Engineering insight
Use the following as an early selection reference. Specific models, datasheets and samples should be confirmed with actual structure drawings.
01
Four mainstream platings: baseline data
The four most common switch contact platings are Au (Gold), Ag (Silver), PdNi (Palladium-Nickel alloy) and Sn (Tin). They differ significantly in resistivity, hardness, oxidation resistance and cost. Selection requires balancing electrical performance, environmental tolerance and target BOM cost.
02
Recommended plating by application scenario
For low-current signal paths in consumer electronics, gold plating is preferred for stable long-term low contact resistance. High current (>1A) power switches can use silver for lower resistance but must consider sulfidation issues. High-cycle connectors suit PdNi for balanced hardness and conductivity. Low-cost volume products can use tin but accept higher initial resistance and oxidation risk.
03
Relationship between plating thickness and service life
Plating thickness directly affects wear life. For micro-motion contacts like tact switches, friction loss per press is minimal (nanometer scale). Rule of thumb: every 0.025μm of gold supports ~100K operations. A 0.5μm gold plating theoretically lasts 2M+ cycles. Actual life also depends on normal force, contaminants and humidity.