So I have an edge connector that according to Alibaba Chinese salesman has tin-plated terminals (datasheet a bit unclear).

I am making a product where I am inserting a PCB into an edge connector and I need to decide on Surface Treatment for the PCB that I am inserting into the edge connector.

The PCB will be inserted only one time during its lifetime (during production) and will stay outdoors (but inside an IP56 box).

So can I get by with only HASL or should I use ENIG? Should I use Goldfingers?

Of course I want to get by as cheap as possible.. but without any quality concerns.

Any advice?


1 Answer 1


Is this for a commercial or a one-off product?

If commercial, don't skimp. Use a gold plated connector with gold plated fingers on the PCB. Gold and tin do not mix which was covered in this post. ENIG is very thin, thus you need to do a proper gold plating of the fingers on the PCB. If you are going cheap and don't mind lubricating the contacts, then use tin plating or HASL on the PCB fingers so you won't have dissimilar metals. In an outdoor environment I would go with gold plating.

If it's for a one-off product for yourself, do what you want and perform periodic maintenance. However, once fretting corrosion sets in, it is difficult to remove the oxide layer from the gold surface.

  • \$\begingroup\$ It is for commercial product. And if I can not change the connector terminals from Tin to gold? (I will check with the manufacturer about gold options) how should I do then? goldfingers? HASL? ENIG? \$\endgroup\$
    – mannen
    Dec 9, 2021 at 7:11
  • \$\begingroup\$ @mannen Find a different connector supplier if they don't have gold plated contacts. There are many manufacturers of card-edge connectors. Gold, in contact with tin, will fail over time, so don't do it. ENIG is not thick enough for connector contacts, so do a hard gold plate on the contacts (talk with your PCB supplier). If you can only get tin-plated connector contacts, then HASL with lubricant in the contact areas. \$\endgroup\$
    – qrk
    Dec 9, 2021 at 8:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.