Gold Plating Brass Pins for High-Temp Soldering

Q. We use brass pins and eyelets in our assemblies that are soldered with HMP solder, we are looking to pre-plate the parts with gold to improve solderability. Is a nickel underplate required or can it be skipped for a simple application such as this? What are the pros and cons, and potential problems without the nickel?

Dear Mike,

You can use electroplated nickel without brightness additives, for example from sulfamic electrolyte. Because you make after gold plating and HMP soldering the nickel coating will not nave micropressing centers. Nickel coating from Sulfamic electrolyte or electroless nickel coating from acetic solution are recommended as underlayer before gold electroplating for this causes.

Dr. Gorker,

Thanks for your response, it is what I had suspected based on my previous work with gold plated printed circuit boards requiring electroless nickel before immersion gold. What would be the recommended thicknesses of the nickel and gold for this application? Thanks again for your assistance.

Gold plating on dull Nickel should NOT EXCEED 0.3 microns. Heavier gold thickness can cause brittle soldered joints.