Ahh-- not quite!
Conical washers are indeed springy. They're perfect for this: a short-throw, high-force spring.
Nord-Lock aren't conical or domed, as far as I know. So they don't take up any spring force. They do prevent unscrewing -- very important in high vibration (especially high shear) applications, but only useful when the bolt and base metal can be relied upon to not creep or stretch. They're also rather expensive AFAIK, so are best reserved for these cases when they're needed.
There's also wave washers, though they tend to be softer than cone washers.
Split washers, by the way, are literally no good at all: as a spring, they crush at even less tension than wave washers do, and in tests, they perform as well, or poorer, than plain old flat washers! Which is often worse than no washer at all, because they add another friction surface and can make the joint easier to move.
FR-4 can creep or flow under pressure, too (especially at high temperature). If you're making high current bolted connections to PCB, consider using spring washers there, too!
Tim