There are dozens of options available on the market for different PCB finishes. Which one is the best match for your printed circuit board? PCB supplier china give you advice.
As addressed above, this should almost exclusively derive from the end use of a product. Cheap consumer goods can afford to use less expensive and less durable finishes, and if they are intended to be thrown away, should probably not contain lead. PCB boards for a space shuttle, by comparison, should use the most advanced and applicable finishes available to ensure that the occupants are protected from their extreme environment.