Soldering to hard gold

To be short, no change in profile is going to get you through this.

As I recall the point of hard gold is to retard the wetting process, so no surprise here. For example a connector might have hard gold plating at the mating surface, but not at the solderable leads. At the leads the gold is thin enough to be dissolved into the solder joint, and still be below the ratio of total gold allowed in the joint.

Too much Gold leads to brittle solder joints, as you are experiencing.

You might find a way be removing the gold by a pre-tinning procedure, that could leave you with an actual solderable surface. But without any additional detail, not much more can be said other than to get id of the excessive gold somehow. 'hege

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Gold in solder alloys can be brittle. We always used to talk about keeping gold LT 3% in order to avoid embrittlement. Some military contracts require removal of gold from soldered contacts.

Adding gold to a solder alloy that you're familiar with will: * Make the surface of the solder connection look less shiny * Require that you add more energy to obtain a smooth solder flow

Here's a paper that explains what's going on http://www.semlab.com/goldembrittlementofsolderjoints.pdf

I receive no benefit from providing this link.

BR davef

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