepared by conventional and efficient processes such as winding, wrapping, braiding, hot pressing, welding, and pressing, with controllable cost, which is convenient for mass production and civilian promotion. Attached Figure Description

[0029] To more clearly illustrate the technical solution of the present invention, the accompanying drawings required for the embodiments are briefly described below. The following drawings are only for illustrating the structure and principle of the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0030] Figure 1 This is a schematic diagram of the low contact resistance electrical connection interface in the unpressurized state according to one embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the low contact resistance electrical connection interface in the crimped state according to one embodiment of the present invention.

[0032] Figure 3 This is a schematic diagram of the structure of a soft elastic conductor module in one embodiment of the present invention.

[0033] Figure 4 This is a schematic diagram of a structure in one embodiment of the present invention, showing a guide groove or receiving groove provided in the contact area of ​​the conductive component.

[0034] Figure 5 This is a schematic diagram of the structure of a flexible conductive element spirally wound on the outer surface of an elastic support body in one embodiment of the present invention.

[0035] Figure 6 This is a schematic diagram of the structure of a flexible conductive element with pre-conducted surface in one embodiment of the present invention.

[0036] Figure 7 This is a schematic diagram of the structure of a flexible conductive element with post-conductivity surface finishing in one embodiment of the present invention.

[0037] Figure 8 This is a schematic diagram of the structure of a soft elastic conductor module fixed on a guide groove of a carrier conductive component in one embodiment of the present invention.

[0038] Figure 9 This is a schematic diagram of the optimized service life of the first conductive element and the second conductive element in one embodiment of the present invention.

[0039] Figure 10 This is a schematic diagram of the structure of the first conductive element and the second conductive element in one embodiment of the present invention, which significantly reduces the cost of metal materials.

[0040] Explanation of reference numerals in the attached drawings: 1. First conductive element; 10. Contact area; 11. Fixed connection area; 12. Groove, guide groove or receiving groove; 13. Limiting structure; 2. Second conductive element; 21. Contact surface; 22. Deformable elastic area; 3. Soft and elastic conductor module; 31. Elastic support; 32. Flexible conductive element; 33. Contact part; 34. Fixed connection part; 321. Fiber skeleton; 322. Good conductor layer; 4. Insulating shell. Detailed Implementation

[0041] The present invention will be further described below with reference to the embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the scope of protection of the present invention. Equivalent substitutions, combinations or adjustments made by those skilled in the art to materials, dimensions, arrangement, terminal shapes, fixing methods or application scenarios under the concept of the present invention may all fall within the scope of protection of the present invention.

[0042] Example 1: Basic Electrical Connection Interface like Figure 1 and Figure 2 As shown, the low contact resistance electrical connection interface includes a first conductive element 1, a second conductive element 2, and a flexible conductor module 3. The first conductive element 1 and the second conductive element 2 can be a male terminal and a female terminal, respectively, or they can be two conductive plates, two conductive sheets, conductive posts, conductive rings, wire terminals, plate terminals, or other conductive components that can cooperate with each other.

[0043] The flexible conductor module 3 is disposed in the contact area 10 of the first conductive element 1 facing the second conductive element 2. In other embodiments, the flexible conductor module 3 may also be disposed in the contact area of ​​the second conductive element 2, or simultaneously disposed in the corresponding contact areas of the first conductive element 1 and the second conductive element 2.

[0044] The flexible conductor module 3 includes an elastic support 31 and a plurality of flexible conductive elements 32 disposed on the outer surface of the elastic support 31. At least a portion of the flexible conductive elements 32 are electrically connected to and mechanically fixed to the first conductive element 1 via a fixing connection portion 34. The fixing connection portion 34 may be located on the bottom, side, end, or locally flattened area of ​​the flexible conductor module 3.

[0045] When the first conductive element 1 and the second conductive element 2 are not connected, the flexible conductor module 3 can remain in a free state or a pre-compressed state. After the first conductive element 1 and the second conductive element 2 are connected, the second conductive element 2 compresses the flexible conductor module 3, causing the elastic support 31 to undergo elastic deformation. The deformation of the elastic support 31 causes the contact portion 33 of the flexible conductive element 32 to conform to the contact surface 21 of the second conductive element 2, forming multiple electrical contact points, electrical contact lines, or local electrical contact surfaces. Since multiple flexible conductive elements 32 participate in conduction simultaneously, multiple parallel conductive paths are formed between the first conductive element 1 and the second conductive element 2.

[0046] Example 2: Terminal structure with positioning groove or receiving groove like Figure 4As shown, the contact area 10 of the first conductive element 1 is provided with a groove, guide groove, or receiving groove 12. The groove, guide groove, or receiving groove 12 may extend along the length direction of the first conductive element 1, or may be provided along the width direction, circumferential direction, spiral direction, or partial contact area. At least a portion of the flexible conductor module 3 is embedded in the groove, guide groove, or receiving groove 12.

[0047] The width, depth, and sidewall shape of the groove, guide groove, or receiving groove 12 can be set according to the free dimensions, pressure deformation profile, insertion stroke, target contact pressure, and target contact resistance of the flexible conductor module 3. In one embodiment, the groove width is slightly larger than the local width of the flexible conductor module 3 in its free state, making it easier to place and position, and facilitating a tighter fit between the flexible conductor module 3 and the groove wall and the surface of the first conductive element 1 after pressure deformation, thereby further shortening the conductive path and reducing the conduction resistance. In another embodiment, the groove depth is smaller than the free height of the flexible conductor module 3, causing the flexible conductor module 3 to protrude from the contact reference surface in its free state, and to be pressed into the groove or form a semi-enclosed contact with the groove wall in the working connection state.

[0048] This structure can reduce slippage of the flexible conductor module 3 during insertion, crimping, vibration, or thermal cycling, and improve the fixation yield of welding or crimping. For connectors requiring multiple insertions or high vibration reliability, a limiting structure 13 can be provided at the end or side of the groove, guide groove, or receiving groove 12, such as a limiting step, undercut, pressing edge, cover plate, riveting part, snap-fit ​​part, or welding area.

[0049] Example 3: Soft and Elastic Conductor Module like Figure 3 and Figure 5 As shown, the flexible conductor module 3 includes an elastic support 31 and multiple flexible conductive elements 32. The elastic support 31 can be a solid structure, a hollow structure, a foamed structure, a surface grooved structure, a corrugated structure, or an irregular cross-section structure. The cross-section of the elastic support 31 can be circular, elliptical, rectangular, oval, polygonal, or other shapes suitable for contacting the conductive elements.

[0050] The flexible conductive element 32 can be arranged approximately parallel to the length of the elastic support 31, or it can be wound spirally around the outer surface of the elastic support 31. It can also be formed into a conductive contact layer using methods such as cross-wrapping, braiding, multi-strand winding, multi-layer composite, or mesh covering. To increase the number of contact units, the flexible conductive element 32 can be made of fine conductor wire, for example, with a diameter or equivalent diameter of approximately 10 μm, ranging from 0.5 μm to 100 μm, preferably from 2 μm to 50 μm, and more preferably from 5 μm to 20 μm.

[0051] The flexible conductive element 32 can be formed into a single-layer or multi-layer structure on the outer surface of the elastic support 31. A single-layer structure is beneficial for reducing thickness and controlling contact height, while a multi-layer structure is beneficial for increasing conductive redundancy and wear resistance life. Adjacent flexible conductive elements 32 can maintain a distance, or they can be in partial contact or overlap. As long as multiple dispersed micro-contact units can be formed under pressure, the technical objective of this invention can be achieved.

[0052] Example 4: Materials, Hardness, and Surface Treatment The conductor material of the flexible conductive element 32 may be copper, silver, gold, nickel, aluminum, copper alloy, silver alloy, gold alloy, nickel alloy, silver-plated copper, gold-plated copper, nickel-plated copper, tin-plated copper, or a combination thereof, and its volume resistivity is preferably not greater than 6.84 × 10⁻⁶. -8 Ω·m. For power connection scenarios requiring low contact resistance, materials or coatings with low resistivity and good oxidation resistance should be prioritized. For high-frequency signal connection scenarios, appropriate surface treatments can be selected based on the target frequency band, insertion loss, surface current distribution, magnetic loss, and oxidation resistance requirements.

[0053] It should be noted that while the flexible conductive element 32 can be made of high-strength metal wire, its small diameter and flexible support by the elastic support 31 result in an effective hardness of the contact surface of the soft-elastic conductor module 3 that is significantly lower than that of traditional brass terminal surfaces. For comparison, the surface hardness of nickel-plated brass, brass, silver-plated brass, and gold-plated brass terminals are approximately 80 HB, 100 HB, 30 HB, and 35 HB, respectively; while the effective hardness of the contact surface of the soft-elastic conductor module 3 can be as low as approximately one ten-thousandth of that of brass under one exemplary condition. According to Holm's contact resistance theory, under the same contact pressure, a contact surface with lower effective hardness can form a larger actual contact area, thereby achieving a significantly lower contact resistance.

[0054] The elastic support 31 is preferably an elastic material with stable resilience at the target operating temperature, such as silicone rubber, foamed silicone rubber, fluororubber, fluorosilicone rubber, ethylene propylene rubber, polyurethane elastomer, high-temperature thermoplastic elastomer, foamed elastomer, or a combination thereof. For power connectors, the elastic support 31 can be made of a material with a temperature resistance of not less than 120°C and a compression set or creep rate of not more than 30% under long-term compression to accommodate terminal heating, internal temperature rise of the equipment, or residual heat effects after welding. Furthermore, the elastic support 31 preferably uses a material or irregular structure with a Poisson's ratio greater than 0.5, such as foamed silicone rubber or silicone rubber with hollow, slotted, or corrugated cross sections, to reduce the stress on the flexible conductive element 32 during lateral expansion under pressure, protecting the flexible conductive element 32 from cracking.

[0055] The first conductive element 1 and the second conductive element 2 can be made of copper, copper alloy, aluminum, aluminum alloy or other conductive metals. Their contact surfaces can be plated with silver, gold, nickel, tin, copper, palladium, platinum or their alloys, or an anti-oxidation conductive protective layer can be provided.

[0056] Example 5: Fixed Connection Method The flexible conductor module 3 can be fixed to the carrier conductive element by brazing, laser welding, ultrasonic welding, resistance welding, thermocompression welding, diffusion welding, conductive adhesive bonding, mechanical pressing, riveting, snap-fit ​​fixing, encapsulation fixing, partial fusion welding, or a combination thereof. The fixed connection serves both to prevent the flexible conductor module 3 from dislodging during insertion, removal, or vibration, and to ensure a low-resistance electrical connection between at least a portion of the flexible conductive element 32 and the carrier conductive element. In a preferred embodiment, the flexible conductor module 3 is pre-welded to the outer surface of the first conductive element 1 facing the second conductive element 2 or into a guide groove to prevent it from being carried away by friction during insertion or removal.

[0057] In power connectors, it is preferable to directly connect the fixed connection portion 34 of the flexible conductive element 32 to the carrier conductive element via brazing, metal welding, pressure welding, or crimping to reduce connection resistance. In signal connectors, the position, length, and parasitic parameters of the fixed connection area can be controlled according to high-frequency performance requirements.

[0058] In one embodiment, a local area of ​​the flexible conductor module 3 is flattened to form a fixed connection portion 34, and then fixed to the bottom wall of the groove, guide groove, or receiving groove 12 by welding or crimping. This method can increase the fixed connection area, improve the fixing yield, and shorten the conductive path from the flexible conductive element 32 to the carrier conductive element.

[0059] Example 6: Preparation Method A method for fabricating a low-contact-resistance electrical connection interface includes the following steps. First, a first conductive element 1, a second conductive element 2, an elastic support 31, and a plurality of flexible conductive elements 32 are provided. The contact area of ​​the first conductive element 1 or the second conductive element 2 can be pre-formed with grooves, guide grooves, positioning grooves, receiving grooves, receiving pits, or limiting grooves, or it can be formed after the terminal is formed by stamping, milling, etching, laser processing, rolling, molding, sintering, or additive manufacturing.

[0060] Next, multiple flexible conductive elements 32 are disposed on the outer surface of the elastic support 31 to form a soft and elastic conductor module 3. This step can be completed by continuous winding, parallel wrapping, braiding, laying, hot air assisted forming, hot pressing forming, local adhesive positioning, tension control forming, or a combination thereof. To ensure the uniformity of the distribution of the flexible conductive elements 32, the tension, winding pitch, helix angle, number of layers, and spacing can be controlled during the winding or wrapping process.

[0061] Next, the flexible conductor module 3 is placed in the contact area of ​​the carrier conductive element, and at least a portion of the flexible conductive element 32 is electrically connected and fixed to the carrier conductive element. After fixing, the flexible conductor module 3 can maintain a certain protruding height relative to the contact reference surface, so as to obtain a predetermined amount of compression deformation in the working connection state.

[0062] Finally, the first conductive element 1 and the second conductive element 2 are engaged, so that the engaging conductive elements compress the flexible conductor module 3 in the working connection state. After being compressed, the flexible conductor module 3 undergoes elastic deformation, and multiple flexible conductive elements 32 and the engaging conductive elements form multiple dispersed electrical contact points, electrical contact lines, or local electrical contact surfaces.

[0063] Example 7: Power Connector Application like Figure 1 , Figure 2 , Figure 9 and Figure 10 In the power connector, the first conductive element 1 and the second conductive element 2 can be a sheet terminal, a post terminal, a cylindrical terminal, a pin terminal, a socket terminal, a blade terminal, or a conductive plate. The flexible conductor module 3 can be arranged along the main contact direction of the terminal or can be arranged around the outer periphery of the post or cylindrical terminal. By forming parallel conductive paths through multiple flexible conductive elements 32, local contact resistance and its fluctuations can be reduced, minimizing the risk of localized heating, thereby increasing the rated current within the same size or significantly reducing the terminal size and weight within the same rated current. Pressure retention is formed by the deformable elastic region 22, effectively addressing the problem of gradual creep of the elastic support 31. This solution is suitable for drones, power tools, robots, vehicles, battery packs, energy storage devices, and other devices sensitive to power density, volume, and weight.

[0064] Example 8: Application of Robot Joints and Through-Shaft Connections In robot joints or hollow shaft motors, connectors need to pass through small shaft holes or narrow wiring spaces. By employing the low contact resistance electrical connection interface of this invention, multiple parallel contact units can be formed with smaller terminal sizes. By reducing the contact resistance of terminals that meet size requirements to approximately 1 / 30th of their original level, it is beneficial to form a power connection structure that is passable through shafts, pluggable, and easy to maintain in the field. This avoids the low assembly efficiency and maintenance difficulties caused by threading wires before soldering.

[0065] Example 9: High-frequency signal connection application like Figure 9 and Figure 10In high-frequency signal connectors, the flexible conductor module 3 can serve as the contact interface for signal terminals or grounding terminals. Since the flexible conductive element 32 forms multiple dispersed contact points or contact lines, and the elastic support 31 provides continuous contact pressure, contact impedance fluctuations can be reduced. Furthermore, utilizing the extremely small mass and inertia of the elastic support 31 and the flexible conductive element 32, which can rapidly recover their original shape, superior vibration resistance compared to twisted pins can be achieved. Further, the deformable elastic region 22 forms pressure retention, effectively addressing the issue of gradual creep of the elastic support 31. Compared to existing button-like structures, this solution is advantageous in reducing costs and improving resistance to contamination and damage. For millimeter-wave, Asia-Pacific Hertz, or other high-frequency connection scenarios, the electrical connection interface can meet target impedance and transmission performance requirements by controlling the diameter, spacing, arrangement direction, contact length, terminal plating, grounding structure, and dielectric structure of the flexible conductive element 32.

[0066] Example 10: Performance Verification Method To verify the technical effects of this invention, the contact resistance of the first conductive element 1 and the second conductive element 2 can be measured using the four-terminal method under specified contact pressure, specified compression, specified temperature, and specified number of mating cycles, and compared with that of a terminal of the same size without the soft elastic conductor module 3. For power connectors, the temperature rise under rated current, the change in contact resistance after thermal cycling, and the contact stability after vibration can be further measured. For high-frequency signal connectors, insertion loss, return loss, contact impedance fluctuation, and changes in transmission performance after repeated mating cycles can be measured.

[0067] In one exemplary test, compared to a terminal of the same size without the flexible conductor module 3, the contact resistance can be reduced by approximately one to two orders of magnitude (e.g., reduced to approximately 1 / 100th of the order of magnitude) after adding the flexible conductor module 3. Correspondingly, for power connectors, the rated current can be significantly increased or the terminal size can be significantly reduced for the same rated current; for signal connectors, high-frequency transmission performance can be significantly improved. The above test methods and values ​​are only used to illustrate optional verification methods and possible effects, and do not constitute a limitation on the scope of protection of this invention. Actual products can select appropriate test conditions according to connector type, rated current, target frequency band, operating environment, and industry standards.

[0068] The above embodiments are merely exemplary embodiments of the present invention. Those skilled in the art can adjust or combine the material, diameter, and arrangement of the flexible conductive element, the material, shape, hardness, resilience, and Poisson's ratio of the elastic support, the shape, plating, and fixing method of the conductive component, and the application scenarios of the connector without departing from the concept of the present invention. All such adjustments or combinations should fall within the protection scope of the present invention.

Claims

1. A low contact resistance electrical connection interface comprising a first electrically conductive member and a second electrically conductive member which cooperate, characterised in that, It also includes a soft elastic conductor module disposed in the contact area of ​​the first conductive element and / or the second conductive element; for ease of description, the conductive element disposed with the soft elastic conductor module is referred to as the bearing conductive element, and the conductive element that contacts and cooperates with the soft elastic conductor module is referred to as the cooperating conductive element; The flexible conductor module includes an elastic support and a plurality of flexible conductive elements disposed on the outer surface of the elastic support. At least some of the flexible conductive elements have a fixed connection portion that is electrically connected to and mechanically fixed to the bearing conductive element, and a contact portion exposed on the outer side of the elastic support. The outer surface of the flexible conductive element is covered with a conductive material. When the first conductive element and the second conductive element are in a working connection state, the mating conductive element presses the flexible conductor module, causing the elastic support to undergo elastic deformation, and causing the plurality of contact portions to form a plurality of dispersed electrical contact points, electrical contact lines or local electrical contact surfaces with the mating conductive element, thereby forming a plurality of parallel conductive paths between the first conductive element and the second conductive element.

2. The low contact resistance electrical connection interface of claim 1, wherein, At least some of the multiple flexible conductive elements are spaced apart from each other, independent of each other, or only partially overlap on the outer surface of the elastic support, so that the multiple contact portions after being compressed form mutually dispersed micro-contact units; The diameter or equivalent diameter of the flexible conductive element is 0.5 μm to 100 μm, preferably 2 μm to 50 μm, and more preferably 5 μm to 20 μm.

3. The low contact resistance electrical connection interface of claim 2, wherein, The flexible conductive element includes a fiber skeleton and a good conductor layer disposed on the outer surface of the fiber skeleton; the fiber skeleton is a high-strength, low-elongation fiber, mainly used to withstand the mechanical load of the composite conductor filament during stretching, bending, torsion, or repeated movement; the good conductor layer is fully or partially tightly attached to the outer surface of the fiber skeleton and forms a continuous or quasi-continuous conductive path along the length direction of the fiber skeleton, so that the composite conductor filament simultaneously has the tensile and bending resistance provided by the fiber skeleton and the conductivity provided by the good conductor layer; The good conductor layer is a single metal layer, an alloy layer, a multilayer composite metal layer, a gradient composition layer, a composite layer of a seed layer and a main conductive layer, or a composite layer of a main conductive layer and a surface protective layer. The good conductor material used in the good conductor layer has a breaking elongation greater than 8%, preferably greater than 10%, under the target operating temperature or equivalent test conditions, so that the good conductor layer does not break as a whole before the fiber skeleton. The fiber skeleton has a breaking strength greater than 2.5 GPa, an elongation before breaking of less than 5%, and a single filament diameter of less than 100 μm; preferably, the single filament diameter of the fiber skeleton is 0.5 μm to 50 μm, more preferably 2 μm to 20 μm; The fiber skeleton is aramid fiber, carbon fiber, modified glass fiber, polyimide fiber, liquid crystal polymer fiber, silicon carbide fiber, basalt fiber, alumina fiber, or a combination thereof that meet the conditions of high strength and low elongation.

4. The low contact resistance electrical connection interface of claim 1, wherein, The elastic support has a temperature resistance of not less than 120°C, and its compression set or compression creep rate under target operating conditions or equivalent accelerated testing conditions is not greater than 50%, preferably not greater than 30%. The elastic support is silicone rubber, foamed silicone rubber, fluororubber, fluorosilicone rubber, ethylene propylene rubber, polyurethane elastomer, high-temperature resistant thermoplastic elastomer, foamed elastomer, or a combination thereof; The cross-section of the elastic support is circular, elliptical, rectangular, oval, polygonal, hollow, foamed, slotted, corrugated, or irregular in shape, so as to produce lateral expansion, local collapse, conformal deformation, or a combination thereof when under pressure; furthermore, the Poisson's ratio of the elastic support is greater than 0.5, so as to reduce the tearing stress on the flexible conductive element when it expands laterally under pressure.

5. The low contact resistance electrical connection interface of claim 1, wherein, The contact area of ​​the conductive component is provided with a groove, guide groove, positioning groove, receiving groove, receiving pit or limiting groove, and at least a portion of the soft elastic conductor module is disposed in the groove, guide groove, positioning groove, receiving groove, receiving pit or limiting groove. The width, depth, and sidewall shape of the groove, guide groove, positioning groove, receiving groove, receiving pit, or limiting groove are set according to the free size and pressure deformation profile of the soft elastic conductor module, so that the soft elastic conductor module forms bottom surface contact, side surface contact, semi-enclosed contact, or a combination thereof with the bearing conductive component in the working connection state. The ends or sides of the groove, guide groove, positioning groove, receiving groove, receiving pit or limiting groove are provided with limiting steps, undercuts, pressing edges, covering pieces, riveting parts, snap-fit ​​parts, welding areas or combinations thereof, to limit the displacement of the soft elastic conductor module during insertion, pressing, vibration or thermal cycling.

6. The low contact resistance electrical connection interface of claim 1, wherein, The flexible conductor module is fixed to the carrier conductive component by brazing, laser welding, ultrasonic welding, resistance welding, thermocompression welding, diffusion welding, conductive adhesive bonding, mechanical pressing, riveting, snap-fit ​​fixing, wrapping fixing, partial fusion welding, or a combination thereof; The fixed connection part is located on the bottom, end, side or locally flattened area of ​​the flexible conductor module, and forms an electrical connection with the bottom surface, side wall, pad, plating or fixed connection layer of the carrier conductive element, so as to shorten the conductive path from the flexible conductive element to the carrier conductive element. The flexible conductor module has a protruding height relative to the contact reference surface of the bearing conductive element in the free state, and the amount of compression deformation in the working connection state is 5% to 70% of the protruding height or the free height.

7. An electrical connection terminal, characterized by The invention includes a conductive body and a soft, elastic conductor module disposed in the contact area of ​​the conductive body; the soft, elastic conductor module includes an elastic support and a plurality of flexible conductive elements disposed on the outer surface of the elastic support, at least some of the flexible conductive elements being electrically connected and fixed to the conductive body, and forming a plurality of dispersed contact units when the conductive body is connected to a mating terminal; the soft, elastic conductor module is the soft, elastic conductor module as described in any one of claims 1 to 24.

8. A connector characterized by comprising: It includes an insulating housing and at least one low contact resistance electrical connection interface as described in any one of claims 1 to 6, or includes at least one electrical connection terminal as described in claim 7; The connector includes multiple flexible conductor modules, which are arranged in an array, side by side, circumferentially, or partitioned along the contact area of ​​the same conductive element to form multiple parallel conductive areas or multiple redundant contact areas.

9. A flexible power conductor module characterized by, For use in the contact area of ​​electrical connection terminals, the soft elastic conductor module includes an elastic support and a plurality of flexible conductive elements disposed on the outer surface of the elastic support; the flexible conductive elements have a fixed connection portion for electrical connection and fixation with the electrical connection terminal and a contact portion exposed on the outside of the elastic support; the contact portion can conformally deform with the elastic support and form a plurality of dispersed electrical contacts when compressed.

10. A method for fabricating a low-contact-resistance electrical connection interface, characterized in that, include: It provides a first conductive element, a second conductive element, an elastic support body, and multiple flexible conductive elements; Multiple flexible conductive elements are disposed on the outer surface of the elastic support body to form a soft and elastic conductor module; The flexible conductor module is disposed in the contact area of ​​the first conductive element and / or the second conductive element, and at least a portion of the flexible conductive elements are electrically connected and fixed to the bearing conductive element; the first conductive element and the second conductive element are pressed against the flexible conductor module in the working connection state, causing the elastic support to undergo elastic deformation, and the multiple flexible conductive elements and the cooperating conductive element form multiple dispersed electrical contact points, electrical contact lines or local electrical contact surfaces; Before setting the soft and elastic conductor module, grooves, guide grooves, positioning grooves, receiving grooves, receiving pits or limiting grooves are formed in the contact area of ​​the conductive component by stamping, milling, etching, laser processing, rolling, molding, sintering or additive manufacturing, and then at least a part of the soft and elastic conductor module is set therein. The flexible conductive element is disposed on the outer surface of the elastic support body by means of continuous winding, parallel wrapping, weaving, laying, hot air assisted molding, hot pressing molding, local adhesive positioning, tension control molding or a combination thereof, and is fixed to the carrier conductive component by means of welding, pressing, conductive adhesive bonding, snap fastening, covering or a combination thereof.

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