The easiest, quickest and cheapest way to protect your pcb is to dip into a Bungard Sur Tin solution.
Green Coat is a new spray coating for all PCBs that are manually soldered
if you use ORIGINAL BUNGARD positive coated PCBs, we have an interesting technical alternative:
We offer the typical green surface finish for printed circuit boards in industrial quality.
Our laminate solder mask is an aqueous alkaline processed dry film mask.
Ormecon immersion tin is a method for chemical tin plating of copper surfaces.
The specialty on Ormecon process is a 0.08 micron thick layer of organic metal.
Since early 1990s the alloy surface (nickel / phosphorus & gold) is one of the most versatile surfaces. In this method, a nickel layer forms the diffusion barrier between copper and solder alloy.
The nickel-gold plating-surface is abrasion-resistant and corrosion free and therefore it is often used for components with increased mechanical stress (male).
Not every surface is suitable for all application. Here you find an overview on the pros and cons: