• Latest
  • Trending

Nickel Underplates and Noble Metal Finish Wear

September 7, 2022

Microwave Multi Line Connectors Mounting and Handling Precautions

March 27, 2023

Samtec New Interconnects Enhances Power and Signal Integrity

March 21, 2023
PCNS Passive Components Symposium 11-14th September 2023

PCB Via Design Selection; Plugging-Filling-Tenting

March 20, 2023

Lemo Releases New Multi Coaxial High Frequency Connector

March 2, 2023

Würth Elektronik Introduces Crimp SKEDD Connectors

March 1, 2023

binder Offers Sensor Connectors in Stainless-Steel to Protect Against Corrosion

March 1, 2023

Board-to-Board Connection & Antennas HF Connection

February 20, 2023

How to Ensure Board-to-Board Connectors Meet High-Speed Automotive Assembly and Use Requirements

February 16, 2023

Amphenol Enhanced its ePower-Lite EV Line to Include 3-Pole Connector

February 15, 2023

BASIC PCB Design Rules – Layout

February 15, 2023

Connector Inrush Current Explained

February 3, 2023

M8 Connectors for Smart Farming Applications

January 31, 2023
  • Privacy Policy
inter-connection blog
  • NEWS
  • Knowledge base
  • Sister Sites
    • Passive Components Blog
    • PCNS Symposium
    • The Passives Times
    • EPCI Home
  • About
No Result
View All Result
  • NEWS
  • Knowledge base
  • Sister Sites
    • Passive Components Blog
    • PCNS Symposium
    • The Passives Times
    • EPCI Home
  • About
No Result
View All Result
inter-connection blog
No Result
View All Result

Nickel Underplates and Noble Metal Finish Wear

September 7, 2022
A A

Nickel underplates in noble metal finishes provide another very important performance benefit that is not related to corrosion. The durability of noble metal finishes during connector mating and unmating is significantly improved by a nickel underplate.

This improvement arises from the hardness of a nickel underplate as compared to that of a gold or palladium contact plating. Hard metals tend to be more wear resistant than softer materials and a nickel underplate increases the composite hardness of a noble metal finish system. This benefit is demonstrated by the data shown in Figure 2.9.

Fig. 2.9: Effect of nickel underplate on contact interface wear

This figure is only one example of an extensive body of work on the durability of noble metal contact finishes carried out at Bell Telephone Laboratories in Murray Hill, New Jersey, USA during the 1970’s. At that time telecom applications were using gold thicknesses in the range of 3 µm (120 microinches) as indicated by the 3.3 µm (130 microinches) thickness in the figure. Note that this example was not intentionally lubricated. Four nickel thicknesses were tested, 0 µm, 1.5 µm (60 microinches), 2 µm (80 microinches) and 4 µm (160 microinches). The data are plotted as Wear Index versus the Number of Passes along the linear mechanically driven wear track. A wear index of 25 means that 25 percent of the length of the wear track showed exposed underplate or base metal, that is, all the gold was worn through in 25% of the track.

Consider the data for 200 gram contact force as a reference for this discussion. With no nickel, the entire wear track, 100 percent wear index, is worn through at about 50 passes. With 1.5 µm (60 microinches) of nickel, a 100 percent wear index occurs at about 600 passes. Extrapolating the data for 2 µm (80 microinches) indicates a wear index of about 85 at about 700 passes. Finally, at 4 µm (160 microinches) of nickel the wear index at 700 passes is about 20. Clearly, as the nickel thickness, and the composite hardness of the finish, increases the wear rate decreases significantly. As noted previously the 4 µm thickness approaches the upper limit of nickel thickness suitable for connectors.

Summary of Nickel Underplate Benefits

To summarize, a nickel underplate reduces:
• the sensitivity of the finish to porosity by passivating pore sites
• the rate of corrosion migration from exposed base metal edges and pore sites to the contact interface
• the rate of copper diffusion from the contact spring to the finish surface where the copper could react with the application environment
• the wear rate of the finish during mating or fretting cycles

Because of these benefits all noble metal contact finishes should include a nickel underplate with a thickness in the range of 1.25 to 2.5 µm (50 to 100 microinches).

Related

Source: Wurth elektronik
Next Post

Non-Noble Finish Degradation Mechanisms

Fretting Degradation Mechanisms

Nickel Degradation Mechanisms

Popular Posts

  • Crimped Connections

    0 shares
    Share 0 Tweet 0
  • Basic Principles of Connectors

    0 shares
    Share 0 Tweet 0
  • Space Saving Molex Connector in AR/VR System designs

    0 shares
    Share 0 Tweet 0
  • THR (Through Hole Reflow) Technology: Introduction & History:

    0 shares
    Share 0 Tweet 0
  • The Electrical Interface: Contact Resistance

    0 shares
    Share 0 Tweet 0

Archive

2023
2022

  • About
  • Inter-Connection News
  • Knowledge base
  • NEWS
  • Privacy Policy
  • Sister Sites

© 2023 EPCI - Premium Passive Components & Inter-Connect News

No Result
View All Result
  • About
  • Inter-Connection News
  • Knowledge base
    • Applications
    • Basic Principles of Connectors
    • Design Selection Assembly
  • NEWS
  • Privacy Policy
  • Sister Sites

© 2023 EPCI - Premium Passive Components & Inter-Connect News

This website uses cookies. By continuing to use this website you are giving consent to cookies being used. Visit our Privacy and Cookie Policy.