High-strength tensile lead-free solder wire

Abstract

The high-strength tensile lead-free tin wire comprises a tin-nickel alloy layer, a tin-antimony alloy layer, a tin-copper alloy layer, a soldering flux layer and a resin layer, the soldering flux layer is located in the tin-nickel alloy layer, and the thickness of the tin-nickel alloy layer, the thickness of the tin-antimony alloy layer and the thickness of the tin-copper alloy layer are gradually reduced from inside to outside. The melting point of the tin-nickel alloy layer is larger than that of the tin-antimony alloy layer, and the melting point of the tin-antimony alloy layer is larger than that of the tin-copper alloy layer. The tin-nickel alloy layer serves as the innermost layer and can provide high tensile strength and structural support for the lead-free tin wire, and breakage is prevented; in the welding process, the tin-copper alloy layer and the resin layer located on the outermost layer are melted firstly, and the tin-copper alloy layer has good conductivity, so that the conductive connection performance of the welding spot position can be improved; the melting point of the tin-nickel alloy layer is the highest, the situation that the whole structure deforms or breaks due to the fact that the lead-free tin wire is melted in advance at the welding high temperature is prevented, and therefore the stability of the welding process is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of lead-free tin wires, in particular to a high-strength tensile-resistant lead-free tin wire. Background Art

[0002] With the rapid development of the electronics industry, the welding quality and reliability of electronic components have become important factors in ensuring the performance and life of electronic products. Traditional lead-containing tin wire has been widely used in the field of electronic welding due to its good welding performance; however, due to the toxicity of lead and its harm to the environment, the use of lead-containing materials has been gradually banned in the market, making lead-free tin wire the main demand of the market.

[0003] In the prior art, although lead-free tin wire is environmentally friendly, it faces many technical problems during use. First, compared with lead tin wire, the mechanical strength of lead-free tin wire, especially the tensile strength, is often lower, which makes it easy to break during use, especially when subjected to large tensile force; secondly, the welding performance of lead-free tin wire is not as good as that of lead tin wire. During the welding process, the solder joints are often not firm and the welding quality is not high due to the low efficiency of the flux or the poor melting state, which affects the reliability of electronic products; and lead-free tin wire is prone to oxidation and corrosion in different use environments, especially in humid or corrosive environments, resulting in solder joint failure and decreased conductivity.

[0004] Therefore, the prior art has defects and needs to be improved. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a high-strength tensile-resistant lead-free tin wire which is not easy to break, effectively improves welding quality and has good weather resistance.

[0006] To achieve this purpose, the utility model adopts the following technical scheme: a high-strength tensile lead-free tin wire, comprising a tin-nickel alloy layer, a tin-antimony alloy layer, a tin-copper alloy layer, a flux layer and a resin layer;

[0007] The solder flux layer is located inside the tin-nickel alloy layer, the tin-antimony alloy layer is coated on the outside of the tin-nickel alloy layer, the tin-copper alloy layer is coated on the outside of the tin-antimony alloy layer, and the resin layer is coated on the outside of the tin-copper alloy layer;

[0008] The thickness of the tin-nickel alloy layer, the tin-antimony alloy layer and the tin-copper alloy layer gradually decreases from the inside to the outside, the melting point of the tin-nickel alloy layer is greater than the melting point of the tin-antimony alloy layer, the melting point of the tin-antimony alloy layer is greater than the melting point of the tin-copper alloy layer, and the melting point of the tin-copper alloy layer is greater than the melting point of the resin layer.

[0009] By adopting the above technical solution, the high-strength tensile lead-free tin wire further includes a TiN coating, and the TiN coating is coated on the outer surface of the tin-copper alloy layer.

[0010] By adopting the above-mentioned technical solutions, in the high-strength tensile lead-free tin wire, the thickness of the TiN coating is 0.5-2 μm.

[0011] By adopting the above-mentioned technical solutions, in the high-strength tensile lead-free tin wire, the thickness of the tin-nickel alloy layer is 0.4-0.5mm, the thickness of the tin-antimony alloy layer is 0.3-0.4mm, the thickness of the tin-copper alloy layer is 0.2-0.3mm, and the thickness of the resin layer is 0.1-0.2mm.

[0012] By adopting the above-mentioned technical solutions, in the high-strength tensile lead-free tin wire, the cross-sectional diameter of the flux layer is 0.1-0.3 mm.

[0013] By adopting the above-mentioned technical solutions, in the high-strength tensile-resistant lead-free tin wire, the melting point of the flux layer is lower than the melting point of the tin-nickel alloy layer.

[0014] By adopting the above-mentioned technical solutions, in the high-strength tensile lead-free tin wire, the filler of the flux layer is rosin.

[0015] By adopting the above-mentioned technical solutions, in the high-strength tensile lead-free tin wire, the resin layer is acrylic resin.

[0016] By adopting the above-mentioned technical solutions, in the high-strength tensile lead-free tin wire, the cross-sectional shape of the lead-free tin wire is circular, and the wire diameter of the lead-free tin wire is 1.2-1.6 mm.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] The tin-nickel alloy layer of the utility model is the innermost layer, and its thickness is the largest, which can provide higher tensile strength and structural support for the lead-free tin wire to prevent breakage; the tin-antimony alloy layer and the tin-copper alloy layer gradually become thinner, and such a configuration can provide a certain flexibility for the lead-free tin wire, so that the lead-free tin wire is not easy to break when stretched or bent; during the welding process, the tin-copper alloy layer and the resin layer located in the outermost layer are melted first, and the tin-copper alloy layer has good electrical conductivity, which can improve the conductive connection performance of the soldering point; the melting point of the tin-antimony alloy layer is lower than that of the tin-nickel alloy layer, but higher than that of the tin-copper alloy layer, and the tin-antimony alloy layer has higher hardness and wear resistance. Using it as an intermediate layer can effectively improve the mechanical strength and tensile performance of the overall structure; the tin-nickel alloy layer has the highest melting point, and during the welding process, it can provide stable mechanical support for the entire multi-layer structure, preventing the lead-free tin wire from melting first at the high welding temperature, causing deformation or breakage of the overall structure, thereby ensuring the stability of the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0021] Figure 1 It is a schematic diagram of the cross-sectional structure of the utility model. DETAILED DESCRIPTION

[0022] In order to make the utility model's purpose, features, and advantages more obvious and easy to understand, the following will be combined with the drawings in the utility model embodiments to clearly and completely describe the technical solutions in the utility model embodiments. Obviously, the embodiments described below are only part of the utility model embodiments, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0024] The technical solution of the utility model is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0025] like Figure 1 As shown, the embodiment of the utility model provides a high-strength tensile-resistant lead-free tin wire, including a tin-nickel alloy layer 10, a tin-antimony alloy layer 20, a tin-copper alloy layer 30, a flux layer 40 and a resin layer 50;

[0026] The flux layer 40 is located inside the tin-nickel alloy layer 10, the tin-antimony alloy layer 20 is coated on the outside of the tin-nickel alloy layer 10, the tin-copper alloy layer 30 is coated on the outside of the tin-antimony alloy layer 20, and the resin layer 50 is coated on the outside of the tin-copper alloy layer 30; the tin-nickel alloy layer 10 has high mechanical strength and hardness. The flux layer 40 is arranged inside the tin-nickel alloy layer 10 to avoid the influence of external environmental factors such as oxygen and moisture on the flux, and prevent it from being oxidized or failing during storage and use. In addition, placing the flux layer 40 inside the tin-nickel alloy layer 10 allows the flux to directly act on the solder joint during the welding process, remove oxides, reduce surface tension, and thus improve the welding effect.

[0027] The thickness of the tin-nickel alloy layer 10, the tin-antimony alloy layer 20 and the tin-copper alloy layer 30 gradually decreases from the inside to the outside. The melting point of the tin-nickel alloy layer 10 is greater than that of the tin-antimony alloy layer 20, the melting point of the tin-antimony alloy layer 20 is greater than that of the tin-copper alloy layer 30, and the melting point of the tin-copper alloy layer 30 is greater than that of the resin layer 50. The tin-nickel alloy layer 10, as the innermost layer, has the largest thickness and can provide higher tensile strength and structural support for the lead-free tin wire to prevent breakage. The tin-antimony alloy layer 20 and the tin-copper alloy layer 30 gradually become thinner. Such a configuration can provide a certain flexibility for the lead-free tin wire, so that the lead-free tin wire is not easy to break when stretched or bent, and the thinner thickness of the outer layer can also better adapt to thermal expansion and contraction during welding. During the welding process, the tin-nickel alloy layer 10 at the innermost layer has the largest thickness and can provide higher tensile strength and structural support for the lead-free tin wire to prevent breakage. The outer tin-copper alloy layer 30 and resin layer 50 melt first, and the tin-copper alloy layer 30 has good conductivity, which can improve the conductive connection performance of the solder joint position; the melting point of the tin-antimony alloy layer 20 is lower than that of the tin-nickel alloy layer 10, but higher than that of the tin-copper alloy layer 30. The tin-antimony alloy layer 20 has high hardness and wear resistance. Using it as an intermediate layer can effectively improve the mechanical strength and tensile properties of the overall structure; the tin-nickel alloy layer 10 has the highest melting point. During the welding process, it can provide stable mechanical support for the entire multi-layer structure, prevent the lead-free tin wire from melting first under the high temperature of welding, causing deformation or fracture of the overall structure, and ensure the stability of the welding process; the resin layer 50 can effectively isolate moisture and corrosive substances in the air, prevent the lead-free tin wire from being oxidized and corroded, thereby extending the service life of the lead-free tin wire.

[0028] Furthermore, a TiN coating 60 is included, and the TiN coating 60 is coated on the outer surface of the tin-copper alloy layer 30. The TiN coating 60 has a high hardness, which can improve the wear resistance and impact resistance of the lead-free tin wire, prevent the lead-free tin wire from being scratched or worn during transportation or use, thereby extending the service life of the lead-free tin wire.

[0029] Furthermore, the thickness of the TiN coating 60 is 0.5-2 μm. In this embodiment, the thickness of the TiN coating 60 is 1 μm.

[0030] Further, the thickness of the tin-nickel alloy layer 10 is 0.4-0.5 mm, the thickness of the tin-antimony alloy layer 20 is 0.3-0.4 mm, the thickness of the tin-copper alloy layer 30 is 0.2-0.3 mm, and the thickness of the resin layer 50 is 0.1-0.2 mm. In this embodiment, the thickness of the tin-nickel alloy layer 10 is 0.4 mm, the thickness of the tin-antimony alloy layer 20 is 0.3 mm, the thickness of the tin-copper alloy layer 30 is 0.2 mm, and the thickness of the resin layer 50 is 0.1 mm.

[0031] Furthermore, the cross-sectional diameter of the flux layer 40 is 0.1-0.3 mm. In this embodiment, the cross-sectional diameter of the flux layer 40 is 0.2 mm.

[0032] Furthermore, the melting point of the flux layer 40 is lower than the melting point of the tin-nickel alloy layer 10. The pre-melted flux layer 40 can effectively prevent the presence of oxides and impurities, reduce the occurrence of welding defects such as pores, slag inclusions and cracks, and thus improve the reliability of the welding point.

[0033] Furthermore, the filler of the flux layer 40 is rosin. Rosin has excellent wetting properties, can reduce the tension of the welding surface, make the molten tin alloy flow more easily, thereby forming a strong welding point, and rosin can generate a certain amount of smoke and gas during the welding process, which can remove oxygen from the welding area and prevent the formation of welding defects such as pores and slag inclusions.

[0034] Furthermore, the resin layer 50 is acrylic resin. Acrylic resin has high toughness and wear resistance, and can effectively absorb and disperse external impact and stress, thereby preventing the lead-free solder wire from being broken or damaged during transportation.

[0035] Furthermore, the cross-sectional shape of the lead-free tin wire is circular, and the wire diameter of the lead-free tin wire is 1.2-1.6 mm. In this embodiment, the wire diameter of the lead-free tin wire is 1.2 mm.

[0036] The tin-nickel alloy layer 10 of the utility model is the innermost layer, and its thickness is the largest, which can provide higher tensile strength and structural support for the lead-free tin wire to prevent fracture; the tin-antimony alloy layer 20 and the tin-copper alloy layer 30 gradually become thinner, and such a configuration can provide a certain flexibility for the lead-free tin wire, so that the lead-free tin wire is not easy to break when stretched or bent; during the welding process, the tin-copper alloy layer 30 and the resin layer 50 located in the outermost layer are melted first, and the tin-copper alloy layer 30 has good conductivity, which can improve the conductive connection performance of the soldering point; the melting point of the tin-antimony alloy layer 20 is lower than that of the tin-nickel alloy layer 10, but higher than that of the tin-copper alloy layer 30, and the tin-antimony alloy layer 20 has higher hardness and wear resistance. Using it as an intermediate layer can effectively improve the mechanical strength and tensile performance of the overall structure; the tin-nickel alloy layer 10 has the highest melting point, and during the welding process, it can provide stable mechanical support for the entire multi-layer structure, preventing the lead-free tin wire from melting first at the high temperature of welding, causing deformation or fracture of the overall structure, thereby ensuring the stability of the welding process.

[0037] As described above, the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A high-strength tensile lead-free tin wire, characterized in that: It includes a tin-nickel alloy layer, a tin-antimony alloy layer, a tin-copper alloy layer, a flux layer and a resin layer; The solder flux layer is located inside the tin-nickel alloy layer, the tin-antimony alloy layer is coated on the outside of the tin-nickel alloy layer, the tin-copper alloy layer is coated on the outside of the tin-antimony alloy layer, and the resin layer is coated on the outside of the tin-copper alloy layer; The thickness of the tin-nickel alloy layer, the tin-antimony alloy layer and the tin-copper alloy layer gradually decreases from the inside to the outside, the melting point of the tin-nickel alloy layer is greater than the melting point of the tin-antimony alloy layer, the melting point of the tin-antimony alloy layer is greater than the melting point of the tin-copper alloy layer, and the melting point of the tin-copper alloy layer is greater than the melting point of the resin layer.

2. The high-strength tensile lead-free tin wire according to claim 1, characterized in that: The invention also comprises a TiN coating layer, wherein the TiN coating layer is coated on the outer surface of the tin-copper alloy layer.

3. The high-strength tensile lead-free tin wire according to claim 2, characterized in that: The thickness of the TiN coating is 0.5-2 μm.

4. The high-strength tensile lead-free tin wire according to claim 1, characterized in that: The thickness of the tin-nickel alloy layer is 0.4-0.5 mm, the thickness of the tin-antimony alloy layer is 0.3-0.4 mm, the thickness of the tin-copper alloy layer is 0.2-0.3 mm, and the thickness of the resin layer is 0.1-0.2 mm.

5. The high-strength tensile-resistant lead-free tin wire according to claim 4, characterized in that: The cross-sectional diameter of the soldering flux layer is 0.1-0.3 mm.

6. The high-strength tensile lead-free tin wire according to claim 1, characterized in that: The melting point of the soldering flux layer is lower than the melting point of the tin-nickel alloy layer.

7. The high-strength tensile-resistant lead-free tin wire according to claim 6, characterized in that: The filler of the soldering flux layer is rosin.

8. The high-strength tensile-resistant lead-free tin wire according to claim 1, characterized in that: The resin layer is acrylic resin.

9. The high-strength tensile lead-free tin wire according to claim 1, characterized in that: The cross-sectional shape of the lead-free tin wire is circular, and the wire diameter of the lead-free tin wire is 1.2-1.6 mm.

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