The pvd coating machine adopts an alternative electroplating process for precious metal coating to reduce precious metal consumption. A more mature approach is to replace silver plating with ternary alloy electroplating.

(1) Triple alloy silver plating
The copper tin zinc ternary alloy coating is bright silver white, and its anti tarnishing performance is better than that of silver plating. Therefore, it is generally used in the Electrical connector industry to replace silver plating for connectors used for external assembly. At this time, the color of its appearance is mainly self brightening and not easy to tarnish. Silver plating is still used for the inner conductor to ensure that the conductivity is not greatly affected.
The process flow of ternary alloy is as follows: self inspection - hanging - chemical degreasing - water washing - ultrasonic degreasing - hot water washing - water washing - acid corrosion - water washing - electrochemical degreasing - water washing - water washing - activation - water washing - pre copper plating - water washing - water washing - activation - acid copper plating - water washing - water washing - water washing - pure water washing - water washing - hot water washing - drying - self inspection - submission for inspection.
(2) Electroplating copper instead of silver plating process
Another trend is to replace silver plating with pure copper coatings with conductivity second only to silver. The ternary alloy instead of silver coating is only similar in color to the silver layer, and its conductivity cannot be compared to the silver layer. At the same time, the ternary alloy still uses a cyanide electroplating system and requires heating, making it difficult to control the composition of the coating. Therefore, it is not suitable for applications with high conductivity requirements, especially for components with high third-order intermodulation requirements for waveguide devices. Experiments have shown that using pure copper plating can replace the silver coating. If copper plating is used instead of silver plating for large-scale microwave device products, the value of saving precious metals is very attractive. From the table, it can be seen that when the DC resistance value of silver is lQ, copper is the closest to it, only 1.05 Ω; The conductivity is also very close, with silver 6.17 * 10-7 S/m and copper 5.80 * 10-7 S/m. Therefore, using copper instead of silver as a conductive coating is completely feasible from the perspective of conductivity indicators.