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Chinese Customer Finds our Gold Plated Surface Contaminated, but US Customer Does Not

May 30, 2014

Q. We make Microwave and RF coaxial connectors. We machine our own parts, plate our parts and assemble them. Plating is >50 microinches gold per ASTM B488 over 50 Microinches Ni per FED-QQN-290 (replaced by AMSQQN290) (sulfamate) on a Beryllium Copper contact (turned).

Our plating line is a state of the art automated line. No other parts are now nor have they been reported as an issue.

We sell this connector in large volumes to a US customer who has them assembled in China and in the US into cable assemblies. The US company has no issues. The China factory shows signs after their assembly (soldering cable to the contact) of sulfur/potassium surface contaminants in spots and at sharp inside corners that are turned on the contact. Soldering temperatures are NOT well controlled per the customer but they state they use skill to not overheat the parts. It is a resistance soldering operation - not a nice controlled iron. We know nothing of flux other than an RMA with SN96.5. Nothing known of flux cleaner used.

Multiple lots are involved so its not a single lot issue and some lots shared US with China. They present as a bluish watermark/spot and in some cases small evulsions look like the plating was pushed off in small (1-5 mil dia.) spots.

Anybody have any thoughts?

Daryll Saunders
Dir of QA - Beverly, Massachusetts USA