CN220474949U

CN220474949U - Multi-plating terminal and conductive structure

Info

Publication number: CN220474949U
Application number: CN202320948520.XU
Authority: CN
Inventors: 王超
Original assignee: Changzhou Jieyi Auto Parts Co ltd
Current assignee: Changzhou Jieyi Auto Parts Co ltd
Priority date: 2023-04-24
Filing date: 2023-04-24
Publication date: 2024-02-09
Anticipated expiration: 2033-04-24

Abstract

A multi-plating terminal and a conductive structure relate to the technical field of electric connection, and comprise an aluminum terminal and a plating layer; the plating layer is arranged on at least part of the surface of the aluminum terminal; the plating layer sequentially comprises a first transition plating layer, a nickel plating layer and a contact plating layer from inside to outside. The first transition coating is arranged on the surface of the aluminum terminal, so that the adhesiveness between the whole coating and the aluminum terminal can be improved, and the coating can be prevented from falling off in a quite long time. The nickel coating has high stability in air, and the whole aluminum terminal can have strong passivation capability by covering the first transition coating, so that an extremely thin passivation film can be rapidly formed on the surface, and the corrosion of atmosphere, alkali and certain acids can be resisted. The contact plating layer is used as the outermost layer which needs to be frequently plugged or rubbed, has good conductivity, good wear resistance and attractive appearance, and can greatly prolong the service life and the conductive efficiency of the aluminum terminal.

Description

Multi-plating terminal and conductive structure

Technical Field

The utility model relates to the technical field of electric connection, in particular to a multi-plating terminal and a conductive structure.

Background

Currently, the application field of electric transmission equipment is more and more wide, and particularly the use of electric automobiles is more and more common. The electronic product needs a large amount of terminals to realize circuit connection in design, the terminals often need operations such as plugging or welding, therefore, the wearing property of the terminals is larger, the worn place is easy to oxidize and corrode, poor electrical contact often occurs, in order to improve the wearing property, corrosion resistance, oxidization resistance and conductivity, the terminals of a plurality of electronic interfaces are all electroplated with an electroplating coating, the terminal coating generally comprises a layer of wear-resisting layer and an oxidization resistance corrosion layer, but the thickness of the current terminal coating is too thick, so that the internal stress is larger, the terminals are easy to fall off, the wearing resistance and corrosion resistance of the terminals are insufficient, and the combination property with a base material is ignored by some electroplating coatings, after electroplating, the adhesion between the electroplating coating and a base band material is poor, so that an electroplating layer falls off in later use. Accordingly, there is a need in the art for a new solution to the above-mentioned problems.

Disclosure of Invention

The utility model provides a terminal with good coating adhesion, corrosion resistance and good conductivity.

A multi-plated terminal comprising an aluminum terminal and a plated layer;

the plating layer is arranged on at least part of the surface of the aluminum terminal;

the plating layer sequentially comprises a first transition plating layer, a nickel plating layer and a contact plating layer from inside to outside.

A second transition plating layer is arranged between the contact plating layer and the nickel plating layer.

The electrode potential of the second transition coating material is between the electrode potential of the nickel and the electrode potential of the contact coating material.

The material of the second transition coating is one or a combination of more of gold, silver, nickel, tin-lead alloy, zinc and zinc alloy.

The electrode potential of the first transition coating is between the electrode potentials of aluminum and nickel.

The first transition coating is made of zinc or zinc alloy.

The thickness of the first transition coating is 0.015 mu m-2.5 mu m.

The contact plating layer is made of one or a combination of more of gold, silver, hard silver, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy.

The aluminum terminal is a flat terminal or one end of a solid aluminum wire.

The aluminum terminal is provided with a connecting hole, and the surface of the connecting hole is provided with a conductive wear-resistant layer.

The conductive wear-resistant layer is made of one or a combination of more of gold, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy.

The thickness of the contact plating layer is 0.012 mu m-40 mu m.

The thickness of the nickel plating layer is 0.012 mu m-15 mu m.

An electrically conductive structure, includes aluminium terminal and electric conductor as described above, aluminium terminal and electric conductor welding form the welding seam, the welding seam surface is provided with the tin plating.

The thickness of the tin plating layer is not less than 8 mu m.

And the welding seam is covered with an insulating protective layer.

The insulating protective layer is made of thermoplastic polymer material or vulcanizable polymer material.

The utility model has the following beneficial effects: the first transition coating is arranged on the surface of the aluminum terminal, so that the adhesiveness between the whole coating and the aluminum terminal can be improved, and the coating can be prevented from falling off in a quite long time. The nickel coating has high stability in air, and the whole aluminum terminal can have strong passivation capability by covering the first transition coating, so that an extremely thin passivation film can be rapidly formed on the surface, and the corrosion of atmosphere, alkali and certain acids can be resisted. The contact plating layer is used as the outermost layer which needs to be frequently plugged or rubbed, not only has good conductivity, but also has good wear resistance and attractive appearance, and the service life and the conductive efficiency of the multi-plating terminal can be greatly prolonged. The second transition plating layer is firstly plated on the surface of the nickel plating layer, so that gaps and holes on the surface can be filled, the surface of the terminal is smooth and seamless, then the contact plating layer is plated, the bonding is firmer, the terminal is flatter, and the service life of the terminal is further prolonged. The electrode potential of the material is selected to be connected with the second transition coating between the electrode potential of the nickel and the electrode potential of the contact coating material, so that electrochemical reaction between metals can be greatly reduced, metal corrosion is reduced, and the service life of the terminal is prolonged.

Drawings

The utility model is described in further detail below with reference to the drawings and the detailed description.

Fig. 1 is a cross-sectional view of one embodiment of a multi-plated terminal of the present application.

Fig. 2 is a cross-sectional view of another embodiment of a multi-plated terminal of the present application.

Fig. 3 is a schematic structural diagram of a conductive structure according to the present application.

Fig. 4 is a cross-sectional view of a conductive structure of the present application.

Reference numerals in the drawings denote:

1-aluminum terminal, 12-weld, 121-tin plating, 13-connecting hole, 2, first transition plating, 3-nickel plating, 4-contact plating, 5-second transition plating, 6-conductor.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1, a multi-plated terminal includes an aluminum terminal 1 and a plated layer;

the plating layer sequentially comprises a first transition plating layer 2, a nickel plating layer 3 and a contact plating layer 4 from inside to outside. In the field of electrical connection, copper is used for conducting current, and the copper has high conductivity and good ductility. However, as copper prices increase, the cost of using copper materials increases. For this reason, alternatives to metallic copper have been sought to reduce costs. The content of the metal aluminum in the crust is about 7.73%, the price is relatively low after the refining technology is optimized, the weight of the aluminum is light relative to copper, the conductivity is inferior to that of copper, and the aluminum can replace part of copper in the field of electric connection. Therefore, aluminum is a trend in the field of automobile electrical connection to replace copper. However, the corrosion resistance and the electrical conductivity of the aluminum terminal are both restricted, the aluminum terminal provided by the application can overcome the problems, the aluminum terminal 1 is made of aluminum or aluminum alloy, and aluminum with high hardness grade such as 6101, 6061, 6063 or 8030 can be selected. The first transition plating layer 2 is plated on the aluminum terminal 1, and the nickel plating layer 3 is plated on the aluminum material, so that the adhesion is poor and the nickel plating layer is easy to fall off, and if the thickness is increased due to other plating layers outside, the nickel plating layer on the aluminum terminal 1 is easy to fall off. The present utility model includes providing the aluminum terminal 1 with a first transition plating layer 2 for increasing the adhesion of the nickel plating layer 3 to the aluminum terminal 1, ensuring that the plating layer does not fall off for a considerable period of time. The nickel coating 3 has high stability in air, and the whole aluminum terminal 1 can have strong passivation capability by covering the first transition coating 2, so that an extremely thin passivation film can be rapidly formed on the surface, and the corrosion of the atmosphere, alkali and certain acids can be resisted. The contact plating layer 4 is used as an outermost layer requiring frequent plugging or rubbing, has good conductivity, good wear resistance and attractive appearance, and can greatly prolong the service life and the conductive efficiency of the aluminum terminal 1.

In some embodiments, a second transition coating 5 is provided between the contact coating 4 and the nickel coating 3. As shown in fig. 2, after the aluminum terminal 1 is coated with the first transition plating layer 2 and the nickel plating layer 3, under the microscopic interface of the real surface, a plurality of gaps and holes exist, which are easy to wear and corrode, and also easy to adhere the contact plating layer 4, the surface of the nickel plating layer 3 is provided with the second transition plating layer 5 for leveling the surface of the nickel plating layer 3, so that the gaps and holes on the surface of the nickel plating layer 3 are filled, the surface of the terminal is leveled without holes, then the contact plating layer 4 is coated again, the combination is firmer, the contact plating layer 4 is leveled, and the service life of the terminal is further prolonged.

Further, the electrode potential of the material of the second transition coating 5 is between the electrode potentials of the nickel and the material of the contact coating 4. The metal with larger electrode potential difference is in direct contact, electrochemical reaction can exist, and under the action of water and air, electrons can be lost from the metal with lower electrode potential, so that the metal is corroded, and the service life of the terminal is reduced. The nickel coating 3 is connected with the contact coating 4 through the second transition coating 5, so that electrochemical reaction between metals can be greatly reduced, metal corrosion is reduced, and the service life of the terminal is prolonged.

In some embodiments, the material of the second transition plating layer 5 is one or more of gold, silver, nickel, tin-lead alloy, zinc and zinc alloy. These metals or alloys are more firmly bonded to the nickel plating layer 3 and more easily fill gaps and holes on the surface.

In some embodiments, the electrode potential of the first transition coating 2 is between the electrode potentials of aluminum and nickel. As described above, the metals with larger electrode potential difference are in direct contact, electrochemical reaction exists, and under the action of water and air, electrons are lost from the metals with lower electrode potential, so that the metals are corroded, and the service life of the terminal is reduced. The nickel coating 3 is connected with the aluminum terminal 1 through the first transition coating 2, so that electrochemical reaction between metals can be greatly reduced, metal corrosion is reduced, and the service life of the terminal is prolonged.

In some embodiments, the material of the first transitional coating 2 is zinc or zinc alloy. The inventor concludes in experiments that the first transition coating 2 is provided by means of zinc precipitation, i.e. the material of the first transition coating 2 is zinc or zinc alloy. The first transition plating layer 2 of zinc or zinc alloy can produce a very good adhesion effect with the aluminum terminal 1, so that the plating layer is not easily detached.

The thickness of the first transition coating layer 2 is 0.015 mu m-2.5 mu m. In order to set a suitable thickness of the first transitional coating 2, the inventors conducted a salt spray experiment on the aluminum terminal 1 having the first transitional coating 2. The experimental mode is that zinc plating layers with different thicknesses are arranged on a plurality of aluminum terminals 1, the damage or falling of the plating layers in a salt spray test are unqualified, and table 1 shows the performances of the zinc plating layers with different thicknesses in the salt spray test.

TABLE 1

As shown in table 1, when the thickness of the zinc plating layer is less than 0.015 μm, the zinc plating layer is broken in the salt spray test, and when it is more than 2.5 μm, falling off occurs because of too great a thickness, so the inventors prefers that the thickness of the first transition plating layer 2 is 0.015 μm to 2.5 μm.

In some embodiments, the material of the contact plating layer 4 is one or a combination of several of gold, silver, hard silver, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy. The use of these materials as the contact plating layer 4 can provide the contact plating layer 4 with better wear resistance and conductivity.

In some embodiments, the aluminum terminal 1 is a flat terminal or one end of a solid aluminum wire. The aluminum terminal 1 can be used for connecting with a cable, and can also be formed by punching one end of a solid aluminum wire such as an aluminum flat belt.

Further, the aluminum terminal 1 has a connection hole 13, and as shown in fig. 1, the surface of the connection hole 13 has a conductive wear-resistant layer. The connection hole 13 may be a through hole or a screw hole for connecting the aluminum terminal 1 with the conductive member by a bolt or other connection member. The inner wall of the connecting hole 13 is used as a metal contact with frequent friction, and good wear-resistant metal is used as a conductive wear-resistant layer, so that the service life can be greatly prolonged, and the connecting hole 13 also needs good conductivity to meet the requirement of electric energy transmission.

Further, the conductive wear-resistant layer is made of one or a combination of more of gold, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy. In order to demonstrate the influence of different conductive and wear-resistant layer materials on the overall performance of the connecting hole 13, the inventor uses the same specification and materials, adopts the aluminum terminal 1 sample piece of the connecting hole 13 of different conductive and wear-resistant layer materials, and uses bolts of the same specification to perform a series of tests on the number of screwing times and the corrosion resistance time. The experimental results are shown in table 2.

The number of screwing times in table 2 is that a plurality of aluminum terminals 1 with different conductive wear-resistant layer materials are respectively fixed on an experiment table, the same bolts are adopted to simulate screwing, and after 100 screwing times, the situation that the conductive wear-resistant layer on the surface of the connecting hole 13 is damaged is stopped, if scratches appear and the self material of the aluminum terminal 1 is exposed, the experiment is stopped, and the number of screwing times at that time is recorded. In this embodiment, the number of screw joints is less than 8000 and is not acceptable.

TABLE 2

The conductivity in table 2 is the conductivity of the aluminum terminal 1 detected by turning on the current after the aluminum terminal 1 is connected to the conductor, and in this example, the conductivity of more than 99% is acceptable.

As can be seen from table 2, when the conductive wear-resistant layer is selected from gold, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy, the experimental result exceeds the standard value more, and the performance is stable. Therefore, the inventors select the conductive and wear-resistant layer material on the connection hole 13 to be one or more of gold, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy.

In some embodiments, the contact coating 4 has a thickness of 0.012 μm to 40 μm. To demonstrate the effect of thickness variation of the contact plating layer 4 on the overall performance of the terminal, the inventors used the same specification of the aluminum terminal 1, adopted the same first transition plating layer 2 and nickel plating layer 3, adopted silver plating layers with different thicknesses as the contact plating layer 4, made a plurality of sample pieces, each sample piece was welded with the same aluminum conductor, and made a series of voltage drop and drawing force tests on the sample pieces, and the voltage drop was more than 4mV or the drawing force was less than 3000N, as disqualification. Table 3 shows the effect of different silver plating thicknesses on voltage drop and pull-out force.

TABLE 3 Table 3

As can be seen from Table 3, when the silver plating layer thickness is less than 0.012. Mu.m, less than 3000N is unacceptable in the pullout force test, and when the silver plating layer thickness is greater than 40. Mu.m, the voltage drop is also unacceptable by more than 4mV, and therefore, the inventors have preferred the thickness of the contact plating layer 4 to be 0.012. Mu.m to 40. Mu.m. In particular 1 μm, 5 μm or 10 μm.

In some embodiments, the nickel plating layer 3 has a thickness of 0.012 μm to 15 μm. In order to find a suitable thickness of the nickel plating layer 3, the inventor performs a salt spray test, puts a plurality of aluminum terminals 1 with the first transition plating layer 2 and the nickel plating layer 3 into a salt spray test box, sprays salt spray on each position of all the aluminum terminals 2 when the thickness of the nickel plating layer 3 of each aluminum terminal 2 is different, takes out and cleans and observes the surface nickel plating layer 3 every 1 hour, namely, a period until the nickel plating layer 3 on the surface of a certain terminal falls off, stops the test, and records the current period number of the terminal. In this embodiment, the number of cycles is less than 80 and is considered unacceptable. The results are shown in Table 4.

TABLE 4 Table 4

As can be seen from table 4, when the thickness of the nickel plating layer 3 is less than 0.012 μm or more than 15 μm, it cannot satisfy the requirement of 80 cycles in the salt spray test, and therefore, the inventors have preferable that the thickness of the nickel plating layer 3 is 0.012 μm to 15 μm, which enables the nickel plating layer 3 to be bonded more firmly.

The utility model also provides a conductive structure, as shown in fig. 3 and 4, comprising a multi-plating terminal and a conductive body 6, wherein the aluminum terminal 1 and the conductive body 6 are welded to form a welding seam 12, and the surface of the welding seam 12 is provided with a tin plating layer 121. After the weld joint 12 is formed, the surface of the weld joint is free of a coating, so that the weld joint is easily corroded by water vapor and impurities in the environment, and the corrosion resistance and the wear resistance of the weld joint 12 can be effectively improved by arranging the tin coating 121 on the surface of the weld joint 12.

In some embodiments, the tin plating layer 121 has a thickness of not less than 8 μm. To demonstrate the effect of different tin plating 121 thicknesses on corrosion resistance, the inventors used the same specifications, materials, but samples of different tin plating 121 thicknesses were used on the weld to test the corrosion resistance time. And (3) placing the sample into a salt spray test box, spraying salt spray on each position of the sample, taking out and cleaning every 20 hours to observe the corrosion condition of the surface, namely, a period, stopping the test until the corrosion area of the welding seam surface of the sample is more than 10% of the total area of the welding seam, and recording the period number at that time. In this embodiment, the number of cycles is less than 80 and is considered unacceptable. The results are shown in Table 5.

TABLE 5

As is clear from table 5, when the thickness of the tin plating layer 121 is less than 8 μm, the number of cycles in the salt spray test is less than 80, and thus the inventors have preferable that the thickness of the tin plating layer 121 is not less than 8 μm.

In some embodiments, the weld 12 is covered with an insulating protective layer. In order to further ensure that the weld joint is not corroded and worn, an insulating protection layer is preferably arranged on the weld joint 12, the insulating protection layer covers the tinning layer, air and water can be isolated at the weld joint 12, oxidation corrosion of the tinning layer is reduced, the service life is prolonged, and the use safety performance is greatly improved.

Further, the insulating protective layer is made of thermoplastic polymer material or vulcanizable polymer material. The thermoplastic polymer material can flow and deform when heated, and can keep a certain shape after cooling, so that the thermoplastic polymer material is easy to carry out extrusion, injection, blow molding and other molding processes. The vulcanizable polymer material is preferably silicone rubber. Because silicone rubber has excellent heat resistance, cold resistance, dielectric properties, ozone resistance, and resistance to atmospheric aging, the silicone rubber has outstanding properties of being used at a wide temperature range and being used for a long period of time at-60 ℃ (or lower) to +250 ℃ (or higher).

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims

1. A multi-plated terminal, comprising an aluminum terminal and a plated layer;

2. A multi-plated terminal according to claim 1, wherein a second transition plating is provided between the contact plating and the nickel plating.

3. A multi-plated terminal according to claim 2, wherein the electrode potential of the second transition plating material is between the electrode potentials of the nickel and the contact plating material.

4. A multi-plated terminal according to claim 1, wherein the electrode potential of the first transition plating layer is between the electrode potentials of aluminum and nickel.

5. The multi-plated terminal according to claim 1, wherein the first transition plating layer is made of zinc or zinc alloy.

6. The multi-plated terminal of claim 1, wherein the first transition plating layer has a thickness of 0.015 μm to 2.5 μm.

7. The multi-plated terminal according to claim 1, wherein the aluminum terminal is a flat terminal or one end of a solid aluminum wire.

8. The multi-plated terminal according to claim 1, wherein the aluminum terminal has a connection hole, and the surface of the connection hole has a conductive wear-resistant layer.

9. A multi-plated terminal according to claim 1, wherein the thickness of the contact plating is 0.012 μm-40 μm.

10. A multi-plated terminal according to claim 1, wherein the nickel plating has a thickness of 0.012 μm to 15 μm.

11. An electrically conductive structure comprising an aluminum terminal as claimed in any one of claims 1 to 10 and an electrical conductor, the aluminum terminal being welded to the electrical conductor to form a weld, the weld surface being provided with a tin plating.

12. A conductive structure according to claim 11, wherein the tin plating has a thickness of not less than 8 μm.

13. A conductive structure according to claim 11, wherein the weld is covered with an insulating protective layer.

14. The structure of claim 13, wherein the insulating protective layer is made of thermoplastic polymer material or vulcanizable polymer material.