A conductor structure with high solder affinity

Abstract

The utility model provides a kind of high welding affinity conductor structure, including the base body of high-strength inert alloy material and the cladding layer of cladding in the outermost layer of conductor, wherein the cladding layer is gold layer;The utility model is by setting gold cladding layer in the outermost layer of conductor, since gold and tin's welding affinity is good, to effectively improve the welding reliability between conductor and implanted device, guarantee that electric signal is stably and reliably transmitted, solve the technical problems of welding difficulty, almost unable to realize effective welding, transmission signal unreliable etc. in prior art, and gold plating layer is also conducive to improving the conductivity and corrosion resistance of conductor.

Description

Technical Field

[0001] This utility model relates to the field of biomedical implantable conductor technology, and in particular to a conductor structure with high welding affinity. Background Technology

[0002] Medical bio-implantable conductors are a class of biocompatible materials used in the medical field. They can interact with human tissues and conduct electrical, mechanical, or other biological signals, and are widely used in fields such as neural modulation, tissue repair, and intelligent drug delivery.

[0003] International patent application WO2014047339A discloses a medical implantable lead and its manufacture, describing that cardiac leads are typically formed by concentrically stranded small-hole leads made of a biocompatible, corrosion-resistant conductive material, such as a nickel-based alloy, which surrounds a biocompatible, corrosion-resistant conductive core (e.g., silver) and is surrounded by a biocompatible, corrosion-resistant, wear-resistant and flexible insulating layer on the outermost layer.

[0004] In certain specific application scenarios and functional requirements, medical bio-implantable conductors involve soldering connections (such as soldering to circuit boards) to achieve electrical signal transmission or connection with other electronic components. The main component of electronic solder is metallic tin, and in existing technologies, the outer layer of the conductor structure is a nickel-based alloy. However, because nickel and tin are immiscible, soldering is difficult, making effective soldering almost impossible and resulting in unreliable signal transmission. Summary of the Invention

[0005] One of the objectives of this invention is to address the shortcomings of existing technologies by providing a conductor structure with high welding affinity. By setting a gold plating layer on the outermost layer of the conductor, the welding reliability between the conductor and the implanted device is effectively improved due to the excellent welding affinity between gold and tin, ensuring stable and reliable transmission of electrical signals. This solves the technical problems of welding difficulties, the near inability to achieve effective welding, and unreliable signal transmission in existing technologies. Furthermore, the gold plating layer also helps to improve the conductivity and corrosion resistance of the conductor.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A conductor structure with high weld affinity includes: a matrix of high-strength inert alloy material and a cladding layer covering the outermost layer of the conductor; wherein the cladding layer is a gold layer.

[0007] As an improvement, the coating layer is a gold-plated layer with a gold content of not less than 99.99% by mass.

[0008] As an improvement, the matrix is ​​made of a nickel-based alloy that is corrosion-resistant and biocompatible in living organisms.

[0009] As an improvement, the composition of the nickel-based alloy by mass percentage is: nickel 40-60%, cobalt 0-40%, chromium 19-21%, molybdenum 9-10.5%, niobium 0.5-8%, titanium ≤1.0%, manganese ≤0.15%, and carbon ≤0.025%.

[0010] As an improvement, the nickel-based alloy is MP35N.

[0011] The composition of MP35N by mass percentage is as follows: nickel 33-37%, cobalt 33-37%, chromium 19-21%, molybdenum 9-10.5%, titanium ≤1.0%, iron ≤1.0%, manganese ≤0.15%, silicon ≤0.15%, and carbon ≤0.025%.

[0012] As an improvement, a high-purity silver layer is also included, which is wrapped around the outside of the substrate, and the coating layer is wrapped around the outside of the high-purity silver layer.

[0013] As an improvement, the high-purity silver layer is formed by a bottom-drawing solid / liquid composite continuous casting method.

[0014] As an improvement, it also includes a high-purity silver layer, wherein the substrate is wrapped around the high-purity silver layer and the coating layer is wrapped around the substrate.

[0015] As an improvement, the mass percentage of silver in the high-purity silver layer is not less than 99.99%.

[0016] As an improvement, the substrate is formed by a composite drawing method involving tube insertion.

[0017] As an improvement, the conductor has a diameter of 0.02-0.08 mm; wherein the cross-sectional area of ​​the substrate accounts for 50-90% of the total area, and the cross-sectional area of ​​the high-purity silver layer accounts for 10-50% of the total area.

[0018] As a further preferred option, the diameter of the conductor is 0.025-0.035 mm.

[0019] Preferably, the conductor has a conductivity ≥20% IACS, resistivity ≤9Ω.m, axial tensile strength ≥9N, tensile strength ≥1800MPa, elongation ≥2%, and internal corrosion resistance ≥10 years.

[0020] As a further preferred embodiment, the conductor has a conductivity of 20-50% IACS, a resistivity of 8.5-9 Ω·m, and an axial tensile strength ≥10N.

[0021] The beneficial effects of this utility model are as follows: (1) By setting a gold coating layer on the outermost layer of the conductor, the welding reliability between the conductor and the implanted device is effectively improved due to the good welding affinity between gold and tin, ensuring stable and reliable transmission of electrical signals. In addition, the gold plating layer is also beneficial to improving the conductivity and corrosion resistance of the conductor.

[0022] (2) The composite conductor structure in this utility model can maintain excellent biocompatibility, conductivity, signal transmission, fatigue resistance and anti-oxidation corrosion properties in the body for a long time, thus meeting the long-term implantation requirements of biomedicine.

[0023] (3) The matrix of this utility model has high strength, high fatigue resistance and high conductivity. The nickel-based alloy has good tensile strength and biocompatibility. Nickel and cobalt have good strength and corrosion resistance. Chromium and molybdenum bring good strength and corrosion resistance to the alloy.

[0024] In summary, the conductor product of this invention has high conductivity, corrosion resistance, relatively stable signal transmission performance, and high solderability. It is especially suitable for medical fields such as nerve implantation, analgesia, electrical pulse therapy, cardiac implantation, and Parkinson's disease, and can be implanted in the body for more than ten years. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the cross-sectional structure of the conductor in Example 4; Figure 2 This is a schematic diagram of the cross-sectional microscope view (100x magnification) of the conductor in Example 4; Figure 3 This is a schematic diagram of the cross-sectional structure of the conductor in Example 5; Figure 4 This is a schematic diagram of the downward continuous casting device in Example 4. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] Example 1 like Figure 1 , Figure 3 As shown, a conductor structure with high weld affinity includes: a substrate 1 of high-strength inert alloy material and a cladding layer 2 covering the outermost layer of the conductor; wherein the cladding layer 2 is a gold layer.

[0029] As an improvement, the coating layer 2 is a gold-plated layer with a gold content of not less than 99.99% by mass.

[0030] In this embodiment, by providing a gold plating layer on the outermost layer of the conductor, the excellent welding affinity between gold and tin effectively improves the welding reliability between the conductor and the implanted device, ensuring stable and reliable transmission of electrical signals. Furthermore, the gold plating layer also helps improve the conductivity and corrosion resistance of the conductor. As an improvement, the substrate 1 is made of a nickel-based alloy that is corrosion-resistant and biocompatible in vivo.

[0031] Example 2 The components in this embodiment that are the same as or corresponding to those in Embodiment 1 above are referred to by the same reference numerals as those in Embodiment 1 above. For the sake of simplicity, only the differences from Embodiment 1 above will be described below. The difference between this embodiment and Embodiment 1 above is that: As an improvement, the composition of the nickel-based alloy by mass percentage is: nickel 40-60%, cobalt 0-40%, chromium 19-21%, molybdenum 9-10.5%, niobium 0.5-8%, titanium ≤1.0%, manganese ≤0.15%, and carbon ≤0.025%.

[0032] In this embodiment, the composition of the nickel-based alloy in matrix 1 is optimized. Nickel and cobalt have good strength and corrosion resistance, while cobalt is expensive and not economical. By increasing the nickel content and decreasing the cobalt content in the alloy, the strength and corrosion resistance of the alloy are guaranteed, while also taking into account economic efficiency. In addition, the increase of niobium further improves the strength of the alloy.

[0033] Example 3 The components in this embodiment that are the same as or corresponding to those in Embodiment 1 above are referred to by the same reference numerals as those in Embodiment 1 above. For the sake of simplicity, only the differences from Embodiment 1 above will be described below. The difference between this embodiment and Embodiment 1 above is that: As an improvement, the nickel-based alloy is MP35N.

[0034] The composition of MP35N by mass percentage is as follows: nickel 33-37%, cobalt 33-37%, chromium 19-21%, molybdenum 9-10.5%, titanium ≤1.0%, iron ≤1.0%, manganese ≤0.15%, silicon ≤0.15%, and carbon ≤0.025%.

[0035] Example 4 The components in this embodiment that are the same as or corresponding to those in Embodiment 1 above are referred to by the same reference numerals as those in Embodiment 1 above. For the sake of simplicity, only the differences from Embodiment 1 above will be described below. The difference between this embodiment and Embodiment 1 above is that: like Figures 1-2 As shown, as an improvement, a high-purity silver layer 3 is also included, which is wrapped around the outside of the substrate 1 and the coating layer 2 is wrapped around the outside of the high-purity silver layer 3.

[0036] In this embodiment, the conductor is composed of a high-strength inert alloy substrate 1 and a high-purity silver layer 3 and a cladding layer 2 sequentially wrapped around the substrate 1, forming a structure from the inside out of high-strength inert alloy-silver-gold. The cladding of the high-purity silver layer 3 is beneficial to improving the transmission rate and localization of high-frequency signals, and silver will not cause irritation to the human body. However, since silver ions are easily oxidized and precipitated, a corrosion-resistant cladding layer 2 is set on its exterior. This comprehensively achieves the conductor to maintain excellent biocompatibility, conductivity, signal transmission, fatigue resistance, and oxidation and corrosion resistance in biological bodies for a long time, and has good welding affinity, meeting the long-term implantation requirements of biomedical applications.

[0037] As an improvement, the mass percentage of silver in the high-purity silver layer 3 is not less than 99.99%.

[0038] As an improvement, the high-purity silver layer 3 is formed by a bottom-drawing solid / liquid composite continuous casting method.

[0039] In this embodiment, the high-purity silver layer is formed by bottom-drawing solid / liquid composite continuous casting, which can achieve continuous, directional, metallurgical grade, and strong bonding silver layer coating. The coated silver layer is uniform and dense, and can effectively realize the drawing process of ultra-fine wire with multi-layer coating structure. The process is efficient and stable.

[0040] As a supplementary explanation, the specific coating and forming method of the high-purity silver layer 3 is as follows: using a downward continuous casting device, the clean surface of the substrate 1 rod is passed through the furnace protected by inert gas, and the other end passes through the center of the crystallizer; the silver melts at a liquid temperature of about 980-1150℃, and the substrate 1 rod is pulled through the continuous casting mold with cooling, so that the silver liquid adheres to the periphery of the substrate 1 rod, and is cooled in the continuous casting mold to form a silver casting layer that is uniformly wrapped around the outer wall of the substrate 1 rod. The thickness of the silver casting layer is determined by the size of the substrate 1 rod or the size of the continuous casting mold.

[0041] The melting point of matrix 1 is approximately 1400℃, and the temperature of the silver solution is approximately 900℃; for example... Figure 4 As shown, a bottom-drawing continuous casting device is used to pass a clean base bar 1 through a furnace protected by an inert gas, with the other end passing through the center of the crystallizer 41. The silver melts at a temperature of approximately 980-1150°C and is pulled through a continuous casting mold 42 with cooling, causing the molten silver to adhere around the base bar 1. The silver is then cooled in the mold to form a uniform silver casting layer that covers the outer wall of the base bar 1. The thickness of the silver casting layer is determined by the size of the base bar 1 or the size of the continuous casting mold.

[0042] As an improvement, the diameter of the conductor is 0.02-0.08 mm; wherein the cross-sectional area of ​​the substrate 1 accounts for 50-90% of the total area, and the cross-sectional area of ​​the high-purity silver layer 3 accounts for 10-50% of the total area.

[0043] Preferably, the diameter of the substrate 1 is 0.02-0.03 mm, the thickness of the high-purity silver layer 3 is 3-5 μm, and the thickness of the coating layer 2 is 0.05-0.5 μm.

[0044] Since excessive thickness of the silver layer will lead to poor overall strength, while insufficient thickness will lead to decreased conductivity, the cross-sectional area of ​​the high-purity silver layer 3 is preferably 25-30% of the total area.

[0045] As a further preferred option, the conductor has a diameter of 0.025-0.035 mm, enabling the fabrication of an extremely fine stranded conductor, which is particularly suitable for wire conductors used for signal transmission within biological organisms.

[0046] Preferably, the core wire 1 has a tensile strength of 1600-1800 MPa and an elongation of ≥20%.

[0047] Preferably, the conductor has a conductivity ≥20% IACS, resistivity ≤9Ω.m, axial tensile strength ≥9N, tensile strength ≥1800MPa, elongation ≥2%, and internal corrosion resistance ≥10 years.

[0048] As a further preferred embodiment, the conductor has a conductivity of 20-50% IACS, a resistivity of 8.5-9 Ω·m, and an axial tensile strength ≥10N.

[0049] Example 5 The components in this embodiment that are the same as or corresponding to those in Embodiment 1 above are referred to by the same reference numerals as those in Embodiment 1 above. For the sake of simplicity, only the differences from Embodiment 1 above will be described below. The difference between this embodiment and Embodiment 1 above is that: like Figure 3 As shown, as an improvement, it also includes a high-purity silver layer 3, with the substrate 1 wrapped around the high-purity silver layer 3 and the coating layer 2 wrapped around the substrate 1.

[0050] As an improvement, the mass percentage of silver in the high-purity silver layer 3 is not less than 99.99%.

[0051] As an improvement, the substrate 1 is formed by a tube-drawing composite coating method.

[0052] As a supplementary explanation, the specific coating forming method of the substrate 1 is as follows: the substrate 1 is a nickel alloy tube. The inner wall of the nickel alloy tube and the outer surface of the high-purity silver layer 3 are cleaned and decontaminated, the oxide layer is brushed off, and plasma activation is performed. After the nickel alloy tube is inserted into the high-purity silver layer 3, it is pulled out so that the contact surface between the two forms an atomic-level bonding layer, thereby achieving a firm coating and bonding of the substrate 1 to the high-purity silver layer 3.

[0053] As an improvement, the diameter of the conductor is 0.02-0.08 mm; wherein the cross-sectional area of ​​the substrate 1 accounts for 50-90% of the total area, and the cross-sectional area of ​​the high-purity silver layer 3 accounts for 10-50% of the total area.

[0054] As a further preferred option, the diameter of the conductor is 0.025-0.035 mm.

[0055] Preferably, the conductor has a conductivity ≥20% IACS, resistivity ≤9Ω.m, axial tensile strength ≥9N, tensile strength ≥1800MPa, elongation ≥2%, and internal corrosion resistance ≥10 years.

[0056] As a further preferred embodiment, the conductor has a conductivity of 20-50% IACS, a resistivity of 8.5-9 Ω·m, and an axial tensile strength ≥10N.

[0057] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A conductor structure with high weld affinity, characterized in that, include: A high-strength inert alloy material matrix (1) and a cladding layer (2) covering the outermost layer of the conductor; wherein the cladding layer (2) is a gold layer; It also includes a high-purity silver layer (3), which is wrapped around the outside of the substrate (1), and the coating layer (2) is wrapped around the outside of the high-purity silver layer (3); The conductor has a diameter of 0.02-0.08 mm; the cross-sectional area of ​​the substrate (1) accounts for 50-90% of the total area, and the cross-sectional area of ​​the high-purity silver layer (3) accounts for 10-50% of the total area. The high-purity silver layer (3) is formed by a bottom-drawing solid / liquid composite continuous casting method.

2. The conductor structure with high weld affinity according to claim 1, characterized in that, The coating layer (2) is a gold-plated layer.

3. The conductor structure with high weld affinity according to claim 1, characterized in that, The substrate (1) is a nickel-based alloy that is corrosion-resistant and biocompatible in living organisms.

4. A conductor structure with high weld affinity according to claim 3, characterized in that, The nickel-based alloy is MP35N.

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