Re: 34 pin Card Edge “Male to Male” Connector

Eric Smith spacewar at
Thu Nov 29 12:52:02 CST 2018

On Wed, Nov 28, 2018 at 7:05 PM Chuck Guzis via cctalk <
cctalk at> wrote:

> > 2) is there some way to specify "hardened" or whatever plating for the
> connector traces?
> My last order from OSHPark came with all traces gold-plated.
> Apparently, it's getting to be standard practice.

Sure, but that's just 0.05 to 0.125 microns of ENIG (electroless nickel
immersion gold). That's not intended for mating surfaces, and will wear
away after only a small number of connector cycles.

For reliable edge fingers you need "hard gold" (AKA "hard electrolytic
gold"), which is 0.75 to 2 microns of gold electroplated over 3 to 6
microns of nickel.

(Be careful out there, a lot of places still specify the nickel and gold
thickness in microinches.)

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