Selecting the proper plating for pin and female header connectors is very important because plating can affect connector’s performance, life cycle, quality and cost. Contacts and plating of connectors are often the main cost drivers. There are many factors to consider when selecting the proper plating for a connector design, but the choice of plating should be low cost while meeting system requirements. Make sure it works to your quality design specifications, but don't over-design the plating.
Following we will illustrate how to correctly select electroplating in connector design through two commonly used electroplating metals, gold-plated and tin-plated.
Gold plating
Gold plating is often used for high reliability, low current and high cycle applications because it is durable and has excellent wear resistance. Its cobalt alloying increases its hardness, making it ideal to use in harsh environments. but owing to it doesn’t contain oxides, which can lead to increased contact resistance. Gold plating is less affected by the environment.
Tin plating
Comparing with gold, tin is a lower cost alternative and has excellent solderability. Unlike gold, tin plating begins to oxidize when exposed to air. Therefore, the tin-plated contact system requires a larger normal force and a longer contact wiping area to penetrate the oxide film. But tin plating is better for low-cycle applications because it is a softer metal that better releases the extra force on the contacts. And tin plating has a better soldering performance than gold plating.
Generally speaking, gold plating is a better choice for its long time stock life, suitable soldering performance and good conductivity. CNT adopt gold flash plated as standard. But also, some projects need high solderability, under this condition, customers will tend to use tin plating.And furthermore, gold plating on the contact contact area, and tin one the tail is also one good choice, but the price is most expensive.
