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CN-122013268-A - Composite coating structure, preparation method thereof, conductive terminal and connector

CN122013268ACN 122013268 ACN122013268 ACN 122013268ACN-122013268-A

Abstract

The disclosure discloses a composite coating structure, a preparation method thereof, a conductive terminal and a connector, and belongs to the technical field of electric appliances. The composite coating structure comprises a base material, an intermediate coating layer and a precious metal coating layer, wherein the intermediate coating layer is arranged on the base material in a laminated mode, the precious metal coating layer is arranged on the intermediate coating layer in a laminated mode, the base material is a copper base material or a copper alloy base material, the intermediate coating layer comprises a first intermediate coating layer and a second intermediate coating layer which are alternately arranged in a laminated mode, the first intermediate coating layer and the second intermediate coating layer are nickel tungsten coating layers or cobalt tungsten coating layers, and the tungsten content of the first intermediate coating layer is different from that of the second intermediate coating layer. The composite coating structure can be used for a terminal of a connector, and endows the terminal with excellent electrical contact performance, excellent corrosion resistance, excellent plug resistance, lower coating internal stress and lower cost.

Inventors

  • Yi Zongxin
  • YE TAO
  • YAN ZHONG
  • ZHANG XU

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260512
Application Date
20241112

Claims (11)

  1. 1. A composite plating layer structure, characterized in that the composite plating layer structure comprises a base material (100), an intermediate plating layer (200) laminated to the base material (100), a noble metal plating layer (300) laminated to the intermediate plating layer (200); wherein the substrate (100) is a copper substrate or a copper alloy substrate; The intermediate plating layer (200) includes a first intermediate plating layer (201) and a second intermediate plating layer (202) which are alternately arranged in a stacked manner, the first intermediate plating layer (201) and the second intermediate plating layer (202) are each a nickel tungsten plating layer or a cobalt tungsten plating layer, and the tungsten content of the first intermediate plating layer (201) is different from the tungsten content of the second intermediate plating layer (202).
  2. 2. The composite plating structure according to claim 1, wherein when a difference in tungsten content between the first intermediate plating layer (201) and the second intermediate plating layer (202) is greater than a set threshold value, the substrate (100) and the noble metal plating layer (300) are each in contact with the one of the first intermediate plating layer (201) and the second intermediate plating layer (202) having the lower tungsten content.
  3. 3. The composite coating structure according to claim 1, characterized in that the atomic percentage of tungsten of the first intermediate coating (201) is 1% -10%.
  4. 4. The composite coating structure according to claim 2, characterized in that the second intermediate coating (202) has an atomic percentage of tungsten of 2% -40%.
  5. 5. The composite plating structure according to claim 1, characterized in that the thickness of the first intermediate plating layer (201) is 0.05-4 μm and the thickness of the second intermediate plating layer (202) is 0.05-4 μm.
  6. 6. The composite coating structure according to any one of claims 1-5, characterized in that the total number of layers of the first intermediate coating layer (201) and the second intermediate coating layer (202) is 3-15.
  7. 7. The composite plating structure according to any of claims 1 to 6, wherein the noble metal plating layer (300) is made of gold, silver, palladium or an alloy thereof, and the noble metal plating layer (300) has a thickness of 0.01 μm to 1.27 μm.
  8. 8. A method of producing a composite coating structure according to any one of claims 1 to 7, comprising: And sequentially forming a first intermediate coating (201) and a second intermediate coating (202) which are alternately arranged on the substrate (100) through a film deposition process to obtain an intermediate coating (200), and continuously forming a noble metal coating (300) on the intermediate coating (200) to prepare the composite coating structure.
  9. 9. The method of claim 8, wherein the thin film deposition process is an electroplating process, and wherein the current density corresponding to forming the first intermediate plating layer (201) is different from the current density corresponding to forming the second intermediate plating layer (202) and is in the range of 0.2ASD-4ASD.
  10. 10. A conductive terminal, characterized in that the conductive terminal adopts the composite plating structure according to any one of claims 1 to 7, and the substrate (100) of the composite plating structure is a conductive substrate of the conductive terminal.
  11. 11. A connector comprising an insulated terminal block and a conductive terminal fixedly connected to the insulated terminal block, the conductive terminal being as claimed in claim 10.

Description

Composite coating structure, preparation method thereof, conductive terminal and connector Technical Field The disclosure relates to the electrical technical field, in particular to a composite coating structure, a preparation method thereof, a conductive terminal and a connector. Background Terminals refer to the metal contact portions of the connector for electrical connection of the connector to other electronic devices, and common terminal forms include pins, plugs, sockets, pins, and the like. In order to enhance the contact reliability of the terminal, to improve the conductivity and to prevent oxidation corrosion, a metal plating layer is generally provided on the surface of the terminal. At present, the metal plating layer disposed on the surface of the terminal is usually a noble metal plating layer, such as a gold plating layer, a silver plating layer, etc., however, when the noble metal plating layer contacts the copper substrate of the terminal, current corrosion is easily induced by a potential difference, and pinholes or other surface defects exist on the surface of the noble metal plating layer. The related art overcomes this technical problem by increasing the thickness of the noble metal plating, however, the increase in the thickness of the noble metal plating causes a significant increase in the amount thereof, which results in higher costs. BRIEF SUMMARY OF THE PRESENT DISCLOSURE The embodiment of the disclosure provides a composite coating structure, a preparation method thereof, a conductive terminal and a connector, which can solve the technical problems existing in the related technology. Specifically, the technical scheme is as follows. In one aspect, a composite coating structure is provided, and comprises a substrate, an intermediate coating layer and a precious metal coating layer, wherein the intermediate coating layer is arranged on the substrate in a laminated mode, the precious metal coating layer is arranged on the intermediate coating layer in a laminated mode, the substrate is a copper substrate or a copper alloy substrate, the intermediate coating layer comprises a first intermediate coating layer and a second intermediate coating layer which are alternately arranged in a laminated mode, the first intermediate coating layer and the second intermediate coating layer are nickel tungsten coating layers or cobalt tungsten coating layers, and the tungsten content of the first intermediate coating layer is different from the tungsten content of the second intermediate coating layer. According to the composite coating structure provided by the embodiment of the disclosure, the intermediate coating is arranged between the base material and the noble metal coating, so that on one hand, the stable resistance is built and maintained through the noble metal coating, and on the other hand, the nickel tungsten coating or the cobalt tungsten coating is used as the intermediate coating, so that the thickness of the noble metal coating is reduced to reduce the cost, the defects such as pinholes are avoided, and meanwhile, the purpose of enhancing the mechanical property of the composite coating structure is achieved based on the excellent corrosion resistance and wear resistance of the intermediate coating. Specifically, the intermediate plating layer includes first and second intermediate plating layers alternately arranged in layers, and the tungsten content of the first intermediate plating layer is different from that of the second intermediate plating layer, which results in a difference in grain size in the plating layers. The higher the tungsten content, the lower the grain size of the coating and the grain is gradually refined, whereas the lower the tungsten content, the higher the grain size of the coating. The first intermediate plating layers and the second intermediate plating layers with different tungsten contents are alternately stacked, so that grain trend and size distribution of the layers of the intermediate plating layers can be changed, on one hand, the through-type vacancy defect of the intermediate plating layers can be effectively avoided, the abrasion resistance and corrosion resistance of the composite plating layer structure can be improved, on the other hand, the interlayer corrosion direction of the intermediate plating layers can be changed, the corrosion speed can be delayed, the corrosion resistance of the composite plating layer structure can be improved, on the other hand, the interlayer stress of the intermediate plating layers can be reduced, the mechanical property of the composite plating layer structure can be improved, the abrasion resistance and corrosion resistance of the composite plating layer structure can be further optimized, and the service life of the composite plating layer structure can be prolonged. Based on the above, the composite plating structure provided by the embodiments of the present disclosure can be used for terminals of conne