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- Technical Info
- Connector Glossary
- Plating of contact points
What is contact point plating?
Contact plating is a surface treatment technique that applies a metal coating to the contact points of connector terminals, which are mainly made of copper alloy, to improve conductivity, corrosion resistance, and wear resistance. It is important for maintaining a stable electrical connection, and gold plating, tin plating, etc., are used depending on the application.
Contact points need to allow even minute currents to flow stably, but oxidation and wear increase contact resistance, leading to signal degradation and poor contact. To prevent this, the appropriate plating material and thickness are selected according to the application.
Main effects of contact plate
- Stabilization of contact resistance
- Prevention of oxidation and corrosion
- Improved wear resistance
- Ensuring long-term reliability
Gold plating is often used in applications where high reliability is required.
On the other hand, when prioritizing a balance between cost and durability, tin plating is generally used.
Furthermore, because nickel has the property of forming a stable oxide film on its surface, it is more often used as a barrier layer for the substrate rather than as a contact point.
summary
Contact platening is "a technology that optimizes the performance of contact points in order to reliably and stably transmit electrical signals over a long period of time."
Selecting the right material for the intended use is a crucial factor that affects both quality and lifespan.
FAQ
Q1. What is the difference between gold plating and tin plating?
Gold plating offers excellent corrosion resistance and contact reliability, making it suitable for high-reliability applications involving low contact force and minute signals.
On the other hand, tin plating offers an excellent balance of cost and reliability and is widely used in general applications. However, with pure tin plating, whiskers (needle-shaped crystals) may grow due to internal stress, which can cause short circuits between terminals in narrow-pitch circuits. For this reason, gold plating is sometimes selected for narrow-pitch applications or applications where long-term reliability is important.
Q2. What happens if the plating on the contact points deteriorates?
The plating on the contact points may deteriorate over time or due to environmental stress.
In gold plating, wear is the main factor reducing reliability, while in tin plating, oxidation, micro-sliding wear corrosion, and whiskers are the main factors. Therefore, it is necessary to select the appropriate plating specification according to the operating environment and required lifespan.